# The Flat Earth Society

## Flat Earth Discussion Boards => Flat Earth Theory => Topic started by: Curious Sceptic on September 30, 2019, 07:03:52 PM

Title: FE Gravity
Post by: Curious Sceptic on September 30, 2019, 07:03:52 PM
Hey Guys,
I'd like to ask You how gravity is supposed to work in FE model? And by gravity I mean the fact that all objects fall 'down' with a constant acceleration of 9.81m/s^2 (if we don't take friction into account that is) and that independently of their mass.
I tried looking around for answers but all of them are either unclear, false or contradict each other or even themselves...
Could You help?
Title: Re: FE Gravity
Post by: TomInAustin on October 01, 2019, 06:49:59 PM
Hey Guys,
I'd like to ask You how gravity is supposed to work in FE model? And by gravity I mean the fact that all objects fall 'down' with a constant acceleration of 9.81m/s^2 (if we don't take friction into account that is) and that independently of their mass.
I tried looking around for answers but all of them are either unclear, false or contradict each other or even themselves...
Could You help?

Try the wiki

https://wiki.tfes.org/Universal_Acceleration

Title: Re: FE Gravity
Post by: Curious Sceptic on October 01, 2019, 07:09:46 PM
Hey Guys,
I'd like to ask You how gravity is supposed to work in FE model? And by gravity I mean the fact that all objects fall 'down' with a constant acceleration of 9.81m/s^2 (if we don't take friction into account that is) and that independently of their mass.
I tried looking around for answers but all of them are either unclear, false or contradict each other or even themselves...
Could You help?

Try the wiki

https://wiki.tfes.org/Universal_Acceleration

Ehh, What's the point of replying if You don't answer the question?
That's why I asked for someone to explain it to me. As I said previously, I looked up the wiki and I found the explanation lacking if not to say completely wrong. They butchered Lorenz's equations and seem to not take into account that in order to accelerate constantly in a direction we would need not only a constant energy source but an INCREASING energy source as required energy in order to keep accelerating would eventually tend towards infinity. They don't even mention why this 'dark energy' would be increasing the first place.
The other model, that Davis thingy is even worse!! The resulting gravitation would be directed vertically only directly over the center of mass of the disk which is only one point. Everywhere else we would have gravity coming from the side which would result in a world in which the farther you are away from the centre, more the gravity is directed horizontally...
Thank You anyway...
Can anyone else help?
Title: Re: FE Gravity
Post by: TomInAustin on October 01, 2019, 07:18:19 PM
Hey Guys,
I'd like to ask You how gravity is supposed to work in FE model? And by gravity I mean the fact that all objects fall 'down' with a constant acceleration of 9.81m/s^2 (if we don't take friction into account that is) and that independently of their mass.
I tried looking around for answers but all of them are either unclear, false or contradict each other or even themselves...
Could You help?

Try the wiki

https://wiki.tfes.org/Universal_Acceleration

Ehh, What's the point of replying if You don't answer the question?
That's why I asked for someone to explain it to me. As I said previously, I looked up the wiki and I found the explanation lacking if not to say completely wrong. They butchered Lorenz's equations and seem to not take into account that in order to accelerate constantly in a direction we would need not only a constant energy source but an INCREASING energy source as required energy in order to keep accelerating would eventually tend towards infinity. They don't even mention why this 'dark energy' would be increasing the first place.
The other model, that Davis thingy is even worse!! The resulting gravitation would be directed vertically only directly over the center of mass of the disk which is only one point. Everywhere else we would have gravity coming from the side which would result in a world in which the farther you are away from the centre, more the gravity is directed horizontally...
Thank You anyway...
Can anyone else help?
I didn't say I believed it, the exact opposite is true.
Title: Re: FE Gravity
Post by: BillO on October 01, 2019, 11:07:13 PM
... that in order to accelerate constantly in a direction we would need not only a constant energy source but an INCREASING energy source ...
This is not true.  From the perspective of the accelerating FoR (like the flat earth and it's environs), to accelerate at a constant rate the accelerating force needs to be constant.  However, it does require a constant supply of energy ... forever.  And a lot too, as apparently not only the entire earth is accelerating, but the whole observable universe.  There is a lot wrong with UA, but the need for an increasing force is not one of them.
Title: Re: FE Gravity
Post by: Curious Sceptic on October 02, 2019, 09:00:02 AM
... that in order to accelerate constantly in a direction we would need not only a constant energy source but an INCREASING energy source ...
This is not true.  From the perspective of the accelerating FoR (like the flat earth and it's environs), to accelerate at a constant rate the accelerating force needs to be constant.

When your speed reaches 1/10 C you can observe relativistic effects and one of them is seeming increase in mass which in turn makes the force required to keep constant acceleration increase too (F = am).

However, it does require a constant supply of energy ... forever.  And a lot too, as apparently not only the entire earth is accelerating, but the whole observable universe.  There is a lot wrong with UA, but the need for an increasing force is not one of them.

I didn't think of it but yeah, it would require to accelerate everything around us or we would have a huge blueshift everywhere...
Does anyone have a working model then?
Title: Re: FE Gravity
Post by: BillO on October 02, 2019, 12:33:09 PM
When your speed reaches 1/10 C you can observe relativistic effects and one of them is seeming increase in mass which in turn makes the force required to keep constant acceleration increase too (F = am).
Given a constant force accelerating you, you won't observe an increase in your mass.  However, a person with respect to whom your velocity is measured will see an increase in your mass.  Also, due to the Lorentz contraction along your line of flight, they will see your rulers (displacement measurement) shrink.  They will conclude that you will not measure any change in acceleration since they know that acceleration is the rate of change of velocity, which itself is the rate of change of displacement.
Title: Re: FE Gravity
Post by: iamcpc on October 03, 2019, 08:36:02 PM
When your speed reaches 1/10 C you can observe relativistic effects and one of them is seeming increase in mass which in turn makes the force required to keep constant acceleration increase too (F = am).
Given a constant force accelerating you, you won't observe an increase in your mass.  However, a person with respect to whom your velocity is measured will see an increase in your mass.  Also, due to the Lorentz contraction along your line of flight, they will see your rulers (displacement measurement) shrink.  They will conclude that you will not measure any change in acceleration since they know that acceleration is the rate of change of velocity, which itself is the rate of change of displacement.

I've been thinking about this. I can sense acceleration. I can feel it. If the car is accelerating I can feel the acceleration. On an airplane I can feel the acceleration. I can feel the thing that i'm on or in actively increasing it's velocity. Even when traveling vertically like on a slingshot or amusement park ride I can feel the change in my velocity. As I'm sitting in my desk I don't fee any change in my velocity. Is this planetary level acceleration different somehow so that it's undetectable?
Title: Re: FE Gravity
Post by: BillO on October 03, 2019, 10:06:44 PM
As I'm sitting in my desk I don't fee any change in my velocity.
Right, because you are not changing velocity, but a force (some of us call it gravity) is certainly holding you down in your chair.  Just the same as if you were sitting in the seat of a rocket out in interstellar space accelerating at a constant 9.8 m/(s^2).

Is this planetary level acceleration different somehow so that it's undetectable?
I'll be darned if I know.  I am not a proponent of this UA thing.  To us I imagine it would feel a lot like gravity, however the energy needed to sustain accelerating the whole universe would be staggering even for a micro second, let alone all eternity.
Title: Re: FE Gravity
Post by: Pete Svarrior on October 04, 2019, 05:52:04 AM
I've been thinking about this. I can sense acceleration. I can feel it. If the car is accelerating I can feel the acceleration. On an airplane I can feel the acceleration. I can feel the thing that i'm on or in actively increasing it's velocity.
You can also feel your weight. Remember that UA is largely equivalent to the gravitational model you consider more intuitive, so your question can well be rephrased of "why don't I feel gravity in RET?"

The answer is simple: You absolutely do feel it, but it's also your "default" state - it's something you've felt your entire life and grown accustomed to. Not feeling it would mean experiencing weightlessness, which you'd likely find remarkable.

Is this planetary level acceleration different somehow so that it's undetectable?
It's entirely detectable. You can pick up a cheap accelerometer and detect it with little effort. And, again, all that "detecting" it entails is realising your weight. You're not currently weightless (I presume you're actually on Earth, and not indefinitely falling in a vacuum - apologies if I'm mistaken about your circumstances), ergo you've already detected your weight/UA.
Title: Re: FE Gravity
Post by: somerled on October 04, 2019, 10:55:52 AM
As I'm sitting in my desk I don't fee any change in my velocity.
Right, because you are not changing velocity, but a force (some of us call it gravity) is certainly holding you down in your chair.  Just the same as if you were sitting in the seat of a rocket out in interstellar space accelerating at a constant 9.8 m/(s^2).

I would say that velocity is constantly changing when sitting in a chair on a rotating earth . Velocity is a vector quantity , it has magnitude and direction . But we never sense this acceleration , which itself must be constantly changing  . Doesn't make sense to me .

UA on flat earth , the force acts down towards the plane - this is measured quite easily and its effects can be predicted using kinetics and ballistics. I might be wrong here because I've not really looked into it but that's a much better fit than the gravity ( through attraction of mass by unknown means ) theory .

Complicated for sure .
Title: Re: FE Gravity
Post by: BillO on October 04, 2019, 11:59:35 AM
I would say that velocity is constantly changing when sitting in a chair on a rotating earth . Velocity is a vector quantity , it has magnitude and direction . But we never sense this acceleration , which itself must be constantly changing  . Doesn't make sense to me .
Yes, on a rotating planet there will be a force created by the rotation.  However, this is minuscule.  Only about .034 m/(s ^2) at the equator and in the direction directly opposite to gravity, and it's constant.  Less than 1/3 of one percent the gravitational force at the equator, and less elsewhere. So how would you feel it?  As for the force of acceleration due to our orbit around the sun, which actually does change as the earth rotates, that is less than 0.0059m/(s^2) at a maximum and changing slowly over 24 hours.  Do you honestly think you could feel that?

UA on flat earth , the force acts down towards the plane - this is measured quite easily and its effects can be predicted using kinetics and ballistics. I might be wrong here because I've not really looked into it but that's a much better fit than the gravity ( through attraction of mass by unknown means ) theory .
So, we are all okay with the problem of the energy involved?  If the entire universe was only the mass of the RE, then it would take about 8x10^19 kilowatt hours of energy every second.  That is about 4 billion times the total energy used on the earth every year.   So, acceleration due to insane amounts of energy from unknown means.
Title: Re: FE Gravity
Post by: pricelesspearl on October 04, 2019, 01:33:08 PM
Quote
UA on flat earth , the force acts down towards the plane - this is measured quite easily and its effects can be predicted using kinetics and ballistics. I might be wrong here because I've not really looked into it but that's a much better fit than the gravity ( through attraction of mass by unknown means ) theory .

What force, other than the normal force would be acting down towards the plane?  The normal force is a contact force and would only come into play when something is in actual contact with the surface.

Title: Re: FE Gravity
Post by: katrex on October 17, 2019, 02:21:59 AM
this brings up an important point...

Why does the universal force act in different amounts on different objects?  If I drop a 1kg and a 10kg ball off the ground. They are both falling towards the earth. So clearly the universal force is not acting on them but is acting on the earth. But if I dig its not acting on the earth underneath me. is there a big metal plate at the bottom of the earth that the universal force acts on?

it also seems to act on random satellites, the moon, the sun, and they seem to accelerate the same amount. Are all objects in the universe that accelerate equally massive? When an asteroid hits the earth, does the force automatically increase to maintain the constant acceleration? How is it regulated?

The more I think about it the more confusing it gets? is all of nutonian physics wrong?
Title: Re: FE Gravity
Post by: Tim Alphabeaver on November 14, 2019, 07:41:35 PM
in order to accelerate constantly in a direction we would need not only a constant energy source but an INCREASING energy source as required energy in order to keep accelerating would eventually tend towards infinity.
Someone needs to take another look at their 'Introduction to Relativity' notes :)
Title: Re: FE Gravity
Post by: TomInAustin on November 15, 2019, 04:02:33 PM
this brings up an important point...

Why does the universal force act in different amounts on different objects?  If I drop a 1kg and a 10kg ball off the ground. They are both falling towards the earth.

Not that I think UA is real but if it was drag from the air would act just like it does with reality.
Title: Re: FE Gravity
Post by: Tom Bishop on November 15, 2019, 04:11:12 PM
I'm under the impression that there are only a few experiments which are actually put forward as evidence for the universal attraction of mass. Most other experiments say that the Equivalence Principle holds.

See https://wiki.tfes.org/Variations_in_Gravity
Title: Re: FE Gravity
Post by: Tim Alphabeaver on November 15, 2019, 05:43:32 PM
I'm under the impression that there are only a few experiments which are actually put forward as evidence for the universal attraction of mass.
I think this is kind of true, but the few experiments that do exist are all pretty consistent so there's no incentive to provide further evidence. Add on to that the fact that there's really no viable alternative and you end up with where we are now: who's going to be interested in doing this experiment?
A professor isn't going to be interested in this - they'd rather do some physics that's new (unless they're a hardcore globie)
A funding body isn't going to be interested in this - it's not new or exciting

It's kind of a sad reality of science, but there's limited money and physicists that would rather be doing something interesting. The Scientific Method is a pure and perfect ideal that's implemented by primates.
Title: Re: FE Gravity
Post by: pricelesspearl on November 15, 2019, 08:23:15 PM
Quote
I'm under the impression that there are only a few experiments which are actually put forward as evidence for the universal attraction of mass. Most other experiments say that the the Equivalence Principle holds.

That's because the Equivalence Principle and by extension, General Relativity, account for the attraction of masses.  It's a bit disingenuous to claim that gravity doesn't exist because the EP says that it is indistinguishable from acceleration, when the whole point of GR is that gravity and acceleration are the same thing.
Title: Re: FE Gravity
Post by: AnApphysicstudent on November 23, 2019, 07:54:28 PM
this brings up an important point...

Why does the universal force act in different amounts on different objects?  If I drop a 1kg and a 10kg ball off the ground. They are both falling towards the earth. So clearly the universal force is not acting on them but is acting on the earth. But if I dig its not acting on the earth underneath me. is there a big metal plate at the bottom of the earth that the universal force acts on?

it also seems to act on random satellites, the moon, the sun, and they seem to accelerate the same amount. Are all objects in the universe that accelerate equally massive? When an asteroid hits the earth, does the force automatically increase to maintain the constant acceleration? How is it regulated?

The more I think about it the more confusing it gets? is all of nutonian physics wrong?

So what you dont understand is why objects of different mass have the same acceleration under gravity. The thing is gravity acts on an atomic level which means it pulls every atom down towards the center of the earth, every atom in the object gets acted on by gravity equally. This is why the difference in mass does not effect the acceleration due to gtavity. To put it simply, (if air resistance is negligble) if you drop an 2 object of equal mass of lets say 1 kg, they would fall with the same acceleration,  now if you have 3 object of mass 1 kg and drop them all at the same time, again they would all fall with the same acceleration. Now if merge 10 of the 1 kg mass together, they would fall with the same acceleration as the 1 kg mass because all 10 of the 1 kg mass gets the same acceleration.  In terms of math, (acceleration due to gravity is 10 to keep it simple) if you drop a 1 kg mass using F=M A  F=1×10  F=10 so the weight is 10N for every kg, if the mass is 10kg F=10×10 = 100N, the weight is 100N, which is equal to the weight of 10 1kg weight. Hence I claim that gravity act on every object equally.
Title: Re: FE Gravity
Post by: Tom Bishop on November 24, 2019, 01:21:56 AM
How does gravity pull object down to the earth at the same rate and ignore the fact that bodies have different inertial resistences to being moved through space?

It's easier to roll a marble versus a bowling ball, for example. All bodies exhibit internal resistences when they are moved through space.
Title: Re: FE Gravity
Post by: AnApphysicstudent on November 24, 2019, 05:02:12 AM
How does gravity pull object down to the earth at the same rate and ignore the fact that bodies have different inertial resistences to being moved through space?

It's easier to roll a marble versus a bowling ball, for example. All bodies exhibit internal resistences when they are moved through space.
So what you dont understand is why objects of different mass have the same acceleration under gravity. The thing is gravity acts on an atomic level which means it pulls every atom down towards the center of the earth, every atom in the object gets acted on by gravity equally. This is why the difference in mass does not effect the acceleration due to gtavity. To put it simply, (if air resistance is negligble) if you drop an 2 object of equal mass of lets say 1 kg, they would fall with the same acceleration,  now if you have 3 object of mass 1 kg and drop them all at the same time, again they would all fall with the same acceleration. Now if merge 10 of the 1 kg mass together, they would fall with the same acceleration as the 1 kg mass because all 10 of the 1 kg mass gets the same acceleration.  In terms of math, (acceleration due to gravity is 10 to keep it simple) if you drop a 1 kg mass using F=M A  F=1×10  F=10 so the weight is 10N for every kg, if the mass is 10kg F=10×10 = 100N, the weight is 100N, which is equal to the weight of 10 1kg weight. Hence I claim that gravity act on every object equally.
Title: Re: FE Gravity
Post by: Tom Bishop on November 25, 2019, 12:46:37 AM
If gravity acted on all objects as if they all had the same inertial resistance/weight then all bodies would have the same weight on a scale.

Why do bodies have different weights if a mystical phenomena is pulling all atoms in objects with the same force, as if all bodies had the same weight, solely to explain for us why bodies fall without exhibition of inertial resistance?
Title: Re: FE Gravity
Post by: AnApphysicstudent on November 25, 2019, 04:07:58 AM
I think you are misunderstanding inertial resistant, inertial resistant is the object trying to stay at a constant velocity, when gravity acts on a body of the same mass, they will have same inertial resistant, if an object is made up of more atom or atoms of higher molar mass then the inertial force is higher the reason why they fall with the same acceleration is because gravity does not apply a constant force on the object as a whole, but it act on every matter that made up the object ( proton, nuetron,electron) and gave them force proportional to their mass .And inertia is not related to the weight of the body. And what you see on a scale when you weight the body is not the inertial force, its the normal force which was cause by gravity pulling the body to the surface and the surface is pushing back at the same force. The body that consist of more matter will have more weight because gravity act more on it as a whole.
Title: Re: FE Gravity
Post by: Tom Bishop on November 25, 2019, 04:55:51 AM
The body that consist of more matter will have more weight because gravity act more on it as a whole.

I thought that you just told us that gravity acts on all bodies the same? Now gravity is acting on some bodies more? So why do bowling balls and marbles fall at the same rate again with everything magically equaling out?
Title: Re: FE Gravity
Post by: AnApphysicstudent on November 25, 2019, 06:16:41 AM
I am sorry that sound confusing, what I mean was that when the mass of the body is the same, the force of gravity act on them equally, and the force is proportional to the weight. If the object has more mass then, the total force that act on the object is higher compare to the one with lower mass, this doesnt change the fact that gravity act on object equally. Imagin putting 1 kg weight on a scale and 2 1 kg weight on the scale. The scale will show more weight on the one with 2 1 kg weight. If you were to drop all of them at the same time, the acceleration of all of them will be equal, if you merge all of them together doesnt change the total force acting on it or the total mass. And you will get the same acceleration if you use the formular F=ma
Title: Re: FE Gravity
Post by: somerled on November 25, 2019, 11:13:34 AM
How does a large body then exert an equal force onto bodies of varying mass ? Why would earth with all its atoms not exert a greater force on a smaller object than a larger one ? How does the attractive force regulate itself to produce constant acceleration upon bodies of differing mass?
Title: Re: FE Gravity
Post by: AllAroundTheWorld on November 25, 2019, 12:43:28 PM
Why do bodies have different weights if a mystical phenomena is pulling all atoms in objects with the same force
Because more massive objects have more atoms in them. That’s pretty much the definition of mass.
This really isn’t hard to understand:

1) The force of earth’s gravity acting on a body (which is the definition of weight, by the way) is proportional to the body’s mass.
2) The force required to accelerate a body at a certain rate is also proportional to the body’s mass (F = ma)

These two things are why all bodies accelerate at the same rate in a gravitational field.

Why is this the case? They’re just properties of the universe. You might as well ask why magnetism is so much stronger a force than gravity such that a small magnet can lift an object, overcoming the gravity of the whole earth.
Title: Re: FE Gravity
Post by: TomInAustin on November 25, 2019, 03:33:37 PM
The body that consist of more matter will have more weight because gravity act more on it as a whole.

So why do bowling balls and marbles fall at the same rate again with everything magically equaling out?

They don't assuming you are not talking in a vacuum.  Mass and drag are the factors that set the terminal velocity of a falling object.
Title: Re: FE Gravity
Post by: Tom Bishop on November 25, 2019, 04:17:32 PM
I am sorry that sound confusing, what I mean was that when the mass of the body is the same, the force of gravity act on them equally, and the force is proportional to the weight. If the object has more mass then, the total force that act on the object is higher compare to the one with lower mass, this doesnt change the fact that gravity act on object equally. Imagin putting 1 kg weight on a scale and 2 1 kg weight on the scale. The scale will show more weight on the one with 2 1 kg weight. If you were to drop all of them at the same time, the acceleration of all of them will be equal, if you merge all of them together doesnt change the total force acting on it or the total mass. And you will get the same acceleration if you use the formular F=ma

If one body is experiencing a more forceful pull from the earth, as to cause it to weigh more, it does not make sense that all bodies would fall at the same rate.

An answer of "Just because they do" is not a very satisfying mechanism, IMO.
Title: Re: FE Gravity
Post by: AllAroundTheWorld on November 25, 2019, 05:08:33 PM
If one body is experiencing a more forceful pull from the earth, as to cause it to weigh more, it does not make sense that all bodies would fall at the same rate.
It does make sense if you understand that it requires a more forceful pull to accelerate an object which is more massive than one which has less mass. And you do understand that because you know it’s easier to move (and therefore accelerate) a toy car than a real car.

Quote
An answer of "Just because they do" is not a very satisfying mechanism, IMO.
Title: Re: FE Gravity
Post by: somerled on November 25, 2019, 05:37:06 PM
Never heard of the Just Because theory although it does remove the need for any proof .
Science freely admits it has no explanation of how "gravity" actually works or how it is transmitted .
Title: Re: FE Gravity
Post by: Tom Bishop on November 25, 2019, 05:56:43 PM
If one body is experiencing a more forceful pull from the earth, as to cause it to weigh more, it does not make sense that all bodies would fall at the same rate.
It does make sense if you understand that it requires a more forceful pull to accelerate an object which is more massive than one which has less mass.

No, it doesn't make sense at all. Gravity also affects photons, which have zero mass.

From a University of Oregon lecture:

http://abyss.uoregon.edu/~js/21st_century_science/lectures/lec07.html

Quote
although a simple and common sense assumption, the equivalence principle has strange consequences such as, photons will be affected by gravity, even though they have zero mass

(https://i.imgur.com/S6p2Od9.gif)
Title: Re: FE Gravity
Post by: pricelesspearl on November 25, 2019, 06:18:40 PM
Quote
No, it doesn't make sense at all. Gravity also affects photons, which have zero mass.

Gravity doesn’t affect the photons directly.  According to GR, gravity warps spacetime, “curving” the space through which light travels. Just like shortest distance between two points on a globe is not a straight line, the shortest distance between two points in curved space time is not a straight line.
Title: Re: FE Gravity
Post by: Tom Bishop on November 25, 2019, 06:24:59 PM
General Relativity is an upwardly accelerating earth simulator.

Quote
Consider a skydiver jumping out of an airplane. The skydiver falls freely, up to the effects of air resistance. According to Einstein, the skydiver's path is the straightest line possible through the curved space-time around the Earth. From the skydiver's perspective this seems quite natural. Except for the air rushing past her, the skydiver feels no perturbing forces at all. In fact, if it weren't for the air resistance, she would experience weightlessness in the same way that an astronaut does in orbit. The only reason we think the skydiver is accelerating is because we are used to using the surface of the Earth as our frame of reference. If we free ourselves from this convention, then we have no reason to think the skydiver is accelerating at all.

Now consider yourself on the ground, looking up at the falling daredevil. Normally, your intuitive description of your own motion would be that you are stationary. But again this is only because of our slavish regard to the Earth as the arbiter of what is at rest and what is moving. Free yourself from this prison, and you realize that you are, in fact, accelerating. You feel a force on the soles of your feet that pushes you upwards, in the same way that you would if you were in a lift that accelerated upwards very quickly. In Einstein's picture there is no difference between your experience sanding on Earth and your experience in the lift. In both situations you are accelerating upwards. In the latter situation it is the lift that is responsible for your acceleration. In the former, it is the fact that the Earth is solid that pushes you upwards through space-time, knocking you off your free-fall trajectory. That the surface of the Earth can accelerate upwards at every point on its surface, and remain as a solid object, is because it exists in a curved space-time and not in a flat space.

With this change in perspective the true nature of gravity becomes apparent. The free falling skydiver is brought to Earth because the space-time through which she falls is curved. It is not an external force that tugs her downwards, but her own natural motion through a curved space. On the other hand, as a person standing on the ground, the pressure you feel on the soles of your feet is due to the rigidity of the Earth pushing you upwards. Again, there is no external force pulling you to Earth. It is only the electrostatic forces in the rocks below your feet that keep the ground rigid, and that prevents you from taking what would be your natural motion (which would also be free fall).

So, if we free ourselves from defining our motion with respect to the surface of the Earth we realize that the skydiver is not accelerating, while the person who stands on the surface of the Earth is accelerating. Just the opposite of what we usually think. Going back to Galileo's experiment on the leaning tower of Pisa, we can now see why he observed all of his cannonballs to fall at the same rate. It wasn't really the cannonballs that were accelerating away from Galileo at all, it was Galileo that was accelerating away from the cannonballs!

See the bolded. "In both situations you are accelerating upwards" and the Earth is "pushing you upwards through space-time."

Different bodies have different weights because the Earth is accelerating upwards, pushing itself into bodies which have different inertial resistances to being moved through space.
Title: Re: FE Gravity
Post by: pricelesspearl on November 25, 2019, 08:56:29 PM
Quote
See the bolded. "In both situations you are accelerating upwards" and the Earth is "pushing you upwards through space-time."

As usual, you pick and choose what suits you.
Quote
But bear in mind throughout:  It is the curvature of space-time that is responsible for it all.
Title: Re: FE Gravity
Post by: AllAroundTheWorld on November 25, 2019, 10:11:03 PM
If one body is experiencing a more forceful pull from the earth, as to cause it to weigh more, it does not make sense that all bodies would fall at the same rate.
It does make sense if you understand that it requires a more forceful pull to accelerate an object which is more massive than one which has less mass.

No, it doesn't make sense at all. Gravity also affects photons, which have zero mass.
Reasonable point, but I was talking about Newton's model of gravity. And you're right this doesn't explain why gravity would affect light.
Einstein's model does explain this as well as why objects of different masses accelerate at the same rate.
That's why it's a better model although for most practical purposes Newton's model does fine.
End of the day, the model of gravity explains how the earth orbits the sun, how the moon orbits earth, how the other planets orbit the sun and how their moons orbit them.
You have no coherent model which explains any of this. I'm always amazed that you pick holes in conventional physics - often based on your lack of understanding - but seem fine believing your model which is full of "that's just how it is".
Title: Re: FE Gravity
Post by: AnApphysicstudent on November 26, 2019, 09:48:20 AM
Can someone explain how the sun and moon revloves in flat earth model (I saw it on the faq but dont really get it). What forces are causing the sun and the moon to move like that, there is nothing in the center so there is no centripital force pulling it
Title: Re: FE Gravity
Post by: somerled on November 26, 2019, 12:21:53 PM
If one body is experiencing a more forceful pull from the earth, as to cause it to weigh more, it does not make sense that all bodies would fall at the same rate.
It does make sense if you understand that it requires a more forceful pull to accelerate an object which is more massive than one which has less mass.

No, it doesn't make sense at all. Gravity also affects photons, which have zero mass.
Reasonable point, but I was talking about Newton's model of gravity. And you're right this doesn't explain why gravity would affect light.
Einstein's model does explain this as well as why objects of different masses accelerate at the same rate.
That's why it's a better model although for most practical purposes Newton's model does fine.
End of the day, the model of gravity explains how the earth orbits the sun, how the moon orbits earth, how the other planets orbit the sun and how their moons orbit them.
You have no coherent model which explains any of this. I'm always amazed that you pick holes in conventional physics - often based on your lack of understanding - but seem fine believing your model which is full of "that's just how it is".

Then why haven't you or science provided us with an explanation of how gravity works and interaction between objects occurs ?

Title: Re: FE Gravity
Post by: ChrisTP on November 26, 2019, 01:56:24 PM
If one body is experiencing a more forceful pull from the earth, as to cause it to weigh more, it does not make sense that all bodies would fall at the same rate.
It does make sense if you understand that it requires a more forceful pull to accelerate an object which is more massive than one which has less mass.

No, it doesn't make sense at all. Gravity also affects photons, which have zero mass.
Reasonable point, but I was talking about Newton's model of gravity. And you're right this doesn't explain why gravity would affect light.
Einstein's model does explain this as well as why objects of different masses accelerate at the same rate.
That's why it's a better model although for most practical purposes Newton's model does fine.
End of the day, the model of gravity explains how the earth orbits the sun, how the moon orbits earth, how the other planets orbit the sun and how their moons orbit them.
You have no coherent model which explains any of this. I'm always amazed that you pick holes in conventional physics - often based on your lack of understanding - but seem fine believing your model which is full of "that's just how it is".

Then why haven't you or science provided us with an explanation of how gravity works and interaction between objects occurs ?
It has provided an explanation as much to our (humans) understanding. There things left unanswered for sure, the universe is mysterious to us and we are but a young civilisation. Regardless, there more detailed explanations of how gravity works than how things would function on a flat earth. Can anyone give a better, more in depth explanation of gravity under the assumption of a flat earth than we have now? An explanation with absolutely everything answered?
Title: Re: FE Gravity
Post by: somerled on November 26, 2019, 04:30:15 PM
What explanation ? We use equations based on observation and experiment then ascribe these to a force which explains neither the how or the why , and then pretend it's something science understands .
Goes well with the fact that we can never measure the curve or find any rotation of the supposed globe .

Gravity is possibly electromagnetic effect - or UA . Neither needs a magical force .
Title: Re: FE Gravity
Post by: ChrisTP on November 26, 2019, 05:44:44 PM
What explanation ? We use equations based on observation and experiment then ascribe these to a force which explains neither the how or the why , and then pretend it's something science understands .
Goes well with the fact that we can never measure the curve or find any rotation of the supposed globe .

Gravity is possibly electromagnetic effect - or UA . Neither needs a magical force .
What exactly is magically forcing the disk to accelerate relatively up forever?
Title: Re: FE Gravity
Post by: somerled on November 26, 2019, 09:20:36 PM
I don't know , personally I prefer the electromagnetic force  but I don't rule UA out because I haven't studied it enough to form an opinion . Density theory also an option.
Title: Re: FE Gravity
Post by: ChrisTP on November 26, 2019, 11:18:39 PM
I don't know , personally I prefer the electromagnetic force  but I don't rule UA out because I haven't studied it enough to form an opinion . Density theory also an option.
Right, so it's pretty easy for you to call gravity magic because humans don't fully understand it but you or anyone else don't fully understand literally any alternative to gravity, so I guess you consider any flat earth explanation magic too? Right, I guess maybe someone should add to the FE wiki that UA is driven by a magical force, since no one knows what's doing it. The explanation given for gravity so far is simply descriptions observations and decent attempts to put those observations into equations so that we can manipulate objects and predict other objects movements... So far so good, even if no one knows why, we can still describe its actions.
Title: Re: FE Gravity
Post by: Tom Bishop on November 26, 2019, 11:42:26 PM
Yep. The official explanation is that the surface of the earth is accelerating upwards through space-time.
Title: Re: FE Gravity
Post by: somerled on November 27, 2019, 10:37:48 AM
I don't know , personally I prefer the electromagnetic force  but I don't rule UA out because I haven't studied it enough to form an opinion . Density theory also an option.
Right, so it's pretty easy for you to call gravity magic because humans don't fully understand it but you or anyone else don't fully understand literally any alternative to gravity, so I guess you consider any flat earth explanation magic too? Right, I guess maybe someone should add to the FE wiki that UA is driven by a magical force, since no one knows what's doing it. The explanation given for gravity so far is simply descriptions observations and decent attempts to put those observations into equations so that we can manipulate objects and predict other objects movements... So far so good, even if no one knows why, we can still describe its actions.

It's easy to call gravity a magic force because we do not know the first basic thing about it - Stop the pretense that we understand it in any way. We have a set of equations describing motions - that is all , everything else is conjecture .Mainstream science has the big bang and expanding universe - could that not possibly be the force that accelerates earth in the UA theory ?
Title: Re: FE Gravity
Post by: pricelesspearl on November 27, 2019, 04:13:20 PM

Quote
Yep. The official explanation is that the surface of the earth is accelerating upwards through space-time.

I sometimes wonder if and FEer even understands what GR is and what it means.  First of all, it postulates, and is dependent upon the Newtonian concept of gravity that matter “attracts” matter being correct.  It is just a proposed theory has to how/why that happens. In Einstein’s field calculations, G is the gravitational constant from Newton's law of gravitation, Guv is the metric tensor, which describes spacetime and gravitational potential and Tuv is the stress-energy tensor, which is the source of the gravitational field.  So if you want to try and use GR to support UA, you can’t do so without also accepting the Newtonian concept of gravity that matter “attracts” matter.  If GR is true, then it is also true that matter “attracts” matter.  It is, after all, a theory of gravitation.

The how or why shouldn’t be relevant to FE because no matter how or why it happens, ultimately, the fact that it does ends with a sphere earth.
Title: Re: FE Gravity
Post by: Tom Bishop on November 27, 2019, 06:16:41 PM

Quote
Yep. The official explanation is that the surface of the earth is accelerating upwards through space-time.

I sometimes wonder if and FEer even understands what GR is and what it means.  First of all, it postulates, and is dependent upon the Newtonian concept of gravity that matter “attracts” matter being correct.  It is just a proposed theory has to how/why that happens. In Einstein’s field calculations, G is the gravitational constant from Newton's law of gravitation, Guv is the metric tensor, which describes spacetime and gravitational potential and Tuv is the stress-energy tensor, which is the source of the gravitational field.  So if you want to try and use GR to support UA, you can’t do so without also accepting the Newtonian concept of gravity that matter “attracts” matter.  If GR is true, then it is also true that matter “attracts” matter.  It is, after all, a theory of gravitation.

The how or why shouldn’t be relevant to FE because no matter how or why it happens, ultimately, the fact that it does ends with a sphere earth.

We have some pages on the topic of the universal gravitation of mass here: https://wiki.tfes.org/General_Physics

Title: Re: FE Gravity
Post by: pricelesspearl on November 27, 2019, 10:56:30 PM

Quote
We have some pages on the topic of the universal gravitation of mass here: https://wiki.tfes.org/General_Physics

I don’t see anything that addresses universal gravitation of matter, just universal acceleration
Title: Re: FE Gravity
Post by: somerled on November 28, 2019, 10:49:40 AM
Quote
The how or why shouldn’t be relevant to FE because no matter how or why it happens, ultimately, the fact that it does ends with a sphere earth.

It isn't relevant to flat earth which is based on experiment , experience and observation .

Imaginary scenarios are only relevant to imaginary theories and nice of you show us how imaginary GR supports imaginary Newtonian gravity . Mainstream science , fantastic.
Title: Re: FE Gravity
Post by: pricelesspearl on November 28, 2019, 04:18:32 PM
Quote
The how or why shouldn’t be relevant to FE because no matter how or why it happens, ultimately, the fact that it does ends with a sphere earth.

It isn't relevant to flat earth which is based on experiment , experience and observation .

Imaginary scenarios are only relevant to imaginary theories and nice of you show us how imaginary GR supports imaginary Newtonian gravity . Mainstream science , fantastic.

I was responding to Tom who apparently thinks GR supports UA and FET (because of the Equivalence Principle as far as I can tell).

If you don’t think it does, then take it up with Tom because I don’t think it does either.
Title: Re: FE Gravity
Post by: Pete Svarrior on November 28, 2019, 06:35:30 PM
I was responding to Tom who apparently thinks GR supports UA and FET (because of the Equivalence Principle as far as I can tell).
For the avoidance of doubt: you're massively misrepresenting (or misunderstanding) what's been said, and you'd benefit greatly from asking more questions and making fewer assumptions.
Title: Re: FE Gravity
Post by: Tom Bishop on November 29, 2019, 09:10:17 PM
It's pretty crazy that the official explanation for gravity is that the surface of the earth is accelerating upwards through space-time. That alone shows everything else to be questionable.
Title: Re: FE Gravity
Post by: pricelesspearl on November 30, 2019, 02:32:37 AM
It's pretty crazy that the official explanation for gravity is that the surface of the earth is accelerating upwards through space-time. That alone shows everything else to be questionable.

Not to those who understand that in GR “accelerating upwards” means traveling through a geodesic and towards objects of greater mass

“Einstein calls it spacetime curvature; Newton calls it tidal gravity. But there is just one agent acting. Therefore, spacetime curvature and tidal gravity must be precisely the same thing, expressed in different languages.

Black Holes and Time Warps: Einstein's Outrageous Legacy by Kip S. Thorne (Author), Stephen Hawking (Foreword)

Title: Re: FE Gravity
Post by: BillO on November 30, 2019, 09:36:34 PM
No, it doesn't make sense at all. Gravity also affects photons, which have zero mass.

This is not a correct statement.  Photons have zero rest mass.  However, photons are never at rest and always have some energy.  Their susceptibility to gravity is given by the mass equivalent to their energy using Einstein's famous mass/energy equivalency theory.  Or you could use GR, but that would be like using a sledgehammer to set a thumb tack.
Title: Re: FE Gravity
Post by: Tim Alphabeaver on December 02, 2019, 07:58:56 PM
No, it doesn't make sense at all. Gravity also affects photons, which have zero mass.
I know that you understand Relativity quite well, so why do you make statements like this just to bait people when you clearly know the answer?
Title: Re: FE Gravity
Post by: BillO on December 02, 2019, 10:02:57 PM
Yep. The official explanation is that the surface of the earth is accelerating upwards through space-time.
Do you have a link to some recognized or suitably qualified physicist stating this (preferably not a link to the FE wiki)?  I'd be seriously interested in seeing how they come to that conclusion.  Or are you trying to apply Einstein's equivalency theory?
Title: Re: FE Gravity
Post by: Tom Bishop on December 03, 2019, 05:40:43 AM
Yep. The official explanation is that the surface of the earth is accelerating upwards through space-time.
Do you have a link to some recognized or suitably qualified physicist stating this (preferably not a link to the FE wiki)?  I'd be seriously interested in seeing how they come to that conclusion.  Or are you trying to apply Einstein's equivalency theory?

Right here:

Quote
Consider a skydiver jumping out of an airplane. The skydiver falls freely, up to the effects of air resistance. According to Einstein, the skydiver's path is the straightest line possible through the curved space-time around the Earth. From the skydiver's perspective this seems quite natural. Except for the air rushing past her, the skydiver feels no perturbing forces at all. In fact, if it weren't for the air resistance, she would experience weightlessness in the same way that an astronaut does in orbit. The only reason we think the skydiver is accelerating is because we are used to using the surface of the Earth as our frame of reference. If we free ourselves from this convention, then we have no reason to think the skydiver is accelerating at all.

Now consider yourself on the ground, looking up at the falling daredevil. Normally, your intuitive description of your own motion would be that you are stationary. But again this is only because of our slavish regard to the Earth as the arbiter of what is at rest and what is moving. Free yourself from this prison, and you realize that you are, in fact, accelerating. You feel a force on the soles of your feet that pushes you upwards, in the same way that you would if you were in a lift that accelerated upwards very quickly. In Einstein's picture there is no difference between your experience sanding on Earth and your experience in the lift. In both situations you are accelerating upwards. In the latter situation it is the lift that is responsible for your acceleration. In the former, it is the fact that the Earth is solid that pushes you upwards through space-time, knocking you off your free-fall trajectory. That the surface of the Earth can accelerate upwards at every point on its surface, and remain as a solid object, is because it exists in a curved space-time and not in a flat space.

With this change in perspective the true nature of gravity becomes apparent. The free falling skydiver is brought to Earth because the space-time through which she falls is curved. It is not an external force that tugs her downwards, but her own natural motion through a curved space. On the other hand, as a person standing on the ground, the pressure you feel on the soles of your feet is due to the rigidity of the Earth pushing you upwards. Again, there is no external force pulling you to Earth. It is only the electrostatic forces in the rocks below your feet that keep the ground rigid, and that prevents you from taking what would be your natural motion (which would also be free fall).

So, if we free ourselves from defining our motion with respect to the surface of the Earth we realize that the skydiver is not accelerating, while the person who stands on the surface of the Earth is accelerating. Just the opposite of what we usually think. Going back to Galileo's experiment on the leaning tower of Pisa, we can now see why he observed all of his cannonballs to fall at the same rate. It wasn't really the cannonballs that were accelerating away from Galileo at all, it was Galileo that was accelerating away from the cannonballs!

Author info:

Quote
Dr Timothy Clifton studied under John Barrow in Cambridge and is now a lecturer at Queen Mary, University of London. He is a specialist in gravitational physics. He has published many research papers on the subject, as well as co-authoring a cover story on gravity in Scientific American.
Title: Re: FE Gravity
Post by: AllAroundTheWorld on December 03, 2019, 07:43:53 AM
Tom, why did you bold the parts you did and not this part:

Quote
The free falling skydiver is brought to Earth because the space-time through which she falls is curved. It is not an external force that tugs her downwards, but her own natural motion through a curved space

Which makes it very clear that it is the sky diver moving, not the earth?
You really need to do some introspection and think about your confirmation bias rather than scanning large sections of text for words or phrases which confirm your world view rather than trying to understand them in context.
Title: Re: FE Gravity
Post by: Tom Bishop on December 03, 2019, 01:24:27 PM
It clearly says that gravity occurs in GR because the earth is accelerating upwards through space-time.

Quote
Going back to Galileo's experiment on the leaning tower of Pisa, we can now see why he observed all of his cannonballs to fall at the same rate. It wasn't really the cannonballs that were accelerating away from Galileo at all, it was Galileo that was accelerating away from the cannonballs!

Quote from: AllAroundTheWorld
Which makes it very clear that it is the sky diver moving, not the earth?

Did you read the content? It says the opposite:

Quote
we realize that the skydiver is not accelerating, while the person who stands on the surface of the Earth is accelerating. Just the opposite of what we usually think.
Title: Re: FE Gravity
Post by: BillO on December 03, 2019, 02:16:26 PM
To me it's clear Clifton is a) not a flat earther, and b) is obviously doing a thought experiment in order to demonstrate how to be more flexible in your thinking.  I'm sure he is not insisting that the planet is accelerating outward in all directions at g, because skydivers accelerate just as quickly toward the earth over Australia as they do over Canada.  The test for these things (whether they are some equivalency for mathematical simplification, or not) is usually the conservation of energy.  That the planet is expanding at an increasing rate such that the surface all over the globe exerts an acceleration of 9.8 m/(sec^2), or it is careening of in some convenient observer preferred direction at the same increasing rate does not conserve energy.

What he is saying, if you read the whole text available, is that the earth is preventing you from following your free path in the curved space around the mass of the planet, and he's just giving you another way of thinking about it - which is just a restatements of Einstein's equivalency.  And, there are limitations of to equivalency - the aforementioned conservation of energy is the prime, but not the only way of telling the difference between gravity and acceleration in real situations (as opposed to interesting, but academic thought experiments).
Title: Re: FE Gravity
Post by: Tom Bishop on December 03, 2019, 02:27:13 PM
We have a source from a physicist which says that the surface of the earth is accelerating upwards through curved space-time.

Quote
the surface of the Earth can accelerate upwards at every point on its surface, and remain as a solid object, is because it exists in a curved space-time and not in a flat space.

Do you have anything to support your opinion that he is wrong or mistating things?
Title: Re: FE Gravity
Post by: BillO on December 03, 2019, 02:57:11 PM
We have a source from a physicist which says that the surface of the earth is accelerating upwards through curved space-time. Do you have any sources to back up your opinion that he is wrong or mistating things?
I wouldn't say he is misstating things.  He is doing thought experiments.  Hence this is why he goes on to say: "For some, the beauty of this description is obvious.  For others it is the fact that it is possible to probe Einstein's theory experimentally that is most compelling".

As to whether or not that view is not a description of reality, I did that already.  Please avail yourself to the law of conservation of energy which states that the total energy of an isolated system remains constant.  A skydiver that goes up, then comes back down due to gravity, conserves energy.  A planet (whole universe?) that accelerates at 9.8m/(sec^2) to catch the skydiver does not.  I did the calculations for this previously on this site.  The numbers are astonishing.  Sources for the discussion of conservation of energy are plentiful.  You can try this one: https://en.wikipedia.org/wiki/Conservation_of_energy (https://en.wikipedia.org/wiki/Conservation_of_energy)

So, let me throw the burden of 'proof' back on you (not that science is about proof, but some folk like to throw the term around).  If you can give me a  reasonable and self-complete hypotheses as to how energy is conserved in the FE UA concept (which I assume you are looking for justification for in Clifton's little thought experiment) and with which I cannot find a demonstrable physical flaw in, then I'll concede.
Title: Re: FE Gravity
Post by: Pete Svarrior on December 03, 2019, 03:01:31 PM
How have you determined that the system you're considering is isolated if you don't even know what the system is?
Title: Re: FE Gravity
Post by: BillO on December 03, 2019, 03:24:24 PM
How have you determined that the system you're considering is isolated if you don't even know what the system is?
Are you talking about the situation Clifton presents, or are you talking about FE UA?  In Clifton's case he describes the system.  He's a physicist, so I assume he's not trying to pull the wool over anyone's eyes and is following protocol.  If there was more to the system than what he mentions, he would have stated that.  Otherwise he would not be very credible, would he?  Then we can just dismiss his little treatise with nary a wave of the hand.

If you are talking about FE UA, then that is what I am asking Tom for.  Or you can pony up the hypothesis if you want to step up.

Or are you saying the FE community cannot provide a self-complete hypothesis for conservation of energy WRT UA?  Then UA it fails immediately, doesn't  it?

Wasn't it your chief editor of the wiki (AKA Tom) that said "If you are making your claim without evidence then we can discard it without evidence."  Can we have some evidence that energy is conserved in the concept of UA?
Title: Re: FE Gravity
Post by: Tom Bishop on December 03, 2019, 03:25:08 PM
Where does he state that it's a thought experiment?
Title: Re: FE Gravity
Post by: Pete Svarrior on December 03, 2019, 04:14:29 PM
Are you talking [...]
If you are talking about FE UA [...]
Or are you saying [...]
I'm not saying anything. You are. You pointed out that the total energy of an isolated system remains constant while simultaneously stating that you don't know what system you're making claims about (A planet (whole universe?)).

I'm asking you to tidy up your claims, because I'd rather rely on you making yourself clear than risk putting words in your mouth.

Wasn't it your chief editor of the wiki (AKA Tom)
I don't see how inventing titles for Tom would absolve you of having to main internally consistent claims, nor do I see how Tom's position has any bearing on yours.
Title: Re: FE Gravity
Post by: BillO on December 03, 2019, 04:27:04 PM
Where does he state that it's a thought experiment?
"For others it is the fact that it is possible to probe Einstein's theory experimentally that is most compelling"

Oh, and let me add to this the fact that he begins the whole discussion of the experiment with the words: "Think now about what all of this means in a practical situation.  Consider ..."
Title: Re: FE Gravity
Post by: BillO on December 03, 2019, 04:29:28 PM
while simultaneously stating that you don't know what system you're making claims about (A planet (whole universe?)).
Where did I state that I didn't know what system I'm making claims about?  I was clearly talking about a planet.  The parenthesis contained an allusion to FE AU.  Which also suffers the same problem.
Title: Re: FE Gravity
Post by: Pete Svarrior on December 03, 2019, 04:34:37 PM
Where did I state that I didn't know what system I'm making claims about?
I already provided you with the relevant quote: A planet (whole universe?)

If you do know which one it is, simply state it. The way you left it suggests you can't quite narrow it down. This is why I'm asking you to make yourself clear.
Title: Re: FE Gravity
Post by: BillO on December 03, 2019, 04:38:12 PM
Where did I state that I didn't know what system I'm making claims about?
I already provided you with the relevant quote: A planet (whole universe?)

If you do know which one it is, simply state it. The way you left it suggests you can't quite narrow it down. This is why I'm asking you to make yourself clear.
See my edited response above.  I was talking about the planet system as described by Clifton and alluded to FE UA in parenthesis.  The suffer the same problem WRT energy conservation.  Nice straw man though Pete.
Title: Re: FE Gravity
Post by: Pete Svarrior on December 03, 2019, 04:53:07 PM
A "straw man"? Asking you to clarify your position while expressly avoiding assumptions is the very opposite of straw manning someone. It's a shame that you'd respond to basic scrutiny with immediate accusations, but let's try to carry on.

So, you wanted to talk about planets, but also made "an allusion" to a different discussion that could be had about the Universe. Excellent, we can work with that. While the former is pretty clear, I'm very interested as to whether you think the Universe is an isolated system. Your claims about UAT seem to rely on that assumption (feel free to elaborate if this is not the case), but it's a rather novel assumption without much mainstream support.
Title: Re: FE Gravity
Post by: BillO on December 03, 2019, 05:30:20 PM
A "straw man"? Asking you to clarify your position while expressly avoiding assumptions is the very opposite of straw manning someone. It's a shame that you'd respond to basic scrutiny with immediate accusations, but let's try to carry on.

So, you wanted to talk about planets, but also made "an allusion" to a different discussion that could be had about the Universe. Excellent, we can work with that. While the former is pretty clear, I'm very interested as to whether you think the Universe is an isolated system. Your claims about UAT seem to rely on that assumption (feel free to elaborate if this is not the case), but it's a rather novel assumption without much mainstream support.
Pete, by definition a universe is an isolated system.   Yeah, I'm in agreement with the definition.

Now, the only thing we need to decide on it whether or not all the stuff subject to FE UA constitutes an isolated system, or are there things in the FE universe WRT which the earth and all celestial bodies are accelerating at 9.8 m/(s^2).
Title: Re: FE Gravity
Post by: Tom Bishop on December 03, 2019, 09:32:45 PM
Where does he state that it's a thought experiment?
"For others it is the fact that it is possible to probe Einstein's theory experimentally that is most compelling"

Oh, and let me add to this the fact that he begins the whole discussion of the experiment with the words: "Think now about what all of this means in a practical situation.  Consider ..."

I don't see where it's stated that the statements he gives do not represent what is occurring in General Relativity. The author clearly states, several times, that the surface of the earth is accelerating upwards through curved space-time, and this is the cause for why bodies of different masses fall at the same rate in the Galileo experiment.

Another paper on the same topic: https://www.docdroid.net/AbDLJgt/earths-surface-accelerates-upwards.pdf
Title: Re: FE Gravity
Post by: BillO on December 04, 2019, 12:07:31 AM
I don't see where it's stated that the statements he gives do not represent what is occurring in General Relativity.
Many of them do, but he's trying to dumb this down too much.

The author clearly states, several times, that the surface of the earth is accelerating upwards through curved space-time
And that's where his analogy falls apart.  He is either using the same equivalency as Einstein, or he is trying to liken the acceleration caused by curved spacetime to that of centripetal acceleration.  I think the 2nd is more likely as it conserves energy.  However, even though centripetal acceleration accelerates the subject body toward a central point, the body does not move in that direction.  Neither is the rope/rod/string/whatever that is holding the subject and exerting the force that causes the acceleration shortening in that direction.  However, that is a two dimensional problem viewed from a three dimensional perspective. If we extend this to sapcetime then we are in a situation where the velocity is no longer spacial, but temporal and any 'acceleration' would also have to be unobservable to us.   So I think 'acceleration' is a real bad way to describe this for anyone who has little understanding GR.  Yes, the planet exerts a force on your feet, but it's not moving you anywhere due to that force.  In my opinion acceleration is a very poor choice of words to explain this in layman's terms.  It will conjure up images that are just not their.

In GR gravity is not a force, it is a curvature of space, but when two bodies try to get into the same piece of space, they hold each other out, and that is a force.  The same force we feel on our feet as the earth block us from following our free-fall path in spacetime..  I think this is a better way to put it.  Acceleration to most people implies movement, force does not.

and this is the cause for why bodies of different masses fall at the same rate in the Galileo experiment.
You don't need any more than newton's 2nd law of motion to explain this.

Another paper on the same topic: https://www.docdroid.net/AbDLJgt/earths-surface-accelerates-upwards.pdf
Thanks.  I've got dinner reservations for 7:30 -  I'll look into that tomorrow.
Title: Re: FE Gravity
Post by: AllAroundTheWorld on December 04, 2019, 07:00:22 AM
Another paper on the same topic: https://www.docdroid.net/AbDLJgt/earths-surface-accelerates-upwards.pdf
A paper literally entitled "The globe model".
Both sources are clearly globe earthers - the first one the brief synopsis of the book talks about how it applies to planetary motions.
So are you now a globe earther trying to understand GE or are you just cherry picking keywords which you think back up your worldview?
Title: Re: FE Gravity
Post by: Pete Svarrior on December 04, 2019, 10:43:24 AM
Pete, by definition a universe is an isolated system.   Yeah, I'm in agreement with the definition.
I cannot find a source that agrees with you. Perhaps you'd like to provide one instead of just saying you're right repeatedly?

The consensus appears to be that it would be entirely meaningless to call the Universe an isolated system (since anything external to the Universe is undefined), but I'm happy for you to defend your case. Just, you know, actually say something more useful than "I am correct.       Yeah, I am very right, yes."

Now, the only thing we need to decide on it whether or not all the stuff subject to FE UA constitutes an isolated system, or are there things in the FE universe WRT which the earth and all celestial bodies are accelerating at 9.8 m/(s^2).
Right, you're going to have to make up your mind on this one. First you said that you don't know what the system is. When I asked you to clarify, you accused me of strawmanning you and declared that you obviously do know what it is. Now you're back to saying you don't know.

Please pick a line of argumentation and stick with it. It's extremely difficult to have a meaningful conversation when you keep arguing with yourself.
Title: Re: FE Gravity
Post by: BillO on December 04, 2019, 05:59:14 PM
Pete, by definition a universe is an isolated system.   Yeah, I'm in agreement with the definition.
I cannot find a source that agrees with you. Perhaps you'd like to provide one instead of just saying you're right repeatedly?

The consensus appears to be that it would be entirely meaningless to call the Universe an isolated system (since anything external to the Universe is undefined), but I'm happy for you to defend your case. Just, you know, actually say something more useful than "I am correct.       Yeah, I am very right, yes."

Now, the only thing we need to decide on it whether or not all the stuff subject to FE UA constitutes an isolated system, or are there things in the FE universe WRT which the earth and all celestial bodies are accelerating at 9.8 m/(s^2).
Right, you're going to have to make up your mind on this one. First you said that you don't know what the system is. When I asked you to clarify, you accused me of strawmanning you and declared that you obviously do know what it is. Now you're back to saying you don't know.

Please pick a line of argumentation and stick with it. It's extremely difficult to have a meaningful conversation when you keep arguing with yourself.
Okay.

So, to bring this back on topic, what I want to know is if you can give me a  reasonable and self-complete hypotheses as to how energy is conserved in the FE UA concept with which I cannot find a demonstrable physical flaw in.
Title: Re: FE Gravity
Post by: Pete Svarrior on December 04, 2019, 06:11:01 PM
Okay.
A second friendly reminder that you're not currently in AR for a change. If you do not want to contribute to the discussion, there's no obligation for you to post.

what I want
That's great, but if you're not willing to defend your claims, you probably shouldn't be making them in the first place. You're welcome to retract them.

One of the "flaws" you're claiming relies on assumptions that you're refusing to justify. Naturally, one has to assume that you have a reason to refuse that.
Title: Re: FE Gravity
Post by: BillO on December 04, 2019, 06:27:48 PM
Another paper on the same topic: https://www.docdroid.net/AbDLJgt/earths-surface-accelerates-upwards.pdf
Yeah, he is just saying the same thing will a little more rigor.  And I have no argument in his math, just in the nomenclature used in describing his findings.  This paperer has an advantage in that it's intended for folks that have some GR under their belt, so they will take his meaning.  However, if I were to tell my wife the earth is accelerating her upward and is accelerating outward in all directions she would think I'm bonkers.  The earth is clearly not increasing in size at an ever increasing rate.  AS he takes you through the math Berry provides the results then states "This form eerily mirrors the form of Newton’s gravity." And it does, in fact it looks just the the acceleration due to gravity, but you have to realize that he began his calculations with the stipulation " ... our  fixed  point  on  the  surface  of  the Earth doesn’t move along any of the last 3 coordinates,r,θ, orφ.  So, its spacetime path and 4-velocity must be directed along the t direction."  That fact does not change through the calculation the acceleration (actualy, 4-acceleration).  So unlike implication of normal acceleration (3-acceleration), nothing is actually moving or increasing in 3-velocity WRT the center of the earth.

BTW, observe the 4-vextor that is the result 〈0,GM/(R^2),0,0〉.  This can only occur on a globe since the t,θ and φ dimensions are invariant so there is no preferred direction.

I have another question:  Does the flat earth even have a Schwarzchild radius?
Title: Re: FE Gravity
Post by: BillO on December 04, 2019, 07:20:38 PM
One of the "flaws" you're claiming relies on assumptions that you're refusing to justify. Naturally, one has to assume that you have a reason to refuse that.
Pete, let me apologize.   The reason I'm not declaring whether or not the FE universe is isolated is because it is not fully pertinent top the question.  However, I did not invent the FE UA system.  I assume you guy's did, so the definitions are up to you.  You can approach the problem either way.  If the description of FE UA in the wiki does encompass an isolated system, then you just show how energy is conserved within that system.  If it does not encompass an isolated system, then just show where the energy is coming from so that an isolated system can be defined (the FE UA system + the Energy system) wherein the energy is conserved.

As to whether or not the universe most RE folk adhere to is and isolated system,  in thermodynamics and isolated system is a system which does not or can not exchange either energy or matter with its surroundings.   By definition, the universe is self contained and therefore cannot exchange energy or matter.

Or you can read this excerpt from Quora:
Quote
The (entire) universe is an isolated system. The observable universe is an open system.

There are 3 main types of thermodynamic systems, defined by what the system can exchange with its surroundings:

An open system can exchange both energy and matter.
A closed system can exchange only energy.
An isolated system cannot exchange anything.

The entire universe, meaning everything there is, including things we cannot see, is an isolated system because it has no "surroundings"; it's literally everything there is. Obviously, a system cannot exchange energy or matter with "surroundings" that do not exist.

The observable universe, meaning only the part of the universe that we can see, is an open system, because the "boundary" of our observable universe is not actually a physical "boundary" in any possible meaning of the word, and both matter and energy can freely pass through it.

What I mean is that our observable universe has a "boundary" because if something is beyond this "boundary", the light from it has not had time to reach us yet (and may never will). Aliens living on the "boundary" of our observable universe will have their own definition of "observable universe" and it will not be the same as our definition, because there are things in the universe they can see that we can't, and vice versa.

what I want
Yeah, I asked this question: "What I want to know is if you can give me a  reasonable and self-complete hypotheses as to how energy is conserved in the FE UA concept with which I cannot find a demonstrable physical flaw in." That's what I want answered, and I asked it before you got involved.  If you have specific things for me to outline for you before taking a stab at it please ask.

One of the "flaws" you're claiming relies on assumptions that you're refusing to justify. Naturally, one has to assume that you have a reason to refuse that.
Justify that the universe is an isolated system?  See above.  Pete, if you don't understand thermodynamics, then why did you involve yourself in this?
Title: Re: FE Gravity
Post by: somerled on December 05, 2019, 10:53:24 AM
If the universe , meaning everything there is , is an isolated system then from what is it isolated ? An isolated system by definition must have boundaries . Oxymoronic argument from quora there.
Title: Re: FE Gravity
Post by: Pete Svarrior on December 05, 2019, 01:02:19 PM
Pete, let me apologize.
You do not need to apologise - merely contribute (if you're posting in the upper).

The reason I'm not declaring whether or not the FE universe is isolated is because it is not fully pertinent top the question.
I already explained to you why it is. I guess I'll have to do so again.

However, I did not invent the FE UA system.  I assume you guy's did, so the definitions are up to you.
The Universe is fairly well-defined, independently of FE vs RE.

You can approach the problem either way.  If the description of FE UA in the wiki does encompass an isolated system, then you just show how energy is conserved within that system.  If it does not encompass an isolated system, then just show where the energy is coming from so that an isolated system can be defined (the FE UA system + the Energy system) wherein the energy is conserved.
I don't need to do either of these things, for a plethora of reasons. The fact that calling the Universe an isolated system is meaningless is crucial here. Your objection has no defined meaning, and cannot be answered until you've fixed it. If you truly believe that meaningless statements require answers, or are in any way significant, then let me ask you this: If the Earth is round, then why zibbidy snorty floorp, de rooba shnort?

As to whether or not the universe most RE folk adhere to is and isolated system,  in thermodynamics and isolated system is a system which does not or can not exchange either energy or matter with its surroundings.   By definition, the universe is self contained and therefore cannot exchange energy or matter.
I'm afraid you restating your position doesn't make it any more mainstream or correct. This is why I asked you for a source.

Or you can read this excerpt from Quora:
If Quora, of all places, is good enough for you, then hopefully you'll be generous enough to accept Wikipedia as a counter-example:

Quote from: https://en.wikipedia.org/wiki/Isolated_system
Sometimes people speculate about "isolation" for the universe as a whole, but the meaning of such speculation is doubtful.

See, the issue here is that you propose something that makes no sense (the Universe is isolated? From what?), assert that it is the case "by definition", and demand that we address your mess. It's not gonna happen, you're going to have to fix your claims. I'm not even asking that you make sure you're correct, merely that you make sure your statements have a discernible meaning.

Pete, if you don't understand thermodynamics, then why did you involve yourself in this?
This is your final friendly reminder that you are currently not in AR/CN. You can discuss just how stupid, uneducated, and smelly I am in the appropriate boards.
Title: Re: FE Gravity
Post by: pricelesspearl on December 05, 2019, 04:25:39 PM
Quote
from what?

Net external forces. “Isolated” in the definition isn’t a relative.  It means the system is not affected by net external force.  Why it isn't effected doesn't matter.  The fact that there are no external forces that could affect the system is irrelevant.  The existence of system y isn’t necessary to determine if system x is effected by net external forces. Either it is or it is not.
Title: Re: FE Gravity
Post by: BillO on December 05, 2019, 06:11:46 PM

As to whether or not the universe most RE folk adhere to is and isolated system,  in thermodynamics and isolated system is a system which does not or can not exchange either energy or matter with its surroundings.   By definition, the universe is self contained and therefore cannot exchange energy or matter.
I'm afraid you restating your position doesn't make it any more mainstream or correct. This is why I asked you for a source.

My source is thermodynamics.  It's not my position, other than I am in agreement with thermodynamics.  It is not something I made up.

Thermodynamics deals with the transfer of energy and matter between systems.  It deals with and recognizes 3 different types of systems.  Open systems, closed systems and isolated systems.  As with many branches of science thermodynamics has specific definitions for the therms used which may or may not align the the common usage for those terms.  In thermodynamics the terms Open system, closed system and isolated system have the following definitions:

Open system - A physical system which can exchange both energy and matter with it's surroundings or other systems.
Closed system - A physical system which can exchange energy but not matter with it's surroundings or other systems.
Isolated system - A physical system which cannot exchange either energy or matter with it's surroundings or other systems.

a) So, in thermodynamics terminology an isolated system is by definition a system that cannot receive energy or matter from outside it, and cannot send energy or matter outside it.

b) The universe, by definition is that which contains everything.  The universe cannot receive energy or matter from outside it, and cannot send energy or matter outside it.

From a) and b), for the purposes of thermodynamics, the universe meets the requirements of being an isolated physical system.

And, yeas, in science definitions are critically important.

The on-line text on thermodynamics here: https://courses.lumenlearning.com/introchem/chapter/the-three-laws-of-thermodynamics/ (https://courses.lumenlearning.com/introchem/chapter/the-three-laws-of-thermodynamics/)  States:

"More simply put: the entropy of the universe (the ultimate isolated system) only increases and never decreases."

The RationalWiki here :https://rationalwiki.org/wiki/Laws_of_thermodynamics (https://rationalwiki.org/wiki/Laws_of_thermodynamics)  States:

"The Universe is an isolated system since it is a term to describe the entire spacetime continuum, including all of the energy stored in it. In reality, the Universe is regarded as the only true isolated system, as perfect isolation on a smaller scale is impossible."

The on-line text on thermodynamics here:https://www.learnthermo.com/T1-tutorial/ch07/lesson-C/pg06.php (https://www.learnthermo.com/T1-tutorial/ch07/lesson-C/pg06.php) States:

"The universe is an isolated system."

But, like I said, it does not matter whether or not the universe is an isolated system.  To show if FE UA is in agreement with conservation of energy, all you need to do is define an isolated system as defined in thermodynamics within the FE universe and show how energy is conserved, or failing to find an such a system, show the source and or sink for the energy transfer required.  So, I'm at a loss as to why we are stuck at whether or not the universe is an isolated system or not as it is not a requirement to tackle the question at hand.

Anyway, as far as I am concerned we are done here.  My challenge was for someone to demonstrate that FE UA was consistent with conservation of energy and this has not been done despite pages of conversation.  I really don't care if anyone believes the universe is an isolated system or not.  By the pertinent definitions it is, but that is not and never was a requirement to meet the challenge.

Score: FE - fail.

The last word to you Pete.
Title: Re: FE Gravity
Post by: Pete Svarrior on December 05, 2019, 11:20:25 PM
My source is thermodynamics.
I'm afraid that's not how citations work.

It is not something I made up.
Unfortunately, I already demonstrated that you're in disagreement with the mainstream on that one. An explanation was given to you. If you have an objection, you need to articulate an argument. If you cannot put together a rebuttal, that's fine, it happens a lot around here. But you won't be allowed to continuously waste people's time by just declaring yourself the victor while contributing nothing of value.

b) The universe, by definition is that which contains everything.  The universe cannot receive energy or matter from outside it, and cannot send energy or matter outside it.
b) is not a logical conclusion, since the "outside of the Universe", something external to the set of everything, is undefined and therefore meaningless. The problem, as always, is that you assert yourself to be correct, and when asked to provide citations, you just assert yourself to be correct some more.

This is not a good look.

And, yeas, in science definitions are critically important.
Indeed. You'd do well to stop botching them. Again, the question here isn't even whether you're right or wrong. It's whether you will eventually put together a coherent sentence.

Score: FE - fail.
It is in particularly poor form to make declarations like these. Trust me, it won't convince the unconvinced, and those who already agree with you will just think you're weakening your argument by acting like a child. I appreciate your effort to join the upper fora, and I'm happy to help you ease into posting here, but you can do so much better than that.
Title: Re: FE Gravity
Post by: Rama Set on December 13, 2019, 03:38:57 PM
It’s not even clear that “outside the universe” is a meaningful statement. How anyone could try and surmise what that is without assumptions is beyond me.
Title: Re: FE Gravity
Post by: BillO on December 13, 2019, 04:34:29 PM
It’s not even clear that “outside the universe” is a meaningful statement. How anyone could try and surmise what that is without assumptions is beyond me.
Who is talking about outside the universe?  It seems to me  many of the people on this site can't assimilate simple discourse and how they can stick their noses into a conversation they demonstrate blatantly they don't understand is beyond me.  If you have an issue with the I way express something, discuss it with me in a civilized manner rather than making uninformed assumptions.  If you can't be civil, we can take this to AR.

Same goes for Pete on this one.  You both know exactly what I mean and my use of "outside the universe" is perfectly correct.  The assumption you both seem to have missed (well Pete quoted it FFS) is: The universe contains everything.  This implies there is nothing "outside the universe" and is the only reason the expression was used.  The pertinence to all this to answer the question "Is the universe an isolated system WRT to thermodynamics."  And it is generally accepted that it is.  In fact it is generally accepted that it is the only true isolated system.  Barring, of course, Pete's wonderful citation (not mainstream BTW), which wafflingly stated it might not be an isolated system.  I think the term used was doubtful.  However,  reading the context of that statement they need to change the definition of the universe from the one in play in this discussion.

Let's make no mistake.  If youwant to say the universe is not an isolated system, and stand by that rather than just cast doubt, you better be prepared to start actually talking about what is "outside the universe".
Title: Re: FE Gravity
Post by: BillO on December 14, 2019, 02:02:34 AM
The problem, as always, is that you assert yourself to be correct, and when asked to provide citations, you just assert yourself to be correct some more.
I provided 5 citations during this thread, BTW.
Title: Re: FE Gravity
Post by: Pete Svarrior on December 15, 2019, 01:15:43 PM
Let's make no mistake.  If youwant to say the universe is not an isolated system, and stand by that rather than just cast doubt, you better be prepared to start actually talking about what is "outside the universe".
No, sorry. You're the one who proposed the concept, and you're the one who's going to have to justify it (again, for now we're not looking for you being correct, we're looking for you saying things that have a discernible meaning). Until then, you keep staying something that's undefined and demanding that we assign a truth value to it. Not gonna happen.

I provided 5 citations during this thread, BTW.
None to this specific effect. Lying makes you look less credible, not more.

Barring, of course, Pete's wonderful citation (not mainstream BTW), which wafflingly stated it might not be an isolated system.
That's not what it says. I quoted it for you, remember? It states that your assertion, and the discussion around it, is dubiously meaningful. To say that something has no meaning is different from saying that it's incorrect - it's a far worse state of affairs.

And, again, "nuh uh I am very right and mainstream literature is not mainstream" is not the sort of rebuttal we're looking for in the upper fora. I appreciate you're making an effort in trying to adjust, I really do, but you need to do away with these lazy responses. Either back your claim up or choose not to make it. Don't just go "(not mainstream btw)" on us.

Once again, if you enjoy discussing the undefined and the meaningless, I encourage you to answer my question. If the Earth is round, then why zibbidy snorty floorp, de rooba shnort?

My last post here (https://forum.tfes.org/index.php?topic=15404.msg201774#msg201770) was a sincere offer of helping you figure out how to be successful in these discussions. I encourage you to take it and good faith and at least think about my suggestions. You won't agree with all of them, of course, but they could help you in the long run.
Title: Re: FE Gravity
Post by: BillO on December 15, 2019, 06:19:31 PM
I provided 5 citations during this thread, BTW.
None to this specific effect. Lying makes you look less credible, not more.

I said the universe was an isolated system, you asked me for a citation.  Remember this?
Pete, by definition a universe is an isolated system.   Yeah, I'm in agreement with the definition.
I cannot find a source that agrees with you. Perhaps you'd like to provide one instead of just saying you're right repeatedly?

I provided links to several sources that stated the universe is an isolated system.  Two were thermodynamics text books.  How am I lying and how more specific can they get?

Your citation from Wikipedia could have been written by anyone, including myself, and merely claims the meaning of the universe as an isolated system is doubtful.  It did not say the concept was completely wrong, nor did it provide any justification.  Just a single statement making a claim.  That is your definition of mainstream consensus?

Title: Re: FE Gravity
Post by: Groit on January 13, 2020, 10:02:54 PM

If one body is experiencing a more forceful pull from the earth, as to cause it to weigh more, it does not make sense that all bodies would fall at the same rate.

An answer of "Just because they do" is not a very satisfying mechanism, IMO.

Acceleration due to gravity is very much different than say acceleration in a car. If you accelerate in a car at 9.81 ms^-2 then you will feel the car seat pushing on your back and shoulders, however, if you jumped of a high rise building, you will also accelerate at 9.81 ms^-2 but you wouldn't feel any force on your shoulders and if there were no air resistance then you wouldn't feel any forces until you reached the ground.

Gravity is a consequence of curved spacetime. Large masses like the Earth curve the geodesics of spacetime and  all falling objects follow the geodesics which point directly towards the centre of the Earth, and that's why all objects fall at the same rate.
Title: Re: FE Gravity
Post by: Pete Svarrior on January 21, 2020, 06:27:03 AM
if you jumped of a high rise building, you will also accelerate at 9.81 ms^-2 but you wouldn't feel any force on your shoulders and if there were no air resistance then you wouldn't feel any forces until you reached the ground.
This is absolute nonsense. You feel your weight at all times. The reason you don't take much note of it is that it's all you've ever known. It's weightlessness that would be remarkable and thus notable, not weight.

And the reason an accelerating car "feels" different is also obvious. You feel something pushing you, because something literally is pushing you - the car seat.
Title: Re: FE Gravity
Post by: pricelesspearl on January 21, 2020, 02:11:29 PM
Quote
This is absolute nonsense. You feel your weight at all times. The reason you don't take much note of it is that it's all you've ever known. It's weightlessness that would be remarkable and thus notable, not weight.

It's odd that you would say that is nonsense, since the observation that in free fall one would not feel their weight is what led Einstein to the Equivalence Principle.

Surely you aren't suggesting that the EP is nonsense.
Title: Re: FE Gravity
Post by: Pete Svarrior on January 21, 2020, 10:12:12 PM
It's odd that you would say that is nonsense, since the observation that in free fall one would not feel their weight is what led Einstein to the Equivalence Principle.
Conveniently, what I said has nothing to do with this. If you didn't understand me, please consider asking for clarification instead of just guessing.
Title: Re: FE Gravity
Post by: pricelesspearl on January 21, 2020, 11:27:57 PM

Quote
if you jumped of a high rise building, you will also accelerate at 9.81 ms^-2 but you wouldn't feel any force on your shoulders and if there were no air resistance then you wouldn't feel any forces until you reached the ground.

You responded

Quote
This is absolute nonsense. You feel your weight at all times. The reason you don't take much note of it is that it's all you've ever known. It's weightlessness that would be remarkable and thus notable, not weight.

I interpreted you to mean that you believed Groit's comment (referred by you as "this") that if you jumped off a building you wouldn't feel any forces (assuming no air resistance) until you hit the ground to be "absolute nonsense"

And I also interpreted your statement that you feel your weight "at all times"...to the mean just that..."all times", including free fall.
Title: Re: FE Gravity
Post by: Pete Svarrior on January 22, 2020, 09:41:04 AM
I don't know how to make this any clearer. You do not feel anything pushing you when you're in freefall, because nothing is pushing you. Our sense of acceleration relies on the acceleration being uneven. A RE gravity would apply the force evenly to all of your body, including all of your inner ear, at the same time. An accelerating car would not.

This is also why Groit's comment on not feeling anything pushing your shoulders was particularly silly - our perception of this would be relative to the rest of our body. But the difference here is purely perceptual, and largely based on what you intuitively consider "feeling" a force.

Surely you aren't suggesting that the EP is nonsense.
Luckily, EP doesn't state what you think it states, Mr Spirit Level.
Title: Re: FE Gravity
Post by: pricelesspearl on January 22, 2020, 01:45:18 PM
Quote
I don't know how to make this any clearer. You do not feel anything pushing you when you're in freefall, because nothing is pushing you. Our sense of acceleration relies on the acceleration being uneven. A RE gravity would apply the force evenly to all of your body, including all of your inner ear, at the same time. An accelerating car would not.

This is also why Groit's comment on not feeling anything pushing your shoulders was particularly silly - our perception of this would be relative to the rest of our body. But the difference here is purely perceptual, and largely based on what you intuitively consider "feeling" a force.

Except you said… You feel your weight at all times, so make up your mind.  Does one feel their own weight in free fall or not?  Or is free fall not included as part of “all” times?

Quote
Luckily, EP doesn't state what you think it states

Does is it explicitly state that you wouldn’t feel your weight in free fall? No.  Does the EP logically follow from the concept?
Einstein thought so.

Quote
Einstein has been quoted as saying that the happiest thought of his life was the realization that someone in free fall from a height would not feel his own weight.

https://en.wikiversity.org/wiki/Theory_of_relativity/Equivalence_principle

Quote
Mr. Spirit Level

I am more than happy to go there again.

EDIT:

Quote
A RE gravity would apply the force evenly to all of your body, including all of your inner ear, at the same time.

What we perceive as weight is not gravity, it is the normal force. It is the force that a surface exerts on an object that prevents gravity from pulling it down.  When a book is sitting on a table, the table exerts normal force on the book and prevents it from being pulled through the table to the floor.
It is a contact force, so if someone is freely falling and has no contact with a surface, no weight is perceived.

Title: Re: FE Gravity
Post by: Pete Svarrior on January 22, 2020, 02:35:39 PM
What we perceive as weight is not gravity, it is the normal force.
You are correct. I should have said "weight". It changes nothing about your failure here, and your obvious attempt at distracting from the subject does not make you look better - it makes you look worse.

This is also why Groit's comment on not feeling anything pushing your shoulders was particularly silly - our perception of this would be relative to the rest of our body. But the difference here is purely perceptual, and largely based on what you intuitively consider "feeling" a force.
Of course, you can perceive weight at all times. However, it will not be the same sensation as feeling something pushing you. The reasons for this are also explained in my post. Try reading it.

Einstein thought so.
You are abusing ambiguous wording moments after I explained the ambiguity. If you want to waste my time clumsy wordplay, you'll have to find someone else to bother.
Title: Re: FE Gravity
Post by: pricelesspearl on January 22, 2020, 03:30:19 PM
Quote
You are correct. I should have said "weight".

You did say weight. And you said again.

Quote
Of course, you can perceive weight at all times.

If you understand that our perception of weight is the result of the normal force, then you should be able to understand that if there is no normal force, there is no perception of weight.

Normal force is a contact force.  When you are in freefall, you aren’t in contact with anything, therefore there is no normal force and no perception of weight.

Quote
You are abusing ambiguous wording
Quote
The breakthrough came suddenly one day.  I was sitting on a chair in my patent office in Bern.  Suddenly the thought struck me: If a man falls freely, he would not feel his own weight
That quote from Einstein is not ambiguous at all.
Title: Re: FE Gravity
Post by: Pete Svarrior on January 22, 2020, 03:32:44 PM
If you understand that our perception of weight is the result of the normal force
Once again, that is not exclusively the case. I'm really tired of repeating myself. Please stop trying to pick at parts of my claim out of context.
Title: Re: FE Gravity
Post by: Tim Alphabeaver on January 24, 2020, 10:16:16 PM
Let's make no mistake.  If youwant to say the universe is not an isolated system, and stand by that rather than just cast doubt, you better be prepared to start actually talking about what is "outside the universe".
No, sorry. You're the one who proposed the concept, and you're the one who's going to have to justify it (again, for now we're not looking for you being correct, we're looking for you saying things that have a discernible meaning). Until then, you keep staying something that's undefined and demanding that we assign a truth value to it. Not gonna happen.
Coming in a bit late here, so sorry if I'm restating anything (I skimmed the thread). Surely one can define the universe as 'all the stuff', which by definition is isolated. Why are there 10+ back-and-forth comments getting more and more off-topic about this?
Title: Re: FE Gravity
Post by: Pete Svarrior on January 25, 2020, 09:53:03 AM
Coming in a bit late here, so sorry if I'm restating anything (I skimmed the thread).
Yeah, sorry, you'll have to read the thread. In short, the concept of the Universe being an isolated system is undefined - it does not have an assigned, coherent meaning. As such, it is not false to claim it, it's just gobbledygook.

BillO relies on his intuition, and he clearly knows what he means by the words he chose. But he repeatedly refused to clarify his meaning, and instead insisted on using words that have no meaning.
Title: Re: FE Gravity
Post by: BillO on January 25, 2020, 01:31:03 PM
But he repeatedly refused to clarify his meaning, and instead insisted on using words that have no meaning.
Again, Pete's perspective in operation here.  The words I chose are those used in many thermodynamics texts, not my intuition.  I found links to 2 of them on-line and provided them for you.  I can also give you the ISBN of my ancient texts too, if that will help you, but there would be no point.  The question I asked, show that UA in the FE universe is thermodynamically sound, has yet o be answered.  As I said, you don't need to have an isolated system to do this.  Thermodynamics is equipped to deal with open systems, closed systems and isolated systems.  I've left the the choice to you, yet you constantly evade.
Title: Re: FE Gravity
Post by: Tim Alphabeaver on January 25, 2020, 07:33:28 PM
Coming in a bit late here, so sorry if I'm restating anything (I skimmed the thread).
Yeah, sorry, you'll have to read the thread. In short, the concept of the Universe being an isolated system is undefined - it does not have an assigned, coherent meaning. As such, it is not false to claim it, it's just gobbledygook.

BillO relies on his intuition, and he clearly knows what he means by the words he chose. But he repeatedly refused to clarify his meaning, and instead insisted on using words that have no meaning.

It looks to me like BillO clarified his position quite well. How can you have any possible confusion about this statement:

You can approach the problem either way.  If the description of FE UA in the wiki does encompass an isolated system, then you just show how energy is conserved within that system.  If it does not encompass an isolated system, then just show where the energy is coming from so that an isolated system can be defined (the FE UA system + the Energy system) wherein the energy is conserved.
Title: Re: FE Gravity
Post by: Pete Svarrior on January 25, 2020, 11:18:29 PM
It looks to me like BillO clarified his position quite well.
In thermodynamics, calling the Universe an isolated system is meaningless. It cannot be true nor false, because it does not have an assigned meaning within physics. The danger of accepting undefined terms in a discussion like this is that it will bring unknown consequences later on. BillO was offered plenty of opportunities to replace that term with a meaningful one, but chose not to. Thus, the conversation can't proceed.
Title: Re: FE Gravity
Post by: pricelesspearl on January 26, 2020, 12:45:37 AM
It looks to me like BillO clarified his position quite well.
In thermodynamics, calling the Universe an isolated system is meaningless. It cannot be true nor false, because it does not have an assigned meaning within physics. The danger of accepting undefined terms in a discussion like this is that it will bring unknown consequences later on. BillO was offered plenty of opportunities to replace that term with a meaningful one, but chose not to. Thus, the conversation can't proceed.

An isolated system is not undefined.  It is a system that does not exchange mass or energy with any other system. The universe fits that definition.
Title: Re: FE Gravity
Post by: Pete Svarrior on January 26, 2020, 09:52:04 AM
An isolated system is not undefined.
If you're not going to bother reading what I said, please don't waste our time with copy-pasted definitions.
Title: Re: FE Gravity
Post by: Tim Alphabeaver on January 26, 2020, 11:51:48 PM
It looks to me like BillO clarified his position quite well.
In thermodynamics, calling the Universe an isolated system is meaningless. It cannot be true nor false, because it does not have an assigned meaning within physics. The danger of accepting undefined terms in a discussion like this is that it will bring unknown consequences later on. BillO was offered plenty of opportunities to replace that term with a meaningful one, but chose not to. Thus, the conversation can't proceed.
Is your opinion somehow more valid that someone else's opinion? I just read through (again) your posts and the only link I could find was an uncited line on a wikipedia article - which I think we can all agree is not meaningful, so do you have some sources?

Sidenote: Can I just ignore the first few sources you link just like you did with BillO's sources?

I'm afraid that's not how citations work.
Title: Re: FE Gravity
Post by: Pete Svarrior on January 28, 2020, 10:22:44 PM
Is your opinion somehow more valid that someone else's opinion?
My opinion is entirely irrelevant to the scientific consensus I've stated.
Title: Re: FE Gravity
Post by: Groit on January 28, 2020, 11:12:37 PM
if you jumped of a high rise building, you will also accelerate at 9.81 ms^-2 but you wouldn't feel any force on your shoulders and if there were no air resistance then you wouldn't feel any forces until you reached the ground.
This is absolute nonsense. You feel your weight at all times. The reason you don't take much note of it is that it's all you've ever known. It's weightlessness that would be remarkable and thus notable, not weight.

Pete, if there were no air resistance then you wouldn't feel any forces at all, and your weight in free fall would be 0 N (Newtons).

Here's a clip showing weighing scales reading zero in free fall. from this height the air resistance is negligible.

https://youtu.be/S7Kw1BUVSbs
Title: Re: FE Gravity
Post by: Tim Alphabeaver on January 28, 2020, 11:37:10 PM
Is your opinion somehow more valid that someone else's opinion?
My opinion is entirely irrelevant to the scientific consensus I've stated.
Ahh ok, and it's a consensus because... you've stated it? Forgive me if I'm missing something, but you can't just state something without citation and then ignore when other people post statements that disagree and are backed up with citations.

As a wise man once said:
I'm afraid that's not how citations work.

Or to put it more simply:
I state that the universe is an isolated system, and that this is a meaningful definition. This is scientific consensus, and you are in fact incorrect.
Title: Re: FE Gravity
Post by: Pete Svarrior on January 29, 2020, 06:11:39 AM
Ahh ok, and it's a consensus because... you've stated it?
If you don't want to discuss this seriously, don't discuss it at all.

Forgive me if I'm missing something, but you can't just state something without citation
I provided a citation of much higher standard than my opponent, and provided my own wording to help make the point clear. If you disagree with it, you'll have to at least provide some reasoning, not just pretend my reference doesn't exist.

I state that the universe is an isolated system, and that this is a meaningful definition. This is scientific consensus, and you are in fact incorrect.
Please stop shitposting in the upper fora. Take this sort of crap to AR.

Here's a clip showing weighing scales reading zero in free fall. from this height the air resistance is negligible.
Of course a scale would read 0. Its reference point is falling just as fast as the top. How was that ever going to help? If anything, you should be looking at accelerometers if you really want to pursue this line of questioning.

Also, it saddens me that you fell for pp's troll of deliberately abusing phrasing to your advantage. It's in very poor form, and unlikely to advance this discussion.
Title: Re: FE Gravity
Post by: Groit on January 29, 2020, 09:11:50 PM

Here's a clip showing weighing scales reading zero in free fall. from this height the air resistance is negligible.
Of course a scale would read 0. Its reference point is falling just as fast as the top. How was that ever going to help? If anything, you should be looking at accelerometers if you really want to pursue this line of questioning.

An accelerometer in free fall will also feel no forces acting on it, and it will read zero.
Jim Al Khalili explains here:

Title: Re: FE Gravity
Post by: Pete Svarrior on January 29, 2020, 09:57:15 PM
An accelerometer in free fall will also feel no forces acting on it, and it will read zero.
Yes, that's why I said you should be using that as your argument instead of a scale. Now that you've agreed with me, it might be time to start making your argument.
Title: Re: FE Gravity
Post by: Tim Alphabeaver on January 29, 2020, 11:36:29 PM
I provided a citation of much higher standard than my opponent, and provided my own wording to help make the point clear. If you disagree with it, you'll have to at least provide some reasoning, not just pretend my reference doesn't exist.
Wikipedia?
Title: Re: FE Gravity
Post by: Tim Alphabeaver on January 29, 2020, 11:49:29 PM
Ahh ok, and it's a consensus because... you've stated it?
If you don't want to discuss this seriously, don't discuss it at all.
Pete, I'm really sorry if I'm missing anything here - but please correct me if I'm wrong. Please.
I'm trying to discuss this seriously.

You stated that calling the universe an isolated system is 'meaningless', and then when challenged, you responded that it's just 'scientific consensus', citing wikipedia.
I must be missing something here because wikipedia is not a useful source.
Title: Re: FE Gravity
Post by: Pete Svarrior on January 30, 2020, 04:31:00 PM
Given that my opponent's reference was a Quora thread, I have no issue with countering it with Wikipedia. You're welcome to consult your physics textbook if you prefer.
Title: Re: FE Gravity
Post by: Tim Alphabeaver on January 30, 2020, 04:35:28 PM
Given that my opponent's reference was a Quora thread, I have no issue with countering it with Wikipedia. You're welcome to consult your physics textbook if you prefer.
Funnily enough, it looks like your wikipedia article has since been edited, and now doesn't agree with you, and is now backed up with citations (which it wasn't previously). Oops.
Title: Re: FE Gravity
Post by: Pete Svarrior on January 30, 2020, 04:55:58 PM
It was the only reference that stated what he wanted to state. Most other things he provided disagreed with him, as I've already explained. I do not see how repeating myself will help here, nor can I force you to read the literature.

It surprises me that you chose to vandalise Wikipedia over this, or that you thought it would be productive. I'll keep that in mind when considering your intentions in the future.

It's clear you're not interested in meaningful discussion, just scoring cheap points. Don't do that in the upper.
Title: Re: FE Gravity
Post by: Tim Alphabeaver on January 30, 2020, 05:05:21 PM
vandalised
I edited it. Please show me in the wikipedia guidelines where it says you can't update uncited lines with more accurate, cited ones. The update was not vandalism. If you disagree, show me why it was vandalism.
https://en.wikipedia.org/wiki/Wikipedia:Verifiability/Removal_of_Uncited_Material (https://en.wikipedia.org/wiki/Wikipedia:Verifiability/Removal_of_Uncited_Material)

Quote from: Pete Svarrior
It's clear you're not interested in meaningful discussion
To me, actually being able to cite a claim is incredibly meaningful - I thought TFES standards for this kind of thing were quite high.
Title: Re: FE Gravity
Post by: Pete Svarrior on January 30, 2020, 06:00:19 PM
Editing a Wikipedia article to "win" a debate on another site is not seen to kindly by Wikipedia. Indeed, it is subject of frequent mockery (https://meta.wikimedia.org/wiki/How_to_win_an_argument), of which you are well deserving.

I undid your edit (and I'm informing you of this, because to do otherwise would be in poor form). If you disagree, I propose that you follow Wikipedia's dispute resolution process - https://en.wikipedia.org/wiki/Wikipedia:Dispute_resolution. I'm sure once you've explained that you edited the article because you thought the mean man on a Web forum was wrong, they'll be very pleased with you.

To me, actually being able to cite a claim is incredibly meaningful - I thought TFES standards for this kind of thing were quite high.
Once again, my opponent presented a Quora thread that agreed with him, and after I displayed the Wikipedia page, he threw in a few sources that don't support his viewpoint. I also explained the reasoning behind this in my own words, which were never addressed or disputed.

I sincerely cannot help you with this, and since you've shown yourself to be arguing in bad faith by vandalising that page, I have very little will to waste my time on you. It'll take some time and effort before I consider taking you seriously again.
Title: Re: FE Gravity
Post by: Tim Alphabeaver on January 30, 2020, 06:06:37 PM
Editing a Wikipedia article to "win" a debate on another site is not seen to kindly by Wikipedia. Indeed, it is subject of frequent mockery (https://meta.wikimedia.org/wiki/How_to_win_an_argument), of which you are well deserving.

To me, actually being able to cite a claim is incredibly meaningful - I thought TFES standards for this kind of thing were quite high.
Once again, my opponent presented a Quora thread that agreed with him, and after I displayed the Wikipedia page, he threw in a few sources that don't support his viewpoint. I sincerely cannot help you with this, and since you've shown yourself to be arguing in bad faith by vandalising that page, I have very little will to waste my time on you.
Yep, of course you're totally right. I vandalised a wikipedia page, please point and laugh all you want if it makes you feel better, and your 'opponent' only had a Quora page to cite, I'll give that all to you for free as this is completely superfluous to the actual issue here.

This doesn't change the fact that you are claiming that something is a scientific consensus based solely on an uncited line from a wikipedia article. That is my problem, sorry if I've not been clear about this in my previous posts.
Title: Re: FE Gravity
Post by: Pete Svarrior on January 30, 2020, 06:15:34 PM
This doesn't change the fact that you are claiming that something is a scientific consensus based solely on an uncited line from a wikipedia article. That is my problem, sorry if I've not been clear about this in my previous posts.
I would argue that some things are so obvious that you really don't need to find a citation for them, and that this isn't a problem. For example, I wouldn't look for a citation to prove that you'll find some H2O in a glassful of orange juice. It's a true statement, but honestly I doubt a citation for it exists because of how oddly specific and simultaneously trivial the issue is.

When presented with a Quora post (one person's opinion, any single person could have posted it), I provided something better - an article that stood unaltered (until your intervention) for quite some time, having been reviewed by a number of users. Is it the be-all-end-all of scientific citation? No. Is it a damn sight better than what my opponent had to offer? Firmly so.

But none of that matters, because I provided supplementary reasoning and explained my logic. It is impossible for the Universe to be an isolated system, because it has nothing to be isolated from. The claim that the Universe is or isn't an isolated system is meaningless, because it does not have a meaningful definition. If one were to dispute this claim, they should simply provide that definition (which, you'll note, is all I initially asked for, and which I was refused).

In fact, this is the pertinent issue that killed this discussion. We cannot proceed without agreeing on a meaningful definition of what he meant. He's refusing to provide that definition, and I won't simply assume it, because then we'd risk discussing entirely different concepts while using the same words. Even if it did turn out that I'm mistaken about the consensus, we can't proceed until he fixes his argument.
Title: Re: FE Gravity
Post by: Tim Alphabeaver on January 30, 2020, 06:18:43 PM
he threw in a few sources that don't support his viewpoint.

And yet if we look at the sources you're talking about:
The on-line text on thermodynamics here: https://courses.lumenlearning.com/introchem/chapter/the-three-laws-of-thermodynamics/ (https://courses.lumenlearning.com/introchem/chapter/the-three-laws-of-thermodynamics/)  States:

"More simply put: the entropy of the universe (the ultimate isolated system) only increases and never decreases."

The RationalWiki here :https://rationalwiki.org/wiki/Laws_of_thermodynamics (https://rationalwiki.org/wiki/Laws_of_thermodynamics)  States:

"The Universe is an isolated system since it is a term to describe the entire spacetime continuum, including all of the energy stored in it. In reality, the Universe is regarded as the only true isolated system, as perfect isolation on a smaller scale is impossible."

The on-line text on thermodynamics here:https://www.learnthermo.com/T1-tutorial/ch07/lesson-C/pg06.php (https://www.learnthermo.com/T1-tutorial/ch07/lesson-C/pg06.php) States:

"The universe is an isolated system."
They all seem to directly say that the universe is an isolated system. Could you elaborate?
Title: Re: FE Gravity
Post by: Tim Alphabeaver on January 30, 2020, 06:23:25 PM
But none of that matters, because I provided supplementary reasoning and explained my logic. It is impossible for the Universe to be an isolated system, because it has nothing to be isolated from.
An isolated system is a system that cannot exchange matter or energy with other systems - there is nothing in the definition of an isolated system that requires other systems to exist.

https://www.definitions.net/definition/isolated+system (https://www.definitions.net/definition/isolated+system)
A system that does not interact with its surroundings, that is, its total energy and mass stay constant.

In fact, this has already been discussed by BillO:

a) So, in thermodynamics terminology an isolated system is by definition a system that cannot receive energy or matter from outside it, and cannot send energy or matter outside it.

b) The universe, by definition is that which contains everything.  The universe cannot receive energy or matter from outside it, and cannot send energy or matter outside it.

From a) and b), for the purposes of thermodynamics, the universe meets the requirements of being an isolated physical system.

It seems to me that your logic is based on a simple misunderstanding of the term 'isolated system' in thermodynamics.
Title: Re: FE Gravity
Post by: Pete Svarrior on January 30, 2020, 06:30:13 PM
Regarding your first post: You're right, it looks like I might be mixing up a few discussions. Let me take a step back and address the quote you provided.

So, your issue is that I cited Wikipedia, and yet you're defending BillO's use of RationalWiki. Are you familiar with RationalWiki? If not, could I encourage you to skim a few of their articles to get an idea of just how rigorous they are?

Another of the three sources, lumenlearning.com, lists its sources. Guess what? Most of them are Wikipedia. So, you don't like me citing Wikipedia, but citing someone who transcribed Wikipedia onto a pretty page is A-OK?

The last source, learnthermo.com, is a personal blog of someone who goes by "Dr. B". He provides a link to a LinkedIn profile, but that appears to have since been deleted. Who is Dr. B? Does Dr. B even exist? We might never know. I fail to see how this is a citation of a higher standard than Quora or Wikipedia.

It really sounds to me like you're unfairly biased against Wikipedia, but completely OK with other random websites with no peer review process in place. We might have to put that one to a simple difference of opinion, but I sincerely do not see how you could hold this over my head.

Regarding your second post: Rama Set already did a good job responding to that point. BillO relies on discussing things "outside of the Universe", which are undefined. This does not help.
Title: Re: FE Gravity
Post by: Pete Svarrior on January 30, 2020, 06:38:46 PM
I should add this to clarify: I think collaborative and independent educational resources are fantastic, and wish them the best of luck. However, I find it extremely hypocritical for you to criticise my use of Wikipedia, while trying to exalt BillO's use of random, unverified sites that he clearly found through a quick Google search. Your claim that his citations are of a high standard while mine are not, in my view, once again illustrates that you're arguing in bad faith.
Title: Re: FE Gravity
Post by: Tim Alphabeaver on January 30, 2020, 06:46:36 PM
However, I find it extremely hypocritical for you to criticise my use of Wikipedia, while trying to exalt BillO's use of random, unverified sites that he clearly found through a quick Google search. Your claim that his citations are of a high standard while mine are not, in my view, once again illustrates that you're arguing in bad faith.
I'm not sure that I commented on the quality of BillO's sources, just yours.

So, your issue is that I cited Wikipedia, and yet[...]
1: I'm not defending anyone. I'm pointing out that you said that BillO's sources disagreed with his viewpoint, despite the fact that they don't. Now you seem to have gone back on this and have conceded that they do agree with his viewpoint, but are not good sources. So which is it? Are they bad sources, or do they not support his viewpoint?

2: BillO's sources being bad is not a free pass to cite wikipedia.

Quote
Regarding your second post: Rama Set already did a good job responding to that point. BillO relies on discussing things "outside of the Universe", which are undefined. This does not help.
You're right that 'outside the universe' is a bit of an oxymoron. I'll point you back to my previous post - an 'isolated system' doesn't require other systems to exist, it simply cannot change the amount of matter or energy within it.
At the very least, I hope you could see how the universe could trivially be considered 'isolated' by some, even if you disagree.

200th post!
Title: Re: FE Gravity
Post by: Tim Alphabeaver on January 30, 2020, 06:58:35 PM
Oh and sorry if I got a bit heated earlier...  ::)
Anyway I think I've said everything I wanted to say for now, or else we might start going in circles a bit
Title: Re: FE Gravity
Post by: Pete Svarrior on January 30, 2020, 07:20:56 PM
So which is it? Are they bad sources, or do they not support his viewpoint?
I already backed off on that one, didn't I?

2: BillO's sources being bad is not a free pass to cite wikipedia.
Again, I disagree that my position needed a citation at all. I said I needed a definition, and that I couldn't find a source that agreed with his idea that this is trivial. He provided me with what I view as non-sources. I said (something like) "if you're ok with citing Quora, I hope you don't mind me bringing up Wikipedia", which he didn't object to.

This is a discussion, not a scientific paper. Neither of us need a "free pass" to bring up opinions. It's just a shame that BillO was not interested in responding to my logic. It was all "by definition" (which he wouldn't provide), or "my source is thermodynamics", but no actual response to the argument presented.

You're right that 'outside the universe' is a bit of an oxymoron. I'll point you back to my previous post - an 'isolated system' doesn't require other systems to exist, it simply cannot change the amount of matter or energy within it.
Frankly, that's all BillO should have said when I asked him to clarify himself on that matter. Though he never clarified whether the system he was alluding to was a planet or the Universe, so we would still have some issues.

At the very least, I hope you could see how the universe could trivially be considered 'isolated' by some, even if you disagree.
I think you somewhat missed the point of my objection. Whether or not I'm right on this one is pretty much irrelevant - I was happy to accept BillO's definitions for the sake of the discussion, be he wouldn't provide them. He kept saying he's right by definition, but not by which definition. That's what killed the discussion.
Title: Re: FE Gravity
Post by: Tim Alphabeaver on January 30, 2020, 07:40:40 PM
I think you somewhat missed the point of my objection. Whether or not I'm right on this one is pretty much irrelevant - I was happy to accept BillO's definitions for the sake of the discussion, be he wouldn't provide them. He kept saying he's right by definition, but not by which definition. That's what killed the discussion.
Yeah okay, maybe I was missing the woods for the trees a bit.
Title: Re: FE Gravity
Post by: Groit on February 04, 2020, 07:06:30 PM
An accelerometer in free fall will also feel no forces acting on it, and it will read zero.
Yes, that's why I said you should be using that as your argument instead of a scale. Now that you've agreed with me, it might be time to start making your argument.

What exactly do we agree on?
Title: Re: FE Gravity
Post by: Pete Svarrior on February 04, 2020, 10:05:25 PM
What exactly do we agree on?
You literally quoted me quoting it. I don't see how I could be of more assistance.