The Flat Earth Society

Flat Earth Discussion Boards => Flat Earth Theory => Topic started by: ICanScienceThat on May 13, 2019, 06:54:35 AM

Title: Clarifications on UA
Post by: ICanScienceThat on May 13, 2019, 06:54:35 AM
I'm researching UA at the moment, and I would like to ask for some clarification. Could anyone speak about this particular topic: "The mass of the earth is thought to shield the objects atop it from the direct force of UA."

If I understand this correctly, something is pushing the Earth upwards at 9.8 m/s2. We feel "gravity" because the Earth is being accelerated upwards. Whatever force that is, it doesn't hit us. If it did, we wouldn't feel "gravity" because we'd just be in freefall with the Earth.

But I believe I've read mentions that if you get up high enough over the Earth, that something will start pushing on you too. Am I correct to understand that this is the explanation for why the Sun, Moon, etc. do not come crashing down? They must be under the same influence of the something that the Earth is. Do I have this correct?
Title: Re: Clarifications on UA
Post by: Pinky on May 13, 2019, 08:56:25 AM
I'm researching UA at the moment, and I would like to ask for some clarification. Could anyone speak about this particular topic: "The mass of the earth is thought to shield the objects atop it from the direct force of UA."

If I understand this correctly, something is pushing the Earth upwards at 9.8 m/s2. We feel "gravity" because the Earth is being accelerated upwards. Whatever force that is, it doesn't hit us. If it did, we wouldn't feel "gravity" because we'd just be in freefall with the Earth.

But I believe I've read mentions that if you get up high enough over the Earth, that something will start pushing on you too. Am I correct to understand that this is the explanation for why the Sun, Moon, etc. do not come crashing down? They must be under the same influence of the something that the Earth is. Do I have this correct?

For a supposedly simple explanation, UA is frustratingly confusing. FE is moving upwards, pushing us humans from below, so we perceive the counter-force as gravity. And we know why we don't sink into the ground when FE comus for from below: The Pauli-principle.

But that also means that there must be a repulsive force that keeps satellites and celestial bodies away from FE as it moves towards them.
Title: Re: Clarifications on UA
Post by: Pete Svarrior on May 13, 2019, 09:58:30 PM
But that also means that there must be a repulsive force that keeps satellites and celestial bodies away from FE as it moves towards them.
That would be the very same UA. Instead of complaining about how confused you are, you could simply read the Wiki page on the subject. Try to address your confusion instead of just whining about it. You'll find it very satisfying, I promise.

If you prefer, I recently provided this short summary:

I would be way more interested in hearing you expand on your thoughts.  That "sufficiently high above the ground" allows mass to be affected by UA.  How would that work?
I think you're approaching this backwards - the fact that an object is affected by an acceleration that's supposedly universal should not be surprising. It's "universal", after all.

Of course, that's a bit of a misnomer, since the entire point here is that objects on or slightly above the Earth are not affected by it, thus creating gravity. In essence, UA acts somewhat like a current, and the Earth shields its immediate surroundings from it.
Title: Re: Clarifications on UA
Post by: ICanScienceThat on May 14, 2019, 04:02:44 AM
Thanks Pete. I had read that brief summary. I think I've got the right idea.

It's like the Earth is a boat in a river - being pushed along by the current. We're in the boat, so the water isn't pushing us. If we could stick our hands out of the boat, we could reach the flow. The UA hypothesis suggests that perhaps satellites are like that - we fling them outside the safety of the boat - out into the flow where they are pushed along beside the boat. Sound right?

Assuming I've got that, I'd like to ask about this bit here: "Alternatively, it is possible that the force of UA can actually pass through objects, but its effect on smaller bodies is negligible (similar to gravity in RET cosmology, which only has a noticeable affect on very large objects)."

I'm not clear on what is meant by this. There are 2 pieces of that I'm having trouble with:
1) Are we suggesting that the force of UA is perhaps proportional to the square of the mass (or something like that) so that it applies more force to massive objects than to lighter objects? If so, has anyone ever tried to dig into this further? What equation would the force of UA have to follow? Can we make any predictions from this hypothesis which we could test?
2) What is meant by "...gravity in RET cosmology, which only has a noticeable affect on very large objects..."? It is my understanding that gravity is felt equally by objects of all sizes. Perhaps you are pointing out that we need one of the masses in the Gm1m2/d2 equation to be large to get a large result. Is that what is meant here? If so, could you offer any clarification for how UA is similar to that?

Thanks again!
Title: Re: Clarifications on UA
Post by: Macarios on May 14, 2019, 07:50:17 AM
So, if you cross the edge you will not fall down, the UA will push you up?
Including the constant replacement of the air lost over the Ice Wall?
During all these centuries?
Title: Re: Clarifications on UA
Post by: Pinky on May 14, 2019, 08:54:30 AM
But that also means that there must be a repulsive force that keeps satellites and celestial bodies away from FE as it moves towards them.
That would be the very same UA. Instead of complaining about how confused you are, you could simply read the Wiki page on the subject. Try to address your confusion instead of just whining about it. You'll find it very satisfying, I promise.

That Wikipage explains precisely nothing.

UA is (at least) four speculations roled into one:
- that Earth accelerates upwards (not experimentally proven)
- that some bodies accelerate upwards as well (not experimentally proven)
- that some bodies are immune to UA (not experimentally proven)
- that whatever UA is, it is influenced by mass (not experimentally proven)

That's FOUR unproven assumptions being made to explain what we see in real life.
Title: Re: Clarifications on UA
Post by: Pete Svarrior on May 14, 2019, 06:27:24 PM
Thanks Pete. I had read that brief summary. I think I've got the right idea.
Judging by your description, yes, you've got it.

"Alternatively, it is possible that the force of UA can actually pass through objects, but its effect on smaller bodies is negligible (similar to gravity in RET cosmology, which only has a noticeable affect on very large objects)."
This is a reference to a fairly old alternative hypothesis. We try to represent FET in a model-agnostic way, so when the hypothesis was growing in popularity, it was included. Personally, I don't put much stock in it, and I don't think its implications make all that much sense. Sorry, I can't be much more help on that one.

That Wikipage explains precisely nothing.
It directly answers your question. If you want to ask FOUR unrelated questions (three of which based on false assumptions on your part), do so in appropriate threads ***after*** you've familiarised yourself with the basics. You're welcome to disagree with us, but your laziness and inability to read won't be met with sympathy.
Title: Re: Clarifications on UA
Post by: ICanScienceThat on May 17, 2019, 04:12:19 AM
On the surface, the concept of UA seems to do a reasonable job of explaining the most basic observations. As a follower of the scientific method myself, it would be my inclination to try testing these hypotheses. However, I get the distinct impression that testing hypotheses isn't really a primary concern practiced by TFES. I'm still trying to fully understand how the zetetic method differs from the scientific method.

So first of all, is it fair to characterize TFES as officially supportive of the zetetic method?

Assuming so, from the wiki: "A zetetic forms the question then immediately sets to work making observations and performing experiments to answer that question, rather than speculating on what the answer might be then testing that out."

I'm trying to apply this logic towards the question of UA. I can do this using the scientific method, and I'm trying to better understand how the zetetic method would approach this differently. Let me try, and if you don't mind, I'd appreciate being schooled on how I've got it wrong.

Scientific Method:
1) UA hypothesizes that the "gravity" force field drops with altitude because UA is flowing around the Earth.
2) This predicts that the force of "gravity" should drop more rapidly near the edges of the Earth and drop significantly less near the center of the Earth.
3) We could test this by measuring the affect of altitude on "gravity" at different places on the Earth.
4) Suppose we did this test and found nothing to indicate either an edge or center of the Earth from this... we might try another hypothesis... (Let me give you a freeby) Perhaps the presence of mass interferes with the UA force.
5) We'd head back up to a prediction and design a new test.
Standard, make a prediction, test the prediction, repeat.

Zetetic Method:
1) In what way does "gravity" vary with altitude and location on the Earth?
2) We'd do the same test described above.
3) We would now have a chart showing the data we collected.
4) We'd look at this chart and draw conclusions about what it's telling us. For example, maybe it could show us that gravity varies by +-0.3% with latitude and varies as an inverse-square with altitude measured from a 4000 mile offset. We'd look at that and draw a conclusion.
Question, observations, conclusion?

Do I have that about right?
Title: Re: Clarifications on UA
Post by: spherical on June 24, 2019, 05:55:27 PM
To make it easy to visualize, I can imagine a 40 thousand km diameter air blower nozzle blowing air underneath FE, pushing it up.  Only the lower layer is being affected by such force, but for such force to act upon Sun, Moon, all the planets, stars, etc, the nozzle must be larger than 40,000 km, so the air flow leaks all around the ice wall, converge and act upon thousands of miles above FE surface.  Yes, I can imagine it inside a wind tunnel.   

There are few problems here. 

First, this seems to be an accelerating force, so the blower is not stationary somewhere in the empty universe, it must accompany the FE movement in order to accelerate it - like a blower inside a ship, blowing air to the sails. 

Second, FE is pretty massy, heavy, imagine PI*20000km²*T where T is thickness, lets imagine T ~= 1000km, = PI * 4E8 * 1E3 = 1.256E12 cubic km, lets consider 1m3 of basalt rock = 3 Ton, lets average with water and other lighter elements, to 2Ton per cubic meter.  A cubic km has 1E9 cubic meter, so 2E12 kg per cubic km, times 1.256E12 = 2.56E24 kg would be the assumed mass of FE. 

That was a wild pretty good guess, looking now at wikipedia, the spherical planet has a mass of 5.97E24 kg, I missed by half.  Then, I wolder the UA force to accelerate such mass at 9.8m/s².  Newton's Second Law of Motion states Force is mass times acceleration, so the UA force will be 2.5E25 Newtons. 

Third, the Saturn V engines could generate a trust of 2.5E7 Newtons, and that was the most powerful thing humans could produce to date.  UA would be 1E18 times stronger than a Saturn V (1,000,000,000,000,000,000, a billion billion Saturn V rockets).  Dividing rockets per square km of the FE, it will be approximate ONE HUNDRED MILLION Saturn V rockets per km², that is pretty amazing energy, and we have no idea where this energy comes from or what it is composition. Interesting.

Fourth, the energy leaking, brushing and flowing up all around the ice wall should be astonishing magnificent, and nobody ever try to use that, that would be the best place to install a rocket launching platform, right? Zero G all the way up and beyond!

Fifth, I wonder how the edge of the ice wall stand such energy pressure/friction without being broken to pieces and pushed up to the atmosphere.  There is no other way, such force must leak all around the ice wall, if not, if it is more concentrated to the center part of the bottom FE, such huge force in the center and huge mass to the edge not being pushed up, would break up the FE. 

Sixth, the actual SUN produces 3.86E26 Watts of energy, one Newton m/s = 15 Watts, so the Sun produces an equivalent force of 2.57 E25 Newtons, the UA energy to push FE up at 9.8m/s² is 1/10E6 of the Sun's power.  So, the UA power plant should be an amazing mini star, producing such cold energy equivalent to a billion billion Saturn V, not melting the ice wall, and the only thing keeping FE to ice cold completely is a tinny puny Sun of 48 km in diameter, at 4800km in altitude.

I don't know about you, but for me it is much more simpler and physically possible for gravity to be as we know it, and deform space/time as predicted and confirmed so many times.
Title: Re: Clarifications on UA
Post by: Uetzicle on June 26, 2019, 10:45:48 PM
I don't see the need for UA to explain the downward force on an FE. Is it really any more fantastical to just say there's a giant 'artificial gravity generator', like something from Star Trek? UA describes a quasi-plausible scenario, but still requires an unknown power source and a designed origin...something purposely built and put into motion. Why not 'artificial gravity'? Accepting that is not even an extra step, just a slightly different path.
Title: Re: Clarifications on UA
Post by: AllAroundTheWorld on June 27, 2019, 10:43:19 AM
I don't see the need for UA to explain the downward force on an FE. Is it really any more fantastical to just say there's a giant 'artificial gravity generator', like something from Star Trek? UA describes a quasi-plausible scenario, but still requires an unknown power source and a designed origin...something purposely built and put into motion. Why not 'artificial gravity'? Accepting that is not even an extra step, just a slightly different path.
Agree up to an extent. I've seen it argued on here that we shouldn't believe in gravity if we don't understand its mechanism but that's nonsense. People believed in rainbows before they understood the way light travelled through water droplets to cause the effect. Understanding the mechanism for a phenomenon is not a prerequisite for believing in it although understandng it is always desirable.

But when it comes to Gravity vs UA, aside from what is "powering" UA there are other reasons to believe gravity is the better explanation. Gravity doesn't just explain why we don't fall off the "bottom" of the globe, it explains variations in gravity across the globe. It explains variations with altitude. It explains how the moon orbits us, how we (and the other planets) orbit the sun.
The Canvendish Experiment is a test of gravity. Neptune was discovered because the understanding of gravity indicated there was something else pulling on bodies:

https://en.wikipedia.org/wiki/Discovery_of_Neptune

This is where gravity (and thus the globe/heliocentric model) wins. It has explanatory and predictive power. In FE other mechanisms have to be invoked to explain why UA doesn't affect the celestial bodies and what makes them move around each other.
Title: Re: Clarifications on UA
Post by: ICanScienceThat on June 27, 2019, 04:31:09 PM
I don't see the need for UA to explain the downward force on an FE. Is it really any more fantastical to just say there's a giant 'artificial gravity generator', like something from Star Trek? UA describes a quasi-plausible scenario, but still requires an unknown power source and a designed origin...something purposely built and put into motion. Why not 'artificial gravity'? Accepting that is not even an extra step, just a slightly different path.

I agree with this completely. Gravity with an unknown source is no worse than UA with an unknown source. Adding UA simply adds a layer of needless complication. It explains literally nothing that "Gravity pulls stuff down" doesn't already explain, and instead it introduces new questions.

Gravity with an unknown source could easily have unknown sources of variation. This makes it far inferior to Newtonian gravity, but it's better than UA already because of this.

I am forced to suggest once more that just MAYBE the person who came up with UA was trolling. Why come up with that in the first place? It explains nothing, but adds complications. The wiki doesn't say who originated the idea. Maybe we should look into that.
Title: Re: Clarifications on UA
Post by: spherical on June 28, 2019, 04:24:06 PM
As it is not listed on Wiki, I previously calculated; the UA force to accelerate the FE mass to 9.8m/s² is equivalent to 1 billion billion Saturn-V rocket engines trust.
AFAIR from the calculation, it is equivalent to 100 thousand Saturn V rockets per km² of FE area.
It would be 1 rocket per each 10m², it would not even physically fit.
I wonder the source of this unimaginable continuous energy flow for eons, a star that comes along?

There is a huge difference between Gravity and UA;  Gravity doesn't need huge forces or energy, UA requires huge amounts of energy to accelerate mass.

Want some comparison?

Try to hold a 100kg block of steel hanging from the ceiling, just using strong neodymium magnets bolt to the ceiling, then, try to do the same using electromagnets.  The later will require constant energy to create the strong magnetic field to hold the steel block, while the neodymium magnets will do the job for years without consuming any extra energy at all.

Title: Re: Clarifications on UA
Post by: ICanScienceThat on June 28, 2019, 05:13:36 PM
As it is not listed on Wiki, I previously calculated; the UA force to accelerate the FE mass to 9.8m/s² is equivalent to 1 billion billion Saturn-V rocket engines trust.
AFAIR from the calculation, it is equivalent to 100 thousand Saturn V rockets per km² of FE area.
It would be 1 rocket per each 10m², it would not even physically fit.
I wonder the source of this unimaginable continuous energy flow for eons, a star that comes along?

There is a huge difference between Gravity and UA;  Gravity doesn't need huge forces or energy, UA requires huge amounts of energy to accelerate mass.

Want some comparison?

Try to hold a 100kg block of steel hanging from the ceiling, just using strong neodymium magnets bolt to the ceiling, then, try to do the same using electromagnets.  The later will require constant energy to create the strong magnetic field to hold the steel block, while the neodymium magnets will do the job for years without consuming any extra energy at all.

I argue that you are being unfair. Simply because we do not know where the energy comes from, it doesn't mean we can't see the energy. For example, before we understood nuclear fusion, we had no idea what powered the Sun, but we were pretty darn sure that the Sun was generating a metric boat load of energy. From more modern times, what powers the expansion of the Universe? We call it "dark energy" because we don't know what it is. Just because we don't know where it comes from, it doesn't mean we say the observations are false.

Here are my thoughts on the subject. I'd love to have you participate.
https://www.youtube.com/watch?v=oZ8XTF1CrEI
Title: Re: Clarifications on UA
Post by: Tom Bishop on June 28, 2019, 06:04:14 PM
On the Weight Variation by Latitude see: https://wiki.tfes.org/Weight_Variation_by_Latitude

This experiment is uncontrolled. Can you reference where these experiments have been conducted in vacuum chambers?
Title: Re: Clarifications on UA
Post by: ICanScienceThat on June 28, 2019, 06:08:05 PM
On the Weight Variation by Latitude see: https://wiki.tfes.org/Weight_Variation_by_Latitude

This experiment is uncontrolled. Can you reference where these experiments have been conducted in vacuum chambers?
You are right. I really should have shown that page along with the altitude one.
Title: Re: Clarifications on UA
Post by: spherical on June 28, 2019, 09:06:24 PM
Interesting. 

A spring (torsion) scale measures the deformation of such spring to indicate weight.  The deformation is based on the mass over the spring, compressing it by the gravity pull.  "Calibration" means to use a standard known weight over the spring, and adjust the dial to show exactly the value of such mass.  Other intermediary standard weights are used to make sure the scale indication still correct after calibration.   Industrial and lab scales are supplied with calibration weights and more precise ones could be bought to produce frequent calibrations.  No industry or "pharmacy" would use a scale that is out of calibration according to procedures stated and followed.  It is imperative for an industry to calibrate their equipment very often, they may be losing money by not doing so, it worth the calibration cost.  Some equipment can not even be calibrated in the field, some need to be sent to calibration labs, where they use super-standards based on NIST, and even those super-standards calibrators need calibration also.   So, you can be sure, an industrial or lab calibrated scale located anywhere in the globe would indicate the same weight for the same pound of mass.  No doubt about that.  Thinking differently is just demonstrating not knowing about how this things work.   A 499g piece of stainless steel will not change its mass based on temperature, humidity, air pressure, it must show 499g on the Equator or on the Poles.  Some electronic scales has self-calibrating features, they do pretty good within certain range.  In the past I worked with load cells, when you work with those you start to understand about all other scales, since they are also used to measure force of deformation in general, bridges steel beams, arcs, building floor beams, vehicles long frames like long trucks, trains, even rockets structures - pounds related to nothing is the most common measurements on those, just related to deformation of resting state.

(https://www.scales.net/media/catalog/product/cache/1/image/940x587/9df78eab33525d08d6e5fb8d27136e95/o/p/op-100_1_1_1_1_1_1_1_1.jpg)
Title: Re: Clarifications on UA
Post by: ICanScienceThat on June 30, 2019, 07:14:47 AM
I'm curious about the origin of the UA concept. Is this one of Rowbotham's inventions? Does anyone know?
Title: Re: Clarifications on UA
Post by: Tom Bishop on June 30, 2019, 03:11:22 PM
Albert Einstein was the probably proginator of the idea of an upwardly accelerating Earth. See the first video on https://wiki.tfes.org/Evidence_for_Universal_Acceleration He used it in his thought experiments to explain Gravity and later adopted it into the Round Earth model with GR.

As for the person who integrated that concept into the Flat Earth discussions and models, no one seems to know. We searched the other theflatearthsociety.org forum which was started in 2007 and the UA concept was already part of FET since the beginning of that forum's creation. It's not a concept in Earth Not a Globe.

It seems to not be a concept discussed by Shenton or Johnson in their materials, which is to be expected since theirs were more biblical and wouldn't have a moving earth. My guess is that it is either from old flat earth discussions on Usenet or possibly the Zetetic Society or Universal Zetetic Society which existed between the mid 1800's to the early 1900's, which was much larger in numbers than any of the post-1950's societies up to present, were philosophically diverse, and would have existed at a time when Einstein came up his Equivalence Principle.

Unfortunately much of the materials of the old Zetetic socities were scattered or lost around the time of World War I and World War II when those societies died out and it is difficult to compile their research.

Dionysios might know where it comes from.
Title: Re: Clarifications on UA
Post by: spherical on July 02, 2019, 03:50:01 PM
Wow, so UA is just a story someone created to try to justify FE mass attraction without using general gravity? without any known origins?  So, we are discussing here something without any reasonable scientific or proven experiences?

Based on that, then UA is merely an idea, an attempt to justify, so I can create my own ideas of FE attraction of matter.
UA creates more problems than solve, it is a bad assumption.

I have a good one for FE, if you think about it makes more sense than UA, I call it GPA (General Polarized Gravity).

For general gravity to work on FE, the waves need to be polarized vertically.  The polarization reduces drastically the horizontal attraction, even so it exists at some level, keeping all the FE together.  Being stronger vertically, it works nicely, without pulling all large masses into a ball format. The assumption of how polarization is build, is based on mass - itself try to attract each other, but more mass in one direction creates perpendicular polarization (magnetic & electric waves fields are also perpendicular), thus, flat things, even the universe. My observation of proof is that you are not being attracted horizontally by FE gravity, only vertically. You are not attracted to a building wall, but to its floor.  Right?  Being polarized, it can even neutralize itself at certain distance, this is why after few thousand miles gravity attraction disappears, and more, it reverses polarity, even pushing things away.   What we see in sky, Sun, Moon, stars, etc, are at the right altitude (floating zone) where gravity is not pushing, nor pulling.   Little droplets of water (most vapor) has the ability to refract gravity polarization, this is why they float and even go up to the clouds, where they form larger droplets and stay afloat until they become larger and lose the ability to refract gravity, so the rain falls.  Also, the reversing of gravity polarization on the "floating zone" started by chance a turn in western direction, it creates torsion right over the North Pole, with a constant pushing for the Sun/Moon/etc to keep rotating over FE.   Also, the Sun is made of material that can convert such polarization turn energy into heat and light, this is the Sun's energy source.  Also, when Sun/Moon/etc interact with the floating zone, they reflects gravity back, you can see its effect on ocean tides.  See how easy? not only eliminate lots of old theory problems, also explains better how things work on FE.

Think about it, and remember, you heard first about Polarized Gravity here from Spherical, based on a symmetric trace free 2x2 tensor, it comes from the Flat Universe assumption.

(http://ned.ipac.caltech.edu/level5/Sept02/Kamionkowski/Equations/eq1.gif)

https://journals.aps.org/prd/abstract/10.1103/PhysRevD.98.022008 (https://journals.aps.org/prd/abstract/10.1103/PhysRevD.98.022008)

But of course, you can ignore my new (GPA) gravity idea and keep UA as a strong headache.
Title: Re: Clarifications on UA
Post by: Pete Svarrior on July 02, 2019, 04:40:56 PM
Wow, so UA is just a story someone created to try to justify FE mass attraction without using general gravity? without any known origins?
I'm not sure where you got that idea.

So, we are discussing here something without any reasonable scientific or proven experiences?
On the contrary, it's something you can experience every day.

Based on that, then UA is merely an idea, an attempt to justify, so I can create my own ideas of FE attraction of matter.
Not in the upper, you can't. Final warning before you're sent back to banhammer land.
Title: Re: Clarifications on UA
Post by: Tom Bishop on July 02, 2019, 07:33:48 PM
Bowling balls, books, and feathers 'drop' at the same rate of acceleration.

Anything which is pushed or pulled through space is subject to the laws of inertia. More massive bodies exhibit more resistance. It is more difficult to push a car in neutral down a road than it is to push a marble.

How does any theory of gravity that moves bodies through space towards the earth apply varrying amounts of energy or force to each body in order to move them all at the same rate? In order to move something through space, energy or force must be involved. Why should it adjust itself for all bodies like that?
Title: Re: Clarifications on UA
Post by: Salviati on July 02, 2019, 08:12:27 PM
Bowling balls, books, and feathers 'drop' at the same rate of acceleration.

Anything which is pushed or pulled through space is subject to the laws of inertia. It is more difficult to push a car in neutral down a road than it is to push a marble.

How does any theory of gravity that moves bodies through space towards the earth apply varrying amounts of energy or force to each body in order to move them all at the same rate? In order to move something through space, energy or force must be involved. Why should it adjust itself for all bodies like that?

You just answered yourself. "It is more difficult to push a car in neutral down a road than it is to push a marble."

An heavier body is attracted with a greater force (not energy!) and thus with greater acceleration, but inertia slows it down by an equal amount.

In other words Gravitational Mass = Inertial Mass

The funny thing is that flat earthers make correct examples of the law of gravity to say that gravity does not exist.
Title: Re: Clarifications on UA
Post by: Tom Bishop on July 02, 2019, 08:59:42 PM
That doesn't make much sense.

Consider the RE Jupiter: Gravity is much higher there, right? Assuming that it had a solid surface, when dropping a bowling ball from an altitude of 10 feet above it's surface, a bowling ball would move at a greater rate of acceleration towards Jupiter than it would on the Earth.

Yet the laws of inertia are the same on Jupiter as they are on the Earth. On Jupiter Gravitational Mass != Inertial Mass. The same would apply to an area where gravity is much lesser, such as a moon somewhere.

Why should the Earth be a special coincidental place where not even the best research laboratories with the best equipment can find a violation of the Equivalence Principle which says that Gravitational Mass = Inertial Mass?
Title: Re: Clarifications on UA
Post by: markjo on July 02, 2019, 09:04:37 PM
Tom, why do you think that the earth is the only place in the universe where gravitational mass = inertial mass?

As you already said, the gravitational acceleration on Jupiter is greater than that of the earth, which means that it would take a greater force to impart that same greater acceleration on the same mass.  As long as you believe that acceleration is indistiguishable from gravity, then it stands to reason that gravitational mass should equal inertial mass all over the universe.
Title: Re: Clarifications on UA
Post by: Tom Bishop on July 02, 2019, 09:10:12 PM
Tom, why do you think that the earth is the only place in the universe where gravitational mass = inertial mass?

As you already said, the gravitational acceleration on Jupiter is greater than that of the earth, which means that it would take a greater force to impart that same greater acceleration on the same mass.  As long as you believe that acceleration is indistiguishable from gravity, then it stands to reason that gravitational mass should equal inertial mass all over the universe.

The laws of inertia aren't different on other planets. The laws of inertia and motion are the same, just like the law of conservation energy, Archimedes Principle, etc, are the same.

On a different planet the gravity would change, but the other laws would remain the same. If there is an inequality between gravity and inertia then gravitational mass != inertial mass.
Title: Re: Clarifications on UA
Post by: Salviati on July 02, 2019, 09:13:10 PM
That doesn't make much sense.

Consider the RE Jupiter: Gravity is much higher there, right? Assuming that it had a solid surface, when dropping a bowling ball from an altitude of 10 feet above it's surface, a bowling ball would move at a greater rate of acceleration towards Jupiter than it would move towards the Earth.

Yet the laws of inertia are the same on Jupiter as they are on the Earth. On Jupiter Gravitational Mass != Inertial Mass. The same would apply to an area where gravity is much lesser, such as a moon somewhere.

Why should the Earth be a special coincidental place where not even the best research laboratories with the best equipment can find a violation of the Equivalence Principle?

You are climbing the mirrors, as we say in my country. You say:"a bowling ball would move at a greater rate of acceleration towards Jupiter than it would move towards the Earth. " And a feather would move at the very same rate of acceleration (in the vacuum of course) i would add. On the moon the rate is smaller, but the key concept is that all those bodies touch the ground at the same moment.

And as usual you answered yourself: "Why should the Earth be a special coincidental place where not even the best research laboratories with the best equipment can find a violation of the Equivalence Principle?"

Easy answer: no special place at all.
Title: Re: Clarifications on UA
Post by: Tom Bishop on July 02, 2019, 09:18:41 PM
Quote
You are climbing the mirrors, as we say in my country. You say:"a bowling ball would move at a greater rate of acceleration towards Jupiter than it would move towards the Earth. " And a feather would move at the very same rate of acceleration (in the vacuum of course) i would add.

Since you agree that gravity would be greater on Jupiter, then there must be an inequality with the laws of inertia which do not change on Jupiter. Inertia depends on mass, and is an intrinsic property of a substance. If you bring a bowling ball to Jupiter, the inertia is the same as it is on Earth. Hence Gravitational Mass != Inertial Mass.
Title: Re: Clarifications on UA
Post by: spherical on July 02, 2019, 09:18:47 PM
Bowling balls, books, and feathers 'drop' at the same rate of acceleration.
Anything which is pushed or pulled through space is subject to the laws of inertia. More massive bodies exhibit more resistance. It is more difficult to push a car in neutral down a road than it is to push a marble.
How does any theory of gravity that moves bodies through space towards the earth apply varrying amounts of energy or force to each body in order to move them all at the same rate? In order to move something through space, energy or force must be involved. Why should it adjust itself for all bodies like that?

Because a body is made of a bunch of atoms, each proton and counterpart neutrons+electrons (Atomic Number = Atomic Mass Units) would require exactly the same amount of energy to be put in motion.  More mass, more necessary energy.  You can move a feather by blowing, since it has much less mass than a car's mass.   It doesn't adjust itself for all bodies, it is a constant per unit of AN/AMU.  To push two trillion atoms of Sodium requires twice the energy of one trillion, no surprise on that, doesn't matter if you will push atom by atom or all of them at once in a huge rock, the total energy is just a scaling of the energy necessary to move a single atom.

Ants can move a dune, grain by grain of sand, with the same effort each time, the dune can be small or big.  To move a larger dune at the same time they move a small, they need much more ants.

Mass, Acceleration, Force and Gravity,  Inertial or Gravitational Mass, are inter-related.
The mass of Jupiter enter in formula as mass of Earth, attracting the same bowling ball 15lbs, here or there.
Even that G (gravitational constant) is the same, the final gravity acceleration (not a force, but you can think as it is a force) will be different due the difference of the masses. Don't mix up everything and confuse yourself.   
The gravitational mass and inertial mass on Jupiter will be the same, since larger mass produces larger gravity acceleration, so F=ma still equal to Gm1m2/r²
This works the same on Earth or in Jupiter.  F = 15lbs*JupiterGravityAcceleration = G*JupiterMass*15lbs/r², with variable r² (distance of masses).
I don't see why and where you think it is different.

I think you are thinking about pushing a bowling ball by hand, and thinking the force to achieve 1m/s² will be the same on Earth or in Jupiter, but gravity will be different on both... yes, but you are mistaken to use an external unequal acceleration, replace it by the planet acceleration of gravity and everything fits in place.
Title: Re: Clarifications on UA
Post by: Tom Bishop on July 02, 2019, 09:42:58 PM
Quote from: spherical
The gravitational mass and inertial mass on Jupiter will be the same, since larger mass produces larger gravity acceleration, so F=ma still equal to Gm1m2/r²

It would not be the same. If you take a bowling ball from Earth to Jupiter, it still has its same mass in F=ma.

The gravity of Jupiter is stronger and it is pulling the bowling ball down at a faster rate of acceleration. Gravity increases, but the laws of inertia remain the same.

Consider a weightless environment out in intergalactic space far away from any gravity source: The laws of inertia do not change in a gravity-free environment. They are universal. It still takes more force and effort to push something more massive through a weightless environment than it does to push something less massive. Those laws don't go away.

If an elephant flies into you at 50mph in weightless space, it's still going to hurt you. See  mainstream RE literature (http://www.qrg.northwestern.edu/projects/vss/docs/space-environment/zoom-travel.html):

Quote from: Northwestern University
Objects in space follow the laws or rules of physics, just like objects on Earth do. Things in space have inertia.
Title: Re: Clarifications on UA
Post by: AllAroundTheWorld on July 02, 2019, 10:04:21 PM
Bowling balls, books, and feathers 'drop' at the same rate of acceleration.

Anything which is pushed or pulled through space is subject to the laws of inertia. More massive bodies exhibit more resistance. It is more difficult to push a car in neutral down a road than it is to push a marble.

How does any theory of gravity that moves bodies through space towards the earth apply varrying amounts of energy or force to each body in order to move them all at the same rate? In order to move something through space, energy or force must be involved. Why should it adjust itself for all bodies like that?
The force of gravity is proportional to the mass of both bodies.
So on earth the force of gravity on an object, Fg, is:

Fg = G x Me x Mo / r2

G = gravitational constant
Me = mass of earth
Mo = mass of object
r = distance between the centre of mass of earth and the object.

But we also know that F = ma
So, rearranging, a = F/m
The acceleration on an object due to gravity, g = Fg / Mo

But from the above, Fg = G x Me x Mo / r2

So:

g = Fg / Mo = (G x Me x Mo / r2) / Mo

The Mo cancels out: g = G x Me / r2

So the acceleration due to gravity on earth is dependant on earth is related to the mass of the earth, not the mass of the object.

If you plug in to the above values for G (6.674×10−11) the mass of earth in kg (5.9722×10+24) and the radius of earth in meters (6,371,000) you should get a pretty decent approximation for g
(I got 9.81986)

So this is why objects of different mass accelerate at the same rate regardless of their mass. Yes, larger objects require more force to accelerate them but the force of gravity is proportional to an object's mass so there is more force due to gravity acting on them.

And yes, on Jupiter the objects would all accelerate faster because of the mass of Jupiter is bigger. Still at the same rate as each other, but faster than on earth. On the moon it's the reverse. They accelerate at the same rate as each other there too but slower than on earth because the moon is less massive than the earth. And because the moon has no atmosphere and feathers don't get affected by other forces exerted by air that's a perfect place to do that exact experiment as David Scott did during Apollo 15:

https://www.youtube.com/watch?v=KDp1tiUsZw8
Title: Re: Clarifications on UA
Post by: Tom Bishop on July 02, 2019, 10:34:11 PM
See my example above with how inertia behaves in intergalactic weightless space far away from any gravity sources: It is the same. When an elephant smacks into you in space at 50mph, the impact of the force will be the same as on Earth. When you are shot in the chest with a bullet in space: you are going to die.

The laws of inertia do not depend on the gravity of the environment. It is a universal property. The laws of inertia are the same on Earth, in weightless space, and therefore on Jupiter. It does not "change".

Gravity does change in different gravity environments, however. Thus gravitational mass will not be equal to inertial mass.

A very wild and surprising coincidence, indeed, that Gravitational Mass should exactly equal Inertial Mass on Earth to the best resolution of modern physics.
Title: Re: Clarifications on UA
Post by: markjo on July 02, 2019, 10:37:43 PM
The laws of inertia do not depend on the gravity of the environment. It is a universal property. The laws of inertia are the same on Earth, in weightless space, and therefore on Jupiter. It does not "change".

Gravity does change in different gravity environments, however. Thus gravitational mass will not be equal to inertial mass.
That seems an awful lot like a non sequitur.  Einstein said that gravity and acceleration are indistinguishable, so why should there be a difference between the two masses?  What's the difference between using a force to match earth's 9.8m/s2 acceleration due to gravity and using a force to match Jupiter's 24.8m/s2 acceleration due to gravity?

A very wild and surprising coincidence, indeed, that Gravitational Mass should exactly equal Inertial Mass on Earth to the best resolution of modern physics.
Perhaps it is a coincidence.  Or, maybe it's just two different ways of describing the same thing.
Title: Re: Clarifications on UA
Post by: spherical on July 02, 2019, 10:41:57 PM
Tom, you still messing up apples with tomatoes.
The elephant inertia has nothing to do with Earth or Jupiter, it is just F=ma, its mass times the acceleration applied, thus, force applied that will hit you if you are stationary.
I still don't know why and where you think those forces are the same on Earth, they do not.
If you apply 50N to the elephant in space it will creates a certain acceleration that has nothing to do with Earth's or Jupiter's Gravity Acceleration.
You still putting both together, as "force=force".
What is the same, is not the number, is the concept, since both were created here on Earth, the same concept that created 1 liter of distilled water = 1kg at sea level.
F=ma is the same concept of Gm1m2/r², not the values, it was not coincidental, it was on purpose.
To accelerate this 1 liter of water to 1m/s it will require 1N, to accelerate to 9.8m/s, will require 9.8N.  The same 1kg dropping from 1 second from the surface of Earth, (G*EarthMass*1kg/r²) will generate an impact of 9.8N, funny, isn't it?  Can't you see they are two different things with same concept, and, if you want, same numbers?
An apple is red and round, the same for tomatoes, different things.
Please call your physics teacher from school and ask him about it.
Title: Re: Clarifications on UA
Post by: Tom Bishop on July 03, 2019, 12:29:49 AM
Here is a image of what occurs on Earth:

(https://i.imgur.com/Fg6EUJA.png)

Inertial Mass and Gravitational Mass are the same. Both bodies will fall together. As Salvaiti said above:

Quote
An heavier body is attracted with a greater force (not energy!) and thus with greater acceleration, but inertia slows it down by an equal amount.

In intergalactic space the gravity is gone. Bodies will float, not fall, but will still exhibit inertial resistance.

On Jupiter the bodies will fall rather than float. Gravitational pull/acceleration in red is much longer and stronger than the image above. Yet the laws regarding inertial resistance should be the same and unchanged from the other scenarios, as it is a universal property unconnected to the gravity of the environment, as demonstrated by the weightless environment example.

If inertia is the same, but gravity is different, then the bodies should fall at different rates in relation to each other.

The inertial-gravitational mass equivalence coincidence on Earth is a piece of evidence against the Copernican and Mediocrity principles: We are indeed special.

https://arxiv.org/ftp/physics/papers/0004/0004027.pdf

(https://wiki.tfes.org/images/8/88/Equivelence-strange.png)
Title: Re: Clarifications on UA
Post by: markjo on July 03, 2019, 02:09:08 AM
If inertia is the same, but gravity is different, then the bodies should fall at different rates in relation to each other.

The inertial-gravitational mass equivalence coincidence on Earth is a piece of evidence against the Copernican and Mediocrity principles: We are indeed special.
Tom, I don't think that the inertial-gravitational mass equivalence is a coincidence.  Rather, it's a natural consequence of Einstein showing that gravity and acceleration are equivalent.  If you're going to use the EP as a rationale for the UA, then you will also need to accept inertial-gravitational mass equivalence as well.  That is unless you have been to Jupiter and have experimentally demonstrated that inertial-gravitational mass equivalence does not hold there.

https://www.youtube.com/watch?v=P55SaeTvXT8
Title: Re: Clarifications on UA
Post by: Tom Bishop on July 03, 2019, 02:22:17 AM
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Tom, I don't think that the inertial-gravitational mass equivalence is a coincidence.  Rather, it's a natural consequence of Einstein showing that gravity and acceleration are equivalent.

How is it not a coincidence that inertia could slow two different bodies being pulled at two different rates towards the earth to an exact same rate of acceleration by multiple decimal points?

Einstein said it was a weird coincidence too. He came up with two versions of gravity: The Equivalence Principle and General Relativity. The Equivalence Principle says that gravity is like being in an upwardly accelerating elevator and General Relativity applies that theory to a round world by saying that gravity is a function to the 'geometry of space' in the vicinity of the earth. The objects are stationary and the earth is accelerating into the objects through the curvature of space.


General Relativity and Accelerating Upwards:

https://books.google.com/books?id=FFQjDgAAQBAJ&pg=PT34&lpg=PT34&dq=%22earth+pushing+you%22&source=bl&ots=MV9ROmx5Eu&sig=ACfU3U17gR2YnIJbxFhEuRhKz2cR-mVBgQ&hl=en&sa=X&ved=2ahUKEwjaoLf6xMHiAhUPpFkKHTqqAMwQ6AEwDXoECB0QAQ#v=onepage&q=%22earth%20pushing%20you%22&f=false

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  “ 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!
Title: Re: Clarifications on UA
Post by: AllAroundTheWorld on July 03, 2019, 10:28:44 AM
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Tom, I don't think that the inertial-gravitational mass equivalence is a coincidence.  Rather, it's a natural consequence of Einstein showing that gravity and acceleration are equivalent.

How is it not a coincidence that inertia could slow two different bodies being pulled at two different rates towards the earth to an exact same rate of acceleration by multiple decimal points?
It's not a coincidence, it just seems to be a property of gravity. It's counter-intuitive, you'd think that more massive objects would fall more quickly than less massive ones, but that's not what we observe.
More massive objects do require more force to accelerate them but gravity does exert more force on those objects. F = ma but
Fg = G x m1 x m2 / r2
So the force of gravity on an object is proportional to its mass, as is the force required to accelerate an object a certain amount. This is why the acceleration of an object in a gravitational field is the same on all objects. It just seems to be a property of how gravity works. It's like asking why light travels at 186,000(ish) miles a second in a vacuum. It just does, it seems to be a property of light.

The thing I don't understand is why you think this is unique to earth. As I showed in the video above, two objects of different mass accelerate and thus fall at the same rate on the moon too, they would on Jupiter too.

The equivalence principle does say that you can't tell the difference between whether objects fall or the earth is accelerating upwards, if you see video taken from a roundabout how can you tell if the roundabout is revolving or the world is rotating around it? It looks from the roundabout's point of view like it's the roundabout is still but we know that isn't the case. Things like the Cavendish experiment, differences in gravitational pull across the globe which work with the model of gravity and globe earth but not UA and our observations of the way celestial objects move show us which is the right explanation. Neptune was discovered because the orbits of other planets indicated there was another body out there pulling on them. Things like this - and of course the ISS and countless other satellites which orbit the globe - show us which is the right explanation.
Title: Re: Clarifications on UA
Post by: Tom Bishop on July 03, 2019, 12:06:06 PM
According to Newtonian Gravity bodies of different masses are pulled at different rates towards the Earth, and they are slowed to the exact same rate of acceleration through inertial resistance via Newton's Mass Equivalence Principle. It's an odd coincidence since inertia is a universal property which still exists independently in a weightless environment and has nothing to do with the gravity field it is in. If the gravitational field of Earth were any stronger or weaker, the inertia would be the same, and there would not be an exact equivalency.

This, and other elements, were too big of a coincidence, which is why Einstein came up with his upwardly accelerating Earth ideas with Einstein's Equivalence Principle and GR.

Cavendish and Neptune discussed here:

https://wiki.tfes.org/Cavendish_Experiment
https://wiki.tfes.org/Discovery_of_Neptune
Title: Re: Clarifications on UA
Post by: AllAroundTheWorld on July 03, 2019, 12:16:12 PM
According to Newtonian gravity bodies of different masses are pulled at different rates towards the earth.
What is your basis for that claim?
I showed using Newton's equations above that objects of different mass are accelerated towards earth (or any body) at the same rate.
The force on them is proportional to their mass, that's why the acceleration is agnostic of their mass.
Title: Re: Clarifications on UA
Post by: spherical on July 03, 2019, 03:47:44 PM
Oh, here is Tom's misconception: 

You can say:
"To accelerate two blocks of metal of different masses to the same speed, requires different forces".

Yes, that is true, for f=m.a.

You can say:
"So, how gravity applies same acceleration for different masses and obtain same speed?"

What you missing Tom, is a complete different way force is applied, and this is why I wrote before "the concept is the same, not the force".

When you PUSH a solid block of metal, you are applying force to a specific point of such block,  this point of contact could be small if using a screwdriver, or large if using a cement brick as contact.  In both cases, you are NOT applying uniform force to all atoms, just the ones on surface of contact, they are transferring movement to the other atoms.  So, the force "F" necessary to accelerate the block is the SUM of force needed to move all the atoms.   Gravity works differently, each atom slides down the space/time deformation, you can call it also force, but all atoms are pushed at once, individually, no matter how many atoms are there, the force applied by gravity is not applied to a surface, but to the guts of the mass, individual atoms.  The final speed achieved is calculated based on individual atoms being pulled at the same time, no matter if 1 or 2 trillion atoms. 

If you think as gravity as a force, it confuses you, because you are used to think and see force being applied to the surface of masses, pushing a car, a refrigerator, a furniture. That force is "compression", since it is transferred from the atoms on the surface being pushed to the next layer, next, etc.  Only when the last layer (opposite surface) of atoms start to move, then your cumulative force are being applied to all atoms of the mass.  Think about pushing a spring or a foam.  In a way, this compression force is entirely applied to the mass, it doesn't move a second mass that is barely touching the first one side-by-side.

There is NO known force in the universe that can push all individual atoms of any solid mass at once.  Imagine you being able to push a very soft foam block without compression, without changing its surface shape even by microns.  Such force doesn't exist.  It needs to go inside the matter, act on individual atoms, same force applied on each one, everything at the same time, and move the whole block without compression.

Think about a mass of 10 layers of atoms.  The force is applied, it acts on the first layer, but it needs to act on the second, third... tenth.  How the force can continue, go through the first and reach the second, go through all the first 9 layers and still have enough energy to push the tenth layer? Go through all the trillions of layers and still being able to keep pushing next layers and so on?  Such kind of force doesn't exist at all.  Oh, wait, you can think of magnetic force, it can act at once in all metallic ferrous metallic atoms without deforming the surface. Ferrous, magnetic and electric forces, different story.  I wrote above "any solid mass".

The only force you can think of doing such magic trick is gravity.  But gravity is not a force, if it is, you will need to explain how it can act on all layers of ANY material at the same time, acting on individual atoms, in order to not deform the surface being pushed, and "being pushed" I mean during acceleration on free fall.   If you accelerate a block of foam by pushing it at 9.8m/s², your hand will deform the surface being pushed.  Gravity doesn't do that.

The best way to understand gravity is comparing with buoyancy on atmosphere.  Any volume of gas less denser (LD) than the gas that surrounds it will seeks escape to a LD direction, even if this density delta is barely measurable.  The trick here is that the LD gas does not seek a LD direction, it is being pushed by the more denser gas all over, the side with LD pressure will allow it to move in that direction, it is not escaping, it is being pushed out.  Gravity changes the density of space, matter being pressed by same space density all around, seeks to slide into such less dense space, and it works over all atoms of the mass, not a surface. So, mass moves towards less denser space, stronger the gravity, lower space density.

Now, the complication is to understand what is space, how can its density could act on individual atoms?

As a slider, doesn't matter how big the mass, its density, how many masses together or separated, they will slide down at once to the less dense space.

Now, even if you don't agree with the above, be a gentleman and give me 10 seconds and think again about your conception of f=m.a being equal to Fg=Gm1m2/r², where Fg is not a force any longer, but the inclination of a slider, while f=m.a is a non inclined slider, same space density all around.

This is a nice and easy reading about this subject:
https://www.science.org.au/curious/space-time/gravity (https://www.science.org.au/curious/space-time/gravity)

February 2016 was the first time our instrumentation could detect gravitational waves originated from space.  Google and understand how they did it.

It is very difficult to build an image representing gravity space distortion, the best people can do is a two dimensional space distortion like the image below, in fact is nothing like that, it is from all angles, all directions, the distortion is all around the mass.  The "sliding vector" happens everywhere around it, another mass will be sliding towards the center of the ball, no matter where it comes from.

(https://regmedia.co.uk/2016/09/12/spacetime_continuum_gravity.jpg?x=442&y=293&crop=1)
Title: Re: Clarifications on UA
Post by: ChrisTP on July 03, 2019, 04:14:55 PM
I was about to make one after you said it's difficult but I found someone else already made a 3d representation;

https://youtu.be/a7uTKwbsFtg?t=8
Title: Re: Clarifications on UA
Post by: Tom Bishop on July 03, 2019, 05:33:34 PM
It is not a misconception at all. Einstein thought it was an astronomical coincidence, which is why he came up with his upwardly accelerating theories.

https://www.sciencedirect.com/science/article/abs/pii/0039368185900020

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Whilst preparing a review article on his new special theory of relativity, he became convinced that the key to the extension of the principle of relativity to accelerated motion lay in the remarkable and unexplained empirical coincidence of the equality of inertial and gravitational masses.

"remarkable and unexplained empirical coincidence"

According to Newtonian gravity bodies of different masses are pulled at different rates towards the earth.
What is your basis for that claim?
I showed using Newton's equations above that objects of different mass are accelerated towards earth (or any body) at the same rate.
The force on them is proportional to their mass, that's why the acceleration is agnostic of their mass.

Under Newtonian Gravity bodies are pulled at different rates towards the earth, and inertia slows them down to exactly the same rate of acceleration. Salviati explained it here:

An heavier body is attracted with a greater force (not energy!) and thus with greater acceleration, but inertia slows it down by an equal amount.

In other words Gravitational Mass = Inertial Mass

That's the coincidence in the paper about Einstein above.
Title: Re: Clarifications on UA
Post by: AllAroundTheWorld on July 03, 2019, 06:08:54 PM
I don’t actually understood Salviati’s post.

“He says a heavier body is attracted with a greater force and thus with greater acceleration

The bit in italics doesn’t make sense to me. The force required to accelerate a body of ‘m’ at a certain rate in proportional to m. Double the mass, double the force required to accelerate the body at the same rate.

But the force of gravity on an object is also proportional to m. Double the m, double the force of gravity acting on it from the earth (or any object).

It’s because both these things are proportional to ‘m’ that the acceleration is the same. Not clear what the issue is.
Title: Re: Clarifications on UA
Post by: Tom Bishop on July 03, 2019, 06:30:03 PM
Here is a source which says basically the same:

https://web.archive.org/web/20120320234442/http://www.physicsclassroom.com/Class/newtlaws/U2L3e.cfm

Quote
Free Fall Motion

As learned in an earlier unit, free fall is a special type of motion in which the only force acting upon an object is gravity. Objects that are said to be undergoing free fall, are not encountering a significant force of air resistance; they are falling under the sole influence of gravity. Under such conditions, all objects will fall with the same rate of acceleration, regardless of their mass. But why? Consider the free-falling motion of a 1000-kg baby elephant and a 1-kg overgrown mouse.

(https://i.imgur.com/rNza3PH.gif)

If Newton's second law were applied to their falling motion, and if a free-body diagram were constructed, then it would be seen that the 1000-kg baby elephant would experiences a greater force of gravity. This greater force of gravity would have a direct affect upon the elephant's acceleration; thus, based on force alone, it might be thought that the 1000-kg baby elephant would accelerate faster. But acceleration depends upon two factors: force and mass. The 1000-kg baby elephant obviously has more mass (or inertia). This increased mass has an inverse affect upon the elephant's acceleration. And thus, the direct affect of greater force on the 1000-kg elephant is offset by the inverse affect of the greater mass of the 1000-kg elephant; and so each object accelerates at the same rate - approximately 10 m/s/s. The ratio of force to mass (Fnet/m) is the same for the elephant and the mouse under situations involving free fall.

See the bolded above. The elephant experiences a greater force of gravity than the mouse. Based on that force alone the elephant would accelerate faster than the mouse.

But inertial resistance equalizes the two so that they move at exactly the same rate of acceleration. Coincidence. See:

https://books.google.com/books?id=5dryXCWR7EIC&lpg=PA148&ots=r75r_jl-VB&dq=%22equivalence%20principle%22%20%22remarkable%20coincidence%22&pg=PA149#v=onepage&q=%22equivalence%20principle%22%20%22remarkable%20coincidence%22&f=false

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This equivalence of the gravitational and inertial masses (which allows us to refer simply to 'the mass'), is a truly remarkable coincidence in the Newtonian theory. In this theory there is no a-priori reason why the quantity that determines the magnitude of the gravitational force on the particle should equal the quantity that determines the particle's 'resistance' to an applied force in general.

http://cosmoschool2018.oa.uj.edu.pl/pdfs/day3/CosmoSchool_Cracow2018_PiorkowskaKurpas.pdf

(https://i.imgur.com/jWr9ir9.png)

Title: Re: Clarifications on UA
Post by: Salviati on July 03, 2019, 06:44:08 PM
I don’t actually understood Salviati’s post.

“He says a heavier body is attracted with a greater force and thus with greater acceleration

The bit in italics doesn’t make sense to me. The force required to accelerate a body of ‘m’ at a certain rate in proportional to m. Double the mass, double the force required to accelerate the body at the same rate.

But the force of gravity on an object is also proportional to m. Double the m, double the force of gravity acting on it from the earth (or any object).

It’s because both these things are proportional to ‘m’ that the acceleration is the same. Not clear what the issue is.

I did not express myself properly. I meant that the acceleration would be greater if there were no inertia. But with inertia the acceleration is the same for all bodies. (English is not my language).
Title: Re: Clarifications on UA
Post by: AllAroundTheWorld on July 03, 2019, 06:44:34 PM
See the bolded above. The elephant experiences a greater force of gravity than the mouse.
Yes

Quote
Based on that force alone the elephant would accelerate faster than the mouse.
No! Literally the next sentence after the one you bolded explains why not. It takes 1000 times more force to accelerate the elephant but the earth exerts 1000 times more force on the elephant so it cancels out and it accelerates at the same rate as the mouse.

That just seems to be a property of gravity, double the mass of one of the bodies and that doubles the force they exert on each other.

And if you’re going to sneer at this and call it a coincidence then you may want to consider the “coincidence” of the sun’s distance varying so much but some effect making it always appear the same size...
Title: Re: Clarifications on UA
Post by: Tom Bishop on July 03, 2019, 06:48:24 PM
See the bolded above. The elephant experiences a greater force of gravity than the mouse.
Yes

Quote
Based on that force alone the elephant would accelerate faster than the mouse.
No! Literally the next sentence after the one you bolded explains why not.

What do you mean? It says that based on the force of gravity alone that the elephant would accelerate faster than the mouse:

Quote
If Newton's second law were applied to their falling motion, and if a free-body diagram were constructed, then it would be seen that the 1000-kg baby elephant would experiences a greater force of gravity. This greater force of gravity would have a direct affect upon the elephant's acceleration; thus, based on force alone, it might be thought that the 1000-kg baby elephant would accelerate faster.

The next sentences start talking about inertia:

Quote
But acceleration depends upon two factors: force and mass. The 1000-kg baby elephant obviously has more mass (or inertia). This increased mass has an inverse affect upon the elephant's acceleration.

It's talking about inertia and inertial resistance. Without inertia, the elephant would accelerate faster than the mouse.
Title: Re: Clarifications on UA
Post by: AllAroundTheWorld on July 03, 2019, 07:16:44 PM
What do you mean? It says that based on the force of gravity alone that the elephant would accelerate faster than the mouse
It says it “might be thought”. As in intuitively you might think that more force results in more acceleration. Which it does for two objects of the same mass.
Literally the next sentence explains that acceleration depends on mass. Which we know:
F = ma, so a = F/m

Twice the mass = twice the force required to accelerate the object at a certain rate.

Isn’t inertia just the same concept? An object of twice the mass has twice as much resistance to being accelerated.

The force required to accelerate an object at a certain rate is proportional to its mass.
The force of gravity acting on an object is also proportional to its mass.

Ergo in a gravitational field objects of different mass accelerate at the same rate.
Title: Re: Clarifications on UA
Post by: Tom Bishop on July 03, 2019, 08:01:59 PM
Quote from: AllAroundTheWorld
The force required to accelerate an object at a certain rate is proportional to its mass.
The force of gravity acting on an object is also proportional to its mass.

Ergo in a gravitational field objects of different mass accelerate at the same rate.

https://web.archive.org/web/20120319085642/http://www.physicsclassroom.com/mmedia/newtlaws/efff.cfm

Quote
Suppose that an elephant and a feather are dropped off a very tall building from the same height at the same time. Suppose also that air resistance could somehow be eliminated such that neither the elephant nor the feather would experience any air drag during the course of their fall. Which object - the elephant or the feather - will hit the ground first? The animation at the right accurately depicts this situation. The motion of the elephant and the feather in the absence of air resistance is shown. Further, the acceleration of each object is represented by a vector arrow.

(https://web.archive.org/web/20120319085642im_/http://www.physicsclassroom.com/mmedia/newtlaws/efff.gif)

Many people are surprised by the fact that in the absence of air resistance, the elephant and the feather strike the ground at the same time. Why is this so? This question is the source of much confusion (as well as a variety of misconceptions). Test your understanding by making an effort to identify the following statements as being either true or false.

TRUE or FALSE:

- The elephant and the feather each have the same force of gravity.
- The elephant has more mass, yet both elephant and feather experience the same force of gravity.
- The elephant experiences a greater force of gravity, yet both the elephant and the feather have the same mass.
- On earth, all objects (whether an elephant or a feather) have the same force of gravity.
- The elephant weighs more than the feather, yet they each have the same mass.
- The elephant clearly has more mass than the feather, yet they each weigh the same.
- The elephant clearly has more mass than the feather, yet the amount of gravity (force) is the same for each.
- The elephant has the greatest acceleration, yet the amount of gravity is the same for each.
 
If you answered TRUE to any of the above, then perhaps you have some level of confusion concerning either the concepts or the words force, weight, gravity, mass, and acceleration. In the absence of air resistance, both the elephant and the feather are in a state of free-fall. That is to say, the only force acting upon the two objects is the force of gravity. This force of gravity is what causes both the elephant and the feather to accelerate downwards. The force of gravity experienced by an object is dependent upon the mass of that object. Mass refers to the amount of matter in an object. Clearly, the elephant has more mass than the feather. Due to its greater mass, the elephant also experiences a greater force of gravity. That is, the Earth is pulling downwards upon the elephant with more force than it pulls downward upon the feather. Since weight is a measure of gravity's pull upon an object, it would also be appropriate to say that the elephant weighs more than the feather. For these reasons, all of the eight statements are false; there is an erroneous part to each statement due to the confusion of weight, mass, and force of gravity.

But if the elephant weighs more and experiences a greater downwards pull of gravity compared to the feather, why then does it hit the ground at the same time as the feather? Great question!! To answer this question, we must recall Newton's second law - the law of acceleration. Newton's second law states that the acceleration of an object is directly related to the net force and inversely related to its mass. When figuring the acceleration of object, there are two factors to consider - force and mass. Applied to the elephant-feather scenario, we can say that the elephant experiences a much greater force (which tends to produce large accelerations). Yet, the mass of an object resists acceleration. Thus, the greater mass of the elephant (which tends to produce small accelerations) offsets the influence of the greater force. It is the force/mass ratio which determines the acceleration. Even though a baby elephant may experience 100 000 times the force of a feather, it has 100 000 times the mass. The force/mass ratio is the same for each. The greater mass of the elephant requires the greater force just to maintain the same acceleration as the feather.
Title: Re: Clarifications on UA
Post by: AllAroundTheWorld on July 03, 2019, 08:24:59 PM
I honestly don’t know what your point is in that post. You’ve quoted an article which says exactly what I’ve been trying to explain to you. ???
Title: Re: Clarifications on UA
Post by: Tom Bishop on July 03, 2019, 08:34:07 PM
It says that with gravity alone, the elephant would accelerate faster than the feather. Gravity does not equal out on its own. In the absence of inertia, heavier and more massive things fall faster.

It is an astounding coincidence that inertia, an entirely different properly of mass, should slow all bodies in Earth's gravity to exactly the same rate of acceleration. If gravity had been any different, such as with gravity on Jupiter, it would not match inertia. Inertia is a universal property of mass which is the same for the same mass in weightless space, on Earth, and on Jupiter.

This is why Newtonian Gravity is wrong.
Title: Re: Clarifications on UA
Post by: AllAroundTheWorld on July 03, 2019, 08:41:39 PM
It literally says the opposite of that ???

It explains that the force of gravity acting on an object is proportional to the object’s mass.

It explains that the force required to accelerate an object at a certain rate is also proportional to the object’s mass.

These two facts mean the acceleration due to gravity is agnostic of an object’s mass.

I honestly don’t know what is confusing you here. You started this thread by stating how more massive objects require more force to accelerate them.
Which is correct.
But the force of gravity is proportional to the mass of the object. Twice the mass means twice the gravitational force acting on the object. And that means the resulting acceleration is constant.

What is confusing about that?
If the gravitational force from earth was only related to the mass of the earth then objects would all have the same force acting on them and that would mean objects of different mass would accelerate at different rates. But that isn’t the case.

In a gravitational field objects of different mass fall at the same rate. That’s true on earth, it’s true on the moon, it’s true on Jupiter.
Title: Re: Clarifications on UA
Post by: markjo on July 03, 2019, 08:55:07 PM
It is an astounding coincidence that inertia, an entirely different properly of mass, should slow all bodies in Earth's gravity to exactly the same rate of acceleration. If gravity had been any different, such as with gravity on Jupiter, it would not match inertia. Inertia is a universal property of mass which is the same for the same mass in weightless space, on Earth, and on Jupiter.

Tom, inertia does not slow things down.  Inertia is the resistance to change in motion.  You might be thinking about friction, which is a completely different concept.  Inertia is solely dependent on mass.  In fact, mass can be thought of as a measure of an object's inertia.
Quote from: https://www.physicsclassroom.com/class/newtlaws/Lesson-1/Inertia-and-Mass
Mass as a Measure of the Amount of Inertia

All objects resist changes in their state of motion. All objects have this tendency - they have inertia. But do some objects have more of a tendency to resist changes than others? Absolutely yes! The tendency of an object to resist changes in its state of motion varies with mass. Mass is that quantity that is solely dependent upon the inertia of an object. The more inertia that an object has, the more mass that it has. A more massive object has a greater tendency to resist changes in its state of motion.
Title: Re: Clarifications on UA
Post by: Tom Bishop on July 03, 2019, 08:57:22 PM
It literally says the opposite of that ???

See this conversation on stack exchange:

https://worldbuilding.stackexchange.com/questions/3396/different-gravitational-and-inertial-mass

Quote
As has been discussed already, different objects would fall at different speeds. Why? Wikipedia led me to an interesting derivation.

...

An object with larger gravitational mass would undergo a greater acceleration. Strange but true; it's an artifact of the equation. So heavy objects would fall a lot faster than lighter objects

See Salvati's quote above:

I did not express myself properly. I meant that the acceleration would be greater if there were no inertia. But with inertia the acceleration is the same for all bodies.

It is an astounding coincidence that inertia, an entirely different properly of mass, should slow all bodies in Earth's gravity to exactly the same rate of acceleration. If gravity had been any different, such as with gravity on Jupiter, it would not match inertia. Inertia is a universal property of mass which is the same for the same mass in weightless space, on Earth, and on Jupiter.

Tom, inertia does not slow things down.  Inertia is the resistance to change in motion.  You might be thinking about friction, which is a completely different concept.  Inertia is solely dependent on mass.  In fact, mass can be thought of as a measure of an object's inertia.
Quote from: https://www.physicsclassroom.com/class/newtlaws/Lesson-1/Inertia-and-Mass
Mass as a Measure of the Amount of Inertia

All objects resist changes in their state of motion. All objects have this tendency - they have inertia. But do some objects have more of a tendency to resist changes than others? Absolutely yes! The tendency of an object to resist changes in its state of motion varies with mass. Mass is that quantity that is solely dependent upon the inertia of an object. The more inertia that an object has, the more mass that it has. A more massive object has a greater tendency to resist changes in its state of motion.

Resistance = Slow Down

If the elephant is accelerating towards the earth faster than the mouse due to gravity alone, then inertial resistance--which is greater for a greater mass--must be slowing it down to match the mouse.
Title: Re: Clarifications on UA
Post by: spherical on July 03, 2019, 09:57:46 PM
Under the pay grade:
If you say the elephant should hit the floor first because there is more force pulling it down, I would say exactly the opposite, the rat should hit the ground first, since the inertia on the rat would be smaller under same acceleration values.  But both statements would be wrong.  The sliding acceleration vector is always the same, no matter the attracted mass, within certain limits, but yes to make you happy, the elephant really accelerates few nanometers/s² faster than the rat, the sum of Earth's + Elephant's masses is bigger than Earth's + Rat's masses.

Over the pay grade:
Inertia is also not a force, you can call it a force if you want - but then gravity will also be a force.
You need to apply certain force to a mass to change its speed, thus acceleration.  F=m.a

Gravity has nothing to do with it.
Fg=Gm1m2/r² is a mere formula to help calculate for the ones under the pay grade.
Gravity does not accelerate or move any mass, it moves the space. Period.
So, there is no matter involved in the "virtual movement" of masses under gravity.
Then, there is no inertia involved, since the masses never moved.

If you could produce a deformation of space right at your side, you would move to the side, without any energy or force involved.
This is exactly the scientific dreams of traveling super fast on space, deform space to be less dense in front of the spaceship.

Sit down, return to the chair.

Then you can ask:
"Oh, what about space-probes using planetary slingshots to accelerate further into space? are they not moving and gaining speed based on gravity?"

The above the pay grade answer is:  No. 
The space-probes does not steal energy from the planet, it concentrates its own energy during certain time and then use it in a shorter time.
They gain speed based on the difference between the time it takes to slide into the space deformed and the time it takes to get out.
It move closer to the planet in a certain angle and gets out in a steep angle.
The steep angle acts faster to achieve the escape velocity from the deformed space (gravity).
The energy resulting from diving into a less dense space during certain time, can be used to escape faster to a more denser space.
If it enters and exit at the same angle, same time, the delta would be zero.
As it changes angle and exit faster, there is a (energy) speed gain not returned due gravity.
If you want, you are free to call this gain in speed "anti-inertial force".

Why it is called "slingshot"?  Think about the slingshot, it does exactly that, you pull the strings/rubber slowly and accumulate energy during such time, then release in a fraction of such time, the pebble or projectile goes much further than if you through the projectile by hand.  All a matter of time.
Title: Re: Clarifications on UA
Post by: Salviati on July 03, 2019, 10:15:07 PM
It is an astounding coincidence that inertia, an entirely different properly of mass, should slow all bodies in Earth's gravity to exactly the same rate of acceleration. If gravity had been any different, such as with gravity on Jupiter, it would not match inertia. Inertia is a universal property of mass which is the same for the same mass in weightless space, on Earth, and on Jupiter.

1). Please note that gravity isn't the same at every point of the earth. The difference is not too much great but isn't too small either. It's sufficient a sensible scale (meaning dynamometer) to measure experimentally this difference, that is caused mainly by 1. Altitude; 2.Proximity to equator; 3. Uneven distribution of the masses in the inner of Earth. The value commonly adopted is only an average. You say "If gravity had been any different, such as with gravity on Jupiter, it would not match inertia", well then, we are in this situation, without need to go to Jupiter or to the Moon! In every point of Earth where this measure was performed, this "incredible coincidence" did happen, but with variable values of gravity acceleration. According to you (see citation above) they should have noted a discrepance in equivalence principle. This never happened.

2). It is rather easy simulate a lower gravity. With an inclined plane we can for example simulate the gravity on the Moon.

(http://www.webassign.net/question_assets/tamucolphysmechl1/lab_2/images/figure2-1.png)

Being alpha the angle, the body on the inclined plane is subiect to a gravity = mxgxsin(alpha). This should mean that it's as if the body is on a planet wit lower gravity. Again according to you there would be a violation of the equivalence principle, but it's not the case.

It was Galileo that first did these experiments with inclined planes, let alone unnumerable others that did the same after him.
Title: Re: Clarifications on UA
Post by: Tom Bishop on July 03, 2019, 10:25:04 PM
Quote
1). Please note that gravity isn't the same at every point of the earth. The difference is not too much great but isn't too small either.

Those experiments are uncontrolled. See: https://wiki.tfes.org/Weight_Variation_by_Latitude

Can you reference experiments that were conducted in a vaccum chamber?
Title: Re: Clarifications on UA
Post by: markjo on July 03, 2019, 10:40:41 PM
Can you reference experiments that were conducted in a vaccum chamber?
Here's one:
https://www.youtube.com/watch?v=lliBy-S4ZPA
Title: Re: Clarifications on UA
Post by: Tom Bishop on July 03, 2019, 10:49:13 PM
Can you reference experiments that were conducted in a vaccum chamber?
Here's one:
https://www.youtube.com/watch?v=lliBy-S4ZPA (https://www.youtube.com/watch?v=lliBy-S4ZPA)

It seems that he forgot to take it to a different latitude to check the weight change.
Title: Re: Clarifications on UA
Post by: markjo on July 03, 2019, 11:15:15 PM
Can you reference experiments that were conducted in a vaccum chamber?
Here's one:
https://www.youtube.com/watch?v=lliBy-S4ZPA (https://www.youtube.com/watch?v=lliBy-S4ZPA)

It seems that he forgot to take it to a different latitude to check the weight change.
Why would latitude be relevant when the experiment is looking at the effects of air pressure? ???
Title: Re: Clarifications on UA
Post by: Tom Bishop on July 03, 2019, 11:31:49 PM
Can you reference experiments that were conducted in a vaccum chamber?
Here's one:
https://www.youtube.com/watch?v=lliBy-S4ZPA (https://www.youtube.com/watch?v=lliBy-S4ZPA)

It seems that he forgot to take it to a different latitude to check the weight change.
Why would latitude be relevant when the experiment is looking at the effects of air pressure? ???

Because the weight variation by latitude experiments you guys constantly reference that 'disproves UA' involves measuring the weight of a mass in one environment and taking the mass and scale to another environment and looking for the difference of a fraction of a percent.

It is astounding that these experiments are uncontrolled for atmosphere. A search for vaccum controlled tests of this bring up zero results for me. Perhaps because they were done 300 years ago and they are only now casually done for educational purposes.
Title: Re: Clarifications on UA
Post by: markjo on July 04, 2019, 12:47:50 AM
Can you reference experiments that were conducted in a vaccum chamber?
Here's one:
https://www.youtube.com/watch?v=lliBy-S4ZPA (https://www.youtube.com/watch?v=lliBy-S4ZPA)

It seems that he forgot to take it to a different latitude to check the weight change.
Why would latitude be relevant when the experiment is looking at the effects of air pressure? ???

Because the weight variation by latitude experiments you guys constantly reference that 'disproves UA' involves measuring the weight of a mass in one environment and taking the mass and scale to another environment and looking for the difference of a fraction of a percent.
Hmmm...  I thought that we were discussing gravitational mass vs inertial mass.  Perhaps we should save the "gravity varies by latitude" for another thread.

It is astounding that these experiments are uncontrolled for atmosphere. A search for vaccum controlled tests of this bring up zero results for me. Perhaps because they were done 300 years ago and they are only now casually done for educational purposes.
I just provided you with a video of an experiment controlled for atmosphere, so your claim that they don't exist is disproven.
Title: Re: Clarifications on UA
Post by: Tom Bishop on July 04, 2019, 04:28:08 AM
I just provided you with a video of an experiment controlled for atmosphere, so your claim that they don't exist is disproven.

You had responded to an exchange between Salviati and I about the weight variation by latitude experiments. How would the experiment you provided contribute to that?
Title: Re: Clarifications on UA
Post by: AllAroundTheWorld on July 04, 2019, 09:42:07 AM
It literally says the opposite of that ???

See this conversation on stack exchange:

https://worldbuilding.stackexchange.com/questions/3396/different-gravitational-and-inertial-mass
That entire conversation is basically "hey, what if the universe worked differently, then we'd observe different things".
Well yes. Obviously.
What if light and sound swapped speeds? You'd hear thunder before you saw the lightening, not the other way around. You'd observe different things.
We can all do thought experiments like that. Not clear what your point is.

If objects with more mass took the same force to move then yes, they'd accelerate to earth faster. But they don't. And it would be a bit odd if they did - it would be as easy to lift a car as a penny.
If gravity pulled all objects with the same force then again, objects with less mass would fall faster. But again, if a force is caused by mass it makes sense that more mass equals more force.
I don't even see how a universe would work if all objects attracted each other with the same force.

The force required to accelerate an object is proportional to the object's mass.
The force of gravity acting on an object is also proportional to the object's mass.
This means objects of different mass fall to earth at the same rate.

Asking why these are properties of the universe is like asking why the speeds of light and sound are what they are.
Title: Re: Clarifications on UA
Post by: Tom Bishop on July 05, 2019, 04:26:08 PM
Alternate reality? It sounds like he's just talking about Newton's laws from Wikipedia to me. Take a look:

(https://i.imgur.com/JVoBKDr.png)

It says the same thing here at the University of Pittsburgh:

https://www.pitt.edu/~jdnorton/teaching/HPS_0410/chapters_August_14_2018/general_relativity/index.html

Quote

(https://www.pitt.edu/~jdnorton/teaching/HPS_0410/chapters_August_14_2018/general_relativity/mass-gravitational.png)

A two pound mass feels twice the gravitational force than does a one pound mass in the same gravitational field, since it has twice the gravitational mass.

(https://www.pitt.edu/~jdnorton/teaching/HPS_0410/chapters_August_14_2018/general_relativity/mass-inertial.png)

One might expect that, if we drop the two masses, the two pound mass would fall faster because it is acted on by twice the gravitational force.

A second factor comes into play that erases the effect of the increase. In Newtonian gravitation theory, a body with a two pound gravitational mass will also have a two pound inertial mass.

The inertial mass of the body tells us how much acceleration the body acquires when acted on by a force. (The precise relation is acceleration = force/mass.)

Thus, in passing from the one pound to the two pound mass, we have doubled both the inertial and the gravitational mass. So we have doubled the gravitational force, but halved the responsiveness of the mass to the gravitational forces.

The outcome is that both masses fall with exactly the same acceleration.

See the underlined above -- "A second factor comes into play that erases the effect of the increase". The second factor that comes into play is inertia and inertial resistance which equalizes the different gravitational pulls to the same rate of acceleration.
Title: Re: Clarifications on UA
Post by: markjo on July 06, 2019, 12:39:27 AM
I just provided you with a video of an experiment controlled for atmosphere, so your claim that they don't exist is disproven.

You had responded to an exchange between Salviati and I about the weight variation by latitude experiments. How would the experiment you provided contribute to that?
It shows the effects of atmospheric pressure on weight in a controlled environment.
Title: Re: Clarifications on UA
Post by: AllAroundTheWorld on July 06, 2019, 11:23:03 AM
See the underlined above -- "A second factor comes into play that erases the effect of the increase". The second factor that comes into play is inertia and inertial resistance which equalizes the different gravitational pulls to the same rate of acceleration.
Yes. A 2lb (a pox on you lot and the imperial system!) ball feels twice as much gravitational force as a 1lb ball). But it takes twice as much force to accelerate a 2lb ball as a 1lb one. These things cancel out. The conversation you linked to above was a thought experiment about “what if they didn’t”. Well then we’d experience different things, as we would in my thought experiment about the speeds of sound and light swapping.

I’m not clear what your point is. If your point is “if the universe worked differently then things would be different” then yeah, obviously.

If your point is “isn’t it an amazing coincidence that these two things are equal” then I don’t know, that’s a bit above my level of physics (and, with respect, yours too). But it makes sense to me that a force which is attractive between two masses increases as the masses do. And it makes sense that a more massive object takes more force to accelerate. The consequence of these two things is that objects of different mass accelerate in a gravitational field at the same rate but that is not unique to earth. It has been shown to be the same on the moon.

And I’d be careful about claiming “amazing coincidences” as a way of attacking the heliocentric model when your model relies on things like some weird effect making the sun appear the exact same angular size and move at a constant angular speed despite the distance to it being about 3 times further at sunrise and sunset as it would be when directly overhead. The same would apply to the moon.
Title: Re: Clarifications on UA
Post by: jimster on July 08, 2019, 01:22:39 AM
If uA is comstantly accelerating, wouldn't we approach the speed of light? Einstein says tht mass increases with velocity, oso wouldn't UA need an ever increasing force? At the speed of light, the mass and thus force required is infinite. According to science web sites, by about 20% of the speed of light, significant energy goes into increasing the mass.

So the FE universe is an infinitely long cylinder which had better be an absolute vacuum, since even a single hydrogen atom will go through everything and create ionizing radiation, a small rock at that speed might make a dinosaur killing level of explosion. At some point, we are going the speed of a particle in an atim smasher. Better not hit anything.

So we have an effectively infinite length cylinder that we know nothing about, and the conventional 3 space outside the cylinder, if it exists, we know nothing about. The known universe on FE with UA is 8000 miles wide and infinitely long, and is damn straight and empty. An unknown force (exponentially increasing?) pushes us along this oh so perfect tube and we never reach a speed where our mass is a problem, even after thousands of years accelerating at 9.8m/sec2.

Meanwhile, on the dome, we have stars, the sun and the moon, who are also propelled. The sun produces a measurable amount of energy over the face of the earth, as studied by makers and users of solar cells. In the disk/dome model, we have all that energy coming from a sun 35 miles across. The energy in that 35 mi sun is about like a million times as dense as the real sun. No explanation of this physics from this model, but somehow, the force goes through the disk and through the air that gets scarcer and scarcer, pretyty much none at 3000 mi. Yet that sun theat produce millions of times more energy per square foot than the real sun. Must be pretty heavy, like infinitely heavy. To hold that weight and survive the heat, that dome must be miraculously strong, or there is completely unknown physics.

I would love to hear the explanation after you have figured all this out. What is the force, how does it not get to light speed, how does it operate on the things above us, why aren't we infinitely massive (and zero length). What is outside the cylinder, what is the force, how does the cylinder stay perfectly empty.

Have I got this right?
Title: Re: Clarifications on UA
Post by: Pete Svarrior on July 08, 2019, 11:16:37 AM
If uA is comstantly accelerating, wouldn't we approach the speed of light?
In what frame of reference?

Have I got this right?
I'll reserve judgement on your first question until you've disambuguated it, but otherwise: no, most of what you said contradicts mainstream physics. You also filled the gaps in your understanding of FET with your imagination - never a good start.
Title: Re: Clarifications on UA
Post by: spherical on July 08, 2019, 08:16:53 PM
If uA is comstantly accelerating, wouldn't we approach the speed of light?
In what frame of reference?

The same frame of reference that measured the acceleration (UA).
Simple, isn't it?

You can even measure acceleration of a car if you are a passenger.
Accumulate acceleration and time, you can calculate actual speed from the moment you started measure it, as speed=time=0.
In this case, there is no frame of reference, other than time.

If you say approaching light speed time changes to avoid reach such speed, and if you remember that acceleration is delta-speed over time, and if time changes, then the acceleration is not constant any longer.  But we don't see it change along the time, still 9.8m/s² at sea level for eons.  Impossible.
Title: Re: Clarifications on UA
Post by: Pete Svarrior on July 09, 2019, 01:23:03 PM
The same frame of reference that measured the acceleration (UA).
Simple, isn't it?
Not at all - that completely ruins the thought experiment. Given that such a frame of reference would only exist a small distance away from the Earth, this would preclude a scenario in which the speed of light is attainable.

So, I ask again: In what frame of reference do you propose this would occur? This time, focus on an answer that's plausible, rather than just "simple".
Title: Re: Clarifications on UA
Post by: AllAroundTheWorld on July 09, 2019, 01:38:39 PM
One thing I'm curious about when it comes to UA.
You use Special Relativity to explain why the earth doesn't go faster than the speed of light but why cherry pick Special Relativity as correct when you dismiss so much mainstream science?

Why not just redefine gravity as a force which acts downwards on objects but whose power reduces with altitude - to the point where celestial objects are not affected and thus don't fall.
You could even make the force dependent on something like the thickness or density of the earth.
That would explain differences in g with altitude and latitude

With UA you have to either deny those effects exist or use other mechanisms to explain them.
If you can have EA which bends light upwards, why not gravity which pulls objects on earth downwards?

It wouldn't explain the motion of the sun/moon/stars/planets but neither does UA.
Title: Re: Clarifications on UA
Post by: Pete Svarrior on July 09, 2019, 01:55:43 PM
Uh, that's not how any of this works. We're working on establishing what actually occurs, not picking explanations to satisfy your whims. You can find plenty of the latter on metabunk if that's what you're after.
Title: Re: Clarifications on UA
Post by: AllAroundTheWorld on July 09, 2019, 02:03:18 PM
Uh, that's not how any of this works. We're working on establishing what actually occurs.
And how do you do that? The whole premise of UA is that is would be equivalent to a force acting downwards and actually you can't tell which it is. Right?
On your Wiki page about UA you have a section about the Equivalence Principle which explains you can't tell.
So how do you establish which it is?

I mean, the RE argument would be "we've been to space, we've observed the globe earth", but if you dismiss that then how do you tell whether the earth is accelerating upwards forever by some unknown force or whether earth exerts a force which doesn't attract towards the centre of mass as mainstream science but acts in a downward direction.

What experiment can you do or observation can you make which distinguishes between those two things?

Quote
not picking explanations to satisfy your whims.

It's not about satisfying my whims, it's about explaining observations. Does my idea not explain observations as well if not better than UA?
Title: Re: Clarifications on UA
Post by: Pete Svarrior on July 09, 2019, 02:12:20 PM
Does my idea not explain observations as well if not better than UA?
Precisely.
Title: Re: Clarifications on UA
Post by: AllAroundTheWorld on July 09, 2019, 02:20:46 PM
Does my idea not explain observations as well if not better than UA?
Precisely.
I'm unclear on your response. Are you saying UA explains observations better?
Can you elaborate? Which observations does UA explain that my idea does not?
Title: Re: Clarifications on UA
Post by: Pete Svarrior on July 09, 2019, 03:51:22 PM
Can you elaborate?
No, I will not let you distract the thread from my question. You can read up on the basics at your leisure.

Meanwhile, I'm here to get a clear answer to the following:

The same frame of reference that measured the acceleration (UA).
Simple, isn't it?
Not at all - that completely ruins the thought experiment. Given that such a frame of reference would only exist a small distance away from the Earth, this would preclude a scenario in which the speed of light is attainable.

So, I ask again: In what frame of reference do you propose this would occur? This time, focus on an answer that's plausible, rather than just "simple".
Title: Re: Clarifications on UA
Post by: rpt on July 17, 2019, 08:31:54 AM
Gravity does change in different gravity environments, however. Thus gravitational mass will not be equal to inertial mass.
You seem to be confusing gravitational mass with weight. On Jupiter an object will weigh more than it does on earth but its gravitational mass will stay the same.

A very wild and surprising coincidence, indeed, that Gravitational Mass should exactly equal Inertial Mass on Earth to the best resolution of modern physics.
This equivalence is not unique to Earth.
Title: Re: Clarifications on UA
Post by: Tom Bishop on July 17, 2019, 06:01:12 PM
Gravity does change in different gravity environments, however. Thus gravitational mass will not be equal to inertial mass.
You seem to be confusing gravitational mass with weight. On Jupiter an object will weigh more than it does on earth but its gravitational mass will stay the same.

Can you provide a source for that statement?

This source (https://www.school-for-champions.com/science/gravity_mass_weight.htm#.XS9hypNKiHs) says that gravitational mass is determined by a weight scale:

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Gravitational mass is the mass of a body as determined by its response to the force of gravity, such as done on a balance scale.

...

Summary

Gravitational mass of an object is determined by using a balance scale to compare its mass with a unit mass. Inertial mass is the measurement of the mass of an object measured by its resistance to acceleration. Gravitational mass and inertial mass have been shown to be equivalent.

Weight is defined as the force of gravity on a mass. A spring scale can be used to measure weight.

https://www.physlink.com/education/askexperts/ae305.cfm

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Gravitational mass is measured by comparing the force of gravity of an unknown mass to the force of gravity of a known mass. This is typically done with some sort of balance scale.

http://www.bozemanscience.com/ap-phys-010-gravitational-mass

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Paul Andersen explains how the gravitational mass is a measure of the force on an object in a gravitational field. The gravitational mass is based on the amount of material in an object and can be measured to a standard kg using a balance.

On Jupiter an object will weigh more... therefore that object will have a greater gravitational mass.

On another note, an interesting quote from Wikipedia is found: (https://en.wikipedia.org/wiki/Mass#Inertial_vs._gravitational_mass)

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Inertial vs. gravitational mass

Although inertial mass, passive gravitational mass and active gravitational mass are conceptually distinct, no experiment has ever unambiguously demonstrated any difference between them. In classical mechanics, Newton's third law implies that active and passive gravitational mass must always be identical (or at least proportional), but the classical theory offers no compelling reason why the gravitational mass has to equal the inertial mass. That it does is merely an empirical fact.

Albert Einstein developed his general theory of relativity starting with the assumption of the intentionality of correspondence between inertial and passive gravitational mass, and that no experiment will ever detect a difference between them, in essence the equivalence principle.

'Gravitational mass' does not exist, only inertial mass.

https://www.echaandscience.com/the-post-modern-modification-of-the-weak-equivalence-principle/

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The characteristics of gravitational mass are the same as that of inertial mass.
Title: Re: Clarifications on UA
Post by: Pete Svarrior on July 17, 2019, 06:24:54 PM
Quote
Gravitational mass is measured by comparing the force of gravity of an unknown mass to the force of gravity of a known mass. This is typically done with some sort of balance scale.
This is consistent with what rpt is saying. Gravitational mass is a ratio of two weights. In a RET gravitational model, this would remain constant between different celestial bodies.
Title: Re: Clarifications on UA
Post by: Tom Bishop on July 17, 2019, 07:46:00 PM
rpt said: "You seem to be confusing gravitational mass with weight. On Jupiter an object will weigh more than it does on earth but its gravitational mass will stay the same."

What is the difference between gravitational mass and weight, if gravitational mass is determined by weight as measured by a scale? If gravitational mass is connected to weight, then on Jupiter an object will have a greater gravitational mass, even if the ratios between the weight of other masses stays the same.

Can we have a quote and a source for these assertions that gravitational mass never changes anywhere? The assertion that "gravitational mass" never changes, and is the same on Earth, on Jupiter, and on the Moon—always unchanging—is something that I would like to request a source on, as it goes against everything I have learned on the subject. Clearly, there is no gravitational mass in weightless space, so it cannot be unchanging.

A Study Packet (https://www.scribd.com/document/242477/phheat)

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Transport the spring balance and the inertial balance to the elevator and determine whether the gravitational mass and the inertial mass can be detected to change as the elevator descends. These determinations shouldonly be attempted after the students are relatively accomplished in usingtheir spring and inertial balances. [The gravitational mass will change but not the inertial mass.]

From A Dictionary of Scientists (https://books.google.com/books?id=AtngooiwXikC&pg=PA158&lpg=PA158&dq=%22gravitational+mass+depends%22&source=bl&ots=ISVmJz6lx4&sig=ACfU3U1Q2kpVzkGNeSAbnatVpLL8QvNb5g&hl=en&sa=X&ved=2ahUKEwjRi5SI2rzjAhUjheAKHZG_C1U4ChDoATAAegQICRAB#v=onepage&q=%22gravitational%20mass%20depends%22&f=false)

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The gravitational mass depends on forces of gravitational attraction between two masses.

From flash cards (https://quizlet.com/70107370/section-72-flash-cards/) based on a physics course:

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Q: How are gravitational mass and inertial mass alike and how are they different?

A: Gravitational mass depends on an objects gravitational pull and inertial remains the same.

Physics Final: (https://www.coursehero.com/file/36928463/Physics-Finalpdf/)

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Gravitational mass: depends on the strength of the force exerted upon it by the gravitational field

From Encyclopedia Britannica: (https://www.britannica.com/science/gravitational-mass)

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Gravitational mass is determined by the strength of the gravitational force experienced by the body when in the gravitational field g.

I cannot seem to find anything which states that gravitational mass is universal and unchanging, or see anything about ratios. However, I do find sources which appear to directly state that gravitational mass is determined by the strength of the gravitational field. I submit that Encyclopedia Britannica is not mistaken.
Title: Re: Clarifications on UA
Post by: Bikini Polaris on July 17, 2019, 10:13:22 PM
I'm somehow curious about the Power Source causing UA.

That source should be quite stable through the whole Earth, otherwise if there was a slight instability we could start flipping like a coin?

Also, that source would be knowledgable of how mass is moved on the surface, so to change the power accordingly on the new location. In saying so I imagine a disk flying through space with a rocket, and stuff over it in a sort of stable way.

And it has been running since a lot of time, that will be a huge energy consumption, probably superior to REs estimates of the Big Bang. Where does that energy continuosly come from?
Title: Re: Clarifications on UA
Post by: kopfverderber on July 18, 2019, 11:29:16 AM
Shouldn't UA stop meteorites from falling on the earth?
Title: Re: Clarifications on UA
Post by: Pete Svarrior on July 18, 2019, 04:42:21 PM
Shouldn't UA stop meteorites from falling on the earth?
No.
Title: Re: Clarifications on UA
Post by: rpt on July 19, 2019, 01:42:33 PM
From Encyclopedia Britannica: (https://www.britannica.com/science/gravitational-mass)
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Gravitational mass is determined by the strength of the gravitational force experienced by the body when in the gravitational field g.
Move the body to a different gravitational field and you will get a different force. But the mass remains the same.
Title: Re: Clarifications on UA
Post by: Tom Bishop on July 20, 2019, 02:28:33 PM
From Encyclopedia Britannica: (https://www.britannica.com/science/gravitational-mass)
Quote
Gravitational mass is determined by the strength of the gravitational force experienced by the body when in the gravitational field g.
Move the body to a different gravitational field and you will get a different force. But the mass remains the same.

Do you guys have a source that gravitational mass is unchanging and permenant in every environment, or do you have only your own opinion?
Title: Re: Clarifications on UA
Post by: kopfverderber on July 20, 2019, 03:40:19 PM
The theory of gravity is a mathematical interpretation of what we observe in nature. Gravity can be demonstrated, but I don't think there is an absolute proof of the law of gravity, if that is what you are asking.  Gravity provides a simple explanation of known facts and allows us to make extremely accurate predictions, that's why it's an established theory.

One cannot rule out alternative explanations to gravity, such as UA or magic. However those alternative models cannot explain what we observe in nature or make predictions as accurately as the law of gravity.

I'm sure you also know what Occam's Razor is. Gravity is a much simpler explanation than UA, because UA requires us to believe in additional things to what we observe.
Title: Re: Clarifications on UA
Post by: Tom Bishop on July 20, 2019, 05:23:26 PM
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The theory of gravity is a mathematical interpretation of what we observe in nature. Gravity can be demonstrated, but I don't think there is an absolute proof of the law of gravity, if that is what you are asking. 

I'm asking for a reference that gravitational mass is defined as static and unchanging in all environments.

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I'm sure you also know what Occam's Razor is. Gravity is a much simpler explanation than UA, because UA requires us to believe in additional things to what we observe.

I didn't observe any gravitons, bendy space, or any spooky action-at-a-distance mechanism when I stepped off a chair and observed the earth accelerate up towards me. Please tell me which scientific instrument I need to buy that will observe this.
Title: Re: Clarifications on UA
Post by: kopfverderber on July 20, 2019, 09:35:48 PM
That's not how it works. Gravitons are a hypothesis. There are problems that modern physics hasn't solved yet.

You might say that UA is also a hypothesis, I would say it's a very weak one. We barely know anything about what UA is supposed to be or  about the energy source that causes it. That's why flatearthers spend more time trying to debunk gravity than investigating their own theory of UA.  Do we already know why UA feels weaker at the equator than at the poles?
Title: Re: Clarifications on UA
Post by: markjo on July 21, 2019, 12:32:49 AM
Quote
The theory of gravity is a mathematical interpretation of what we observe in nature. Gravity can be demonstrated, but I don't think there is an absolute proof of the law of gravity, if that is what you are asking. 

I'm asking for a reference that gravitational mass is defined as static and unchanging in all environments.
Gravitational mass is determined by the strength of the gravitational field.  Mass will always be static and constant, but gravitational mass will vary with the strength of the gravitational field.
Title: Re: Clarifications on UA
Post by: The Listener on July 21, 2019, 08:29:34 PM
Gravitational mass is determined by the strength of the gravitational field.  Mass will always be static and constant, but gravitational mass will vary with the strength of the gravitational field.

@markjo, I think you are confusing weight and gravitational mass there.  Here is what I learned from physics textbooks in grad school:

Let mg be the gravitational mass of object 1, Mg be the gravitational mass of object 2, G be the gravitational constant, and r be the separation between the masses.  Then the gravitational force on object 1 is Fg = GmgMg/r2.  So, the gravitational mass determines the strength of the gravitational force on an object.  The strength of the gravitational field created by object 2 at location r is g = GMg/r2.  Then the force is Fg = mgg.  (Although many people do it, I think it is confusing to call g the "acceleration of gravity".)  The force Fg is called the "weight" of object 1.  According to this treatment (which is the standard treatment taught in university physics classes), the gravitational mass of an object does not depend on the gravitational field, but the weight does.  Note also that the gravitational mass of object 1 does not depend on object 2 at all.  For example an object's gravitational mass is the same on Earth and on Jupiter, but the weights on Earth and Jupiter are very different because Earth and Jupiter create different gravitational fields.

Let mi be the inertial mass of object 1.  When a force F acts on object 1 its acceleration will be a = F/mi.  The inertial mass determines the relationship between any force (whatever its cause) and object 1's acceleration.

Experiments showing that mg = mi are routinely done in introductory physics laboratory classes.  In my opinion the coincidence that mg = mi is very surprising!!!  For all other types of forces (for example electrical forces) there are other "charges" that determine the strength of the force, but in this way gravity is special.  The theory of general relativity is built in such a way that mg = mi from the foundation of the theory, but it still does not really tell us why gravity has this property that other forces don't have.  This coincidence of mg = mi is the main problem of uniting gravity and quantum theory -- the biggest current problem of fundamental physics.

I have seen these quotes from sources like Encyclopedia Britannica, which says "Gravitational mass is determined by the strength of the gravitational force experienced by the body when in the gravitational field g.", but I think they are confusing because of their use of passive voice.  What they mean is that you can determine an object's gravitational mass by putting it in a gravitational field g and measuring the force Fg.  If you know g and Fg, then you can calculate mg=Fg/g.  Given the way that the Encyclopedia Britannica article discusses weight vs mass earlier in the article, it would not make sense to interpret this sentence in any other way.  The authors assume that the reader has already understood that "mass" always refers to an object's own properties not related to its location or other surrounding objects.