#### spherical

• 214
##### Re: Clarifications on UA
« Reply #40 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.

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.

#### ChrisTP

• 589
##### Re: Clarifications on UA
« Reply #41 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;

Tom is wrong most of the time. Hardly big news, don't you think?

#### Tom Bishop

• Zetetic Council Member
• 6746
• Flat Earth Believer
##### Re: Clarifications on UA
« Reply #42 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

Quote
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.
« Last Edit: July 03, 2019, 06:09:26 PM by Tom Bishop »
"The biggest problem in astronomy is that when we look at something in the sky, we don’t know how far away it is" — Pauline Barmby, Ph.D., Professor of Astronomy

#### AllAroundTheWorld

• 2907
##### Re: Clarifications on UA
« Reply #43 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.
If you are making your claim without evidence then we can discard it without evidence.

Nearly all flat earthers agree the earth is not a globe.

#### Tom Bishop

• Zetetic Council Member
• 6746
• Flat Earth Believer
##### Re: Clarifications on UA
« Reply #44 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.

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:

Quote
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

« Last Edit: July 03, 2019, 06:45:39 PM by Tom Bishop »
"The biggest problem in astronomy is that when we look at something in the sky, we don’t know how far away it is" — Pauline Barmby, Ph.D., Professor of Astronomy

#### Salviati

• 17
• I don't have a personal text.
##### Re: Clarifications on UA
« Reply #45 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).

#### AllAroundTheWorld

• 2907
##### Re: Clarifications on UA
« Reply #46 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...
If you are making your claim without evidence then we can discard it without evidence.

Nearly all flat earthers agree the earth is not a globe.

#### Tom Bishop

• Zetetic Council Member
• 6746
• Flat Earth Believer
##### Re: Clarifications on UA
« Reply #47 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.
« Last Edit: July 03, 2019, 06:50:14 PM by Tom Bishop »
"The biggest problem in astronomy is that when we look at something in the sky, we don’t know how far away it is" — Pauline Barmby, Ph.D., Professor of Astronomy

#### AllAroundTheWorld

• 2907
##### Re: Clarifications on UA
« Reply #48 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.
If you are making your claim without evidence then we can discard it without evidence.

Nearly all flat earthers agree the earth is not a globe.

#### Tom Bishop

• Zetetic Council Member
• 6746
• Flat Earth Believer
##### Re: Clarifications on UA
« Reply #49 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.

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.
« Last Edit: July 03, 2019, 08:20:25 PM by Tom Bishop »
"The biggest problem in astronomy is that when we look at something in the sky, we don’t know how far away it is" — Pauline Barmby, Ph.D., Professor of Astronomy

#### AllAroundTheWorld

• 2907
##### Re: Clarifications on UA
« Reply #50 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.
If you are making your claim without evidence then we can discard it without evidence.

Nearly all flat earthers agree the earth is not a globe.

#### Tom Bishop

• Zetetic Council Member
• 6746
• Flat Earth Believer
##### Re: Clarifications on UA
« Reply #51 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.
« Last Edit: July 03, 2019, 08:42:26 PM by Tom Bishop »
"The biggest problem in astronomy is that when we look at something in the sky, we don’t know how far away it is" — Pauline Barmby, Ph.D., Professor of Astronomy

#### AllAroundTheWorld

• 2907
##### Re: Clarifications on UA
« Reply #52 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.

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.
If you are making your claim without evidence then we can discard it without evidence.

Nearly all flat earthers agree the earth is not a globe.

#### markjo

• Purgatory
• 4119
• Zetetic Council runner-up
##### Re: Clarifications on UA
« Reply #53 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.
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.
Abandon hope all ye who press enter here.

Science is what happens when preconception meets verification.

If you can't demonstrate it, then you shouldn't believe it.

#### Tom Bishop

• Zetetic Council Member
• 6746
• Flat Earth Believer
##### Re: Clarifications on UA
« Reply #54 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.
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.
« Last Edit: July 03, 2019, 10:21:27 PM by Tom Bishop »
"The biggest problem in astronomy is that when we look at something in the sky, we don’t know how far away it is" — Pauline Barmby, Ph.D., Professor of Astronomy

#### spherical

• 214
##### Re: Clarifications on UA
« Reply #55 on: July 03, 2019, 09:57:46 PM »
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.

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.

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

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.

#### Salviati

• 17
• I don't have a personal text.
##### Re: Clarifications on UA
« Reply #56 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.

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.

#### Tom Bishop

• Zetetic Council Member
• 6746
• Flat Earth Believer
##### Re: Clarifications on UA
« Reply #57 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?
"The biggest problem in astronomy is that when we look at something in the sky, we don’t know how far away it is" — Pauline Barmby, Ph.D., Professor of Astronomy

#### markjo

• Purgatory
• 4119
• Zetetic Council runner-up
##### Re: Clarifications on UA
« Reply #58 on: July 03, 2019, 10:40:41 PM »
Can you reference experiments that were conducted in a vaccum chamber?
Here's one:
Abandon hope all ye who press enter here.

Science is what happens when preconception meets verification.

If you can't demonstrate it, then you shouldn't believe it.

#### Tom Bishop

• Zetetic Council Member
• 6746
• Flat Earth Believer
##### Re: Clarifications on UA
« Reply #59 on: July 03, 2019, 10:49:13 PM »
Can you reference experiments that were conducted in a vaccum chamber?
Here's one: