#### WTF_Seriously

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##### Re: Reasoning behind the Universal Accelerator
« Reply #20 on: December 16, 2021, 04:22:20 PM »
Quote
Yes.  But aren't the relative velocities of the earth and object prior to being dropped zero always?

Assuming the object is supported by the earth, the relative velocity would be zero,  and the clocks would be synchronized before it is dropped.  But once the object is dropped, they would become unsynchronized. When the object hits the ground, the clocks would start keeping time at the same rate again, but they still wouldn’t agree unless they were synchronized again.

I understand that.  What I'm questioning is how the scenario would change 5 minutes from now if in both cases the relative velocities of the two are zero.  That was the premise of your original statement.  The situation would be different because the earth under acceleration would be traveling at a different speed.  But the clock would also have accelerated the same amount during that 5 minutes so at the time it's dropped the relative velocities are still zero which result in the time jumping of the chair to be the same 5 minutes later.
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#### scomato

• 175
##### Re: Reasoning behind the Universal Accelerator
« Reply #21 on: December 16, 2021, 04:46:32 PM »
The biggest impossibility with Universal Acceleration is that you'd reach relativistic speeds within the month, and hit the speed of light within a year. From an initial velocity of 0, a constant acceleration of 9.8 m/s would mean that the Flat Earth would reach the speed of light in 11.6 months. So UA needs an entirely different physics paradigm, because depending on the age of the Earth, we would currently be experiencing a velocity that is trillions of times the speed of light.
« Last Edit: December 16, 2021, 04:49:28 PM by scomato »

#### Tom Bishop

• Zetetic Council Member
• 10690
• Flat Earth Believer
##### Re: Reasoning behind the Universal Accelerator
« Reply #22 on: December 16, 2021, 05:00:54 PM »
The biggest impossibility with Universal Acceleration is that you'd reach relativistic speeds within the month, and hit the speed of light within a year. From an initial velocity of 0, a constant acceleration of 9.8 m/s would mean that the Flat Earth would reach the speed of light in 11.6 months. So UA needs an entirely different physics paradigm, because depending on the age of the Earth, we would currently be experiencing a velocity that is trillions of times the speed of light.

I don't see why there should need to be a speed limit to the universe. Some experiments suggest that c can be surpassed. After the invention of SR scientists performed the Michelson-Morley light velocity experiment that assumed the Earth was moving on a horizontal plane with an experiment involving a moving detector in the laboratory:

https://wiki.tfes.org/Sagnac_Experiment

Quote
On p.306 of the book Unified Field Mechanics II we find a paper by Physicist José R. Croca, Ph.D. (bio), where we see:

“  Since the realization of this [Sagnac] experiment, which has been done with photons [25], electrons [26] and neutrons [27], many trials have been made to interpret the observed results seen, for instance, Selleri [28]. Indeed, Sagnac utilized the habitual linear additive rule and with that he was able to correctly predict the observed results. Still, since his prediction lead to velocities greater than c and consequently are against relativity which claims that the maximal possible velocity is c this raised a large amount of arguing. In fact, many authors tried to explain the results of the experiment in the framework of relativity which assumed that the maximal possible velocity is c. As can be seen in the literature, there are almost as many explanations as the authors that have tried to explain the results in the framework of relativity. In some cases the same author [29] presents even more than one possible explanation. The complexity of the problem stems mainly from the fact that the experiment is done in a rotating platform. In such case, there may occur a possible accelerating effect leading the explanation of the experiment to fall in the framework of general relativity.

This controversy, whether Sagnac experiment is against or in accordance with relativity, was settled recently by R. Wang et al. [30] with a very interesting experimental setup they called linear Sagac interferometer. In this case the platform is still, what moves is a single mode optical fiber coil, Fig. 12.

They did the experiment with a 50 meter length linear interferometer with wheels of 30 cm. The observed relative phase shift difference for the two beams of light following in opposite directions along the optical fiber was indeed dependent only on the length of the interferometer and consequently independent of the angular velocity of the wheels. From the experimental results obtained with the linear Sagnac interferometer one is lead to conclude that in this particular case the linear additive rule applies. Consequently we may have velocities greater than c, which clearly shows that relativity is not adequate to describe this specific physical process. ”

See the bolded.
« Last Edit: December 19, 2021, 02:45:54 AM by Tom Bishop »

#### Pete Svarrior

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##### Re: Reasoning behind the Universal Accelerator
« Reply #23 on: December 16, 2021, 05:18:27 PM »
a constant acceleration of 9.8 m/s[^2, presumably]
Relative to what? You can't talk about "relativistic speeds" in such a cavallier manner, only to then ignore relativity.

If you'd rather skip the song and dance of probing your ignorance, you could simply read up on the Lorentz transformation to find out why your argumentation is nonsense. There exists no frame of reference in which an EA-FET would exceed the speed of light. If you think otherwise, define that frame of reference.

Furthermore, it would have been extremely prudent of you to read the Wiki prior to commenting. Consider this a friendly reminder that that is expected from you if you choose to post here.
« Last Edit: December 16, 2021, 05:26:20 PM by Pete Svarrior »
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#### Rog

• 69
##### Re: Reasoning behind the Universal Accelerator
« Reply #24 on: December 17, 2021, 12:19:53 AM »
Quote
I understand that.  What I'm questioning is how the scenario would change 5 minutes from now if in both cases the relative velocities of the two are zero.  That was the premise of your original statement.  The situation would be different because the earth under acceleration would be traveling at a different speed.  But the clock would also have accelerated the same amount during that 5 minutes so at the time it's dropped the relative velocities are still zero which result in the time jumping of the chair to be the same 5 minutes later.

You aren’t taking the frame of reference of the jumper into account.

Elapsed time at a body T0 is the time according to an observer on the ground and elapsed time at observer T is our jumper.

If the earth is moving at 200,000 mph, an observer on the ground will measure 1s for the jumper to meet the ground, but the jumper will measure 1.3s to meet the ground.

Five minutes later and the earth is moving at 250,000.  The ground observer still measures 1s to meet the ground, but the jumper measures 1.8s.

https://keisan.casio.com/exec/system/1224059993

The jumper will always measure a different time to meet the ground than an observer on the ground.  And that measurement will change over time as the earth accelerates and increases velocity
« Last Edit: December 17, 2021, 12:27:00 AM by Rog »

#### Pete Svarrior

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##### Re: Reasoning behind the Universal Accelerator
« Reply #25 on: December 17, 2021, 11:41:36 AM »
If the earth is moving at 200,000 mph
Relative to what? It sounds like you're talking about the jumper. If so, how did the jumper manage to exceed terminal velocity by three orders of magnitude? How, exactly, did they manage to start falling at 200,000mph?

...Or 200,000km/s for that matter - your screenshots are inconsistent with what you wrote by a facor of ~2237. That would, of course, make things much worse - you're now either off by about 7 orders of magnitude for the jumper's velocity compared to their terminal velocity (assuming km/s), or your calculations are completely irrelevant (assuming you wanted mph). I'll consider both scenarios in remaining parts of the post.

Five minutes later and the earth is moving at 250,000.
How did the jumper manage to remain in the air for five minutes? Why are they still accelerating relative to Earth's surface when they're already massively exceeding terminal velocity (in either the km/s or the mph scenario)? They should be decelerating rapidly, and probably burning to a crisp in the atmolayer. Did you eliminate air resistance from your example? Were they subject to UA at the time?

There is also a fundamental problem in how you calculated a ∆v of 50,000 of any unit.
If you meant to use km/s, even if we ignore all relativistic effects and assume no drag, the maximum you should arrive at would be 9.8m/s^2 * 300s = 2,940m/s = 2.94km/s. A far cry from the 50,000 you got.
If you did mean to use mph, the maximum becomes 6,577mph. This, again, is not 50,000.

What an absolute train wreck.

And that measurement will change over time as the earth accelerates and increases velocity
Relative to what? For someone who just complained about not taking frames of reference into account, this looks to be a critical omission.

Out of curiosity: what are your views on spirit levels?
« Last Edit: December 17, 2021, 02:05:14 PM by Pete Svarrior »
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#### Clyde Frog

• 1045
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##### Re: Reasoning behind the Universal Accelerator
« Reply #26 on: December 17, 2021, 02:31:31 PM »
The biggest impossibility with Universal Acceleration is that you'd reach relativistic speeds within the month, and hit the speed of light within a year. From an initial velocity of 0, a constant acceleration of 9.8 m/s would mean that the Flat Earth would reach the speed of light in 11.6 months. So UA needs an entirely different physics paradigm, because depending on the age of the Earth, we would currently be experiencing a velocity that is trillions of times the speed of light.
This is wildly wrong, even if you take the shape of the Earth out of the conversation and replace it with a ship accelerating constantly at 1G. The observer on the ship always measures their velocity with respect to c to be 0m/s, because light moves away from them at c. This is a pretty foundational principle according to the funny-haired guy that wrote it all down originally. The hypothetical ship could accelerate at a steady 1G forever (assuming it had fuel to do so, but that's an engineering problem not a physics issue) and according to anyone on that ship it would never even begin to approach anything like c. And an outside observer is going to see that ship asymptotically approaching c, never exceeding it.

Now. Having thought about this without the distraction of a FE to cause you to forget everything you ever learned about how2physx, replace the ship with the thing that makes you upset to think about.

#### Rog

• 69
##### Re: Reasoning behind the Universal Accelerator
« Reply #27 on: December 17, 2021, 09:13:09 PM »
If the earth is moving at 200,000 mph
Relative to what? It sounds like you're talking about the jumper. If so, how did the jumper manage to exceed terminal velocity by three orders of magnitude? How, exactly, did they manage to start falling at 200,000mph?

...Or 200,000km/s for that matter - your screenshots are inconsistent with what you wrote by a facor of ~2237. That would, of course, make things much worse - you're now either off by about 7 orders of magnitude for the jumper's velocity compared to their terminal velocity (assuming km/s), or your calculations are completely irrelevant (assuming you wanted mph). I'll consider both scenarios in remaining parts of the post.

Five minutes later and the earth is moving at 250,000.
How did the jumper manage to remain in the air for five minutes? Why are they still accelerating relative to Earth's surface when they're already massively exceeding terminal velocity (in either the km/s or the mph scenario)? They should be decelerating rapidly, and probably burning to a crisp in the atmolayer. Did you eliminate air resistance from your example? Were they subject to UA at the time?

There is also a fundamental problem in how you calculated a ∆v of 50,000 of any unit.
If you meant to use km/s, even if we ignore all relativistic effects and assume no drag, the maximum you should arrive at would be 9.8m/s^2 * 300s = 2,940m/s = 2.94km/s. A far cry from the 50,000 you got.
If you did mean to use mph, the maximum becomes 6,577mph. This, again, is not 50,000.

What an absolute train wreck.

And that measurement will change over time as the earth accelerates and increases velocity
Relative to what? For someone who just complained about not taking frames of reference into account, this looks to be a critical omission.

Out of curiosity: what are your views on spirit levels?

Obviously, I didn’t set up the paramters clearly enough.   T0 is the earth (or an observer on earth). “T” is the jumper.

If the relative velocity between them is 200000km/s (IOW, if the earth (and the observer) is accelerating up at 200000ms and the jumper is inertial with no velocity) and T0  records an elapsed time of 1s from the time T leaves the surface of the chair and meets the ground, T will record an elapsed time of 1.34s.

When, after meeting the ground,  T climbs back onto the chair, say 5 minutes later, the relative velocity between T0 and T has increased to 250000ms.  When T jumps again,  T0  will record 1s elapsed time from leaving the chair to meeting the ground again but T will record 1.8s.

T isn’t falling so terminal velocity and drag isn’t relevant, but to avoid getting dragged into the weeds on the subject assume this thought experiment is taking place in vacuum drop tower...like this https://www.zarm.uni-bremen.de/en/about-us.html and T is jumping from the chair at the top of the tower.

The whole set up is unnecessary, however, because some common sense and logic should tell you that if one observer is constantly accelerating and increasing in velocity and another observer is not, the relative velocity between them will change over time.  If the relative velocity between them changes over, then the time it takes the observers to meet over the same distance will also change over time. If the relative velocity never changes, they never meet.  That’s true whether we’re talking relativistic velocities and time dilation or not.

#### Clyde Frog

• 1045
• [kʰlaɪ̯d fɹɒg]
##### Re: Reasoning behind the Universal Accelerator
« Reply #28 on: December 17, 2021, 09:17:04 PM »
Obviously, I didn’t set up the paramters clearly enough.   T0 is the earth (or an observer on earth). “T” is the jumper.

If the relative velocity between them is 200000km/s (IOW, if the earth (and the observer) is accelerating up at 200000ms and the jumper is inertial with no velocity) and T0  records an elapsed time of 1s from the time T leaves the surface of the chair and meets the ground, T will record an elapsed time of 1.34s.
I'm not sure you know how to set up initial parameters at all based on this. The initial velocity between the jumper and the Earth should be 0 m/s, shouldn't it? After all, isn't the jumper at a fixed distance above the Earth, relative to the Earth, when they jump?

#### Pete Svarrior

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##### Re: Reasoning behind the Universal Accelerator
« Reply #29 on: December 17, 2021, 09:49:30 PM »
If the relative velocity between them is 200000km/s (IOW, if the earth (and the observer) is accelerating up at 200000ms and the jumper is inertial with no velocity)
OK, so, a few things here:
• ms is not a unit of acceleration, it's a unit of time
• The Earth isn't accelerating at 200,000 of any common unit, relative to any frame of reference. It's accelerating at 9.81m/s^2 relative to an observer that just started falling.
• Ignoring your lack of understanding of units, you also just said that velocity is "in other words" an acceleration. This is not the case, and RE'ers failing to distinguish between the two is a running joke around here.
• If the relative velocity between a jumper and the Earth is 200,000km/s, you've got a lot of explaining to do. How did they reach this scenario? Why did the jumper not disintegrate while smashing themselves into the atmolayer? Do you have even the faintest of ideas of the magnitude of 200,000km/s? Would it help if I pointed out that, in RE cosmology, your jumper would reach the moon in less than 2 seconds of zooming through space at 200,000km/s? That's quite the jump.

When, after meeting the ground,  T climbs back onto the chair, say 5 minutes later, the relative velocity between T0 and T has increased to 250000ms
No, it didn't, both because milliseconds are not a unit of velocity, and because a person standing on a chair on Earth is not moving relative to the Earth. If they were, they'd be phasing through the chair, or phasing through the Earth together with the chair. In other words, their velocity relative to the Earth is 0m/s.

You seem not to understand what motion is. That's pretty bad, even for a RE'er.

I also already explained why, even if the jumper was free-falling for those 5 minutes (the most generous scenario for you, and not the one you're arguing at all!), the delta-v would not approach 50,000 of any of the units you blindly tried to use thus far. If we assume km/s, the unit you actually showed in your screenshots, then the number you're looking for is 2.94, and not 50,000.

T isn’t falling so terminal velocity and drag isn’t relevant
That, too, is incorrect. Terminal velocity is the velocity at which which the forces of drag and gravity (imaginary as it may be) are in equilibrium. A free-falling body whose velocity exceeds its terminal velocity will decelerate, not accelerate, as time progresses. The act of "falling" is just motion, and motion is relative. If the Earth is moving upwards relative to the jumper, then the jumper is falling relative to the Earth. The two are inseparable, because they're one and the same. That, in a nutshell, is the cornerstone of relativity.

some common sense and logic
Considering the many posts you've made on previous accounts here in which you demonstrated not to understand anything about the world that surrounds you, you really are not in the position to talk about common sense.
« Last Edit: December 17, 2021, 10:06:16 PM by Pete Svarrior »
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#### Rog

• 69
##### Re: Reasoning behind the Universal Accelerator
« Reply #30 on: December 17, 2021, 09:56:28 PM »
Quote
I'm not sure you know how to set up initial parameters at all based on this. The initial velocity between the jumper and the Earth should be 0 m/s, shouldn't it? After all, isn't the jumper at a fixed distance above the Earth, relative to the Earth, when they jump?

While the jumper is on the chair, he would be accelerated at the same rate with the same velocity as the earth and the relative velocity would be zero.

But once he jumps, he is no longer being accelerated.  There is no force on him, no acceleration, no velocity. He's just hanging there inert. But the earth is still accelerating while he is hanging there, so the relative velocity between the jumper and the earth would be whatever the velocity the earth is moving relative to the jumper.

#### Iceman

• 1825
• where there's smoke there's wires
##### Re: Reasoning behind the Universal Accelerator
« Reply #31 on: December 17, 2021, 10:11:44 PM »
Quote
I'm not sure you know how to set up initial parameters at all based on this. The initial velocity between the jumper and the Earth should be 0 m/s, shouldn't it? After all, isn't the jumper at a fixed distance above the Earth, relative to the Earth, when they jump?

While the jumper is on the chair, he would be accelerated at the same rate with the same velocity as the earth and the relative velocity would be zero.

But once he jumps, he is no longer being accelerated.  There is no force on him, no acceleration, no velocity. He's just hanging there inert. But the earth is still accelerating while he is hanging there, so the relative velocity between the jumper and the earth would be whatever the velocity the earth is moving relative to the jumper.
You’re going to have to try again, but also a lot harder I think

#### Pete Svarrior

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##### Re: Reasoning behind the Universal Accelerator
« Reply #32 on: December 17, 2021, 10:13:12 PM »
But once he jumps, he is no longer being accelerated.  There is no force on him, no acceleration, no velocity.
Velocity relative to what? And, assuming it's not the Earth, how do you reconcile this magical disappearance of velocity with the law of conservation of momentum?

Also, what makes you think that a free-falling body is not subject to any forces or acceleration?
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#### Rog

• 69
##### Re: Reasoning behind the Universal Accelerator
« Reply #33 on: December 17, 2021, 11:00:47 PM »
Quote
ms is not a unit of acceleration, it's a unit of time
.  It’s also an expression of velocity.

Quote
Ignoring your lack of understanding of units, you also just said that velocity is "in other words" an acceleration. This is not the case, and RE'ers failing to distinguish between the two is a running joke around here.

I’m not equating acceleration and velocity.  A body that is accelerating, by definition, has velocity and is accelerating “with a velocity”.  Two different concepts that can and do exist at the same time.  They are accelerating and they have a velocity “ is accelerating up and has a velocity of  200000ms.”  Is that better?

Quote
If the relative velocity between a jumper and the Earth is 200,000km/s, you've got a lot of explaining to do. How did they reach this scenario? Why did the jumper not disintegrate while smashing themselves into the atmolayer? Do you have even the faintest of ideas of the magnitude of 200,000km/s?

Since this is a hypothetical on how it would work on a flat earth, I think those are questions that someone on the FE side needs to answer. Tom is the one who suggested jumping off a chair to test the concept of a universal accelerator.

Quote
No, it didn't, both because milliseconds are not a unit of velocity, and because a person standing on a chair on Earth is not moving relative to the Earth. If they were, they'd be phasing through the chair, or phasing through the Earth together with the chair. You seem not to understand even the very basics of motion.

I thought it was obvious I meant that the relative velocity had changed during the jump time, while the jumper is not on the chair. But I guess not, so let me clarify.  When T is no longer in contact with the chair, the relative velocity between T and T0 has increased from the previous jump, while T was also not on the chair, because T0 has accelerated and T0’s velocity has increased, whereas T’s velocity while he is not on the chair has not changed from the previous jump.

Quote
Velocity relative to what? And, assuming it's not the Earth, how do you reconcile this magical disappearance of velocity with the law of conservation of momentum?

The Jumper “T” has no velocity relative to the earth because T has no force to create velocity while he is in the air, at least not on a flat earth, in a vacuum drop chamber. Not sure what you are getting at with the conservation of momentum.  While in the air T has no momentum

Quote
Also, what makes you think that a free-falling body is not subject to any forces or acceleration?

A free falling body on RE isn’t subject to any force because it is following a geodesic through spacetime.  It will have coordinate acceleration, but no proper acceleration. What force (or any other reason) is there on a flat earth, without gravity and in a vacuum drop tower, that would cause a “free falling” body to accelerate and have velocity?

#### Pete Svarrior

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##### Re: Reasoning behind the Universal Accelerator
« Reply #34 on: December 18, 2021, 12:54:34 AM »
It’s also an expression of velocity.
No, it is not.

A body that is accelerating, by definition, has velocity
This is incorrect. It is perfectly possible for a body to have a velocity of 0m/s and to be accelerating at the same moment in time.

and is accelerating “with a velocity”.
That's not even wrong, it's just nonsensical. An acceleration leads to a change in velocity, but it is meaningless to be "accelerating 'with a velocity'".

“ is accelerating up and has a velocity of  200000ms.”  Is that better?
No, it isn't, because ms is still still not a unit of velocity, and none of the valid units you hinted at so far (km/s, m/s, mph) make any sense for a person that's falling down from a chair at 200,000 of that unit. Try, something like 10m/s instead of 200,000 and you might have a realistic scenario.

Since this is a hypothetical on how it would work on a flat earth, I think those are questions that someone on the FE side needs to answer.
Not at all. You presented a hypothetical scenario that's entirely impossible for a number of reasons. Those were explained to you. If your scenario came to pass, it would create more problems for RE than FE (though only by a small margin). But it can't come to pass, because it relies on discarding basic physics.

I thought it was obvious I meant that the relative velocity had changed during the jump time, while the jumper is not on the chair.
No, you made certain this was not the case when you specified that the change in velocity would take place over the course of five minutes. I defy you to find a chair it would take you five minutes to fall from.

To give you an idea, Joe Kittinger holds the current record for the longest free fall at around 4 minutes and 36 seconds when he jumped from 102,000 feet. That is one tall chair you're gonna have to find!

When T is no longer in contact with the chair, the relative velocity between T and T0 has increased from the previous jump
Increased? How? Relative to what?

because T0 has accelerated
Relative to what?

and T0’s velocity has increased
How? Why? How do you reconcile this with conservation of momentum?

whereas T’s velocity while he is not on the chair has not changed from the previous jump.
Relative to what?

The Jumper “T” has no velocity relative to the earth because T has no force to create velocity
You are once again mistaking velocity for acceleration. There is no direct link between force and velocity. The presence of a force would affect acceleration, which in turn is the rate of change of velocity.

Furthermore, you have yet to demonstrate that the jumper is affected by no forces. I already named a few for you.

While in the air T has no momentum
Momentum is a function of mass and velocity. As long as we agree that the jumper has a mass, we have to assume that you suggest the jumper has no velocity relative to the Earth. Since velocity is the rate of change of distance, and this rate is 0 by your allegation, the distance between the jumper and the Earth is not changing. In other words, you believe that someone who jumped off the chair will never fall to the surface - they will hover.

If you do not believe in falling, there really is no helping you.

A free falling body on RE isn’t subject to any force
This, of course, is also incorrect, but you already know that.
« Last Edit: December 18, 2021, 01:02:25 AM by Pete Svarrior »
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#### Clyde Frog

• 1045
• [kʰlaɪ̯d fɹɒg]
##### Re: Reasoning behind the Universal Accelerator
« Reply #35 on: December 18, 2021, 02:18:16 AM »
Quote
I'm not sure you know how to set up initial parameters at all based on this. The initial velocity between the jumper and the Earth should be 0 m/s, shouldn't it? After all, isn't the jumper at a fixed distance above the Earth, relative to the Earth, when they jump?

While the jumper is on the chair, he would be accelerated at the same rate with the same velocity as the earth and the relative velocity would be zero.

But once he jumps, he is no longer being accelerated.  There is no force on him, no acceleration, no velocity. He's just hanging there inert. But the earth is still accelerating while he is hanging there, so the relative velocity between the jumper and the earth would be whatever the velocity the earth is moving relative to the jumper.
This jumper isn't subject to momentum magically somehow? Let's think about this for a second. Let's pretend he's standing on a platform that's, oh, say 30 meters (-ish) above this disc that's accelerating ever upwards at 10m/s/s (-ish, again, for funsies, ok?). The disc has been accelerating for <who the fuck really cares it doesn't matter but let's have fun> 1 hour. The jumper does a trust fall from the platform he was standing on. Once he's in a "free fall" state, after 1 second has transpired, and ignoring air resistance, how fast do you figure that jumper sees the ground approaching him? In other words, what's the relative velocity between the disc and the jumper? Hint: It's not 200000ms.

Edit: Let's ignore the minuscule relativistic effects too, for the sake of ease. Unless you want to try and make the case that it matters somehow in this specific example, in which case I am waited with eager anticipation.

#### Rog

• 69
##### Re: Reasoning behind the Universal Accelerator
« Reply #36 on: December 18, 2021, 04:11:31 AM »
Quote
No, you made certain this was not the case when you specified that the change in velocity would take place over the course of five minutes. I defy you to find a chair it would take you five minutes to fall from.

Did you miss this? I’m talking about 2 separate jumps 5 minutes apart.

Quote
When, after meeting the ground,  T climbs back onto the chair 5 minutes later, the relative velocity between T0  and T has increased to 250000ms.  When T jumps again,  T0  will record 1s elapsed time from leaving the chair to meeting the ground and T will record 1.8s.

Quote
In other words, you believe that someone who jumped off the chair will never fall to the surface - they will hover.

No, that’s not what I believe but according to numerous statements in the wiki, that is what the FE position is. Or do I misunderstand that the FE position is that an object doesn’t “fall”, but that the earth comes up to meet it?  What does that object do during the time it takes for the earth to meet it (in a vacuum)?

The scenario I’ve described is conceptually the same as the bowling ball/feathers video that is in the wiki.  A part of the commentary of the video says “At the moment of release the feathers cease being accelerated upwards, are inert in space”. Synonyms for “inert” are “motionless”, “unmoving”, “stationary” (is this where I am supposed to ask “motionless”, “unmoving”, “stationary”  relative to what”?) I think “hover” would be an applicable synonym as well since it means to be motionless in the air.

So the questions are
1) when you perform the experiment the first time on a flat earth with UA, would a clock on the bowling ball and feathers show them meeting the ground in the same amount of time as a clock that is being accelerated on the ground?

According to time dilation, no.  A clock on the feathers/bowling ball is inert (motionless, unmoving, stationary, hovering). A clock that is being accelerated on the ground is moving at some velocity close to c relative to the feathers/bowling ball.  A moving clock measures time more slowly than an inert (motionless, unmoving, stationary, hovering) clock, so the accelerated clock will measure a different time.

One also has to wonder why the bowling ball and feathers didn’t disintegrate while smashing into the atmolayer.

2) Second question is if you perform the same experiment a second time, say 5 minutes later, would a clock on the bowling ball and feathers measure the same amount of time to meet the ground as it measured the first time?

Again, the answer is no because during the intervening 5 minutes, the accelerating flat earth has increased its velocity but the clock on the bowling ball and feathers is just as inert (motionless, unmoving, stationary and still hovering) for the second experiment as it was for the first.  That means the relative velocity between the earth and the bowling ball and feathers is different for the first and second experiment,  so the time it would take them to meet would also change. It should also be noted that the clock on the feathers/bowling ball still wouldn’t match a clock being accelerated on the ground for the second experiment either, and the difference between the clocks would be even greater than the first experiment since the relative velocity has increased.

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This, of course, is also incorrect, but you already know that.

Nope, its a basic principle of GR (and the equivalence principle) that free fall is inertial motion, not accelerated motion and therefore no force is involved.  An object in free fall is moving along a geodesic, so what we experience as gravity isn’t an effect of a force, but an effect of the curvature of spacetime.  I’m surprised you don’t  know that.

#### Rog

• 69
##### Re: Reasoning behind the Universal Accelerator
« Reply #37 on: December 18, 2021, 04:12:48 AM »
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This jumper isn't subject to momentum magically somehow? Let's think about this for a second. Let's pretend he's standing on a platform that's, oh, say 30 meters (-ish) above this disc that's accelerating ever upwards at 10m/s/s (-ish, again, for funsies, ok?). The disc has been accelerating for <who the fuck really cares it doesn't matter but let's have fun> 1 hour. The jumper does a trust fall from the platform he was standing on. Once he's in a "free fall" state, after 1 second has transpired, and ignoring air resistance, how fast do you figure that jumper sees the ground approaching him? In other words, what's the relative velocity between the disc and the jumper? Hint: It's not 200000ms

Clyde, refer to my response to Pete and see if that clarifies things for you.

#### Clyde Frog

• 1045
• [kʰlaɪ̯d fɹɒg]
##### Re: Reasoning behind the Universal Accelerator
« Reply #38 on: December 18, 2021, 02:19:06 PM »
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This jumper isn't subject to momentum magically somehow? Let's think about this for a second. Let's pretend he's standing on a platform that's, oh, say 30 meters (-ish) above this disc that's accelerating ever upwards at 10m/s/s (-ish, again, for funsies, ok?). The disc has been accelerating for <who the fuck really cares it doesn't matter but let's have fun> 1 hour. The jumper does a trust fall from the platform he was standing on. Once he's in a "free fall" state, after 1 second has transpired, and ignoring air resistance, how fast do you figure that jumper sees the ground approaching him? In other words, what's the relative velocity between the disc and the jumper? Hint: It's not 200000ms

Clyde, refer to my response to Pete and see if that clarifies things for you.
I checked, and in not part of your response to Pete did you answer the questions I asked.

#### Rog

• 69
##### Re: Reasoning behind the Universal Accelerator
« Reply #39 on: December 18, 2021, 04:07:24 PM »
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This jumper isn't subject to momentum magically somehow? Let's think about this for a second. Let's pretend he's standing on a platform that's, oh, say 30 meters (-ish) above this disc that's accelerating ever upwards at 10m/s/s (-ish, again, for funsies, ok?). The disc has been accelerating for <who the fuck really cares it doesn't matter but let's have fun> 1 hour. The jumper does a trust fall from the platform he was standing on. Once he's in a "free fall" state, after 1 second has transpired, and ignoring air resistance, how fast do you figure that jumper sees the ground approaching him? In other words, what's the relative velocity between the disc and the jumper? Hint: It's not 200000m

I didn’t answer your question because it has nothing to do with the concept that is being discussed.  How fast the jumper sees the ground approaching him is irrelevant.  We are talking about how clocks measure time and a clock measures time objectively

Doesn’t matter how fast the jumper sees the ground approaching,  Doesn’t matter if he is accelerating or decelerating or doing back flips or the hokey pokey.  A clock doesn’t care what the jumper is doing, what he sees or what he thinks.  None of that effects how a clock objectively measures the time it takes for the jumper to get from point A to point B. What is happening between points A and B is irrelevant.

What does matter is that if jumper’s clock objectivelymeasures one second to hit the ground, then a clock on the ground will objectively measure 1.3s to hit the ground.  And that’s all that matters.  When your are ready to discuss the implications of that, let me know.