41

Flat Earth Theory / Re: Reasoning behind the Universal Accelerator

« on: December 17, 2021, 12:19:53 AM »

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

42

Flat Earth Theory / Re: Reasoning behind the Universal Accelerator

« on: December 15, 2021, 11:10:08 PM »

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.

43

Flat Earth Theory / Re: Reasoning behind the Universal Accelerator

« on: December 15, 2021, 08:03:36 PM »

Here’s an experiment.  Jump from the same chair 5 minutes apart.  If the time it takes to meet the floor is not less on the second attempt, then the earth is not accelerating up and increasing in velocity.

Would you be so kind as to humor an old codger and show me the physics behind this statement.

 I was being a bit facetious.  I don’t think you could such an experiment from a chair, at least not without some unrealistically sensitive measuring equipment but it stands to reason.

Since we are talking relativistic velocities, a clock on a dropped object (which would be in an inertial reference frame) and a clock on the ground (presumably in an accelerating reference frame at close to c) would read differently.  Each would perceive the other as going slower (this is ignoring any gravitational time dilation that might happen) and the difference would increase as the velocity of the clock on the ground increases relative to the clock on the inertial object. 

Drop tower experiments are performed all over the world everyday.  You’d think somebody would’ve noticed that the time it takes to perform the same experiment is different at different times and/or depending on whose clock you are looking at.  Not to mention that a skydiver’s watch would read differently than an observer on the ground.  They’d have two different measurements for how long it took the skydiver to “fall”.

Dr. Edward Dowdye says that the medium of the Solar Corona bends light, not gravity. And the observations further away from the edge of the sun fails to match prediction.

I’m not sure why you’d reject the idea that light bends around the sun.  It bends in an upwardly accelerating elevator on earth, so according to the equivalence principle, why couldn’t it bend around the sun if the earth is accelerating upwards?

44

Flat Earth Theory / Re: Reasoning behind the Universal Accelerator

« on: December 15, 2021, 01:13:41 PM »

Experiment 1: Step up onto a chair and step off of its edge while watching the surface of the earth carefully. If you pay attention closely, you will observe that the earth accelerates upwards to meet your feet.

Here’s an experiment.  Jump from the same chair 5 minutes apart.  If the time it takes to meet the floor is not less on the second attempt, then the earth is not accelerating up and increasing in velocity.

The curvature has also been directly measured. 

http://www.thephysicsmill.com/2015/12/27/measuring-the-curvature-of-spacetime-with-the-geodetic-effect/

45

Flat Earth Theory / Re: Universal Zetetic Society - Scientific Accreditation?

« on: December 11, 2021, 08:16:07 PM »

That fascination probably stems from the fact that flat earthers use Rowbotham's Bedford Level Experiment as their "best evidence".

If your fascination stems from something you made up, and which finds no confirmation in reality, then your situation is even worse than what I describe.

Definitely work on your introspection.

I didn't make it up.  That is what is says in the FAQ in the wiki.

Perhaps the best example of Flat Earth proof is the Bedford Level Experiment. In short, this was an experiment performed many times on a six-mile stretch of water that proved the surface of the water to be flat. It did not conform to the curvature of the Earth that Round Earth proponents teach

https://wiki.tfes.org/Flat_Earth_-_Frequently_Asked_Questions

46

Flat Earth Theory / Re: Universal Zetetic Society - Scientific Accreditation?

« on: December 11, 2021, 06:49:23 PM »

The fascination with Rowbotham comes from Round Earthers who seem to think their best shot at discrediting empirical observation is not to debate the facts, but rather to attack a long-dead man of little modern significance.

That fascination probably stems from the fact that flat earthers use Rowbotham's Bedford Level Experiment as their "best evidence".   It would be analogous to flat earthers discrediting photos from space or Einstein.

47

Flat Earth Theory / Re: Gravitational Time Dilation on Flat Earth

« on: December 11, 2021, 06:43:40 PM »

According to this time should speed up as light moves towards the surface of the earth, not slow down. Your examples do not make any sense at all

Shortest distance between two points is straight.  The red line is going straight, the blue line is not.  Going the same speed as the red line, it would take the blue line longer to reach the edge, because it is not going straight.  If you couldn’t perceive the curve, it would appear that the blue line is going slower because it takes longer to go the same perceived distance.

The earth isn't moving towards the released photons or signals at the same rate at all times. Once the signal of the lower clock hits the detector at the bottom the earth is still moving at an increasing pace into the line of photons from the second higher clock

I get the concept of what you are trying to explain and you are actually right.  But you don’t understand the implications of what you are saying. So I’ll help you out.

This is the scenario that you are describing.


The first flash travels the distance L1 and the second flash travels the shorter distance L2. It is a shorter distance because the ship is accelerating and has a higher speed at the time of the second flash. So if the two flashes were emitted from clock A one second apart, they would arrive at clock B  at less than one second since the second flash doesn’t spend as much time on the way. The same thing will also happen for all the later flashes   From outside the rocket, it is clear that the distance between the clocks is getting shorter and shorter, but this is what you don’t understand….inside the rocket, the distance between the clocks remains the same.

An observer outside the rocket, who is not accelerating sees the distance the light travels decreasing.  An observer inside the rocket doesn’t. That is the sense in which acceleration warps space time.  Distance (and therefore time) is measured differently depending on if you are in accelerating frame or not.

A couple of other things worth noting.

Note that Rindler observers with smaller constant x coordinate are accelerating harder to keep up. This may seem surprising because in Newtonian physics, observers who maintain constant relative distance must share the same acceleration. But in relativistic physics, we see that the trailing endpoint of a rod which is accelerated by some external force (parallel to its symmetry axis) must accelerate a bit harder than the leading endpoint, or else it must ultimately break. 

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

IOW, the clock at the bottom and the clock at the top cannot be accelerating at the same rate. 

It’s also worth noting that the longer the acceleration continues, the distance the light has to travel would get shorter and shorter resulting in the difference between rates of the clock increasing.  The clock at the top would get faster and faster relative to the clock at the bottom.  But that is not what we see on earth.  The difference in the clock rates are static as long as the relative distance between them doesn’t change. The difference in the clock rates at different elevations don’t change over time on earth, so there is no constant acceleration with increasing velocity on earth.

48

Flat Earth Theory / Re: Gravitational Time Dilation on Flat Earth

« on: December 09, 2021, 11:54:11 PM »

If you and I, both atomic clocks, and the Burj Khalifa itself, are all accelerating upwards at the same constant rate of 9.8 m/s^2, I don't quite get why "the greater velocity the Earth will hit them," when the rate of acceleration is constant for all people/things involved. What is this "greater velocity"? Is there some sort of "UA Potential", that the further away you get from the upward accelerating earth time moves faster? Even if your not moving, not in freefall, just standing there way up high. And if so, why? Does the constant rate mentioned in the wiki actually change the higher up you go?

At least there is one person who gets what I am trying to say 

Bob is observing a  clock at the top of a skyscraper (or accelerating rocket) and Alice is observing one at the bottom  Both Bob and Alice agree that Alice’s clock is running slower.  According to flat earth theory, Bob,  Alice, both clocks, and the building (or rocket) are accelerating at the same rate with the same velocity, so there shouldn’t be any velocity related time dilation.

Even if there was, they wouldn’t agree that Alice’s clock is running slower because velocity time dilation is mutual.  Each observer sees the other’s clock running slower.

Contrarily to velocity time dilation, in which both observers measure the other as aging slower (a reciprocal effect), gravitational time dilation is not reciprocal. This means that with gravitational time dilation both observers agree that the clock nearer the center of the gravitational field is slower in rate, and they agree on the ratio of the difference.

https://en.wikipedia.org/wiki/Time_dilation#Reciprocity

49

Flat Earth Theory / Re: How do FE proponents explain flying over the south pole?

« on: December 09, 2021, 02:49:03 PM »

Like a frisbee, the Earth wobbles once a year

.

How does it wobble if the whole surface is being accelerated at the same rate all the time?

50

Flat Earth Theory / Re: Gravitational Time Dilation on Flat Earth

« on: December 09, 2021, 11:58:32 AM »

You are explaining what it does, not why it should do it. We could also imagine that time moves faster when there is greater gravitational potential, or a scenario where gravitational potential does not affect time. Why should it move slower with greater gravitational potential? Explaining what it does does not demonstrate why it should do so.

More warp=slower time because it takes longer to move through a more warped area than one less warped.   Its the same reason it takes longer to drive up a mountain on a curvy, winding road with a lot of switchbacks than it takes to just go straight up. 

The concept of time dilation due to velocity was derived in Newtonian space by another author before Special Relativity was invented. Einstein merely adopted time dilation due to velocity into his Relativity theory to be more inclusive. It doesn't actually say that spacetime is bending when bodies accelerate. This effect is not exclusive or unique to SR

Again, I am not talking about TD due to velocity.  I am asking about, time dilation due to a difference in gravitational potential. Two different things.
Gravitational time dilation is part of general relativity, not special relativity. And both phenomena can happen at the same time.  Clocks on GPS satellites have to account for both.  They run slower because they are in motion relative to clocks on earth, but part of that is made up for because their elevation.

Because an observer on the ground sees the satellites in motion relative to them, Special Relativity predicts that we should see their clocks ticking more slowly (see the Special Relativity lecture). Special Relativity predicts that the on-board atomic clocks on the satellites should fall behind clocks on the ground by about 7 microseconds per day because of the slower ticking rate due to the time dilation effect of their relative motion [2].
Further, the satellites are in orbits high above the Earth, where the curvature of spacetime due to the Earth's mass is less than it is at the Earth's surface. A prediction of General Relativity is that clocks closer to a massive object will seem to tick more slowly than those located further away (see the Black Holes lecture). As such, when viewed from the surface of the Earth, the clocks on the satellites appear to be ticking faster than identical clocks on the ground. A calculation using General Relativity predicts that the clocks in each GPS satellite should get ahead of ground-based clocks by 45 microseconds per day.
dThe combination of these two relativitic effects means that the clocks on-board each satellite should tick faster than identical clocks on the ground by about 38 microseconds per day (45-7=38)

http://www.astronomy.ohio-state.edu/~pogge/Ast162/Unit5/gps.html
So even assuming that your “accelerating into the photons” is correct, that doesn’t negate the fact that the spacetime inside of an upward accelerating object is warped. The worldline of an inertial object (which would include a beam of light) curves when it is in an accelerating frame of reference. That happens independent of anything related to time dilation due to velocity.

An inertial object, by definition moves in a straight line, at constant velocity and doesn’t deviate from that unless a force is applied.  Why would that inertial object’s path change from straight to curved when it is in an accelerating frame of reference?

EDIT:

An observer on the ground with photon clocks above his head at various elevations will see the clocks at increasing elevations above them run increasingly faster. As the photons are in the air the Earth is accelerating into the photons at increasing velocities, causing the perceived increase in clock rate for the higher clocks. The higher they are, the longer the photons will stay in the air, and the greater velocity the Earth will hit them at. This is why higher clocks run faster than lower clocks.

An observer at lower elevations isn’t accelerating into the photons that the clock is measuring. A photon clock at the top will count time at one rate and another rate at the bottom.  An observer will see the two clocks measuring different rates.  That’s the point.

51

Flat Earth Theory / Re: Gravitational Time Dilation on Flat Earth

« on: December 08, 2021, 08:51:16 PM »

I guess you don’t understand what is meant by spacetime warp.  If you agree that time moves differently at different elevations, you are conceding spacetime warp, whether you realize it or not.  Spacetime warp is about how the relationship between space and time changes.  If time changes due to elevation, then so does space because the two are inextricably linked. Space expands as time contracts and vice versa. If time changes, so does space.  The faster you go in space, the slower you go in time.  Everything moves at c in spacetime.  If velocity is increased in space, then velocity through time has to decrease.

In the diagram below, three objects are moving through space at different elevations.  If space time were flat, space and time would “line up” and you could connect the objects with the straight red lines.  Instead, connecting the objects with the green line shows how the relationship between space and time changes from the higher elevation and the lower.  That relationship is clearly warped. Space expands and time contracts at lower elevations and space contracts and time expands at higher elevations.  If that’s not the definition of warped, I don’t know what is. 


If time moves faster at the top of an accelerating rocket ship it is because the space inside the rocket is warped due to acceleration.  This goes back to the point I made before about the equivalence principle and what happens to the worldline of an inertial object when you accelerate the frame of reference.  It changes from straight to curved. I am sure you have seen or read about how light falls in an accelerating elevator.  If you shine a light across an elevator at rest, the beam will shine straight across.  When you accelerate the elevator upwards, the beam curves down. But there is no reason for it to curve down unless the space in the accelerating elevator is warped.  There is no force on it to change its path through spacetime, so it must be the spacetime itself that is warped. Same concept applies to an accelerating rocket. As it accelerates, the spacetime inside becomes warped, just like the spacetime in the elevator as it accelerates.

Really, and why should it cause time to slow down at lower altitudes rather than cause time to speed up at lower altitudes?

I told you why.  Lower altitude means more curvature.  More curvature means more space and more space means less time.



The speed of light is always constant, and the distance is fixed, so time equals distance divided by speed. Now consider light traveling from point C to point D but in a curved line. The speed is constant, but the distance is longer than before. This means that the numerator is bigger than the previous equation. With a bigger numerator, this means that the time it takes for the light to travel the exact same distance is longer. Therefore time has just been warped.
Here is another way of looking at it.  The lines are traveling at the same speed but the straight line is higher in elevation and not as effected by the warp.  Therefore, it travels farther in the same amount of time.

52

Flat Earth Theory / Re: Gravitational Time Dilation on Flat Earth

« on: December 08, 2021, 04:26:37 AM »

Time dilation is not actually caused by warped spacetime in the conventional model. This is a misconception. The explanation they use is that light travels at a set speed and it takes longer for a light ray to travel diagonally in a moving clock than when stationary.

I’m not talking about time dilation due to relative velocity (one moving clock and one stationary). I’m talking about Gravitational Time Dilation (two stationary clocks at different elevations)  Those are two different phenomena.

In physics and relativity, time dilation is the difference in the elapsed time as measured by two clocks. It is either due to a relative velocity between them (special relativistic "kinetic" time dilation) or to a difference in gravitational potential between their locations (general relativistic gravitational time dilation). 

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

“ Many of the important features of general relativity can be obtained via rather simple arguments that use the equivalence principle. The most famous of these is the thought experiment that leads to gravitational time dilation, illustrated in figure 1.1. Consider an accelerating frame. which is conventionally a rocket of height h, with a clock mounted on the roof that regularly disgorges photons towards the floor. If the rocket accelerates upwards at g, the floor acquires a speed v = gh / c in the time taken for a photon to travel from roof to floor. There will thus be a blueshift in the frequency of received photons, given by Δv / v = gh / c^2, and it is easy to see that the rate of reception of photons will increase by the same factor.

Now, since the rocket can be kept accelerating for as long as we like, and since photons cannot be stockpiled anywhere, the conclusion of an observer on the floor of the rocket is that in a real sense the clock on the roof is running fast. When the rocket stops accelerating, the clock on the roof will have gained a time Δt by comparison with an identical clock kept on the floor. Finally, the equivalence principle can be brought in to conclude that gravity must cause the same effect. Noting that ΔΦ = gh is the difference in potential between roof and floor, it is simple to generalize this to Δt / t = ΔΦ / c^2 ”

Note in the wikipedia quote that GTD is caused by a difference in gravitational potential (not relative motion or velocity), that is also the cause noted in your quote that I have bolded.    A clock at the top of rocket and at the bottom aren’t moving relative to one another.  They are effectively stationary.  Just like a clock on the top and bottom of a skyscraper are stationary. Even according to flat earth, they would be accelerating at the same rate with the same velocity. Why would two stationary clocks show different times?

It is an interesting quote, but it refutes the point you are making.  The only reason the Equivalence Principle is true  in the first place is because of warped spacetime.

In an unaccelerated frame of reference, without gravity, an inertial object’s worldline will be straight.  Put that inertial object in an accelerated frame of reference and its worldline curves. Just as if it were accelerated by gravity.  That is the reason you can’t tell the difference between a gravitational field and an accelerated frame of reference.

But it is still inertial, it is still going “straight” and there is no force or gravity to change its path. The only reason that its worldline would deviate from straight to curved is because it is moving through curved spacetime.

Why should this space bending mechanism cause photons to travel faster from higher altitudes rather than slower from higher altitudes or no difference at all? What physical reason is there other than to claim that it must be the case because that is what is experienced? One quickly finds a lack of answers.

It doesn’t cause photons to travel faster in space from higher altitudes.  It causes time to slow down in lower altitudes because the closer to the center of a mass, the more spacetime is warped. The more spacetime is warped, the farther light has to travel.

53

Flat Earth Theory / Gravitational Time Dilation on Flat Earth

« on: December 07, 2021, 04:06:00 AM »

From the Wiki I see that flat earth theory accepts gravitational time dilation.

Conventional wisdom is that it is caused by warped spacetime but I'm guessing that's not the flat earth explanation.

If not warped space time, then what is the cause of GTD on a flat earth?.