Is this Relativity Falsified?

[ronians1]

I'm having a little trouble following what you're trying to say. I sort of see the point you're making, but not well enough to address it well. Could you try rephrasing your point or giving a more detailed example of where you see the problem so I can fully understand the issue?

 

It seems to me that matters are not relative between frames of reference because time dialation can actually happen in one's own frame of reference (contrary to popular perception) hence slow motion in the case of the astronaught twin. How can the laws of physics be the same in all reference frames when velocity and time can change the dynamics of the laws of science in all timelines?

Edited August 13, 2012 by ronians1

[ACG52]

It seems to me that matters are not relative between frames of reference because time dialation can actually happen in one's own frame of reference (contrary to popular perception)

 

No it does not. In one's own frame, time is always measured at the same normal rate.

 

The Laws of Physics are the same in all reference frames, but you must always take the enironmental conditions, i.e. gravity, relative movement, into consideration when applying them. The laws being the same does not mean you will get the same result under all conditions.

[ronians1]

No it does not. In one's own frame, time is always measured at the same normal rate.

 

Take two caesium clocks, synchronise them and put one in the spacecraft travelling at the near speed of light and one at its base on Earth.

 

The clock on the spaceship will run slow. Running slow = slow motion (a second may still be a second on the spacecraft but that second will take longer to pass) At the near speed of light the astronaught would be running so slow that he would be virtually frozen in time. You can't deny the saga of the two clocks

 

The Laws of Physics are the same in all reference frames, but you must always take the enironmental conditions, i.e. gravity, relative movement, into consideration when applying them. The laws being the same does not mean you will get the same result under all conditions.

 

Gravity, relative movement......how many more exclusions is one going to incorporate? What is more important is does SP relativity predict the "reality" of the situation? If not why not?

[Greg H.]

Take two caesium clocks, synchronise them and put one in the spacecraft travelling at the near speed of light and one at its base on Earth.

 

The clock on the spaceship will run slow.

 

From the frame of reference of Earth, yes, the ship's clock will run slow.

From the frame of reference of someone on the ship, no, the ship's clock will run at normal speed, and the Earth based clock will run slow.

 

 

Frame of reference is everything.

[ACG52]

Gravity, relative movement......how many more exclusions is one going to incorporate

 

You don't really seem to know what the laws of physics are, or how they are applied.

 

Gravity, relative movement, acceleration, all are factors which the laws of physics deal with.

 

If your experiment is to see how fast objects fall in a vacuum, adding air will change the result. But the same laws of physics apply to both situations.

[ronians1]

You don't really seem to know what the laws of physics are, or how they are applied.

 

Gravity, relative movement, acceleration, all are factors which the laws of physics deal with.

 

If your experiment is to see how fast objects fall in a vacuum, adding air will change the result. But the same laws of physics apply to both situations.

 

A ball bounces more slowly on the spaceship than on Earth say.

 

There must be some equivalence factor to equate both measurements of the energy used if the laws of physics are the same in all reference frames.

 

No it does not. In one's own frame, time is always measured at the same normal rate

 

That's just the point...... in one's own frame of reference it isn't -just look at the clocks.

A second on the spaceship takes longer to pass = slow motion in one's own FOR.

Edited August 15, 2012 by ronians1

[swansont]

A ball bounces more slowly on the spaceship than on Earth say.

 

There must be some equivalence factor to equate both measurements of the energy used if the laws of physics are the same in all reference frames.

The laws are the same. If you measure the energy in a frame, it will be conserved, because that's what the law says. The law does not say the energy will be the same when measured in different frames.

[Greg H.]

A ball bounces more slowly on the spaceship than on Earth say.

 

From whose frame of reference? The ship or the Earth?

You have to get away from this idea that there is some universally absolute frame of reference. It doesn't exist.

 

That's just the point...... in one's own frame of reference it isn't -just look at the clocks. A second on the spaceship takes longer to pass = slow motion in one's own FOR.

That isn't the point. The point is that in your own frame of reference you will never notice a difference, no matter how fast you're accelerating moving. Only observers outside your frame of reference will see any difference at all.

 

Consider this example (hopefully it helps):

 

Two astronauts (Harry and Bob) are floating in an otherwise featureless void - no stars, no galaxies, no planets. They pass each other at 1/2 the speed of light, and measure that the other's space suit clock is running slow.

 

So which astronaut is accelerating moving? There's no way to tell*, and in fact, it doesn't matter. The laws of physics don't care which one of them is actually accelerating moving Harry will witness Bob's clock run slow, and Bob will witness just the opposite.

 

All that matters is your frame of reference. If you were perched on Bob's shoulders (and thereby shared his Frame of Reference), you would observe the exact same effects that Bob does - his clock runs normally, while Harry's appears to run slow.

 

(*In actual fact there probably is a way to tell - rocket exhaust, energy usage or some such, but for the purposes of the example, it doesn't matter).

Edit to fix some terminology problems on my end. Thanks guys.

Edited August 15, 2012 by Greg H.

[Delta1212]

Ah, ok. (Note: I don't have a strong enough handle on the math in relativity to give accurate numbers, so I'm going to basically make some up that roughly correspond to the general idea. If someone wants to go through and apply accurate math to the examples for better illustration, feel free to do so).

 

Let's say superman throws a ball so hard that it flies off at half the speed of light. Now let's say he's on a spaceship flying past you at half the speed of light. When he throws the ball, he sees it fly away at half the speed of light. However, since he's in a different reference frame than you, you see him moving in slow motion, let's say half speed. This means you see the ball moving away from him at only 25% the speed of light. Since it was already moving at half the speed of light, you see it moving at 75% the speed of light.

 

How can superman apply a specific amount of energy to the ball and have it change speeds by different amount in different reference frames? Doesn't this create an inconsistency that means the laws of physics work differently at different speeds? The answer is no, and here's why.

 

Objects don't have a linear relationship between the amount of energy applied to them and their change in speed. The faster an object is moving, the more energy it takes to accelerate it by the same amount. It might tale the same amount of energy to accelerate something to half the speed of light from rest as it does to accelerate it from half the speed of light to three quarters of the speed of light.

 

We're experiencing motion in such a narrow range of speeds that this isn't really noticeable. 100 mph is approximately 0.0000015% of the speed of light. The energy required to accelerate something from 0 to 100 mph would then accelerate something from 100 mph to 199.9999985 mph. To put that in prospective, if you traveled for 100 years at that speed, you'd have traveled to the sun and back and be less than a mile and a half behind where you'd be at 200 mph.

 

So from an Earthly perspective, twice the energy = twice the acceleration. That's not 100% accurate, but it only becomes noticeable at extremely high speeds.

[ronians1]

The laws are the same. If you measure the energy in a frame, it will be conserved, because that's what the law says. The law does not say the energy will be the same when measured in different frames.

 

I have been told that the law the "does" say energy will be the same when measured in different frames as it is a scalar invariant.

[Delta1212]

From whose frame of reference? The ship or the Earth?

You have to get away from this idea that there is some universally absolute frame of reference. It doesn't exist.

 

[/size]

That isn't the point. The point is that in your own frame of reference you will never notice a difference, no matter how fast you're accelerating. Only observers outside your frame of reference will see any difference at all.

 

Consider this example (hopefully it helps):

 

Two astronauts (Harry and Bob) are floating in an otherwise featureless void - no stars, no galaxies, no planets. They pass each other at 1/2 the speed of light, and measure that the other's space suit clock is running slow.

 

So which astronaut is accelerating? There's no way to tell*, and in fact, it doesn't matter. The laws of physics don't care which one of them is actually accelerating Harry will witness Bob's clock run slow, and Bob will witness just the opposite.

 

All that matters is your frame of reference. If you were perched on Bob's shoulders (and thereby sharing his acceleration Frame of Reference), you would observe the exact same effects that Bob does - his clock runs normally, while Harry's appears to run slow.

 

(*In actual fact there probably is a way to tell - rocket exhaust, energy usage or some such, but for the purposes of the example, it doesn't matter).

You mean speed/velocity/movement. Accelerated reference frames are different from inertial reference frames. It's impossible to tell who is moving and who is at rest, but it's fairly easy to tell who is accelerating.

[MigL]

I recognise the two astronaut example from Kip Thorne's book, But it is uniform, non-accelerated motion which is indistinguishable. Acceleration, as you describe, is always distinguishable.

Otherwise, good example.

[Greg H.]

You mean speed/velocity/movement. Accelerated reference frames are different from inertial reference frames. It's impossible to tell who is moving and who is at rest, but it's fairly easy to tell who is accelerating.

 

Yeah - I always manage to get them confused, even when I try not to.

 

I recognise the two astronaut example from Kip Thorne's book, But it is uniform, non-accelerated motion which is indistinguishable. Acceleration, as you describe, is always distinguishable.

Otherwise, good example.

 

Thanks for the correction(s) from both of you - one day maybe I'll remember which one I mean.

[Delta1212]

I have been told that the law the "does" say energy will be the same when measured in different frames as it is a scalar invariant.

Correct, as far as I'm aware. It's just important to note, as I explained above, that energy doesn't accelerate objects in a linear way. It accelerates objects as a fraction of the speed of light (which is why it would take infinite energy to accelerate a massive object to the speed of light, preventing anything from moving that fast).

 

When dealing with the incredibly small range of motion that we normally do, this difference is effectively imperceptible. It only becomes relevant at very high speeds.

[swansont]

I have been told that the law the "does" say energy will be the same when measured in different frames as it is a scalar invariant.

No, it is not, and you don't have to get into special relativity to see that. If I walk to my car at speed v, I have a certain KE with respect to the car's frame. But in my frame, the car (and everything else in it) is moving toward me at v but has much more mass. We don't have the same energy.

[Delta1212]

No, it is not, and you don't have to get into special relativity to see that. If I walk to my car at speed v, I have a certain KE with respect to the car's frame. But in my frame, the car (and everything else in it) is moving toward me at v but has much more mass. We don't have the same energy.

But when you bump into your car, will I measure the amount of force you apply to each other as being different if I am moving with respect to you than if I am not?

[ronians1]

As matters are getting a little convoluted I'd like to get back to basics if I may.

 

The scenario is thus:

 

The astronaught twin comes back to Earth many years younger than his twin on Earth. Intuition, something evolved over thousands of years by natural selection as opposed to a theory created by one man over a lifetime albeit successfully..... Intuition tells us, from an Earth frame of reference ( I call it reality) that this is impossible. Scientists tell us that this is possible by a scientific sleight of hand (special relativity). The layman is told that he just has to accept it.........well I am reluctant to accept it!

 

Common sense tell me that the only way the astronaught twin could have come back having aged less is by living in slow motion in space. I feel that this fact has been proved on this thread. It appears to me that science in general believe that the astronaught led a normal life whilst in space.

 

Who is correct? What are the implications on relativity theory if the astronaught did in actuality live in slow motion during his journey?

Edited August 15, 2012 by ronians1

[Greg H.]

As matters are getting a little convoluted I'd like to get back to basics if I may.

 

The scenario is thus:

 

The astronaught twin comes back to Earth many years younger than his twin on Earth. Intuition, something evolved over thousands of years by natural selection as opposed to a theory created by one man over a lifetime albeit successfully..... Intuition tells us, from an Earth frame of reference ( I call it reality) that this is impossible. Scientists tell us that this is possible by a scientific sleight of hand (special relativity). The layman is told that he just has to accept it.........well I am reluctant to accept it!

 

Common sense tell me that the only way the astronaught twin could have come back having aged less is by living in slow motion in space. I feel that this fact has been proved on this thread. It appears to me that science in general believe that the astronaught led a normal life whilst in space.

 

Who is correct? What are the implications on relativity theory if the astronaught did in actuality live in slow motion during his journey?

 

First, and foremost, common sense is a really bad judge of reality, especially those areas of reality that common sense has not evolved to handle (like near-relativistic speeds for example). Relying on common sense to explain reality in those instances is a terrible idea.

 

Second, no frame of reference has some unique reality to it. The Earth's frame of reference is no more or less valid than any other, and using it as some kind of absolute guide is simply incorrect.

Edited August 15, 2012 by Greg H.

[Janus]

But when you bump into your car, will I measure the amount of force you apply to each other as being different if I am moving with respect to you than if I am not?

 

 

While the force remains the same the results and energy change can be different.

 

consider this example:

 

You are in a car traveling at 20 m/s with respect to the road. You throw a 100 g ball at at the back of the car at 1m/s and have it bounce back to you. In the frame of the car, the ball leaves you at 1m/s and returns to you at 1m/s for no net change in kinetic energy.

 

Now consider things from the frame of the road. When the ball leaves your hand it is moving at 19 m/s and when it returns it is moving at 21 m/s. This results in a net energy difference of 40 joules.

[ACG52]

Intuition, something evolved over thousands of years by natural selection as opposed to a theory created by one man over a lifetime albeit successfully..... Intuition tells us, from an Earth frame of reference ( I call it reality) that this is impossible.

 

As you've been told before, intuition has been formed in a low-energy, slow moving universe, and does not apply to any other evironment.

 

You're not falsifying Relativity, you're just denying it because you don't understand it.

[zapatos]

...well I am reluctant to accept it!

Then by all means don't!

 

But if you think your personal incredulity is going to sway those who have studied the evidence and understood the math, you are wasting your time. On the other hand, if at some point you do wish to understand it, you can start by trying to understand how what people are telling you can be true, rather than by assuming it must be false and looking for problems.

 

Once you really understand the theory and its implications, it will be much easier for you to take pot shots at it if you are still so inclined.

[ronians1]

Believe it or not I've come across scientists who actually believe that time dialation does not happen in one's own frame of reference - something that only happens in frames of reference other than one's own. There are others who are convinced that everything must always be normal in one's own frame of reference and that the astronaught twin actually lived an existence at a normal rate during his journey at the near speed of light when clearly he didn't. Then there are the ones who do not accept the fact that when travelling at the near speed of light, a second may still be a second but it takes longer to pass. The fact that one could be moving in slow motion on Earth (albeit minimally) has been questioned. There has been argument over whether Engery is scalar invariant and so on.......

 

Whilst such disparity of perception exists and added to the fact that General Relativity cannot be reconciled with Quantum Theory so that science is incomplere, how can one blame anybody for being slightly sceptical when some scientific postulates seem beyond the realms of reality? I know the problem of reconciliation lies with General Relativity and not SP Relativity, but surely there is a relationship and in life it is often through the smallest inconsistancy in a remote corner of a discipline that greater problems are solved.

 

Why aren't scientists obsessivley scouring the depths of science theory in search for that elusive Holy Grail that is the reconciliation of GR and QM, something that has eluded science for more than forty years and something that might be picked up through a slightest inconsistancy in a remote place? Surely the rewards would be great?

Edited August 16, 2012 by ronians1

[imatfaal]

Believe it or not I've come across scientists who actually believe that time dialation does not happen in one's own frame of reference - something that only happens in frames of reference other than one's own.

Time is not dilated within the rest frame - you do only notice time being kinematically dilated in frames in relative motion to your own rest frame

 

There are others who are convinced that everything must always be normal in one's own frame of reference and that the astronaught twin actually lived an existence at a normal rate during his journey at the near speed of light when clearly he didn't.

{Ignoring the "when clearly he didn't"} No - these are the same people. These two sentences do not represent opposite views.

 

Then there are the ones who do not accept the fact that when travelling at the near speed of light, a second may still be a second but it takes longer to pass.

FRAMES! You need to specify frames of reference. A second always takes the same time to pass (clunky phrasing) when viewed within one single frame.

 

The fact that one could be moving in slow motion on Earth (albeit minimally) has been questioned. There has been argument over whether Engery is scalar invariant and so on.......

No scientist would claim that people live in slow motion

 

Whilst such disparity of perception exists and added to the fact that General Relativity cannot be reconciled with Quantum Theory so that science is incomplere, how can one blame anybody for being slightly sceptical when some scientific postulates seem beyond the realms of reality?

You are being blamed because your approach is a misunderstanding and misrepresentation of Special Relativity. Really learned people (and I do not include myself in that group) have been patiently explaining where you are wrong and you are just ignoring them and restating your original incorrect ideas.

 

I know the problem of reconciliation lies with General Relativity and not SP Relativity, but surely there is a relationship and in life it is often through the smallest inconsistancy in a remote corner of a discipline that greater problems are solved.

The first thing you must do in order to be in a position to criticise an idea is to understand it - you do not understand special relativity. Please take a few hours to work though wikipedia introduction - or hyperphysics - or the physics usenet faq; you will find it an immensely rewarding experience and your incredulity and confusion will disappear (only to be be replace by deeper problems when you start GR)

 

Why aren't scientists obsessivley scouring the depths of science theory in search for that elusive Holy Grail that is the reconciliation of GR and QM, something that has eluded science for more than forty years and something that might be picked up through a slightest inconsistancy in a remote place?

They are! But the problem does not lie in an inconsistency in Special Relativity. SR is mathematically self-consistent and we would require firm experimental evidence to start doubting it - it is not possible to disprove SR with thought-experiments.

 

Surely the rewards would be great?

Yep - a first class trip to Sweden, a big cheque, permanent bragging rights, and somewhere to park the car

[ronians1]

Time is not dilated within the rest frame - you do only notice time being kinematically dilated in frames in relative motion to your own rest frame

 

{Ignoring the "when clearly he didn't"} No - these are the same people. These two sentences do not represent opposite views.

 

FRAMES! You need to specify frames of reference. A second always takes the same time to pass (clunky phrasing) when viewed within one single frame.

 

No scientist would claim that people live in slow motion

 

You are being blamed because your approach is a misunderstanding and misrepresentation of Special Relativity. Really learned people (and I do not include myself in that group) have been patiently explaining where you are wrong and you are just ignoring them and restating your original incorrect ideas.

 

The first thing you must do in order to be in a position to criticise an idea is to understand it - you do not understand special relativity. Please take a few hours to work though wikipedia introduction - or hyperphysics - or the physics usenet faq; you will find it an immensely rewarding experience and your incredulity and confusion will disappear (only to be be replace by deeper problems when you start GR)

 

They are! But the problem does not lie in an inconsistency in Special Relativity. SR is mathematically self-consistent and we would require firm experimental evidence to start doubting it - it is not possible to disprove SR with thought-experiments.

 

Yep - a first class trip to Sweden, a big cheque, permanent bragging rights, and somewhere to park the car

 

[swansont]

Believe it or not I've come across scientists who actually believe that time dialation does not happen in one's own frame of reference - something that only happens in frames of reference other than one's own. There are others who are convinced that everything must always be normal in one's own frame of reference and that the astronaught twin actually lived an existence at a normal rate during his journey at the near speed of light when clearly he didn't. Then there are the ones who do not accept the fact that when travelling at the near speed of light, a second may still be a second but it takes longer to pass. The fact that one could be moving in slow motion on Earth (albeit minimally) has been questioned. There has been argument over whether Engery is scalar invariant and so on.......

Rubbish.

 

Moving in slow motion has been questioned … by you. That does not make it a legitimate point of contention. Similarly, "There has been argument over whether Engery is scalar invariant" is something mistakenly raised by you as well, and I gave a counterexample showing it to be false. This is science, not journalism. The mere existence of an objection does not balance the scales.

 

Whilst such disparity of perception exists and added to the fact that General Relativity cannot be reconciled with Quantum Theory so that science is incomplere, how can one blame anybody for being slightly sceptical when some scientific postulates seem beyond the realms of reality? I know the problem of reconciliation lies with General Relativity and not SP Relativity, but surely there is a relationship and in life it is often through the smallest inconsistancy in a remote corner of a discipline that greater problems are solved.

 

Why aren't scientists obsessivley scouring the depths of science theory in search for that elusive Holy Grail that is the reconciliation of GR and QM, something that has eluded science for more than forty years and something that might be picked up through a slightest inconsistancy in a remote place? Surely the rewards would be great?

Simple — they are. But science is a big place and not everyone is crowded in that particular corner.