Einstein's Thought Experiment

[Dubbelosix]

I find it remarkable that Einstein surmised that as he travelled away on his bus from the clock tower, that if the bus travelled at the speed of light, the clock would essentially stop, thus making him come to the realization that time was relative. Has anyone ever heard arguments for automobiles at the lightspeed moving towards the source, can they not measure still the passage of time, because you are not leaving the light source at speed of light, you are approaching a light signal at the speed of light. I assume though you cannot measure the time, because the thought experiment seems to have a flaw, because anything moving at light speed will no longer have a frame of reference, nor can such a system be made of matter. 

[Moronium]

By hypothesis, for an object moving at the speed of light, it's mass is infinite, all distances shrink to nothing, and time stops.

 

So you could travel the entire length of the universe, and back, an infinite number of times, in "nothing flat," which is quite a trick for something with infinite mass.

 

Given that, time just stops, so, no, you couldn't measure the time, because there would be none to measure.

 

That's the theory.  Does it make sense, as a matter of supposed fact?  Not to me, it doesn't.

Edited July 3, 2018 by Moronium

[Moronium]

To put the theory more in terms of Einstein's thought experiment, you might look at it this way:

 

No matter how far away from a given clock you might be, you would arrive at, and then pass it, before it ever had a chance to make a single tick.

[sluggo]

He was a genius no doubt and I DO NOT deny the supremacy and experimental evidence that supports time dilation and length dilation (I don't like the use of the words ''length contraction'' as this is not really the case.)

Dilation means lengthening, so that contradicts the idea of getting shorter. The distance increases the same as for the light clock, but that decreases the field strength for em interactions, allowing particles to get closer during acceleration, i.e. length contraction.

Experiments with electrons at the SLAC accelerator can measure the contraction indirectly from increased electric field strength as the particles become elliptical at high speeds.

[Moronium]

Well it makes sense to me. 

 

Why is the speed of light finite, then?

[OceanBreeze]

By hypothesis, for an object moving at the speed of light, it's mass is infinite, all distances shrink to nothing, and time stops.

 

So you could travel the entire length of the universe, and back, an infinite number of times, in "nothing flat," which is quite a trick for something with infinite mass.

 

Given that, time just stops, so, no, you couldn't measure the time, because there would be none to measure.

 

That's the theory.  Does it make sense, as a matter of supposed fact?  Not to me, it doesn't.

 

 

It doesn't make sense because no object with mass can travel at light-speed.

[OceanBreeze]

Why is the speed of light finite, then?

 

Nobody knows.

[Moronium]

Nobody knows.

Well, Popeye, I was asking him in the context of the thread.

 

If an object travelling the speed of light could travel an infinite distance in zero time, then I would conclude that it's speed would be infinite, not finite.

[Moronium]

Light having a finite velocity is true from our frame or reference. If relativity is right, then no time passes at all, you could traverse the whole universe and not a second will go by. But to have an inertial frame of reference, you require a system has some mass. This is why it is said it is better to say a photon has no frame of reference - this isn't an ad hoc suggestion, since the speed of light does reveal a maximum velocity at which radiation moves. But since light travels from the sun and back our case must be because we are measuring this from an inertial reference frame. Since the photons frame does not exist, that leaves our frame our reference.

 

Saying a photon has no frame of reference explains nothing.  Nothing has a frame of reference--that is a thing that's in our heads, not "out there."

 

You seem to be implying that a photon has no mass.  But, as I understand it, a photon only said to have no rest mass.  But a photon aint at rest, so.....

Photons are traditionally said to be massless.  This is a figure of speech...When the particle is at rest, its relativistic mass has a minimum value called the "rest mass." ...As the particle is accelerated to ever higher speeds, its relativistic mass increases without limit.

 

In special relativity, we are able to define the concept of "energy" E, such that E has simple and well-defined properties just like those it has in newtonian mechanics.

 

Alternative theories of the photon include a term that behaves like a mass, and this gives rise to the very advanced idea of a "massive photon"....It is almost certainly impossible to do any experiment that would establish the photon rest mass to be exactly zero.

 

 

http://math.ucr.edu/home/baez/physics/ParticleAndNuclear/photon_mass.html

 

Light has energy, and energy is mass.

Edited July 3, 2018 by Moronium

[Moronium]

The speed of light always moves at the speed of light, no matter what inertial frame you are in. This is an experimental fact. 

 

Fact, eh?  Heh.  If you think that's a fact, why don't you respond to the last substantive post I made in the "faster than light" thread, eh?

 

The link to the quote is right below it.

Edited July 3, 2018 by Moronium

[Shustaire]

Guess that's why its called a Null geodesic ie ds^2=0 which does not have a proper time associated with it. Hence its not a valid inertial frame.

[Shustaire]

Yes, these are the technicalities for the photon. They follow null geodesics. All very boring... want to know something exciting? Einstein found out when you replace particles with varying singularities, it removed the notion of geodesics? Get your head round that because I never could. 

 

Citation please.

[Shustaire]

Please do as it sounds like a misunderstanding

[Shustaire]

Why do you automatically assume your integrity is being questioned when one is questioning your understanding or interpretation ?

[Shustaire]

Well for one thing I don't see how you believe the ER/EPR means that particles are removed specifically when that link refers to entangled particles.

Edited July 4, 2018 by Shustaire

[Moronium]

Oh yes it is a fact, we have done measurements proving this. There is no deviation to the speed of light no matter what speed you are moving at.

 

 

People didn't just accept these things for no reason.

 

 

I had asked you to respond to my post #449 from the other thread in response to this issue, rather than just keep repeating yourself without ever looking at the issue in any detail.   Is that too much for you?

 

http://www.scienceforums.com/topic/32241-yes-you-can-go-faster-than-speed-of-light/page-27

Edited July 4, 2018 by Moronium