Einstein untested? (split from A maximum speed in Newtonian Physics)

[Charles 3781]

1 hour ago, geordief said:

Are there other scenarios in Newtonian physics where a separation velocity  is calculated to be able to increase without a limit?

Newton didn't set a limit to velocity, as you know.   It was Einstein who claimed there is a  limit to velocity, which is  - the velocity of "light" in empty space.

Einstein's claim doesn't seem to have been verified by any practical experiments.  Such as firing a 10, 000 stage rocket into space, then seeing whether the final stage eventually goes faster than light. These experiments have not been attempted because the theory claims they can't work.

Doesn't it remind you of similar claims made in the past, about the impossibility of heavier-than-air flying machines?  Theory said they couldn't work.  But they do.

 

[OldChemE]

52 minutes ago, Charles 3781 said:

Newton didn't set a limit to velocity, as you know.   It was Einstein who claimed there is a  limit to velocity, which is  - the velocity of "light" in empty space.

Einstein's claim doesn't seem to have been verified by any practical experiments.  Such as firing a 10, 000 stage rocket into space, then seeing whether the final stage eventually goes faster than light. These experiments have not been attempted because the theory claims they can't work.

Doesn't it remind you of similar claims made in the past, about the impossibility of heavier-than-air flying machines?  Theory said they couldn't work.  But they do.

 

There is a difference. The arguments about heavier than air flying machines, like may similar arguments, were arguments based on ignorance of the science.   The theory with regard to light speed has implications that have been tested and found to be correct, even though nobody has propelled a rocket to light speed.  Einstein's predictions have been tested in so many ways and found to be correct to such an extent that the preponderance of evidence suggests he was right.

[Janus]

57 minutes ago, Charles 3781 said:

Newton didn't set a limit to velocity, as you know.   It was Einstein who claimed there is a  limit to velocity, which is  - the velocity of "light" in empty space.

Einstein's claim doesn't seem to have been verified by any practical experiments.  Such as firing a 10, 000 stage rocket into space, then seeing whether the final stage eventually goes faster than light. These experiments have not been attempted because the theory claims they can't work.

Doesn't it remind you of similar claims made in the past, about the impossibility of heavier-than-air flying machines?  Theory said they couldn't work.  But they do.

 

Or maybe it has something to do with the fact that even without taking relativity into account, even if we had rocket engines 100 time more efficient than the most efficient one presently available,  such a rocket would have to mass over 19 times the mass of the Earth, just to get a 1 kg payload up to the speed of light.

However, we do have countless practical observations and experiments that do give results that lend support to Einstein's Theory.  This is why it is accepted, for the very reason that it has passed every test thrown at it.   It would have never gained the level of acceptance it has without such experimental evidence.  And science continues to throw tests at it.

[Halc]

1 hour ago, Charles 3781 said:

Einstein's claim doesn't seem to have been verified by any practical experiments.

Accelerating an electron to nearly light speed is regularly done in particle accelerators, which then go on to add momentum to said electron perhaps another thousand-fold, and the electron still doesn't go faster than c.  I think that is a practical example of verification that's been done.

 

5 hours ago, geordief said:

Say we have 2  bodies ,mass=M composed of a set of smaller bodies ,mass=m set in a vacuum, what might be the maximum speed of separation  from the respective centres of gravity.?

I cannot parse what you have in mind with the M and the little m's. A rock is composed of a bunch of molecules, which is a set of smaller masses making up a larger mass. That fact seems totally irrelevant to the limit the separation rate of a pair of rocks.

GR limits separation speed locally to c, but non-locally, this is not the case. Hence there are distant galaxies increasing their proper distance from us at a rate greater than c. No object can have a peculiar velocity greater than c.  Peculiar velocity is local in a sense: it is its velocity relative to the center of mass of all matter within some radius (typically the size of the visible universe, or possibly the Hubble radius) centered at the location of the object.

Edited September 20, 2020 by Halc

[Markus Hanke]

11 hours ago, Charles 3781 said:

Einstein's claim doesn't seem to have been verified by any practical experiments.

You can’t possibly be serious...? Lorentz invariance is one of the most thoroughly tested phenomena in the history of science, it is difficult to even estimate how many experiments have been done to test (and confirm) it over the past 100 years, but it’s certainly many thousands. You might want to take a look at this, just for starters, and remember that it continues to be tested and confirm directly in every particle accelerator run we do.

[swansont]

17 hours ago, Charles 3781 said:

Newton didn't set a limit to velocity, as you know.   It was Einstein who claimed there is a  limit to velocity, which is  - the velocity of "light" in empty space.

Einstein's claim doesn't seem to have been verified by any practical experiments.  Such as firing a 10, 000 stage rocket into space, then seeing whether the final stage eventually goes faster than light. These experiments have not been attempted because the theory claims they can't work.

Not attempted because we can't get stuff that massive to move that fast.

But we've done the equivalent in particle accelerators, as Halc has said. if you get a proton up to 1 TeV, it should be moving about 45x the speed of light according to Newtonian physics. 

The easiest effect to measure is on time, and we have done multiple tests that confirm relativity, the most obvious of which is GPS. That you are ignorant of the experiments and technologies that confirm it carries no weight in any discussion.

 

Quote

Doesn't it remind you of similar claims made in the past, about the impossibility of heavier-than-air flying machines?  Theory said they couldn't work.  But they do.

This is criminally naive.

!

Moderator Note

Split from original thread, which was asking about Newtonian physics.

Hijacking, and also an argument not made in good faith. Please stop doing that.