Why matter can't reach the speed of light ?

[1977ub]

I would be the first to admit I am stalled for pre-relativistic intuitive reasons. My 'denial' is I don't know how to take a meaning leap, honestly stating that I see how the faster I run, the more the universe contracts in that direction (however slightly).

Only for you. Think about how you would measure the length of a bench you are running past, and then think about how you would do it if you were running.

 

[jtbell]

Time dilation and length contraction are two sides of the same coin - you can't have one without the other.

Better: they're two (out of three) sides of the same triangle, the third side being relativity of simultaneity.

 

[Mentz114]

I would be the first to admit I am stalled for pre-relativistic intuitive reasons. My 'denial' is I don't know how to take a meaning leap, honestly stating that I see how the faster I run, the more the universe contracts in that direction (however slightly).

If you do make the leap, it will free you from the search for 'mechanical' explanations. Most people are saying, put it down to relativity of simultaneity and be done.

 

[RealityQuest]

Better: they're two (out of three) sides of the same triangle, the third side being relativity of simultaneity.

And relativity of mass, right? There appear to be four. Relativity of length, duration, simultaneity, and mass.

I think I see where I was getting stuck. Relativity only describes two objects or rest-frames at a time. I was trying to show how a third rest-frame would contradict the conclusions reached among the other two, but (eureka!) that's why the theory is called "relativity." In my defense, I didn't realize I was doing that until I tried to come up with an experiment to affirm or contradict my sense. My feeling was that the ground frame should somehow tie the other two together.

While I think I'm getting closer to grasping the logic and math of relativity, I still find something unsatisfying about it. To attribute relativistic behavior to "rules" governing how the universe works suggest a very Matrix-like universe to me. Even worse, every person (every subatomic particle) seems to carry it's own Matrix. I want someone to explain WHY c is the maximum velocity, not just assert that it just appears to be the rule.

The limit of relativity to only describe two bodies at a time in isolation also seems like a weakness. To me, at the moment, it seems to lack a certain holism...

But I am still chewing on it.

 

[Naty1]

I want someone to explain WHY c is the maximum velocity, not just assert that it just appears to be the rule.

To derive that from first principles would be great. But when you request that answer, be sure to also ask why we have four different forces, why the mass and charge of the electron is what we observe [ditto for the other fundamental particles] and why our man made math sometimes even fits the universe.

Regarding getting stalled, nothing is more misleading that V[total] = V1 + V2. And that
V = at...assuming uniform acceleration...we all 'learn' those and follow the 'logic' until relativity...then comes quantum mechanics, which is crazier still!

 

[Mentz114]

And relativity of mass, right? There appear to be four. Relativity of length, duration, simultaneity, and mass.

I can't agree with that. Energy is relative but rest mass ( as in inertial) is an invariant.

I think I see where I was getting stuck. Relativity only describes two objects or rest-frames at a time. I was trying to show how a third rest-frame would contradict the conclusions reached among the other two, but (eureka!) that's why the theory is called "relativity." In my defense, I didn't realize I was doing that until I tried to come up with an experiment to affirm or contradict my sense. My feeling was that the ground frame should somehow tie the other two together.

...

The limit of relativity to only describe two bodies at a time in isolation also seems like a weakness. To me, at the moment, it seems to lack a certain holism...

I don't know why you think relativity only describes two objects at a time. It is true that relative velocity is a binary relation - but all pairs of objects have a relative velocity, and all inertial frames are equivalent.