Recent content by Ookke

And I didn't mean it that way. It's always about limits of applicability too, but overthrowing SR altogether is not reasonable to even try. CMB frame is interesting, though.

This is nice. Not exactly what I thought, but there is some concentration of stars and the rear view gets empty. At least we can rule out the possibility that Earth is moving very fast relative to the stars we see? CMB frame that was brought up sounds like preferred frame to me, at least for...

Please see the picture. Red dots are stars, lines are the path that light takes, our observer is at center. Assuming that stars are somewhat uniformly spread around us, I suppose that stationary observer (left picture) sees about as many stars in every direction, but an observer moving in...

Ok, nice. But if no single boost causes any rotation, why would two boosts in a row do that? It's like space remembers that we already had boost in one direction, and when we have another, this mysterious Thomas rotation takes place. Maybe I'm thinking this rotation too literally. Assuming that...

It seems that combining two Lorentz boosts cause rotation: https://en.wikipedia.org/wiki/Lorentz_transformation#Composition_of_two_boosts Do you think this rotation is something that could be measured by gyroscope? Or is it like space rotates around the accelerating observer, and the observer...

Ok, let's try. Hopefully I understand your advice correctly. So the worldlines in #20 are the following, and we need to use t' instead of t. (It's the setup of #20 I'm considering from now on, and we can forget the original #1 setup.) (t',x',y') = (10t,10vt,0.5) (t',x',y') = (10t,10vt,-0.5)...

If that is not ok, I don't know what to do. Actually the two rails system of #20 (forgetting the observer, the black dot) doesn't have any length in ##x##-direction, so that dimension shouldn't have effect on relativity of simultaneity, but maybe the equations are still wrong. I suppose that...

I suppose post #20 gives some idea of solving this question too. If runners have the same proper length, slightly uphill going runner is length contracted and much shorter than the runner that is moving horizontally.

Here is a simpler version demonstrating the same problem, or maybe there is no problem, just that the direction of length contraction is not as straightforward as someone (at least I) might expect. The upper picture is in black rail's rest frame. Black rail's proper length is 1. The red rail is...

Here is some effort on the mathematical approach. Luckily I got some practice in this forum last autumn, here is the link if someone wants to take a look: https://www.physicsforums.com/threads/an-apparent-paradox-with-couple-of-frames.774710/ Looking at #1 left picture, let's fix the origin at...

"I understood it until it was explained to me" :smile: Maybe I didn't explain it very well, but the key ideas I had in mind in #1 right picture - vertical rail, as a whole, is moving to right, in the rest frame of horizontal rail - vertical rail is strictly vertical i.e. perpendicular to...

I agree. Now the funny part is that the vertical rail must be length contracted in y-direction by factor 10, although the y-velocity is only 0.1c. If it had its proper length, even approximately, this combined with well below c speed would result that the markings in horizontal and vertical rail...

Both x- and y-velocity cannot be close to c, as you already suggested in #7, because the diagonal speed would exceed c. I don't know how to solve this thought experiment, but it's interesting.

It can be a bit misleading, but the arrows in the first picture are intended to show that the vertical rail, as a whole, is moving to right, and the vertical rail also has some velocity in y-direction. To be more accurate, the red arrow in the first picture would be strictly horizontal, as the...

Here is a picture about the value 0.1c. I don't draw all the arrows, because it would be messy, but the motion is the same as in previous picture. Upper picture is in crossing's (red point) rest frame. Blue point is a clock that is stationary and synchronized with the crossing, the distance...