Asklemmy

https://youtu.be/6g2bHqV01es

EDIT: It's in Polish, but it's still a good video.

Next, I suppose you'll want to know about the speed of dark 🤨

Go find a 30' stick and let us know if you can point it at the moon.

This is actually a great example for why that stick must not exist.

You can also do this with a unbreakable stick and an unbreakable shorter tube. Throw the stick at a high velocity through the tube and it contracts for the point of view of the tube. Then close it shut. Now you have a stick that's longer than the tube fully contained in it.

If you're openminded enough to listen to those who disagree with the standard model,
take an elastic band and turn one end. Instead of the band turning, you'll have a twist in your band
and it takes time to unravel the twist if you let go on the other end.
That's what will happen to the stick and this travels at lightspeed,
because this is how light works. Light works like 'the stick' in your example.
And if you try turning it faster the 'elastic band'/stick/'atom on the other end' starts breaking.

If you need FTL communication, then use gravity..somehow.

why wouldn't this work

because bullets are faster than whatever the fuck speed stickman is achieving
and even bullets are slower than light

always had this question as a kid

And then went, draw it out, and asked.
I applaud that (and the art), good for you.

(And the good people already provided answers.)

That's what he meant by we'll use sticks on the other side

The problem lies in what "unstretchable" and "unbendable" means. Its always molecules and your push takes time to reach the other end. You think its instantaneous because you never held such a long stick. The push signal is slower than the light

This wouldn't work because the moon is more than 300k km away :P

Perhaps also worth pointing out that the speed of light is that exact speed, because light itself hits a speed limit.

As far as we know, light has no mass, so if it is accelerated in any way, it should immediately have infinite acceleration and therefore infinite speed (this is simplifying too much by using a classical physics formula, but basically it's like this: a = f/m = f/0 = ∞). And well, light doesn't go at infinite speed, presumably because it hits that speed limit, which is somehow inherent to the universe.

That speed limit is referred to as the "speed of causality" and we assume it to apply to everything. That's also why other massless things happen to travel at the speed of causality/light, too, like for example gravitational waves. Well, and it would definitely also apply to that pole.

Here's a video of someone going into much more depth on this: https://www.pbs.org/video/pbs-space-time-speed-light-not-about-light/