Linked Questions

2
votes
0answers
53 views

Superluminal Thought Experiment [duplicate]

If I had a weightless, indestructible rod that was 1,145,915,590 meters long and I moved it 15° would the end of the rod go faster than the speed of light? (Assuming it's path is unobstructed.) ...
0
votes
0answers
39 views

Speed of light vs Tug of war [duplicate]

Suppose there's a "theoretical rope" that's 299 792 459 meters long in empty space. The speed of light is 299 792 458 m/s. Is it possible that if the rope is "tugged" on one end, ...
2
votes
0answers
33 views

What will happen if a stick and a beam of light is to race [duplicate]

I don't know whether the question is asked before on not on this website as I can't found it anywhere so I have to ask. What will happen if a place a long stick with a length of a light year. Rather ...
0
votes
0answers
29 views

Is it possible to rotate a very very long (almost infinite) and rigid pole such that its end reach the speed of light? [duplicate]

$v=\omega r$ relation shows that even with a fixed $\omega$ and large $r$, the end of the pole can be rotated at a high speed. So if I make pole sufficiently long such that $v=c$, will it be possible ...
0
votes
0answers
17 views

What is the speed of transferring of energy in an inelastic solid? [duplicate]

Assuming that there is an inelastic, very low mass, very long, solid rod which is 150 million km long. This distance requires approximately 8.333 minutes for light to travel. If I apply a force at one ...
25
votes
4answers
5k views

What are some scenarios where FTL information transfer would violate causality?

I've always heard people saying, "Faster than light information transfer can't happen because it would violate causality! Effects can precede their causes!" However, I'm trying to think of a ...
20
votes
4answers
8k views

Do all massless particles (e.g. photon, graviton, gluon) necessarily have the same speed $c$?

I suppose there was a discussion already on speed-of-gravity-and-speed-of-light. But I silly wonder whether all the massless mediators of four fundamental forces, i.e. Graviton: $g_{\mu\nu}$ (...
9
votes
6answers
6k views

How long must escape velocity be maintained?

Escape velocity from Earth's surface is 11.2 Kilometres/second. How long would one need to maintain this escape velocity to actually escape Earth's gravitational pull? Must this 11.2 km/s velocity ...
14
votes
2answers
17k views

Does magnetic propagation follow the speed of light?

Does magnetic propagation follow the speed of light? E.g. if you had some magnet of incredible strength and attached an iron wire that is one light year long to it, would the other end of the iron ...
8
votes
3answers
3k views

Extended Rigid Bodies in Special Relativity

I was reading Landau & Lifshitz's Classical Theory of Fields and I noticed that they mention that an extended rigid body isn't "relativistically correct". For example, if you consider a rigid ...
9
votes
2answers
3k views

How quickly is motion transferred in a solid object?

Just for example: assume an iron bar one foot in length. If you push on one end, the entire bar will move. This seems instantaneous. but actually, from my understanding, the atoms all push against ...
3
votes
3answers
321 views

The speed of light also applies for 'distance' materials?

The question is hard for me to put into one sentence so please try to completely read the example: If I had a stick that is 1000KM long and I would push it forward with 1 millimeter in lets say... ...
2
votes
2answers
755 views

Dipping a Dyson Ring below the event horizon [duplicate]

The basic assumption about inescapability beyond the Event Horizon is that the necessary escape speed (orbital speed) would exceed speed of light, therefore no object can achieve it. Now, would it be ...
4
votes
2answers
515 views

Steel rod to Mars vs the speed of sound, how is supersonic travel possible?

I remember reading this passage in the "Feynman Lectures", where Dr. Feynman describes an experiment in which a theoretical metal rod of length equal to the distance between Mars and Earth is arranged ...
-3
votes
5answers
201 views

If I pull a long stick one meter towards me, how long will it take before the other end is displaced one meter?

Imagine that I pull a stick one meter towards me. And say the stick is 100 (m) long. My friend looks at the stick on the other side. How long will it take before my friend sees the stick to be one ...

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