288 views

### A question about twin frog paradox

This is the Twin frog paradox. I have two questions. First, what does it mean by there is no rigid body in special relativity? What I have known is that the length can be changed from one frame to ...
59 views

### Moving a 2x2 the length of the solar system [duplicate]

If we were able to push a 2x2 piece of wood that is the length of our solar system, how would it behave? My colleague says since its all part of the same molecular structure, the whole piece of wood ...
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 ...
57 views

### Faster than light morse code v2 [duplicate]

Imagine a theoretical superhard steel cylinder pointed towards the moon , 1 cm in radius and 380,000 km long, traveling at 1km per hour towards the moon. Parallel to this cylinder, 1 meter away we ...
53 views

### What's the speed of force? [duplicate]

Brain storm: Suppose we have a perfect lever, which has 0 quality, and perfect rigidity. It is long enough that can reach Proxima Centauri from the earth. Someone push one side of lever from Proxima ...
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, ...
60 views

### Does an Optical Diametric Vacuum Solenoidal Drive could prove itself against information speed limit?

About these two publications, I came up with a different answer an ask for validation. The scissor paradox: can we pass the information faster than light? Is it possible for information to be ...
111 views

### How long would it take for something really far away, say $300,000,000 \ \text{meters}$, to feel the force from a pull of a rope attached to it?

My friend phrased the original question like this: If I tied a rope to myself and wrapped it all the way around the earth and then pulled (assuming the rope was already taut), which direction would I ...
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 ...
61 views

### What is the speed of Pushing/Pulling? [duplicate]

If there was a huge rod the length of a light-year in space and someone pulled one end of it, when would the other end move?
63 views

### Information Propagation at the Speed of Light [duplicate]

Imagine a thought experiment: You have a rod 10 ft or 10 light nanoseconds long. On each side you have perfectly synchronized super high-speed cameras looking at the surface of the rod. You rotate ...
113 views

### Black holes, and faster than light communication

Lets say we have a black hole that has a diameter > 1 light year and we can somehow push and pull this black hole {though the push and pull itself can never exceed lightspeed of course}.Will the other ...
65 views

### A theoretical object that doubles in length pushing an object through space [closed]

If you were to have a theoretical object that could double itself along a chain so you would start off with 1 then it doubles to two, four, eight etc eventually the width of the object would be such a ...
$v=\omega r$ 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 ...