Quote (ozzyarmy3 @ Mar 4 2011 02:11pm)

I was looking at one of those "problem ___?" posts, where they have the troll image, and one of them made sense...  If we had the ability to create something long enough to touch, lets say venus, all we would have to do is move the object, and it would touch it..  Does this mean Kenetic Energy is faster than light?

Quote (ozzyarmy3 @ Mar 4 2011 03:11pm)

I was looking at one of those "problem ___?" posts, where they have the troll image, and one of them made sense...  If we had the ability to create something long enough to touch, lets say venus, all we would have to do is move the object, and it would touch it..  Does this mean Kenetic Energy is faster than light?

Quote (bentherdonethat @ Mar 4 2011 08:40pm)

The problem with that is the opposite end of the really long poll doesn't move the instant you push it. It looks instantaneous on a small scale because that push force travels at the speed of sound in that material (and the speed of sound in a metal pole is much greater than the speed of sound in air). So if you push on something that's really far away like in that troll physics image:

http://i.imgur.com/ZJsQJ.jpg

The push force doesn't get there faster than light does. In steel, the speed of sound is about 6000 m/s (which is almost 50,000 times slower than light) so a pushing force will still get there long, long after a radio signal.

Edited to add: The reason a push isn't instantaneous is because solids aren't TRULY incompressible. When you push on a pole, you're really pushing on the atoms on one end at the pole, and those atoms then push on the next ones down the line etc etc. This happens at the speed of sound.

Quote (bentherdonethat @ Mar 4 2011 03:40pm)

The problem with that is the opposite end of the really long poll doesn't move the instant you push it. It looks instantaneous on a small scale because that push force travels at the speed of sound in that material (and the speed of sound in a metal pole is much greater than the speed of sound in air). So if you push on something that's really far away like in that troll physics image:

http://i.imgur.com/ZJsQJ.jpg

The push force doesn't get there faster than light does. In steel, the speed of sound is about 6000 m/s (which is almost 50,000 times slower than light) so a pushing force will still get there long, long after a radio signal.

Edited to add: The reason a push isn't instantaneous is because solids aren't TRULY incompressible. When you push on a pole, you're really pushing on the atoms on one end at the pole, and those atoms then push on the next ones down the line etc etc. This happens at the speed of sound.

Quote (general_patton @ Mar 5 2011 05:05pm)

I work a lot with frictionless pulleys and massless ropes. Your explanation is good for a real world scenario imo, but troll physics happen ideally
Given an incompressible solid, I still don't think that the communication is going faster than the speed of light since there's nothing in Einstein's theories that bars relative speed being faster than light. For example, two galaxies moving at maybe .6c but in opposite directions have a relative velocity (if one was standing still) of roughly 1.2 times the speed of light. One end of the pole moving relative to the other end of the pole would only be going a few miles per hour if you push it.

Quote (ozzyarmy3 @ Mar 4 2011 12:11pm)

I was looking at one of those "problem ___?" posts, where they have the troll image, and one of them made sense...  If we had the ability to create something long enough to touch, lets say venus, all we would have to do is move the object, and it would touch it..  Does this mean Kenetic Energy is faster than light?

Quote (bentherdonethat @ Mar 9 2011 12:39pm)

Now, if you want some mind-bending Troll Math, consider this one:

http://i.imgur.com/ri3dT.jpg

Quote (bentherdonethat @ Mar 8 2011 07:39pm)

There's something called the "relativistic addition of velocities" that covers that scenario as well. If something is going 0.6c in one direction and something else is going 0.6c in the opposite direction, then if you look at the second galaxy from the first velocity's reference frame, that second galaxy will be moving at a speed of [(|v1| + |v2|) / (1 + |v1|*|v2|)] = (1.2/1.36) = 0.882c.

If a one lightyear long rod could be constructed that was incompressible though (and relatively massless so it'd be easy to move, but still having a strong enough integrity to not deform at all or be bent etc), I'm thinking that that really WOULD violate the speed of light. Even though the pole itself isn't moving faster than light (just at the push speed), two people that were a lightyear apart could communicate with morse code instantly. The information is travelling faster than light, and not even information is allowed to travel faster than light. That's why it's a Troll Physics, because in an ideal world with that incompressible, perfect lightyear long rod, relativity is definitely violated.

Now, if you want some mind-bending Troll Math, consider this one:

http://i.imgur.com/ri3dT.jpg

Quote

The use of Manhattan distance leads to a strange concept: when the resolution of the Taxicab geometry is made larger, approaching infinity (the size of division of the axis approaches 0), it seems intuitive that the Manhattan distance would approach the Euclidean metric

but it does not. This is essentially a consequence of being forced to adhere to single-axis movement: when following the Manhattan metric, one cannot move diagonally (in more than one axis simultaneously).