Question

[ChrisLove]

Here is a question, any thoughts welcome……


Imagine you are in deep space nowhere near any other object and you have a pole that was a million miles long. The pole is made of some amazing carbon fibre weightless stuff so you can move it around really easily.

You and you mate sync your watches and go and stand at opposite ends of the pole.

You agree that at exactly 12 o clock you will give your end of the pole a push. So standing at one end of the pole you give it a push so that it moves quickly to being about an arm length away from you.

So what does your mate see at his end of the pole at 12 o clock? Presumably nothing because nothing can travel faster than the speed of light so the push or the information of the push will not reach his end of the pole for about 5 seconds – so I guess 5 seconds later he sees the pole move.

But does that mean that during those 5 seconds, the pole actually shrank in length, afterall, if one end has moved and the other hasn’t then it must be shorter, right? But its not like the pole has been squished in anyway ie the density of the pole would surely stay the same all the way along its length, or would it?

Or is something really funky going on like some distortion of space and time?

Its really doing my head in,

Any of you suckers got any thoughts

[Qdrop]

But does that mean that during those 5 seconds, the pole actually shrank in length, afterall, if one end has moved and the other hasn’t then it must be shorter, right? But its not like the pole has been squished in anyway ie the density of the pole would surely stay the same all the way along its length, or would it?


no, the pole doesn't shrink.

if you believe existence is perception, then both sides will percieve the pole correctly...as you cannot percieve 2 differant realities at once.

and even if you don't believe existence is reality....
the pole never shrinks....
as nothing can move faster than light, never is there a "time" when the pole has not "moved" yet.....as the time doesn't go faster than light.

[ChrisLove]

no, the pole doesn't shrink.

if you believe existence is perception, then both sides will percieve the pole correctly...as you cannot percieve 2 differant realities at once.

and even if you don't believe existence is reality....
the pole never shrinks....
as nothing can move faster than light, never is there a "time" when the pole has not "moved" yet.....as the time doesn't go faster than light.


Ok that makes since, so your mate will look through his telescope at you waiting for you to push at 12 on his watch, but then he will see that you don’t actually seem to get round to pushing until 5 seconds past at which point the pole moves at his end. Everything seems fine but the two will disagree at what moment the pusher actually pushed the pole.

And then its just one of those weird situations where both observers are right – so it is a bit of relativity going on then….


So my next thought is, if you push a pencil along the desk in front of you, the same thing must be going on but the time 'distortion' effect is much much smaller so that you cant see it – but its there….

But the time distortion effect (this is probably the wrong term to describe it) is a function of distance rather than velocity in this case. Which is cool

[TonsOfFun]

if you think as time and light as a measurment rather than something that is fixed, it'll all make sense. Nothing shrinks. Just delayed.

I thought that Austrain cleared all this up years back :p

[icy manipulator]

no, the pole doesn't shrink.

if you believe existence is perception, then both sides will percieve the pole correctly...as you cannot percieve 2 differant realities at once.

and even if you don't believe existence is reality....
the pole never shrinks....
as nothing can move faster than light, never is there a "time" when the pole has not "moved" yet.....as the time doesn't go faster than light.
well actually the light barrier can be broken thru quantum entanglement or once you pass an event horizon, but i couldn't be bothered explaining. this sounds like a guy who's really fucking stoned asked this question :confused:

[ChrisLove]

if you think as time and light as a measurment rather than something that is fixed, it'll all make sense. Nothing shrinks. Just delayed.

I thought that Austrain cleared all this up years back :p


Yea I think what strikes me as odd is that until I thought about this pole, I visualised relativity as something that was to do with velocities and time rather than distance and time. Of course its obvious now, as distance, velocity and time are all so closely linked each other and space time but still, its cool to think about. I guess it was thinking about this type of problem that set old Alert off on to relativity in the first place.

[Tzar]

i have a physics question.

if im standing at the front end of a bus, and the bus is going, say 70k's an hour in a straight line, if i jump straight up in the air... will i move down the bus a bit?

[TonsOfFun]

I like to trip on stuff like that. If a group of you are stoned it offers hours of conversation that no one seems to get bored of.

In thinking like this and the thought that space is curved thus you can go back in time for that reason and the fact I beleive in reincarnation, I think it'd be pretty cool that you can actually reborn to any point in time. After of hours of thinking me and a friend came to this conclusion. I forget the specifics but it was fun at the time :o

[TonsOfFun]

i have a physics question.

if im standing at the front end of a bus, and the bus is going, say 70k's an hour in a straight line, if i jump straight up in the air... will i move down the bus a bit?

yes

edit: if you ever go on a boat, this is the best place to prove it. Works with buses as well I can only assume

[ChrisLove]

well actually the light barrier can be broken thru quantum entanglement or once you pass an event horizon, but i couldn't be bothered explaining. this sounds like a guy who's really fucking stoned asked this question :confused:
Not stoned, just curious.

There was no event horizon around the pole so quantum tunnelling or whatever has not got anything to do with this really, it was just a straight bit of relativity I couldn’t get my head around but now can thanks to Q Drop.

[Tzar]

yes

edit: if you ever go on a boat, this is the best place to prove it. Works with buses as well I can only assume
yeah our family has had many boats. it most certainly works on boats.

[ChrisLove]

yes

edit: if you ever go on a boat, this is the best place to prove it. Works with buses as well I can only assume


I don’t think it would work on a bus – the thing moving you down the boat is wind resistance which you remove when you are in an enclosed space like a bus or a train.

It might work a bit though. Ignoring friction or acceleration there should be no difference between jumping on a moving platform such as a bus to jumping on a stationary platform – afterall the ground outside is zooming through space very fast and you don’t move alng a bit when you jump up and down on dry land…

[TonsOfFun]

I've only tried it on Ferries and it works indoors in ferries which is why it should work on a bus

[ChrisLove]

I've only tried it on Ferries and it works indoors in ferries which is why it should work on a bus

shouldnt, if it does, it probably the result of one of three things

1) the pitch and roll of the boat ie if the front of the boat is raised when you jump, then you are actually jumping in a direction opposite to the motion of the boat although you think you are jumping vertically (it looks vertical cos you cant see the pitch of the boat)

2) you jump funny

3) The boat is not in constant motion ie it is accelerating when you did the jump, the effect of this is as if a gravity like force was pulling you toward the back of the boat. Like the force that pins you to your seat when a car accelerates

[TonsOfFun]

I've just remembered I've forgot to buy a head lamp bulb and it's already gone dark. D'oh.

Nothing to do with the thread but I remembered as I pressed reply and forgot what I was gonna say...

[icy manipulator]

yeah trust me it works on ferries not bus's. cbf explaining again. too drunk

[ChrisLove]

I've just remembered I've forgot to buy a head lamp bulb and it's already gone dark. D'oh.

Nothing to do with the thread but I remembered as I pressed reply and forgot what I was gonna say...

doh