Naked Science Forum
Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: MomentaryLapseOfReason on 17/01/2010 23:44:42
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So let us assume that I am in my living room running in circle at 99.9999% the speed of light for (in my perspective) 5 seconds. When I stop, more time has passed than the 5 seconds I perceive to the others that remained stationary.
Now I am unsure of how MUCH time would have elapsed to those that were stationary, so for argument's sake, let's say 5 years.
Did those that come to my house see me running in circles for 5 years?
Of course this is a big hypothetical and there are a lot of boundaries to doing this but I'm just a bit confused on this one...
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Fair question.
My immediate thought is yes, assuming you can see something moving at 99.9999% the speed of light (or its effects)
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Fair question.
My immediate thought is yes, assuming you can see something moving at 99.9999% the speed of light (or its effects)
Again this is a hypothetical .... you should be able to see the blur of me running around... Just wondering if it'd be for 5 years (or whatever that would equate to)
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Yes
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Yes. They see you running in slow motion. You see them coming into the house speeded up like somebody pressed the fast-forward button.
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In addition to what they have already written to you, MomentaryLapseOfReason:
Not only you would live for 5 seconds while the stationary others for 5 years; since you are running in a circle, the part of your body near the centre of rotation would live more time than the other part of your body... [:)]
Please: don't ask me how it's possible.... [:-X]
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In addition to what they have already written to you, MomentaryLapseOfReason:
Not only you would live for 5 seconds while the stationary others for 5 years; since you are running in a circle, the part of your body near the centre of rotation would live more time than the other part of your body... [:)]
Please: don't ask me how it's possible.... [:-X]
LOL... that's a very valid point and all the other responses make sense. It's just odd that the would see me increasing speed until some point at which time I would actually begin to slow down.
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If you're running at 99.9999% of 'c' then time will be passing at 0.00141421 times its normal rate for you, so 5 seconds of your time will equate to 3535.53 seconds i.e. 58 minutes and 55.53 seconds, for your stationary friends.
You will naturally appear to be a blur to your friends, but if you had agreed to flash a light to them once every second of your time, they would only see 5 flashes in that period of 58 min, 55.53 sec. Your friends will appear to be speeded up to you, for you are seeing 58 min, 55.53 sec of their time compressed into just 5 seconds of your time. If your friends had agreed to flash a light towards you, you would see 3535 flashes during the 5 seconds you spent moving.
The duration of each flash of light would appear to be different too, had you and your friends agreed to use the same flash duration, and depending upon whether you are moving towards or away from your friends, the frequency of the light would be respectively blue or red shifted.
Whether one side of your body would age significantly more than the other side, due to being on the inside of the circle and so covering less distance and hence moving slightly slower, would depend upon your width and the diameter of the circle you're running around. For relatively large circles with a diameter many times your width the difference would be negligible but for very tight circles you'd run into some interesting issues.
Let's assume that you are 0.5 metres wide and you're basing your linear speed on the centerline of your body at a radius of 0.5 metres. This means that the inside of your body is circling at a radius of 0.25 m but the outside of your body is circling at a radius of 0.75 m. As a result, the outside of your body is must travel three times as far as the inside of your body on each 'lap'. However, if you're basing your speed at the centerline of your body this would mean that the outside of your body was moving correspondingly faster than the inside and so not only would it age at a significantly different rate, but as no part of you can exceed 'c' the outside of your body must start to lag behind you; you'll start to get 'smeared' back along the path. This smearing effect isn't something that happens abruptly, and only when you get close to 'c' though: it'll start happening as soon as you start moving in a circle, but the effects will only become pronounced as you start to approach 'c'.
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Very cool LeeE but just for fun.
Assume that you are moving at a straight velocity. Then all your bodyparts will have the same speed, right?
So now you will have to make a course change. As a system, won't you still have the same speed overall as you make it?
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you won't, would you?
Would that make course changes impossible near 'c'?
It would introduce the equivalent of 'tidal forces' on a body wouldn't it?
And the inertia would differ too i presume.
Always something new :)
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Very cool LeeE but just for fun.
Assume that you are moving at a straight velocity. Then all your bodyparts will have the same speed, right?
So now you will have to make a course change. As a system, won't you still have the same speed overall as you make it?
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you won't, would you?
Would that make course changes impossible near 'c'?
It would introduce the equivalent of 'tidal forces' on a body wouldn't it?
And the inertia would differ too i presume.
Always something new :)
Well of course there would be very strong g-forces on you if you could get to C in the first place and much more if you changed course. However, if you look at Fermilab or any other accelerator, the proton is always changing direction so...
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Yeah, i was thinking in terms of 'rigid bodies' but it seems correct to assume that the wider something is the more unequal the speed will be in that 'body'. So what a particle might be able to do won't be possible for us.
Sort of makes all SF using the more accepted 'under/near light speed' engines kind of redundant :)
"Captain, a meteor ahead."
"Signal Earth, send another..."
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I suppose my ex would age 3-4 times more on the side toward the middle of the turn. She would also more than likely set off an earthquake at that speed.
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can u imagine what centrifuge force u would have to survive in this kinda motion?
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guissepe - You wrote: "can u imagine what centrifuge force u would have to survive in this kinda motion?"
First, if he is doing this in his house he would not survive for any number of reasons, not the least of which is air friction. However, there is a reasonable and sort of analogous situation in the real world. Black Holes.
Assume MLOR manages to move his air tight living room into the accretion disk of a Black Hole. He will accumulate velocity as he spirals in. At some point, however, the part of him closest to the BH center will be pulled from the rest of him due to gravitational tidal forces. Eventually, however, his remains will increasingly approach the speed of light to such an extent his time will come to a virtual halt from our point of view. He will be spread out over a sort of shell at some distance from the center. And there he will remain.
A more interesting variant, however, assumes he runs away from us in a straight line with nuclear powered legs and carries his house like a snail shell. One milestone will be reached when his apparent speed reaches 86% the speed of light. Time dialation is 50%.
We see him travel one light year in about 14 months. He reports back, however, that he got there in only seven months. Further, as he travels he will also report, through astronomical geometry, that he seems to be traveling faster then the speed of light.
The theoretical implications are stupendous. Specifically, assuming our spaceship does not burn up due to 'stuff' in space ahead of us as we pass, it is entirely possible to create a starship that could explore much of the normal universe. It is more an engineering problem then theoretical.
If my space ship travels so fast my time slows down to almost nothing, I could travel hundreds of light years in seconds. This actually seems to be the case with some cosmic rays. Some of them travel so fast that they have been in existence only a matter of seconds since the big bang. Or so I have heard!
PS: The propulsion device for such a starship may already be in prototype. Just straighten out the CERN accelerator into a linear accelerator. Add a nuclear power source of sufficient for the journey. Then expel protons out the back to the speed of cosmic rays. I have read cosmic rays carry about the same kinetic energy as a tennis ball traveling at 100 mph. The number of protons in a pack of cigarettes might be adequate for the purpose.
Just musing....