Twin Paradox Question

N

newbie_0

Temporal Navigator
Has Nasa or anyone with the resources tried this :

Take 3 clocks all in sync on our planet, sent two of them into space in the same ship, had them split apart and have 1 travel very slow(slower than the earth relative to the galaxy) and one faster.

Return both clocks to earth and compare the times. I've heard that when you accelerate a clock towards the speed of light it "travels to the future" in a sense because when you compare it to your stationary clock, it will indicate more time has passed.

So would the clock moving slower than the earth indicate that less time has passed? Could this be interpreted slower clock has traveled to the past?

If gravity probe b, Nasa's frame dragging experiment comes back yielding no results does that mean that the twin paradox has been resolved?


(First question should have been : does the twin paradox refer to acceleration or any velocity? If it's acceleration towards C then why does this clock experiment work at all? Wouldn't the clocks have to decelerate the exact same amount to come to rest so you could check their results - in effect nullifying any "time travel" the clock experienced? )
 
The effects of the "Twin Paradox" depend only the relative speed between the two clocks, as long as you (the observer) are not accelerating. That is - as long as you don't feel the force of an engine pushing you back to your seat.

If you are on earth watching an earth-bound clock, then the only thing you need to know about your space-faring twin is his speed relative to the earth. His speed relative to the galaxy is irrelevant. Even if your twin accelerates or deccelerates his ship (and he must do that to return home), you only need to know his speed at any given moment in order to calculate the time dilation.

It is also possible to analyze the entire scenario from the point of view of the space-faring twin. But he needs to take his own accelerations into account in such an analysis: Everytime he operates the engines, his own clocks slow down due the force felt inside the ship. In the end, he will reach the exact same result as you did: That he'll be the younger twin once he return home.
 
I've heard that when you accelerate a clock towards the speed of light it "travels to the future" in a sense because when you compare it to your stationary clock, it will indicate more time has passed.
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This is incorrect. When you accelerate a clock (lets say a very accurate atomic clock) the more you accelerate it towards the speed of light "C", the Less time it will indicate has passed compared to the clock on the slower spinning/moving Earth.

For an example if you travel 200,000 MPH towards the closest star, taking your atomic clock which is synchronized with the one on earth. Travel for a year or so, come back. 2 years passed for you. It still, always, takes 2 years. However you traveled faster, so time slowed down for you, meaning by the time you get back it may be 2-1/2 years later. This is an exaggeration and 200,000 mph is Not very fast at all in terms of the speed of light. But this is an accurate representation of what happens when you travel faster.


btw, Nasa has done simple experiments and proven this phenomenon. Atomic clocks sent to outer space, orbiting space stations, shuttles, etc, have shown a very small BUT measurable difference. something on the order of a few microseconds but still a difference as Atomic Clocks are VERY precise.
 
Ok so it has to be acceleration? And the accelerating clock will show a time in the past when it arrives back on earth? Why doesn't deceleration towards 0 have the reverse effect?

Why does the experiment with one clock on the ground and one very high work? Aren't both clocks acceleration 0 if they are fixed to the Earth?

I thought the clock experiments were not 100% proof of that theory and that if results gravity probe b showed the right amount of frame dragging then it would mean more proof this was actually happening. And if the results GPB don't work out as expected, could it mean that the results from the clock experiments are caused by some other phenomenon not associated with special relativity? Does this questions make any sense? /ttiforum/images/graemlins/tongue.gif
 
if results gravity probe b showed the right amount of frame dragging then it would mean more proof this was actually happening.
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Gravity probe B is very advanced, the 4 gyros made from quartz and free of almost any imperfection down to the atomic level, will tell us in the next year or so if frame dragging is whats going on. I guess since we actually have a way to test this we will just have to be patient and find out.


As for deceleration, you really need to have an understand of the doppler affect to know why the clock won't be going in reverse. Listen to the pitch of an ambulance coming towards you, as it gets closer, the pitch gets higher. As it goes by you and is traveling away from you, the pitch gets lower, and lower, until you can just barely hear it. Whats happening here is the doppler effect and if you think of each wave of the siren that hits you, and could see them, label them each second they arrive, and time them, you would notice as the object moves towards you the waves are closer together and their timing is closer together. Further away, the waves take longer to get to you and are further apart.
 
I guess since we actually have a way to test this we will just have to be patient and find out.
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Are frame dragging and this twin paradox connected though? If GPB comes back showing not what they expected, does that mean the time difference that has been shown in experiments might be caused by something unknown?

As for deceleration, you really need to have an understand of the doppler affect to know why the clock won't be going in reverse.
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Doesn't the doppler effect work with 0 acceleration though? How does the doppler effect tie into why the clocks time will differ?
 
There may be something different than frame dragging going on, I really won't venture a guess until the results come in...

As for your other question, the Doppler effect can show you How time is distorted. I would suggest researching some of this on your own, try google. but I think I can dumb it down enough that anyone could understand whats going on.

Lets say you start at earth, we turn on a beacon that flashes light once a second ( a sort of strobe light if you will ). You start travelling away from earth, and lets say you travel Exactly at the speed of light (ignoring all laws of physics for this experiment of course). Because you are travelling at the same speed the light will never reach you but hundreds of waves of light are headed towards you. Now you start slowing down, the waves start to reach you, they are constantly spaced apart by 1 second. Now when you grind to a halt in your starship, you receive them at exactly 1 per second. Now you start Racing back towards earth, speeding up and speeding up and hitting all of the light waves that have been traveling towards you. The faster you go the quicker you run into them.

Now imagine if this was a clock and not a beacon, and you have a telescope powerful enough to see it from a trillion miles away. As you travel away from earth At the speed of light the clock doesn't move, when you slow down it moves slowly when you grind to a halt you would be able to see the seconds tick by as normal. Now you speed up Towards the earth and thats when things get funky, the clock stars Spinning and Spinning, and thats how much time has passed on earth, but you experience it much faster and thus you were less effected by time and have not aged as much.

Relativity all rolled into one simple experiment.
 
Ok so it has to be acceleration?
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Speed. Not acceleration.

The faster the ship is moving, the slower it's clocks will be ticking.

A clock moving at 50% the speed of light will reckon 52 minutes for every hour passing on earth.
A clock moving at 90% the speed of light will reckon 26 minutes for every earth-hour.
A clock moving at 99% the speed of light will reckon 8.5 minutes for every earth-hour.

If you accelerate a ship from 0 to 90% the speed of light, the ship's clock will slow down from 60 ship-minutes/earth-hour to 26 ship-minutes/earth-hour. If you deccelerate a ship from 90% the speed of light to 0, the ship's clock will speed back up from 26 ship- minutes/earth-hour to the normal 60 ship-minutes/earth-hour.

Why does the experiment with one clock on the ground and one very high work?
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Because gravity also slows down time. The earth's gravity is a little weaker at a great hight, so the clock on the ground will tick a little bit slower.
 
"When you accelerate a clock (lets say a very accurate atomic clock) the more you accelerate it towards the speed of light "C", the Less time it will indicate has passed compared to the clock on the slower spinning/moving Earth."

Thats what I was going to say! /ttiforum/images/graemlins/smile.gif
 
Ren,

Now you start Racing back towards earth, speeding up and speeding up and hitting all of the light waves that have been traveling towards you. The faster you go the quicker you run into them.
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As you very closely approached the speed of light you'd see some very "interesting" effects. Spacetime would fold up into a compressed point directly in front of you. Every photon in the universe would be contained in that point and headed directly at your nose from a distance approaching zero and a doppler shift approaching infinity. Better raise the "heat" shields.

And our pilots are complaining about getting hit with pen lasers. This would be the Mother of all laser beams.
 
I'm not sure if I understand this. I'm moving away at close to light speed and if he looks through a telescope at my clock, it appears to be moving slower than his clock. So if was playing a movie on the ship (on a LCD 30fps progressive scan) and he was watching through his telescope, would it be in slow motion fade from frame to frame Or would it resemble more of a slide show? Or would it just make the whole movie a bright shade of red AND be in slow motion???

Say I have a magic walky talky that could defy the laws of physics to communicate infinatly fast back to my stationary twin. If we are talking on the walky talky and we said our times outloud at the same time, we would say the same time right? Time isn't actually moving or anything, the events just take longer to appear to us because the doppler-ish effect of light waves.


btw, Nasa has done simple experiments and proven this phenomenon. Atomic clocks sent to outer space, orbiting space stations, shuttles, etc, have shown a very small BUT measurable difference. something on the order of a few microseconds but still a difference as Atomic Clocks are VERY precise.
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I also heard of experiments where they put a clock in a high tower and compare it to a ground clock. The clock in the tower has a larger velocity because the circumference of it's orbit takes it over a longer distance in the same amount of time. When the clocks are compared side by side the times are different. So this is where I start to get confused. If the phenomenon is supposed to be only because of the way light works, then why do the times appear different when the twins are reunited?


Does the theory also say that my mass is also supposed to increase towards infinity as I approach the speed of light? Essentially if some advanced race could accelerate any amount of mass to the speed of light they could destroy the universe? Talk about WMD's.
 
ok let me answer the last part, too sick to think that hard this morning to answer the rest. This has to do with how time is perceived, that is relative to your speed. Light just happens to be the limit.

an alien civilization would not be able to accelerate anything TO the speed of light because it would take increasingly more energy (to infinity) to push the increasingly more massive craft. If you want to go faster in your car you give it more gas, well the amount of gas required to push an object TO the speed of light is infinite and therefore impossible to obtain.

However, as I said before there are ways around this, folding space time, wormholes, even relativity theory if you read closely says nothing about moving Faster than the speed of light, just that you cannot accelerate TO the speed of light.

Also I would like to point out if you were traveling faster than the speed of light you would in essence be Energy and not Mass. As far as we currently understand it anyway.
 
an alien civilization would not be able to accelerate anything TO the speed of light because it would take increasingly more energy (to infinity) to push the increasingly more massive craft.
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Say they arranged a bunch of stars or black holes to make a huge intergalactic rail-gun. All of a sudden the mass is infinate and to me, infinate means that I cease to exist. Am I the only one who's got a problem with these "limits"?
 
Newb0' I don't want to hurt feelings here, but do you think that you could make your question a little better in order and clean up the intent of what you are trying to say, please?
 
Creedo, I don't understand the following:

The phenomenon time on a clock slowing down is only supposed to appear when you watch the clock move away at the speed of light because of the doppler effect.

So why is it when they try this experiment by sending a clock into orbit and bringing it back to earth that the time it reads is no longer in sync with the ground clock?

I can accept the clock 'appears' to slow down, but not that it is 'really' slowing down.


And...

Has anyone ever tried to resolve e=mc^2 in a way that doesn't have any limit? ( I don't understand E so that's probably be a silly question but the limit bugs me.)
 
Newbe' the mass does not increase so much, as the contiguality of mass to this reference of space and time does.

In other words, this situation would be like finding a very pretty girl, that you want to make love to, however when your driving her away from her neighborhood, she starts to say more and more, "Oh my mom and dad, oh my brothers"! however at an incrreasily alarming rate, as you drive faster away.

It's not so much the mass increasing, as the involvement of her to her homeworld, that becomes more apparent.

By the time your driving very far away, she is saying Oh'me-Gud so fast, that her saying this, now becomes a blur.

The last thing you're ever thinking of is making love to her, as she has mommy, daddy coming out of her mouth at a tremendous rate now.

This is how mass is affected within acceleration ranges, as there is both foreshortening and time in mass, your ship starts to slow down, due to that mass saying, Oh no!, I don't want to leave home.

Going back to the girl in your car, if one reaches light speed, she will get so distressed, she at the speed of light, will finally blow up.

This is not a comforting thought for her parents, however fully illustrates my point.

This space-time is an assigned network, not a network that more often can be gotten out of easily.

The only break to this rule, is time holes that sometimes appear and go into other realities.

Gravity spots, that are also advertised, can at times, accomplish the same feat, as weight and gravimetric pull over gravity mass, sometimes overcomes what is known as M+, which is string contigular time and space, or null space, which empty space is more often referred to.

Hope this helps?
 
Gravity spots, that are also advertised, can at times, accomplish the same feat, as weight and gravimetric pull over gravity mass, sometimes overcomes what is known as M+, which is string contigular time and space, or null space, which empty space is more often referred to.
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Sounds like an exception to me. I don't buy it.
 
In other words, this situation would be like finding a very pretty girl, that you want to make love to, however when your driving her away from her neighborhood, she starts to say more and more, "Oh my mom and dad, oh my brothers"! however at an incrreasily alarming rate, as you drive faster away.
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And There we have it, Relativity as Explained by Creedo.

So, as you approach the speed of light, your g/f's constant nagging increases the faster you go. Makes sense to me.

Going back to the girl in your car, if one reaches light speed, she will get so distressed, she at the speed of light, will finally blow up.
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I have this problem all the time, darn g/f's blowing up on me and pissed off parents.
 
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