Registered: Nov 2001
Location: Rio de los Brazos de Dios
Posts: 3876

I am not a physicist , Smug, in fact I can get lost in Popular Science Magazine, so you may have to help me state the problem as well as tell me the solution. Here is the situation:

\Captain Smith and Captain Jones have each been given a new supersonic (2.1 mach cruise) aircraft and are under contract to continuously fly these aircraft around the world at the equator for an indefefinite time but longer than two years. in order to test them. They meet just before take-off and synchonize their watches and the wives of each are vacationing for these two years in Barbados awaiting their return and they synchronize also. We will ignore the fact that the pilots have to sleep--say they have a swell new autopilot and are flying at 120,000 ft free of all other traffic and their aircraft are nuclear fueled. Just before they leave Jones asks Smith "Which way are you going to fly, west to east or east to west?" Smith replies "I'm flying east to west". Jones says "What a fool you are, Smith, I am flying west to east. and you will age much more than I in this two years even though we both will age more than our wives in Barbados. Because both the special and general theories of relativity will dictate that our speed relative to a fixed point on the earth (Barbados) will cause our watches to run slower with reference to a fixed point on earth, but you will have to accelerate far more than I will because you do not have
the earth's motion to help you out so your watch will run even slower than mine and you will thus age more in a given time by your watch.
Were they both full of crap or neither or have I mistated the proiblem?

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Registered: Aug 2001
Location: Hilbert Space
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You catch me just as I am going to sleep (3am here) but I think that this is a version of the twin paradox (two twins, one flies off into space really fast and then comes back; has one aged more than the other?). It does seem to be true that one will have to accelerate more to achieve orbiting velocity and I think that it is in the acceleration that the twin paradox is solved in the normal statement of it. He will have to decelerate more at the end, too.

Hmm, i will have to think this through a bit as I am tired and no specialist in the relativities. Alternatively, I can ask my girlfriend who is...

I will have to try and get back to you on this, I am afraid.

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Registered: Jul 2000
Location: Minneapolis, MN
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the way i understand it (and trust me, i don't understand it) their watches will run at normal speed (at least as far as theyre concerned, a second will still be a second). now assuming there's such a thing as 'the speed of time', the faster they travel towards that speed the slower their 'watches' will tick, where as if they traveled at the same speed as time, time would not pass for them at all (in comparison with stationary people on earth). faster than the speed of time and so if you traveled at half the speed of time for a year, you would be 6 months older than someone born at the same time who was stationary on earth. the direction you traveled shouldnt make a difference.

but then again, what the fuck do i know.

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Registered: Aug 2001
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On reflection, I think that the guy who is travelling against the earth's spin will appear, to the women on earth, to be going faster and so he should have slower running clocks as seen by them. That guy should age slower, is my guess.

If the women age less than the men, that must be a general relativity (GR) effect (stronger gravity = slower clocks); without gravity, the men, as the moving ones, should age slower (faster speed = slower clocks from special relativity (SR)). There must be a trade off between the GR and the SR effect which would be quite easy to work out I think.

I must apologise for this shoddy performance and can only point out that I am more a quantum physics nerd and not so much a relaitivity one.

The statement that I made before about accelerations is a little confused, the acclelerations are just the signature which tells you which one is moving (if you look up the twin paradox, you will see any mention of accelerations derided, but if it is good enough for Feynmann then it is good enough for me; the accelerations just tell you that you are moving between different inertial frames (and are indeed necessary to do so), they do not themselves cause the effect)

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Registered: Aug 2001
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I am still only guessing though, mind...

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Registered: Jan 2002
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Oxsan, as smug says this is a version of the twin paradox, basically as I see it there are two things you need to take into account here
1) the relative speeds of the wives with respect to the pilots
2) the fact that the guy going against the
direction of rotation will reach his desination quicker (I'm not sure whether you are fixing the number of revolutions they have to make)

With regard to the first point both guys will age slower than their wives in the wives reference frame. And the one travelling against the earth's rotation will be the youngest. This is purely a result of special relativity. General relativity doesn't come into this question, that would only start being important if the pilots were travelling near very massive bodies like black holes. The effect from time dilation will be absolutely infinitesimally small if they are travelling at 2.1 mach - they'd need to be near light speed or travel and extraordinary distance to make any effect

The main effect is the second classical one,boringly, basically because the guy going round the one way has the earth's motion helping him then he will reach his starting point sooner than the other, by a substantial amount if they travel many times round.

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Registered: Jul 2000
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A pogrom (timed rightly) in this thread could rid us of all our nerds in one fell swoop.

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quote:

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Originally posted by Goatboy
A pogrom (timed rightly) in this thread could rid us of all our nerds in one fell swoop.

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To smug, the physics of men and women aging is reduced to one simple rule. As men get older they become cooler and more desirable as women get older men get rid of them for a younger upgrade.

So the pilots' flights are just accentuating smug's natural law - on their return they won't be interested in their wives, but the bermudan beach babes surrounding them.

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quote:

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Originally posted by weedy
To smug, the physics of men and women aging is reduced to one simple rule. As men get older they become cooler and more desirable as women get older men get rid of them for a younger upgrade.

So the pilots' flights are just accentuating smug's natural law - on their return they won't be interested in their wives, but the bermudan beach babes surrounding them.

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Registered: Nov 2001
Location: Rio de los Brazos de Dios
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Most lucid post Mr. Weedy and even understandable to this old Brazos River farmer. Thank y'all for all your help and let us thank whatever gods may be that GB's pogrom did not befall us. After all the world needs a few nerds.

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Registered: Jan 2002
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Actually, it's Ms Weedy ,Oxsan, I may as well come clean, I am Smug's (nerdy) girlfriend.

Last edited by weedy on 01-19-2002 at 03:40 PM

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Registered: Nov 2001
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quote:

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Smug's quote of Mr Weedy, "---on their return home they won't be interested in their wives but in the bermudan beach babes beside them."

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quote:

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Originally posted by weedy
Actually, it's Ms Weedy ,Oxsan, I may as well come clean, I am Smug's (nerdy) girlfriend.

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