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Author Topic:   The Twins Paradox and the speed of light
Maartenn100
Member (Idle past 4592 days)
Posts: 39
From: Belgium Antwerp
Joined: 08-13-2011


Message 136 of 230 (628848)
08-13-2011 12:31 PM


Yes, that makes sense. Hubble's law.
But first: When the astronaut/twin is accelerating away from (the other twin on) Earth and tries to reach escapevelocitiy, the object (Earth) where he is moving away from, is not only moving away from him from his point of view, but begins also to turn around its axis more and more, no?
There is no redshifting yet.
So, while the astronaut is accelerating away from the object, the object begins to move around it's axis (with the twin on it)
This acceleration of the object around itself or in the gravitational field while the twin is moving away from it, will cause timedilation for that heavy object. (Earth).
(because Earth is moving too)
So these timedilations will cancel eachother out, I think. The accelerating astronaut will not be younger than its twin brother on Earth. Because the other brother at home will move too in the gravitational field. There is no paradox. (I think)
Edited by Maartenn100, : No reason given.
Edited by Maartenn100, : No reason given.
Edited by Maartenn100, : No reason given.
Edited by Maartenn100, : No reason given.
Edited by Maartenn100, : No reason given.

Replies to this message:
 Message 137 by cavediver, posted 08-13-2011 1:16 PM Maartenn100 has replied
 Message 138 by NoNukes, posted 08-13-2011 2:01 PM Maartenn100 has replied

  
cavediver
Member (Idle past 3643 days)
Posts: 4129
From: UK
Joined: 06-16-2005


Message 137 of 230 (628861)
08-13-2011 1:16 PM
Reply to: Message 136 by Maartenn100
08-13-2011 12:31 PM


ut first: When the astronaut/twin is accelerating away from (the other twin on) Earth and tries to reach escapevelocitiy, the object (Earth) where he is moving away from, is not only moving away from him from his point of view, but begins also to turn around its axis more and more, no?
No - from the point of view of the astronaut, the Earth is turning less and less. Each day Big Ben sounds noon in London, we sends a signal to the astronaut. But each day, the astronaut is further away, so the time interval he measures between receiving each signal gets longer and longer.

This message is a reply to:
 Message 136 by Maartenn100, posted 08-13-2011 12:31 PM Maartenn100 has replied

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NoNukes
Inactive Member


Message 138 of 230 (628867)
08-13-2011 2:01 PM
Reply to: Message 136 by Maartenn100
08-13-2011 12:31 PM


Not so fast...
So these timedilations will cancel eachother out, I think. The accelerating astronaut will not be younger than its twin brother on Earth. Because the other brother at home will move too in the gravitational field. There is no paradox. (I think)
The time dilation effects that result from high speed velocity (significant fraction of c) dwarf those that result from differences in potential in earth's gravitational field. In a typical twin paradox problem, the rocketing twin's speed produces a gamma of 1.5 or more in order to yield an impressive result. The twin paradox is not a gravitational effect. It can be explained strictly with special relativity.
The acceleration by one twin when turning around to come home, which is not experienced by the other twin, does introduce an asymmetry in the experience of the twins, but it does not produce any significant time dilation effect per se.
Also consider that the famous mu-meson experiment is a real life validation of the twin paradox result.
By the way, your English is just fine.
Edited by NoNukes, : English remark

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 Message 136 by Maartenn100, posted 08-13-2011 12:31 PM Maartenn100 has replied

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Maartenn100
Member (Idle past 4592 days)
Posts: 39
From: Belgium Antwerp
Joined: 08-13-2011


Message 139 of 230 (628869)
08-13-2011 2:14 PM
Reply to: Message 138 by NoNukes
08-13-2011 2:01 PM


ok thanks.

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Maartenn100
Member (Idle past 4592 days)
Posts: 39
From: Belgium Antwerp
Joined: 08-13-2011


Message 140 of 230 (628871)
08-13-2011 3:05 PM
Reply to: Message 137 by cavediver
08-13-2011 1:16 PM


No - from the point of view of the astronaut, the Earth is turning less and less. Each day Big Ben sounds noon in London, we sends a signal to the astronaut. But each day, the astronaut is further away, so the time interval he measures between receiving each signal gets longer and longer.
ok, but when you are just leaving earth with an escapevelocity, the object 'Earth' begins to move more and more. Because you are escaping gravity. So you will see the Earth turning around.
So, when you are moving away from any object in space with escapevelocity and you leave the gravitational field (gravitational relativity), this object, where you are moving away from, begins to spin slowly - more and more - in its gravitational field, irrespective of your veliocity.
Edited by Maartenn100, : No reason given.
Edited by Maartenn100, : No reason given.
Edited by Maartenn100, : No reason given.

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 Message 141 by fearandloathing, posted 08-13-2011 3:39 PM Maartenn100 has replied

  
fearandloathing
Member (Idle past 4145 days)
Posts: 990
From: Burlington, NC, USA
Joined: 02-24-2011


Message 141 of 230 (628875)
08-13-2011 3:39 PM
Reply to: Message 140 by Maartenn100
08-13-2011 3:05 PM


Hi and welcome,
Maartenn100 writes:
ok, but when you are just leaving earth with an escapevelocity, the object 'Earth' begins to move more and more. Because you are escaping gravity. So you will see the Earth turning around.
When you are on the launch pad you are still in earths reference frame, As soon as you launch you are in a new one, the rockets. As you gain altitude you may or may not notice the earth turning depending on lots of things, from a geostationary orbit you would always be over the same place, if you were on your way to the moon you would notice the earth turn because you would be in a separate frame of reference independent of the rotational motion of the earth. It is all relative to what frame of reference you are using.

"No sympathy for the devil; keep that in mind. Buy the ticket, take the ride...and if it occasionally gets a little heavier than what you had in mind, well...maybe chalk it off to forced conscious expansion: Tune in, freak out, get beaten."
Hunter S. Thompson
Ad astra per aspera
Nihil curo de ista tua stulta superstitione.

This message is a reply to:
 Message 140 by Maartenn100, posted 08-13-2011 3:05 PM Maartenn100 has replied

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 Message 142 by Maartenn100, posted 08-13-2011 5:06 PM fearandloathing has replied

  
Maartenn100
Member (Idle past 4592 days)
Posts: 39
From: Belgium Antwerp
Joined: 08-13-2011


Message 142 of 230 (628881)
08-13-2011 5:06 PM
Reply to: Message 141 by fearandloathing
08-13-2011 3:39 PM


yes that's truth.
What I mean is:
The twin on earth is accelerating too, in circles. This spiral and spinning acceleration is equal to the straightforward acceleration of the traveling twin. (in relativity)
So both twins are travelling with the same speed away from eachother. Both will have the same age when they reunite. (and will stand still next to eachother).
Because their distortions where equal.
Both twins have traveled away from eachother with the same speed.
Relativitytheory does not has calculated the timedistortion of the moving twin on Earth in its gravitational field, spinning more and more.
The twin paradox is truth in a uniform gravitational field. But not in space, when the twin is leaving the gravitational field. (I think)
Edited by Maartenn100, : No reason given.

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 Message 141 by fearandloathing, posted 08-13-2011 3:39 PM fearandloathing has replied

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 Message 143 by fearandloathing, posted 08-13-2011 5:42 PM Maartenn100 has replied

  
fearandloathing
Member (Idle past 4145 days)
Posts: 990
From: Burlington, NC, USA
Joined: 02-24-2011


Message 143 of 230 (628883)
08-13-2011 5:42 PM
Reply to: Message 142 by Maartenn100
08-13-2011 5:06 PM


The twin on earth is accelerating too, in circles.
Please explain. What is causing the earths rotation to increase? Maybe I don't understand you... Is it really accelerating?....Or is the increase in your velocity causing it to appear to you not to match your clock? Gravity is really a moot point, your velocity on the spaceship is what truly makes a difference.

"No sympathy for the devil; keep that in mind. Buy the ticket, take the ride...and if it occasionally gets a little heavier than what you had in mind, well...maybe chalk it off to forced conscious expansion: Tune in, freak out, get beaten."
Hunter S. Thompson
Ad astra per aspera
Nihil curo de ista tua stulta superstitione.

This message is a reply to:
 Message 142 by Maartenn100, posted 08-13-2011 5:06 PM Maartenn100 has replied

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Maartenn100
Member (Idle past 4592 days)
Posts: 39
From: Belgium Antwerp
Joined: 08-13-2011


Message 144 of 230 (628886)
08-13-2011 6:40 PM
Reply to: Message 143 by fearandloathing
08-13-2011 5:42 PM


When you leave your twinsister on Earth she begins to rotate first from your point of view (rotation Earth), then to wobble with a moon, then to start speeding up around the sun. This happens while you are accelerating away from her.
This is your view of your twinsister on Earth while you are accelerating away from it:
https://www.youtube.com/watch?v=lkWyM-M8o0c
She is speeding up too in the gravitational field.
That's what I mean with: you are accelerating, but the twinsister is too. So her time will distort too. Your ages will not differ.
Edited by Maartenn100, : No reason given.
Edited by Maartenn100, : No reason given.
Edited by Maartenn100, : No reason given.

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 Message 145 by NoNukes, posted 08-13-2011 7:55 PM Maartenn100 has replied

  
NoNukes
Inactive Member


(1)
Message 145 of 230 (628894)
08-13-2011 7:55 PM
Reply to: Message 144 by Maartenn100
08-13-2011 6:40 PM


When you leave your twinsister on Earth she begins to rotate first from your point of view (rotation Earth), then to wobble with a moon, then to start speeding up around the sun. This happens while you are accelerating away from her.
Looks like my first post made no impression.
Do you know the magnitude of the dilation effects you are describing? They are all extremely small. You'd never detect any difference in the life span of a human due to either gravitational time shift or the accelerating away from earth.
For example, the gravitational frequency shift at earth's surface compared to that an infinite distance from earth is about one part in 10^9. Maybe if a neutron star or black hole is involved you can generate gravitational twin paradox worth discussing. But not from flitting about the solar system.
The effect to be concerned about here is time dilation due to the relative motion resulting from the acceleration.
Edited by NoNukes, : No reason given.

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Maartenn100
Member (Idle past 4592 days)
Posts: 39
From: Belgium Antwerp
Joined: 08-13-2011


Message 146 of 230 (628922)
08-14-2011 5:29 AM
Reply to: Message 145 by NoNukes
08-13-2011 7:55 PM


My hypothesis:
When you try to go outside the solar system, you must challenge gravity. You can not follow a linear path. When you do follow a straight line, you are turning around the sun. Why? Because gravity will pull you back. (straight lines in a curved spacetime).
I even believe that "straight forward" en "curved" is relative given by your 'frame of reference' in the gravitational field. (the universe)
(gravitational relativity: curved versus straightforward, given the frame of reference in the gravitatonal field (the universe))
You can make a resemblance with us here on earth: when you follow a straight line on earth, you will turn around earth, seen by an observer from out of space. From your point of view, you accelerate straight forward. But, from the point of view of an observer outside Earth's gravity, you are following a curved road and are forming circles.
The only 'straigh line' your see from out space is a coriolispath on earth.
So, you must first follow a coriolispath to follow a straight line. (a curved road).
You must always hold a centripital acceleration in the beginning according to yourself. Because when you accelerate straighforward, you are following straight lines in a curved spacetime, curved by the sun, the solarsystem etc. (gravity will pull you back).
And
When you try to escape the gravity of the solar system, by following these curved road,
your time wil distort by gravitational timedistortion.
And
Whey you escape gravity by following this curved road, you are not accelerating to near the speed of light.
(it will be very difficult)
And finally, you see the Earth redshifting.
So, when you do the - very complex - math: the clocks will be the same I think.
It's far more complex then you think.
So, I do not disagree on the twin paradox!!!
I only think it's truth for a uniform gravitational field. Not in the universe when you talk about different gravitational fields.
So it works on earth, when two objects move in the same "gravitational frame of reference".
It's too simple in a complex whole as the universe (I think): a straight forward speed versus hanging still.
In the universe you have gravity, curved spacetime, Hubble's law etc. A straight line is no straight line anymore.
A curved road can be straight depending on the gravitational frame of reference.
It's relative.
But in the same gravitational field: the twinparadox will do it.
Edited by Maartenn100, : No reason given.
Edited by Maartenn100, : No reason given.
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Edited by Maartenn100, : No reason given.
Edited by Maartenn100, : No reason given.
Edited by Maartenn100, : No reason given.
Edited by Maartenn100, : No reason given.

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cavediver
Member (Idle past 3643 days)
Posts: 4129
From: UK
Joined: 06-16-2005


(1)
Message 147 of 230 (628924)
08-14-2011 7:14 AM
Reply to: Message 146 by Maartenn100
08-14-2011 5:29 AM


It's far more complex then you think.
Yes, it is. But also more complex than *you* think
If you want to talk about realistic situations with gravity, then we need to be thinking about General Relativity, not Special Relativity. Which means forgetting everything you think you know about the Twin's Paradox and starting from the beginning again.
The space-time we live in is four-dimensional and curved. Our lives are paths through space-time. The distance along a path represents how much time is experienced moving along that path.
The straightest paths are those followed by objects (spaceships, astronauts, planets) in free-fall - so falling freely or in orbit. In other words, those objects that have no forces exerted on them. So the Earth in orbit around the Sun is in free-fall, and its path through space-time is as straight as possible. Same with the Moon, and with an astronaut in the ISS.
Us, standing on the Earth, are experiencing an upward force from the surface of the Earth, preventing us from falling freely to the centre of the Earth. So our path through space-time is not so straight.
Here's the strange bit: in space-time, the straightest path between two points is the LONGEST PATH. Any path that is not straight must be shorter than the straight path. This is because in space-time has a different type of geometry (Pseudo-Riemannian) to our normal experience of the geometry of just space.
So: our path through space-time stood on the Earth is actually shorter than that of an astronaut orbiting in the ISS. Remember, length of space-time path equals time experienced. So, we experience less time stood on the Earth than we would orbiting. We usually think of this as gravitational time-dilation.
As your astronaut accelerates away from the Earth, his acceleration is forcing his space-time path to become much less straight. This makes his path shorter. When he returns to the Earth, his path will have been much shorter than the Earth's. The Earth was in free-fall all the time, and so followed the longest path possible. And so the Earth experiences much more time than the astronaut, and the astronaut appears young compared to his twin on the Earth.
Edited by cavediver, : No reason given.

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Maartenn100
Member (Idle past 4592 days)
Posts: 39
From: Belgium Antwerp
Joined: 08-13-2011


Message 148 of 230 (628927)
08-14-2011 8:43 AM
Reply to: Message 147 by cavediver
08-14-2011 7:14 AM


gravitational theory of relativity
very interesting.
I will complete my hypothesis here on gravitational relativity effects.
I think that there is an effect in gravitational relativity that is not mentioned in relativity:
straight forward path versus curved path.
These are relativistic observations in and outside a 'gravitational frame of reference' like lengthcontraction is in a uniform gravitational field between a moving observer and a an observer who stands still.
1) When I accelerate lineair on Earth, I go straightforward according my gravitanal frame of reference.
2)When an astronaut sees me, he sees me going around in circles on a sphere (Earth).
This from within and from out a gravitational field.
This is a gravitational relativity effect.
(like moving earth versus earth standing still)
So, when you think you go straighforward in the solarsystem, you are following a curved road around the sun.
Relativity=
straight forward acceleration = centripetal acceleration
a = g
I worked this out as follow:
g0 = a = Fb
g0 = relative observed centripetal acceleration of the body from "outside the gravitational system frame of reference".
Fb = actual Newtonian gravitational force on the body of the graviational system.
a = acceleration of the body from the body 'frame of reference (lineair)
The expanding universe
Far starclusters should have a big centripetal acceleration (towards the universe as a whole), so we can calculate their mass by their observed relativistic straightforward acceleration and Newton’s law of gravity. (following this hypothesis)
a = Fb
Fb = G . m1.m2/r^2
So 'curved road' (coriolispath) = "straigh forward speed" and vice versa in gravitational relativity.
So "the expanding universe" is in this hypothesis a relativistic
effect of gravitational relativity instead of caused by a Big Bang.
Edited by Maartenn100, : No reason given.
Edited by Maartenn100, : No reason given.
Edited by Maartenn100, : No reason given.
Edited by Maartenn100, : No reason given.
Edited by Maartenn100, : No reason given.

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 Message 149 by NoNukes, posted 08-14-2011 12:14 PM Maartenn100 has replied

  
NoNukes
Inactive Member


Message 149 of 230 (628931)
08-14-2011 12:14 PM
Reply to: Message 148 by Maartenn100
08-14-2011 8:43 AM


Re: gravitational theory of relativity
g0 = a = Fb
g0 = relative observed centripetal acceleration of the body from "outside the gravitational system frame of reference".
Fb = actual Newtonian gravitational force on the body of the graviational system.
a = acceleration of the body from the body 'frame of reference (lineair)
Some of the quantities you claim are equal (Force and acceleration) do not even have the same units of measurements. So something is definitely wrong with your "math".
Please don't take my comments as encouragement to continue along these lines. But before guessing that some gravity effect is "missing" with respect to relativity, you should at least understand general relativity. So far you have not claimed to have such knowledge and your "hypothesis" does not suggest that you have such knowledge.
For example, we know from actual measurement that GPS satellites experience exactly the relativistic effect predicted by GR/SR, said effect amounting to 45 microseconds/day of time dilation.

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Maartenn100
Member (Idle past 4592 days)
Posts: 39
From: Belgium Antwerp
Joined: 08-13-2011


Message 150 of 230 (628936)
08-14-2011 2:02 PM
Reply to: Message 149 by NoNukes
08-14-2011 12:14 PM


Re: gravitational theory of relativity
g = GM/r^2
I agree with gravitational timedilation but
you can see with your own eyes (I hope) that a when you follow a straight line here on earth, it's a circular path from out of space.
That's the only thing you need to know, when you want to know that a this is a relativistic effect.
it's a very obvious observation.
Ellipsode versus straight path.
The difference in time (gravitationale timedilation) gives this relativistic effect.
That's logic and observable.
Edited by Maartenn100, : No reason given.
Edited by Maartenn100, : No reason given.
Edited by Maartenn100, : No reason given.
Edited by Maartenn100, : No reason given.

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