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orgaelin · Jan 26, 2004, 06:01 am

I really can't decide whether I'm just not getting it or whether there's some obvious flaw with the idea of time dilation. Any knowledge I have is from reading books and thinking, so the lack of any formal science/physics education often leads to holes in my theories because of little bits and pieces I don't know so well.

That's where you guys come in!

Going over the twins paradox... the version I have comes courtesy of wife-battered Stephen Hawking (the poor sod!). He says that if twin (A) is on a planet and then twin (B) goes off in a space-craft at a speed close to the speed of light, when the two are brought together again, twin (B) will be younger than (A) because time will have been slower for him.

So here's my problem with it: if time is going slower for twin (B), then he will be in the past relative to twin (A) when he returns. In other words, isn't there a chance that he wuold simply come back earlier in compensation for the time-dilation effects and the twins would in fact be the same age still?

OR

Could it be that two frames of reference can be going at a different rate through time (effectively 'rate of change') but still be present together in the same moment of time?

I'm also unsure about the idea that 'every frame of reference has equal right to view themselves as stationary relative to another moving objcet'. Doesn't that cancel out the time dilation too - because either or both twins would/could have dilated?

What am I missing?

harami · Jan 26, 2004, 06:58 pm

I hope there is a physics PhD in the audience. I have been perplexed by this paradox for quite a while and have heard no good answer yet. You would suspect that this question must be asked of physics PhD candidates on doctoral oral examinations quite frequently.

LogicaLunatic · Jan 26, 2004, 09:53 pm

Hey there...

This one bugged me for a LONG time until I started thinking of it in very simple terms.

When you get right down to it here is how it works...

light = time
time = light

We are all moving relative to time. Time is flying past us. The thing that throws most people off is the idea of time flying past us in all directions. Therefore, moving in ANY direction is moving WITH time. When you move WITH time, less time passes you just like less water or wind passes you when you move with it.

In actuality, it has a lot to do with the fact that the faster you go, the more massive you are, etc.

Hope I've clarified it at least a little. I'm actually more confused than I was before I wrote this :)

orgaelin · Jan 27, 2004, 03:52 am

LogicaLunatic - I absolutely *love* your signature! Fantastic!!

I like your thinking on the light/time thing. Very original. I think I gathered that you were implying it just as a 'model', i.e. a way of thinking about it but not the way it actually is? Or did I just imagine that?!

I think the nature of time is one of the greatest mysteries, but also one of the most important things to understanding the way the universe works. If you can crack time, everything else should just come easily.

If Einstein had lived longer, do you think he would have cracked it by now?

How about this model: space is multi-directional, in that you can go any which way you please. What if time, as just another dimension like the other three, was multi-directional too? That would mean that when time appears to slow down for you it could be because you are going 'diagonally' in time, relative to a stationary person going in a straight line. Then either person could view themselves as going at the correct rate through time, and either could/would see the other as going slower relative to them. The true measure of time, then, would be in-between them... I think?

I think the hardest thing is getting an idea from your own head in to somebody else's without having it missunderstood or without sending the other person into a deep hypnotic trance!!

Another thing I struggle to get my head around is the whole light-speed thing. I just don't like it at all! I refuse, for example, to believe that light has no mass. If it did it would not be limited on speed and it would not be slowed down upon 'contact' (how can something with no mass come into contact with anything else?) with water or glass.

But that's another argument! This is why I love physics... it's like the ultimate mystery, the solution to which is always just one step away, or so it seems.

orgaelin · Jan 27, 2004, 04:34 am

This image should illustrate my point.

The red A is the path through time of a stationary object. The red B is the path through time that another object takes if it is moving very fast through space. You can see that red A will reach the red line first (red line = a specific moment in time)

Then we turn the diagram slightly so that red B (now shown in black) is now going straight. Remember all we have changed is the point of view from which we are looking at it. From this second point of view we can see that now red (now black) A is moving more slowly through time relative to B.

Basically, it all depends on which one you look at or measure. But what happens if you don't measure either? I have a hard time believing the accepted view that they are in a superposition of states - both ahead and both behind in time untill someone chooses one to measure.

LogicaLunatic · Jan 27, 2004, 08:50 am

Thats the diagram that I've always used when thinking about the subject.

Now, on the the nature of light and the problems with how it is currently seen...

Speculations on the Nature of Light

orgaelin · Jan 27, 2004, 08:57 am

Do you wanna run by us a little explanation of that diagram?!

LogicaLunatic · Jan 27, 2004, 09:15 am

Yes sorry :)

A & B are two points in space. 1, 2 & 3 are events on the vertical line that represents time. The jumble of lines between the events is a way to show when A sees event X relative to when event X actually happened at point B.

This actually started out quite simply, with two vertical lines and a diagonal line between them but as I started thinking about it more I needed to add more lines and its gotten to the point that perhaps I'm the only person that understands my jumbled diagram :)

Take event 1 for example. It happens at the same TIME for both A and B(same spot on the verticle lines). The first horizontal line represents when both points SEE the others' event in SPACETIME.

Also, if you imagine the dialonal lines as more of a spiral and assume the points are the Earth and the Sun you can begin to see the following...

1) Everything travels through time in a strait line.
2) Spacetime is curved and is why bodies appear to go around eachother.

LogicaLunatic

orgaelin · Jan 27, 2004, 11:55 am

Have to admit I'm still struggling! Am I being stupid? This is what I mean about the difficulty of transferring great ideas using not-so-great language!

FC Mellon · Jan 27, 2004, 03:05 pm

If Christ were born twins...and the three wise men thought it was best to separate them at birth so as to justify their beliefs and convince others whom they may have alerted as to what their mission was all about....and then many years later if the missing twin were to come back at a convenient time and recognized his twin brother before the cruxifiction and decided to take advantage of the situation and after the cruxifiction and when no one was looking knocked out the guard and rolled the boulder away from the cave and took his dead brother away and buried him..and then returned as the 'Incarnated Christ'...I guess one could determine 'Time & Space' would have no effect on Objects whether they were 'of this time or another time'..no matter the distance/time which had passed. Belief in any system/theory/religion/philosophy/etc. might always have the opportunity to be wrong...but then that is why we might have erasers on the ends of some of our pencils.
p.s. ..imo..until we humans have absolute proof...but not necessarily proof by our means...then we may never fully understand the uncertainties of 'time/space'....just a thought. 8?)
p.p.s.s. ...the above scenario might allow Christ to be seen in two places at the same time...especially places which were many many many miles apart...and others might think this would have to be of a 'divine nature' to have this happen...or of a scientific feat utilizing both time/space to justity this happening. So whether one is using a 'rod for their divining'...or a 'rod for their measurements'...the speed of which they may discover 'The Truth' may have nothing to do with the 'space' involved...even though 'time' may have been of the essence. }?]
....OK...so I am just being stupid...but it is a thought!!

orgaelin · Jan 28, 2004, 07:05 am

Melon, I think your point in all that was that even if you're really really really certain, there still could have been some other thing that really happened or really is that you just didn't think of. In other words, you could always be wrong.

You're right!

There's always an element of uncertainty and a chance that you could be wrong (with some more so than with others!) but when we do arrive at a 'final' conclusion it is not based on absolutes, proof, or anything so concrete. (Actually maybe I should be saying 'me' instead of "we".)

Like I said in another post to you today, you have to always be open to new possibilities.

I have to wonder, though, why on earth you're ranting about Jesus in the science & technology section, in a topic which relates to time dilation!

I know you were taking the piss. But I've only seen (I think) two of your posts and both were taking the piss. Have you read the etiquette for this site? It has a link to a site which gives a lengthy treatise on 'how to argue' and it states very clearly, often in red and emboldened text, that the very moment you mock, or cause to look foolish or silly, your oponent in any argument/debate, you have lost.

'nuf said?

FC Mellon · Jan 28, 2004, 08:41 am

Orgaelin...
You are correct...and I will properly flush now and sorry I left the door open while relieving myself of things which apparently have no business here. Sorry...I will do my business elsewhere. Though if one had an open mind..(and not necessarily even deep)..one might start to understand the 'Time/Space' aspects of what I was presenting...no matter the model I was using. I realize it is difficult to make a silk purse out of a sow's ear...even if the ear possesses 'rings' which give the appearance of the ability to 'get it'...sorry for disturbing your silence.
p.s. sorry for 'tinkling' on your parade...and during the A's and B's of things...don't forget the other dimensions...and at least start to 'C' there are other ways of understanding things...even if these things are dimensions one has never allowed themselves to entertain.
8?) ...off to find another room where some of the guests don't appear to be running the show...especially when they...oh...nevermind.....

nokton · Feb 13, 2004, 01:55 pm

Hi Daydreamer,if you believe Albert,and I do,most of the time....
An observers awareness of the passage of time is dictated by the
relative speed of the observer,and the local gravity conditions.
Albert demonstrated quite clearly in this instance,that speed
and gravity affects the passage of time,as we understand it.
Go to the event horizon of a black hole,Daydreamer,to me here,
you are in stasis,to yourself,everything is normal.We exist in different
time frames,so it follows,if you embark on a journey through space at near
lightspeed for a few months,you will come back to see your daughter a
grandmother.
My first time on this site,a newby,so to speak,but I like and enjoy,
the posts I read here.Ignorance may be bliss,but knowledge and understanding
is the true joy

Xander · Feb 14, 2004, 11:03 am

Alright...

Einstein's Special Theory of Relativity states that as an object approaches the Speed of Light, Time for that object begins to slow down RELATIVE to its "stationary" surroundings. And when an object reaches EXACTLY the Speed of Light, Time for that object ceases completely RELATIVE to its "stationary" surroundings. Note that I put 'stationary' in "" because supposedly there is nothing in the Universe that is ABSOLUTELY stationary in that things are always moving somewhat in reference to another object. But that is slightly another subject...

There is actually proof that Time Dilation exists. Take the GPS (Global Positioning Satellite) for example. It rotates the earth at some 18,000 miles per hour, and it MUST by very purpose keep precise and acurate time for equipment here on earth ALL of the time. Because it travels at this speed, the engineers who developed it designed it to COMPENSATE for the Time loss.

Yeah...put that in your pipe and smoke it!

nokton · Feb 14, 2004, 12:43 pm

Xander,thanks,but I smoke only Louisiana Perique in my pipes.
Alberts STR,if you study it,denies your assertion that time only
starts to slow down at near lightspeed.Time varies progressively
as speed/gravity increases,and slows.Time does not dilate,it is a variable
determined by the above speed/gravity scenario.Conversely,time runs
'faster'when speed/gravity decreases.
When matter reaches lightspeed it becomes energy,hence E=MC^.
Your contention that 'nothing in the universe is stationary',
contradicts the fact of absolute zero and it's implication.

Feb 15, 2004, 01:53 pm

I read a book by Paul Davies that seemed to clear the twins up for me. There is a simple solution to it, it is just always overlooked. Next time I'm on I'll read it to you its a little long and I'm about to eat. LogicaLunatic, where did you go to college or are you still in college?

Mathieu · Feb 15, 2004, 02:26 pm

One of the best proof of time dilatation is the observation of Muons. Muons are the most abundant particle in the cosmic ray at an altitude around some kilometer. They travel in direction of the ground at speed close to speed of light. The experience consisted of mesuring the time took by the muons to to travel a couple thousand meters, with clock constitued of the muons themselves and other clock fixed to earth referential. THey installed one detector of the summit of mount Washington, at a 1910m altitude. The detector was set to detect particles with a speed between 0.9950c and 0.9954c. So around 99.52% of speed of light. The detector at the summit of the mount detected 563+-10 muons/hour with such speed. When they moved the detector to an altitude of around 3 meter above sea level, they detected 408+-9 muons by hours. The muons detected on ground an in altitude were not the same, but the intensity of the cosmic rays do not changefrom a place to another, at least, not with the distance wich separated the detectors. If we calculate the time it took for the muons to travel from the summit to the ground, in the earth referential, we find that (1910-3)/(0.992c)=5.4 * 10^-6 s. The half life of muons in the lab referential is determined by experience and is 1.53 * 10^-6 sec.
As much more than the half of the muons made it to the ground, we must derive that the time in the muon referential must be quite smaller than the one in the earth referential.

To know the number of particles wich stay after a certain time we use this equation:

N =N0 e ^(-t/to) where to is the average life of a particle.
If you solve for N = N0/2 and t = half life, you get to=2.21*10^-6.

Using the result form the detector, setting 563 as N0 and 408 as N, we find a time of 0.715*10^-6 wich is the time in the muon referential.If we do the ratio of the muon referential time and the earth referential time, we get 0.11. Using time dilatation formula, the ration is

(1-(o.992)^2)^(1/2) =0.13.

The result include each other, taking in consideration the error margin.

In accelerators , we deal with particle with half time much smaller than the one of the muon. As the desintegration here took 9 time more time than the one in the lab, we must understand that time dilatation is an every day reality for particle physicist.

Comrade · Feb 15, 2004, 07:16 pm

Time travel is an interesting but pointless debate.
Time is human concept. There is no giant timeline of events that you can fast forward or back on.

Mathieu · Feb 15, 2004, 11:02 pm

What about the entropy? The universe entropy always stays equal or grow. This to me appear like a direction in time, a least until universe thermalize.

Edge · Feb 16, 2004, 01:59 pm

</span><blockquote><span class="smallfont">Quote:</span><hr size="1" />Originally Posted by (Comrade,)
Time travel is an interesting but pointless debate.
Time is human concept. There is no giant timeline of events that you can fast forward or back on.<hr size="1" /></blockquote><span class='postcolor'>

I believe that Richard Feynman (physicist from from Cal Institute of Tech), Einstein, and a few others would dissagree with you. Time is not a human concept but our observation of it is. According to quantum mechanics, time is itself quantized. The smallest unit of measurement is (I believe) about 1x10-33 seconds. Time, like other dimensions, are curled and "coupled", for lack of a better term that I can think of right now, with every other dimension, and every particle in the universe. You "see" time through the perspective of space-time, as such, your observation of time is colored by the space that you exist in.

Jan 26, 2004, 06:01 am	#1 (permalink) (top)
orgaelin Igneous Magma Location: Midlands UK Posts: 704	I really can't decide whether I'm just not getting it or whether there's some obvious flaw with the idea of time dilation. Any knowledge I have is from reading books and thinking, so the lack of any formal science/physics education often leads to holes in my theories because of little bits and pieces I don't know so well. That's where you guys come in! Going over the twins paradox... the version I have comes courtesy of wife-battered Stephen Hawking (the poor sod!). He says that if twin (A) is on a planet and then twin (B) goes off in a space-craft at a speed close to the speed of light, when the two are brought together again, twin (B) will be younger than (A) because time will have been slower for him. So here's my problem with it: if time is going slower for twin (B), then he will be in the past relative to twin (A) when he returns. In other words, isn't there a chance that he wuold simply come back earlier in compensation for the time-dilation effects and the twins would in fact be the same age still? OR Could it be that two frames of reference can be going at a different rate through time (effectively 'rate of change') but still be present together in the same moment of time? I'm also unsure about the idea that 'every frame of reference has equal right to view themselves as stationary relative to another moving objcet'. Doesn't that cancel out the time dilation too - because either or both twins would/could have dilated? What am I missing? "Only two things are infinite, the universe and human stupidity, and I'm not sure about the former." - Albert Einstein

Jan 26, 2004, 09:53 pm	#3 (permalink) (top)
LogicaLunatic Hrm... Location: MN Posts: 445	Hey there... This one bugged me for a LONG time until I started thinking of it in very simple terms. When you get right down to it here is how it works... light = time time = light We are all moving relative to time. Time is flying past us. The thing that throws most people off is the idea of time flying past us in all directions. Therefore, moving in ANY direction is moving WITH time. When you move WITH time, less time passes you just like less water or wind passes you when you move with it. In actuality, it has a lot to do with the fact that the faster you go, the more massive you are, etc. Hope I've clarified it at least a little. I'm actually more confused than I was before I wrote this :) "Statistics show that of those who contract the habit of eating, very few survive." -- Wallace Irwin

Jan 27, 2004, 03:52 am	#4 (permalink) (top)
orgaelin Igneous Magma Location: Midlands UK Posts: 704	LogicaLunatic - I absolutely love your signature! Fantastic!! I like your thinking on the light/time thing. Very original. I think I gathered that you were implying it just as a 'model', i.e. a way of thinking about it but not the way it actually is? Or did I just imagine that?! I think the nature of time is one of the greatest mysteries, but also one of the most important things to understanding the way the universe works. If you can crack time, everything else should just come easily. If Einstein had lived longer, do you think he would have cracked it by now? How about this model: space is multi-directional, in that you can go any which way you please. What if time, as just another dimension like the other three, was multi-directional too? That would mean that when time appears to slow down for you it could be because you are going 'diagonally' in time, relative to a stationary person going in a straight line. Then either person could view themselves as going at the correct rate through time, and either could/would see the other as going slower relative to them. The true measure of time, then, would be in-between them... I think? I think the hardest thing is getting an idea from your own head in to somebody else's without having it missunderstood or without sending the other person into a deep hypnotic trance!! Another thing I struggle to get my head around is the whole light-speed thing. I just don't like it at all! I refuse, for example, to believe that light has no mass. If it did it would not be limited on speed and it would not be slowed down upon 'contact' (how can something with no mass come into contact with anything else?) with water or glass. But that's another argument! This is why I love physics... it's like the ultimate mystery, the solution to which is always just one step away, or so it seems. "Only two things are infinite, the universe and human stupidity, and I'm not sure about the former." - Albert Einstein

Jan 27, 2004, 04:34 am	#5 (permalink) (top)
orgaelin Igneous Magma Location: Midlands UK Posts: 704	This image should illustrate my point. The red A is the path through time of a stationary object. The red B is the path through time that another object takes if it is moving very fast through space. You can see that red A will reach the red line first (red line = a specific moment in time) Then we turn the diagram slightly so that red B (now shown in black) is now going straight. Remember all we have changed is the point of view from which we are looking at it. From this second point of view we can see that now red (now black) A is moving more slowly through time relative to B. Basically, it all depends on which one you look at or measure. But what happens if you don't measure either? I have a hard time believing the accepted view that they are in a superposition of states - both ahead and both behind in time untill someone chooses one to measure. "Only two things are infinite, the universe and human stupidity, and I'm not sure about the former." - Albert Einstein

Jan 27, 2004, 08:50 am	#6 (permalink) (top)
LogicaLunatic Hrm... Location: MN Posts: 445	Thats the diagram that I've always used when thinking about the subject. Now, on the the nature of light and the problems with how it is currently seen... Speculations on the Nature of Light "Statistics show that of those who contract the habit of eating, very few survive." -- Wallace Irwin

Jan 26, 2004, 06:58 pm	#2 (permalink) (top)
harami bear Posts: 88	I hope there is a physics PhD in the audience. I have been perplexed by this paradox for quite a while and have heard no good answer yet. You would suspect that this question must be asked of physics PhD candidates on doctoral oral examinations quite frequently.

Jan 27, 2004, 08:57 am	#7 (permalink) (top)
orgaelin Igneous Magma Location: Midlands UK Posts: 704	Do you wanna run by us a little explanation of that diagram?! "Only two things are infinite, the universe and human stupidity, and I'm not sure about the former." - Albert Einstein

Jan 27, 2004, 09:15 am	#8 (permalink) (top)
LogicaLunatic Hrm... Location: MN Posts: 445	Yes sorry :) A & B are two points in space. 1, 2 & 3 are events on the vertical line that represents time. The jumble of lines between the events is a way to show when A sees event X relative to when event X actually happened at point B. This actually started out quite simply, with two vertical lines and a diagonal line between them but as I started thinking about it more I needed to add more lines and its gotten to the point that perhaps I'm the only person that understands my jumbled diagram :) Take event 1 for example. It happens at the same TIME for both A and B(same spot on the verticle lines). The first horizontal line represents when both points SEE the others' event in SPACETIME. Also, if you imagine the dialonal lines as more of a spiral and assume the points are the Earth and the Sun you can begin to see the following... 1) Everything travels through time in a strait line. 2) Spacetime is curved and is why bodies appear to go around eachother. LogicaLunatic "Statistics show that of those who contract the habit of eating, very few survive." -- Wallace Irwin

Jan 27, 2004, 11:55 am	#9 (permalink) (top)
orgaelin Igneous Magma Location: Midlands UK Posts: 704	Have to admit I'm still struggling! Am I being stupid? This is what I mean about the difficulty of transferring great ideas using not-so-great language! "Only two things are infinite, the universe and human stupidity, and I'm not sure about the former." - Albert Einstein

Jan 27, 2004, 03:05 pm	#10 (permalink) (top)
FC Mellon Molten Ash Location: So Cal Posts: 51	If Christ were born twins...and the three wise men thought it was best to separate them at birth so as to justify their beliefs and convince others whom they may have alerted as to what their mission was all about....and then many years later if the missing twin were to come back at a convenient time and recognized his twin brother before the cruxifiction and decided to take advantage of the situation and after the cruxifiction and when no one was looking knocked out the guard and rolled the boulder away from the cave and took his dead brother away and buried him..and then returned as the 'Incarnated Christ'...I guess one could determine 'Time & Space' would have no effect on Objects whether they were 'of this time or another time'..no matter the distance/time which had passed. Belief in any system/theory/religion/philosophy/etc. might always have the opportunity to be wrong...but then that is why we might have erasers on the ends of some of our pencils. p.s. ..imo..until we humans have absolute proof...but not necessarily proof by our means...then we may never fully understand the uncertainties of 'time/space'....just a thought. 8?) p.p.s.s. ...the above scenario might allow Christ to be seen in two places at the same time...especially places which were many many many miles apart...and others might think this would have to be of a 'divine nature' to have this happen...or of a scientific feat utilizing both time/space to justity this happening. So whether one is using a 'rod for their divining'...or a 'rod for their measurements'...the speed of which they may discover 'The Truth' may have nothing to do with the 'space' involved...even though 'time' may have been of the essence. }?] ....OK...so I am just being stupid...but it is a thought!!

Jan 28, 2004, 07:05 am	#11 (permalink) (top)
orgaelin Igneous Magma Location: Midlands UK Posts: 704	Melon, I think your point in all that was that even if you're really really really certain, there still could have been some other thing that really happened or really is that you just didn't think of. In other words, you could always be wrong. You're right! There's always an element of uncertainty and a chance that you could be wrong (with some more so than with others!) but when we do arrive at a 'final' conclusion it is not based on absolutes, proof, or anything so concrete. (Actually maybe I should be saying 'me' instead of "we".) Like I said in another post to you today, you have to always be open to new possibilities. I have to wonder, though, why on earth you're ranting about Jesus in the science & technology section, in a topic which relates to time dilation! I know you were taking the piss. But I've only seen (I think) two of your posts and both were taking the piss. Have you read the etiquette for this site? It has a link to a site which gives a lengthy treatise on 'how to argue' and it states very clearly, often in red and emboldened text, that the very moment you mock, or cause to look foolish or silly, your oponent in any argument/debate, you have lost. 'nuf said? "Only two things are infinite, the universe and human stupidity, and I'm not sure about the former." - Albert Einstein

Jan 28, 2004, 08:41 am	#12 (permalink) (top)
FC Mellon Molten Ash Location: So Cal Posts: 51	Orgaelin... You are correct...and I will properly flush now and sorry I left the door open while relieving myself of things which apparently have no business here. Sorry...I will do my business elsewhere. Though if one had an open mind..(and not necessarily even deep)..one might start to understand the 'Time/Space' aspects of what I was presenting...no matter the model I was using. I realize it is difficult to make a silk purse out of a sow's ear...even if the ear possesses 'rings' which give the appearance of the ability to 'get it'...sorry for disturbing your silence. p.s. sorry for 'tinkling' on your parade...and during the A's and B's of things...don't forget the other dimensions...and at least start to 'C' there are other ways of understanding things...even if these things are dimensions one has never allowed themselves to entertain. 8?) ...off to find another room where some of the guests don't appear to be running the show...especially when they...oh...nevermind.....

Feb 13, 2004, 01:55 pm	#13 (permalink) (top)
nokton Sedimentary Rock Posts: 7	Hi Daydreamer,if you believe Albert,and I do,most of the time.... An observers awareness of the passage of time is dictated by the relative speed of the observer,and the local gravity conditions. Albert demonstrated quite clearly in this instance,that speed and gravity affects the passage of time,as we understand it. Go to the event horizon of a black hole,Daydreamer,to me here, you are in stasis,to yourself,everything is normal.We exist in different time frames,so it follows,if you embark on a journey through space at near lightspeed for a few months,you will come back to see your daughter a grandmother. My first time on this site,a newby,so to speak,but I like and enjoy, the posts I read here.Ignorance may be bliss,but knowledge and understanding is the true joy

Feb 14, 2004, 11:03 am	#14 (permalink) (top)
Xander Sedimentary Rock Posts: 3	Alright... Einstein's Special Theory of Relativity states that as an object approaches the Speed of Light, Time for that object begins to slow down RELATIVE to its "stationary" surroundings. And when an object reaches EXACTLY the Speed of Light, Time for that object ceases completely RELATIVE to its "stationary" surroundings. Note that I put 'stationary' in "" because supposedly there is nothing in the Universe that is ABSOLUTELY stationary in that things are always moving somewhat in reference to another object. But that is slightly another subject... There is actually proof that Time Dilation exists. Take the GPS (Global Positioning Satellite) for example. It rotates the earth at some 18,000 miles per hour, and it MUST by very purpose keep precise and acurate time for equipment here on earth ALL of the time. Because it travels at this speed, the engineers who developed it designed it to COMPENSATE for the Time loss. Yeah...put that in your pipe and smoke it!

Feb 14, 2004, 12:43 pm	#15 (permalink) (top)
nokton Sedimentary Rock Posts: 7	Xander,thanks,but I smoke only Louisiana Perique in my pipes. Alberts STR,if you study it,denies your assertion that time only starts to slow down at near lightspeed.Time varies progressively as speed/gravity increases,and slows.Time does not dilate,it is a variable determined by the above speed/gravity scenario.Conversely,time runs 'faster'when speed/gravity decreases. When matter reaches lightspeed it becomes energy,hence E=MC^. Your contention that 'nothing in the universe is stationary', contradicts the fact of absolute zero and it's implication.

Feb 15, 2004, 01:53 pm	#16 (permalink) (top)
theophysics Guest Posts: n/a	I read a book by Paul Davies that seemed to clear the twins up for me. There is a simple solution to it, it is just always overlooked. Next time I'm on I'll read it to you its a little long and I'm about to eat. LogicaLunatic, where did you go to college or are you still in college?

Feb 15, 2004, 02:26 pm	#17 (permalink) (top)
Mathieu Igneous Magma Location: Montreal Posts: 216	One of the best proof of time dilatation is the observation of Muons. Muons are the most abundant particle in the cosmic ray at an altitude around some kilometer. They travel in direction of the ground at speed close to speed of light. The experience consisted of mesuring the time took by the muons to to travel a couple thousand meters, with clock constitued of the muons themselves and other clock fixed to earth referential. THey installed one detector of the summit of mount Washington, at a 1910m altitude. The detector was set to detect particles with a speed between 0.9950c and 0.9954c. So around 99.52% of speed of light. The detector at the summit of the mount detected 563+-10 muons/hour with such speed. When they moved the detector to an altitude of around 3 meter above sea level, they detected 408+-9 muons by hours. The muons detected on ground an in altitude were not the same, but the intensity of the cosmic rays do not changefrom a place to another, at least, not with the distance wich separated the detectors. If we calculate the time it took for the muons to travel from the summit to the ground, in the earth referential, we find that (1910-3)/(0.992c)=5.4 * 10^-6 s. The half life of muons in the lab referential is determined by experience and is 1.53 * 10^-6 sec. As much more than the half of the muons made it to the ground, we must derive that the time in the muon referential must be quite smaller than the one in the earth referential. To know the number of particles wich stay after a certain time we use this equation: N =N0 e ^(-t/to) where to is the average life of a particle. If you solve for N = N0/2 and t = half life, you get to=2.2110^-6. Using the result form the detector, setting 563 as N0 and 408 as N, we find a time of 0.71510^-6 wich is the time in the muon referential.If we do the ratio of the muon referential time and the earth referential time, we get 0.11. Using time dilatation formula, the ration is (1-(o.992)^2)^(1/2) =0.13. The result include each other, taking in consideration the error margin. In accelerators , we deal with particle with half time much smaller than the one of the muon. As the desintegration here took 9 time more time than the one in the lab, we must understand that time dilatation is an every day reality for particle physicist.

Feb 15, 2004, 07:16 pm	#18 (permalink) (top)
Comrade Hot Lava Location: Texas Posts: 1,229	Time travel is an interesting but pointless debate. Time is human concept. There is no giant timeline of events that you can fast forward or back on. Oh, it's really too bad, isn't it? -- http://story.news.yahoo.com/news?tmpl=story&u=/050121/480/watw10701210224 Hahaha, that's funny. Liberals are so silly!

Feb 15, 2004, 11:02 pm	#19 (permalink) (top)
Mathieu Igneous Magma Location: Montreal Posts: 216	What about the entropy? The universe entropy always stays equal or grow. This to me appear like a direction in time, a least until universe thermalize.

Feb 16, 2004, 01:59 pm	#20 (permalink) (top)
Edge Molten Ash Posts: 76	</span><blockquote><span class="smallfont">Quote:</span><hr size="1" />Originally Posted by (Comrade,) Time travel is an interesting but pointless debate. Time is human concept. There is no giant timeline of events that you can fast forward or back on.<hr size="1" /></blockquote><span class='postcolor'> I believe that Richard Feynman (physicist from from Cal Institute of Tech), Einstein, and a few others would dissagree with you. Time is not a human concept but our observation of it is. According to quantum mechanics, time is itself quantized. The smallest unit of measurement is (I believe) about 1x10-33 seconds. Time, like other dimensions, are curled and "coupled", for lack of a better term that I can think of right now, with every other dimension, and every particle in the universe. You "see" time through the perspective of space-time, as such, your observation of time is colored by the space that you exist in.