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#15335 09/20/06 08:06 PM
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Alnitak Offline OP
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We were having a discussion recently about 'the other side of the SOL (Speed Of Light)' when the following became apparent (and please, I am no 'varsity boffin): If time slows down as you approach SOL, at 99.9% time is almost infinitely (?) slow, and AT SOL time stands still, does part of the problem in exceeding SOL lie in a break-down of the basic speed formula V=D/T (Velocity = Distance divided by Time)? Point raised is that - in sticking to the formula fundamentals - in order to get velocity X you need time Y. In (our) layman's terms: as you're approaching SOL and time is "compressed" to near zero, that's OK - you still "have time left" (note the pun), though miniscule, to complete the equation and derive an answer (S). But AT SOL time stands still and you you're left with a zero to divide your D by - you've run out of time to go any faster!? The formula breaks down - or so it seems. Does the argument hold (any) water or are we missing the boat completely?

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#15336 09/21/06 03:03 AM
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From an external viewpoint, (watching the object go by), mass increases as speed increases, and time slows down. - The same force produces less accelleration.

From a internal viewpoint, (inside the moving object), you might believe that you've exceeded C as you get there 'quicker` because your time has slowed.

In relativistic thinking, stick to one 'observer`.

Because it is a 'assymptotic approach` situation,
(1/2, 1/4, 1/8, 1/16....) your exterior observed
time rate approaches zero, but never gets there,
as the energy required to accellerate, increases,
as your mass approaches infinity at C.

#15337 09/25/06 10:03 PM
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I am always mystified by the idea that speeding objects, especially people, will have time "slowed down" for them. My ignorance asks what does time have to do with motion? If my organic clock, the time it takes for certain cells to wear out or die, has a set rate on planet Earth why would that rate excellerate or deminish because I was moving through space faster?

Those of you that are heavy into Einstein's GR seem to accept this on faith, much like some people accept the bible on faith. It is one thing to have a few contentions of a very complex theory find some confirmation in reality but that can not of itself argue for the truth of the entire theory. A comment like "mass increases as speed increases" suggests that while my body functions slowed down and I aged slower as I approsch the speed of light I will be a lump prone on the floor of the ship due to the increased mass of my body that my legs can no long support.

I am confident you all are correct but it is my way to wonder at the idea.

jjw

#15338 09/27/06 02:56 AM
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jjw asks:
"If my organic clock, the time it takes for certain cells to wear out or die, has a set rate on planet Earth why would that rate excellerate or deminish because I was moving through space faster?"

It doesn't. That is not what relativity teaches. From your standpoint, accellerating, changes nothing. What changes is the speed at which the clock, in your frame of reference ticks, in relationship to another clock in a different frame of reference. You are getting confused because you are making an assumption not rooted in relativity.

jjw wrote:
"Those of you that are heavy into Einstein's GR seem to accept this on faith"

No we don't. I don't accept it. I accept what relativity teaches which is not what you stated.

The difference may seem subtle but it is not.


DA Morgan
#15339 09/27/06 07:13 PM
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OK DA:

I leave Earth where my Earth clock has an hour composed of 60 minutes. I am now on a space craft going very fast so my on board clock has 80 minutes in an hour. Your GR, I am told, will have me aging 3/4 as fast as my spot on Earth.

You suggest this is not what is intended. From your presentation I simply have two clocks running at different speeds but my aging is not changing in any way. If so why do so many like to talk about the crew being younger than their Earth stay-at-homes when the travelers return.
That, I admit, is confusing to me. If it is only the clocks that are different then the issue is not relevant to anything except external events?
jjw

#15340 09/27/06 09:22 PM
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jjw wrote:
"I leave Earth where my Earth clock has an hour composed of 60 minutes. I am now on a space craft going very fast so my on board clock has 80 minutes in an hour. Your GR, I am told, will have me aging 3/4 as fast as my spot on Earth."

No NO and NO! That's my point ... you are mis-stating the theory. Your clock does not have 80 minutes in an hour. You continue to age at the exact same rate as always.

Let me see if I can point you down a path that will allow you to see relativity as it actually is.

When I measure distance what am I measuring?
The distance between two points.
I can put a stake in the ground at point A
I can put a stake in the ground at point B
I can run a string between them and declare the distance to be equal to the length of the string.

When I measure time what am I measuring?

What does it mean when we say that a clock measures time?

What does it mean when we say that one clock is more accurate than another?

I want you to give this some serious thought and then I will take you the next step.


DA Morgan
#15341 09/29/06 12:08 AM
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Hi:

I am sorry but I think you are going to become impatient with me and my purpose. Measuring is something I can do but I never use a rubber tape.

I never say "a clock measures time". If pushed to it I would likely say a clock measures elapsed time or possibly, while waiting for my date, I might say a clock measures my time to wait. To me the use of a clock is like a calendar. It tells me what is gone and what should be comming.

You ask; "what does it mean when we say one clock is more accurate than another?" Really!
How do you decide which one is faulty? If we are getting to a point where velocity causes clocks to differ, that is between the one on Earth and the one racing to Neptune, I could likely accept that as reasonable but I still fail to see where people use that to argue space travelers at close to SOL age less. You are very convinced of your GR. I appreciate your efforts.
jjw

#15342 09/29/06 05:58 PM
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I promise not to get impatient so long as we keep somewhere withing sight of the path.

you wrote:
"I never say "a clock measures time".
But you should. That is precisely what it does.

What a clock does is measure the number of times a specified event occurs within a measured period. It might be the pendulum swinging back and forth. Or it might be the number of times a Cesium atom jumps from one energy level to another.

What makes one clock more accurate than another is if you build a bunch of them and put them together ... the more accurate ones stay most closely synchronized.

So lets return to your original premise which was two clocks ticking at rates due to acceleration.

What we are saying is not that the clocks change. Each clock will record exactly the same number of transformations of a cesium atom per minute, or hour, or whatever.

What will change, relatively between the two clocks, is that the number of transformations will be greater for one than the other. In a one hour period one clock might have x transformations whereas the other, perhaps, 1.1x transformations. But to each person observing their clock nothing will change. Only someone observing both clocks will observe a difference.

Hope this helps.


DA Morgan
#15343 09/30/06 12:14 AM
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Hi DA:

That helps me to understand why I find the idea confusing. Your x and 1.1x is about like my 60 minute and 80 minute hour but the "transformations" being used are smaller.

I said: "If it is only the clocks that are different then the issue is not relevant to anything except external events?"

Is that what you are saying?

I know you have better things to do. I do read for myself on these issues and much of my confusion can be trraced to people writting articles with different interpretations and/or explanations. Thank you.
jjw

#15344 09/30/06 05:52 AM
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No 1x and 1.1x are not like 60 and 80 because you are approaching it backward.

Both clocks show 60 minutes. But in one case more measured events happen within that 60 minutes.

It is not the clocks that are different. It is the number of events that correspond with a measurement made by the clock that are different.


DA Morgan
#15345 09/30/06 10:05 PM
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JJW,
My , (hopefully helpful), 2 cents:
You wrote "Measuring is something I can do but I never use a rubber tape."

That is exactly what relativity tells us to do, and
it defines just how, and in what direction to stretch
the 'tape`, both in time and space to make our
observations add up when we look from one set of
conditions, (frame), of gravity or velocity, to another.

It is against our instincts, but it agrees well with our observations to date.

#15346 09/30/06 11:57 PM
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Thank you all for your assist.
jjw


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