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 Be the first pioneers to continue the Astronomy Discussions at our new Astronomy meeting place...The Space and Astronomy Agora Time Dilation Explained (as I Know It) In Illustrative Fashion...{attn: Paul Rest} Forum List | Follow Ups | Post Message | Back to Thread TopicsPosted by nåte/">nåte on October 6, 1998 05:53:45 UTC

First, one has to visualize the dimension of time and space as an entity beyond nothingness. It is true that space is nothing, and besides itself holds nothing. However, a way to visualize time and space is to observe how the effects of gravity and velocity reveal its very nature. What a better way to observe "nothingness" than to observe two, if you will, "recipricols" of time/space.

Lets start with gravity. The phenomenon of gravity is quit amazing in fact. The force that a mass has among another mass is that of attraction to eachother. One can visualize this in a two dimensional field by assuming a rubber sheet suspended in air being held at the four corners of the mat. place a heavy ball or object in the center and notice the distortion the "mass" has on the mat. (space time) If you were to place a smaller mass near this depression it would "pull" towards the center of the mass. the key thing here is 'center' of the mass. gravity always has its point of origin from the center. One can see how this relates to, and is reality in our dimension of time and space. The effect is there.

Now, where does time and velocity come in here? Well, imagine a grid of lines inscribed on that rubber mat. If there is a mass present those lines that form a grid are now quite distorted. (depending on the amount of gravitation...) Now the concept of time comes in... Imagine time moving at the speed of light traveling on those lines on the mat. Without the presence of gravity the lines seem straight. In the presence of gravity the lines seem distorted, right? well in fact they are, but it depends on what frame of reference you are observing. Imagine you are an observer from the "straight" line area observing the "curved" space/time far away. well, when light (which remains at a constant velocity (c)) is traveling along the "curved" portion of time/space it appears to takes longer for it to travel the same "apparent" distance from your perspective. Now on the same note, say you were observing light travel on the "straight" portion of space/time, from the "curved" portion of time/space. Well, the "apparent" time it takes for the light to travel on the straight path seems to go faster; thus time dilation in both instances.

Now, time dilation is not limited to gravitational forces... it also is related and affected by velocity.. If you could approach the speed of light, time and space would become more and more curved; until eventually space and time would be infinitely curved. this, however, would only be possible if one could achieve the velocity of light. thus the effects of time dilation are apparent in velocity factors as well.

there are other factors that happen in both gravitional and velocity time dilation as well. Like length contraction, mass increase, ect. However, these are all apparent increases. They are only observable from someone observing from a stationary reference. It is interesting to note that given that these effects (mass increase) are apparent to the stationary observer, how these "affect" the traveler are quite apparent. Thus the reason it is impossible to reach the speed of light, due to theoritical mass increase. Even though if you were to observe your own space craft traveling this speed you would notice no mass increase or length contraction, just you would notice the ever increasing need of energy to accelerate at an exponential rate.

Note: You would observe, looking at the outside universe, time and space "becoming" infinitely curved, till eventually (if you could travel (c)) time would stop, this dimension would be gone... But your apparent mass would be infinite and your apparent volume... zero. :)

I hope this will clarify or illustrate for you. I choose visual exzamples because this is the way I think and visualize much of physics.

take care...

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