What does light speed have to do with time?

Question

There is a theory that says if you move at the speed of light you will stop time. why? what does a speed have to do with time? Light speed is just a way of measuring a cartain speed. It's like saying "if you go 60mph you can pass through solid matter. There is no reason that you should be adle to. So why if you are traveling at the speed of light would time stop?

It is not actually you that you r looking at it is just your image. it is like when a star goes out, the light could take millions of years to get here but the star still went out even thought the light has not stopped traveling twardsd us.

Answer 1

The first thing you have to do to find an answer to your question is to stop thinking of time as being a natural feature of the universe. It isn't. Time is a human concept we use to separate events into past, present and future. There is no Cosmic Master Clock that keeps track of correct universal time. Einstein theorized this, and countless experiments since have proven him right. Time is not absolute. Time is relative. If you leave Earth at some high percentage of light speed and I can somehow monitor a clock on your spaceship (..which I couldn't really do) that clock would seem to be moving slower than mine. On the other hand, if you could somehow monitor my clock back here on Earth you'd see it ticking away faster. I could say that your time is wrong, and you could say that my time is wrong. Who's right? Both of us! Time is relative.

The only direct relationship of light to time is that it takes time (..as we perceive it) to move from one point to another.

Answer 2

As people have already tried to explain it thoroughly I'll give a simple example.

Image an airplane that can move at 1000mph top speed.

It can move 1000 up, 1000 left, OR 1000 forward (note the OR, not an and)

If the plane is going to move up and to the left, only some of the speed will be in each direction and add up to 1000 diaganally.

Now add a fourth direction, time. If the plane is stationary it is moving through time at 1000 mph. If it is moving forward at 1000mph than it can't be moving in any other direction (including time) - (this assumes the speed of light is 1000mph which it isn't).

If you were a photon of light created during the big bang, you wouldn't think you've aged a single bit. In fact you wouldn't have even had your first thought yet.

Answer 3

This theory gets confused in interpretation. If you move at the speed of light, time does not really stop. It only appears to stop...alright, I'll explain. The reason we see an object is because light bounces off of it and hits our eyes moving at the speed of light. Now suppose our eyes were moving away from the reflected light at the speed of light, so our eyes and the reflected light were moving at the same speed. This means I would be seeing the same moment of reflected light, making it seem as if time were standing still.
This goes into a discussion that time is "Relative," which goes into a lengthy discussion. Stephen Hawkings "a brief history of time" is a short read that will clarify any questions you may have on this topic.

Answer 4

the theory isnt that you will stop time it just means time will as far as the person traveling at such a speed is concerned time will stop until they reach sub-light speed. and unlike saying "if you go 60mph you can pass through solid matter" It has ben proven velosity can effect time using nuclear clocks, one sitting still and the other traveling for 12 hours at twice the speed of sound caused a nanoseconds difference.

Answer 5

No, time never stops, but you can speed it up and slow it down relative to the rest of the universe.

We commonly think in 3 dimensions, time is the fourth dimension of our personal universe ... and you know it ... it is passing right now wherever you are.

Time is very much a part of our universe. If you went to Mars and back faster than the speed of light ( 186,000 Miles per Second ) you would arrive back here before you left!

What, you don't believe that, neither do I but it's part of the true understanding of ourselves and the universe we exist in!

Albert Einstein understood this and it is this theory that , unfortunately, led to the atomic/hydrogen bomb, ( not Al's fault !)

Time is a physical dimension in our universe ... and it can be changed. Time is quite clearly the fourth dimension in our space time continuum. There are four dimensions in our world, not three!

Hope you can come to understand.

Your question provoked me to think about how I could begin to explain it to you. Thanks for the question. It's a deep subject ... hope I explained a little.

Yours Truly;
Jonnie,
AKA DrChicago
Email me if you want.

Answer 6

This is known as time dilation and was discovered by a mathematician named Lorentz.

It is best explained by the light clock visual example:
http://home.earthlink.net/~chkingston/LightClock.htm
http://en.wikipedia.org/wiki/Light_clock

Basically let's say there is a cart with your friend on it. The cart has a light clock on it which consists of two plates and a photon of light bounces up and down between the two plates. Up and down once counts as one second.

You and your friend calibrate your watches to the light clock and then your friend in the cart takes off and travels at something like half the speed of light.

As your friend on the cart goes speeding by, to you, the photon no longer appears to travel up and down, because it's moving horizontally at the same time, since the cart it is on is moving. So from your perspective, the photon takes a diagonal path up and down, and if you traced it you'd see the path forms zigzaging triangles. like /\/\/\/\/\/\/\/\/\/\/\

If you know some basic trigonometry you know that the slanted part, the hypotenuse, of a right triangle is longer than the legs of the triangle. So from your perspective the photon takes a longer path.

Since the speed of light is a constant, the photon can't speed up to strike the plates at the same time your watch ticks. it takes longer to do this because it must travel a longer path from your perspective. So when you compare your watch to the light clock, the light clock is running slow.

But wait, to your friend on the cart, the photon still travels up and down because he is traveling with the light clock, and his watch ticks with the light clock. This means, from your perspective your friend is running slow too. In fact, everyone on the cart looks like it's running slow!

Not only that, but to your friend, his watch is running fine and everyone on the ground that he is passing on the cart looks like it's running slow, because if the light clock were on the ground, he'd see the photon take the longer path.

Now why does time stop at the speed of light? It doesn't really, the actual equation describing all of this is "undefined" at the speed of light. It can't give any useful information for what happens at that point. But it can tell us what happens infinitly close to that point, an what happens is the closer you get to the speed of light, the slower time goes.

Back to the light clock. The faster you see the cart go, the the shallower the angle the path of the photon takes becomes, and with this, the longer the path becomes and the longer it takes for the photon to strike each plate from your perspective. As the cart nears the speed of light, things start to move so slow on the cart from your perspective, it looks as if time has stopped on the cart. Your friend is nearly "paused" as is the light clock.

From your friend's point of view, you and everyone on the ground looks much the same way.

I hope this helps. The wikipedia link will show you the math if you should care to see it.

Answer 7

You just mention 60mph? -- miles per hour, right? there are time factor involved! So do the SPEED of light, there time involved too.Light travels in the form of wavelenght at a speed of about 300,000 km per sec. in space. A about 186,000 miles per sec. Meaning light can goes around the Earth eight times in one second. That why people like to compare speed and time with light, because it travel so fast!

Answer 8

Good question ... me and my friends used to ponder over such things when we first knew about relativity this was my explanation then

Imagine you are an abnormal person and you can do things (i mean everything) at the speed of light ...
So you are like the fastest guy relative to any other person around you and from an observer's point of view you do things heck fast and they seemingly believe that you are in fast forwarded motion(implying time is faster around you). Now from your point of view you observe that all the people are pretty lazy and doing things very very slow or as if in slow motion and hence as if time is very slow around them . Hence relatively time has changed with respect to both of them just with the difference in the light speed working of one....

P.S The abnormal guy will also die quick and age quick as all his metabolic activities work pretty quickly and w.r.t him he has lived the normal life(say 60 years) but for the others it's like he lived only a few hours !!!!!!!!!!!!!

Answer 9

Speed, time, and matter are all inter-related. The faster something moves, the slower time goes for that object....therefore time is relative to matter and its relation to the space around it. Did you also know that gravity speeds up time as well? Why does it happen? We don't know. We've barely started scratching the surface as to why the universe behaves the way it does. Most of what we do know comes from mathematics and watching the behavior of the universe around us. If you're interested in the subject, watch Brian Greene's Nova special "The Elegant Universe". His books are good too....here's the PBS link so you can watch it free: http://www.pbs.org/wgbh/nova/elegant/program.html

Answer 10

As seen by a stationary observer, time does not elapse on something moving at the speed of light. This is an implication of special relativity, which has some strange consequences for things moving at near the speed of light. The particular phenomenon is seen in the decay of fast-moving mesons, whose lifetime as seen by a stationary observer is longer than it would be if they were moving more slowly.