do we age slower as we travel at speeds approaching the speed of light?
341309
We age slower compared to those that seem stationary.  However, absolute time is irrelivent because everyone experiences time dependent only on themselves.  The lorenz transforms that arise in special relativity show that if you are moving faster than the surroundings time will seem the same to you but you will see everyone else moving faster than you, time will be proceeding at a faster rate to them. You would not age faster when you slow because time is not absolute so you don't need to keep up.  Yes runners have prolonged youth but they are too tired to realize it.
1040099
I saw a lot of good answers out there that hit the answer pretty much on the head.  I only wanted to point out one minor mistake in what you wrote (which you probably won't run into in most freshman courses in relativity).  That the astronauts would actually be older than those who stayed on Earth.  The special relativity people were explaining was correct.  If you move => time slows down.  The thing is that gravity has a greater effect in slowing down clocks and the gravitational field you experience in orbit is weaker than on the surface of the Earth (obviously it won't matter though if you are flying around space at speeds near the speed of light, then the special relativity part becomes dominant over the general relativity i.e. gravity).
170084
The correct formula for calculating tiem dilation is t'=t/gamma where t' is the new time, t is the time in the rest frame and gamma is the inverse square root of (1 - v^2/c^2)\n\nAs a result of this, if v (velocity) tends towards c (the speed of light), then the gamma factor tends towards infinity (because 1/sqrt(0) goes to infinity). So actually, if you do travel at the speed of light, you do not experience time at all - a photon is one such example; however anything with mass cannot travel at the speed of light, so unfortunately you cannot 'freeze' time for any object with mass. But if you are travelling at a velocity only slightly greater than 0 with respect to the rest frame, you actually experience less time than a person who is in the rest frame, albeit by a tiny tiny factor.\n\nNot sure what you mean by splitting space time in half :S
671137
Actually....according to Einstein...if you could survive traveling at that speed the answer would be yes. Einsteins theory states the light from your headlights would be traveling at the speed of light! Let me make this simple...if the auto you were driving was travelling at the speed of light the light from the headlights at any given point in your travel would still be traveling forward again at the speed of light. His theory also states that at the speed of light the only variable that changes is time. Personally, I dont believe in the theory, in particle physics it has been proven that paired particles "know" when their particle twin has had a change of state regardless of how far away from each other they are...this being said...some form of communication between the two must travel faster than the speed of light!
297501
I'm sure you are spekaing strictly hypothetically, but don't forget the closer you get to the speed of light (c), the slower time moves around you.  So if you were to go like 90% of c for 1 year, more than 1 year would pass for everyone else.
10479
The answer is really quite simple:\n\nWhen we speak of the 'age of the universe' we are talking about how old all the rest of the mass of the universe would appear from within _our_ frame of reference.\n\nSo, to a cosmic radiation particle traveling at near the speed of light the whole universe would "appear" to be just seconds or minutes old. (As if such a particle could have perception, which it cannot).\n\nYet we, all living on the same planet and having less than a thousand mile-per-hour difference in our respective velocities, are unable to notice the effect of Relativity.
1062755
That question goes in line with my latest thought on einstein theory of relativity.  If something approaches the speed of light (or at the speed of light) time slows for it but not the observer, so how do we measure it if the light itself is time compressed?
1084318
Actually, the way modern physicists think of it, the question doesn’t quite make sense.  The problem is the “traveling at the speed of light” part, because one of the conclusions of Einstein’s Special Theory of Relativity is that nothing can travel that fast.\n\nInterestingly, though, its was consideration of a similar question that started Einstein down the path toward relativity… Light is best described by Maxwell’s Equations, which predict that any experiement will measure same speed for light in a vacuum.  When Einstein thought about traveling at the speed of light, he realized that there must be a problem.  In fact, Maxwell’s Equations don’t allow for a “standing wave” solution, which is what a light wave would look like if you were traveling at the speed of light. \n\nSo Einsten took things back to basics, which is what he was good at.  Let’s start with what he actually said… His Special Theory of Relativity started with two postulates (or assumptions): 1) that the laws of physics are observed to be the same in any non-accelerated “reference frame” and 2) that the speed of light (c) is observed to be the same for all observers.\n\nThe first assumption basically says that as long as you’re traveling at a constant speed, all your experiments will give the same results.  That seems reasonable.  But the thing about the speed of light always being the same sounds a little odd: the Michelson-Morley experiment (and others) had detected no change in the speed of light when measured from a moving frame of reference, however, and as I already mentioned, Maxwell’s Equations yield a specific value for the velocity of light.\n\nStarting from there, Einstein worked out how to add velocities together, and it comes out to be not simple addition, but a fraction that never gets larger than c. Basically, what happens is that the measurement of time and distance changes, so a physical object (e.g., a spaceship) can never achieve lightspeed.\n\nSo”  That’s a long-winded way of saying that your headlights themselves can’t travel at the speed of light.  If we want to think about them traveling very, very close to the speed of light, however, we realize that the light they emit still travels at lightspeed (as measured by the fast-moving headlights themselves), so they stil work the same way headlights would work on a car traveling much slower.\n\n\nRyan Wyatt\nRose Center for Earth & Space\nNew York, New York
492519
There is nothing like antidirection. \nWell, if it becomes possible (assuming) to move at the speed of light, the time dilation formula of the special theory of relativity says that the time would not elapse. That means your aging will stop!\nIf it becomes possible (assuming) to move with speeds higher than that of light, many things could happen. According to the time dilation formula, the time would become an imaginary quantity. One of the interpretation of this imaginary time goes like this: the time will start moving backward. Possibly, that is the situation when you can expect moving back to past. But, further mathematics shows that you are not necessarily going to reach to your own past. Rather, you could land onto some other, strange, alien universe!\nAt this point we have not talked about the change in your mass or length if you are moving with such a high speed. But, for sure you are not going to be the same!
62229
Actually, yes. traveling forward in time is definately possible, but we're not sure about back. \n\nVelocity distorts time. The faster you go, the slower time goes for you. This effect is negligable unless you are going very close to the speed of light. In fact the formula is:\nt'= t/sqrt(1-v^2/c^2)\nwhere t' is the time that has passed for a stationary observer, t is the time that has passed for you, sqrt means square root and ^2 means squared. As you can notice, when v is small, since c^2 is so huge, you get a miniscule decimal, and 1 minus that number is basically as small as .999999999999999 or something very very close to one, and so t' stays basically the same as t and time is not really affected. As v gets larger(it can never be the speed of light, then the denomonator would be zero) that fraction becomes closer to 1, so when you subtract it from one, the denomonator gets smaller and smaller, meaning t gets smaller(in order for t' to remain constant) this means that time slows down for the object moving at such velocities! time slows down, so it would feel like lets sayThis formula is correct, it is part of Einstein's theory of relativity, and I have had to derive it myself from ordinary mechanics formulas. \n\nThis proves the formula:\nAccording to the same factor, length also contracts. It has been observed in certain tiny particles coming to the earth's surface. These particles have a certain lifespan before they become unstable and decay. They are also moving at a certain speed. (which is very fast; close to the speed of light.) You should simply be able to calculate v=d/t (velocity=distance/time) to find out how far they would travel. However, they somehow travel farther than that. When this calculated distance is put into that formula, we come up with the correct distance they actually travel! \n\nSo yes, as you get faster and faster, since time slows down for you, theoretically, you could be moving at these speeds for a short time and time will seem to be moving normally for you, but have years and years pass for everyone else, thus traveling forward in time.
11171
yes, traveling forward in time is definately possible, but we're not sure about back.  This has nothing to do with wormholes or anything, that probably wouldn't work.\n\nanyway, velocity distorts time. The faster you go, the slower time goes for you. This effect is negligable unless you are going very close to the speed of light. In fact the formula is:\nt'= t/sqrt(1-v^2/c^2)\nwhere t' is the time that has passed for a stationary observer, t is the time that has passed for you, sqrt means square root and ^2 means squared. As you can notice, when v is small, since c^2 is so huge, you get a miniscule decimal, and 1 minus that number is basically as small as .999999999999999 or something very very close to one, and so t' stays basically the same as t and time is not really affected. As v gets larger(it can never be the speed of light, then the denomonator would be zero) that fraction becomes closer to 1, so when you subtract it from one, the denomonator gets smaller and smaller, meaning t gets smaller(in order for t' to remain constant) this means that time slows down for the object moving at such velocities! time slows down, so it would feel like lets sayThis formula is correct, it is part of Einstein's theory of relativity, and I have had to derive it myself from ordinary mechanics formulas. \n\nThis proves the formula:\nAccording to the same factor, length also contracts. It has been observed in certain tiny particles coming to the earth's surface. These particles have a certain lifespan before they become unstable and decay. They are also moving at a certain speed. (which is very fast; close to the speed of light.) You should simply be able to calculate v=d/t (velocity=distance/time) to find out how far they would travel. However, they somehow travel farther than that. When this calculated distance is put into that formula, we come up with the correct distance they actually travel! \n\nSo yes, as you get faster and faster, since time slows down for you, theoretically, you could be moving at these speeds for a short time and time will seem to be moving normally for you, but have years and years pass for everyone else, thus traveling forward in time. As far as back in time... well, if you think about it, if things travel slower and slower the closer you get to light, does that mean it would stop when you reached it? and what would happen when you went faster, would it go back in time?  the only problem with this is that nothing can go faster than the speed of light, which has been considered "the ultimate speed limit of the universe."  Plus, if you were to go faster, the v^2/c^2 would be greater than one, meaning you'd get a negative number after subtracting it from one and have a negative number under the square root in that formula.  This is impossible.  Also, the problem with even traveling forward in time is that it would require immense amounts of energy to accelerate objects that fast.  It requires particle accelerators miles long just to get small sub-atomic particles to go that fast, imagine massive objects, it would be crazy. and distorting time by any reasonable amount would require going at least 90% the speed of light.. probably faster.  The closer you got to the speed of light, the more time would slow down for you.\n\nThere are also some other methods described in the book "time travel in einstein's universe" by Richard Gott, if you're interested.
15796
Its not proven but heres how eistine put it.\n\nThe faster you travel the more you weigh. Since light is the fastest moving thing in the universe if you went faster then that you would way infinite pounds and that would be impossible so you cannot go faster than the spped of light
598949
Depends on your perspective.  As you travel closer and closer to the speed of light, time for you will seem to be normal, but you will see it speed up for others who are stationary.\n\nIf you are the one who is stationary, time will seem normal to you, but it will slow down for the one traveling.\n\nAn example - your twin has just been chosen to go on an interstellar trip.  Thankfully you're telepathic and can communicate over any distance.  As she speeds up, you will notice that there are longer and longer times between her transmissions to you, even though she says she'd contacting you at the same time every day.  And when she returns to earth 50 years later, you find she's only aged 10 years! (Robert Heinlein wrote a great novel about just this scenario - "Time for the Stars").\n\nScientists have proven this amazing fact in many experiments. They've put an atomic clock on a fast jet and flown it around the world.  When they returned, the clocks had different times than those on the ground.  But not by much - the clocks were between 50 and 270 nanoseconds different than their stationary counterparts - that's 50 billionths of a second.  Not much - but 500 mph is pretty slow compared to the speed of light.\n\nAnother way this is used in everyday life is the GPS satellites.  This navigation system has to take relativistic effects into account in it's transmission signals in order to get the high accuracy it's capable of. Every GPS satellite has an atomic clock aboard.  Because of the speed of the satellites, a ground observer will see them ticking slower than real time, so the signals have to be adjusted.\n\nTo answer your question - if you traveled around the world at 700 mph for a week, you'd be a few thousandths of a second younger than your friends who stayed behind.
468247
The speed of light is constant, approximately 300,000km/second. \n\nThe principals of relative motion are that if you are travelling at a speed, and you look at something else travelling at another speed, your perception of the speed of that something else will be the difference between your two speeds. For example if you are travelling 60, and you get overtaken by someone going at 70, you perceive them to be travelling at 10, since they travelling at 10 relative to you. \n\nHowever, you can never perceive the speed of light to be anything different than it's constant value. Therefore, if you travel at half the speed of light, time actually slows down to half of what it normally is, since this is the only way for the speed of light to remain constant. \n\nTherefore if you travel at the speed of light, time stands still. To answer your question, I don't know what you'd see, but probably nothing!\n\nTheres a more complicated explanation involving the magnetic and electric fields of a photo of light, but that's the basics.
313900
Think of this\nwhen it comes to space the constant thing is the speed of light. Speed is the TIME it takes something to travel set distance.\nAt the moment we are moving through space. An hour ago we were a few hundred thousand miles from where we are now. If you were sitting still where we were a few hous ago, you would be slightly older than us.\nThis is because the constant thing in space is the speed of light. As we get closer to the speed of light either time gets smaller or distance gets smaller.\n\nIf this does not seem possible, just think of a unit of time as one vibration of an atom. Go faster, atoms vibrates slower, your time is therefore slower than some one who is still. (this is a metaphor people can comprehend, not quantum fact)\n\nSo question 1. Light is travelling at speed of light. Time and space do whatever they have to do to accomodate this.\n\nQ2 No, see Q1. You also would no be strong enough to throw the ball\n\nQ3. The closer one gets there first. just like anything else.\n\nQ4. What fuel? It would accelerate exponentially as the mass decreased. Top speed comes dowon to rates of accelerate, motor efficiency, drag, ect. Then as you got really fast your mass increases. Mass increases (again I'll use a compehendable metaphor and not quantum physics) because distance decreases, things are closer together, denser, heavier. Then your rate of fuel consumption would increase exponetially and your velocity would barely change. Then you'd run out of fuel
1165520
Yes, in a way, looking at distant objects in our universe is like looking back in time.\nThe farther away we look, the older the image we are seeing is.\nAs fast as light travels, it still only travels at a finite speed and takes time to cross the VAST distances of interstellar (or even intergalactic) space.\nThings we wee in the sky could be billions of years old, we could be watching the formation of a new star (or for that matter, be receiving transmissions from an alien life form) that has since died long ago.
799784
In theory, yes.  Because the light particles that were traveling slower than you would have been slower.  Very good question.  However, speeding past the speed of light would mean the fundamentals of E = Mc^2, would cease to make sense.