what happens when you approach the speed of light for ten years at 99.999 percent?
546523
Well according to Relativity Theory it is known that an Object of Mass (M) travelling at Velocity (V) would have a Change in Mass: ie\n        \n          Mass at Velocity (V)  = ( Rest Mass) / sqrt(1-(V^2/C^2) ) \n\nTherefore if we replace C^2 by V^2 then the Whole Equation becomes Infinite. in other Words You cannot Travel at the Speed of Light, because according to Physics an Object cannot have Infinite Mass.
417984
As Einstein said you get time contraptions if you move at a speed aproaching the speed of light. For you time moves faster. You move a year with a speed close to the speed of light and when you stop everyone will be 7  years older and you've spent only one year. The problem is...what if you don't like the future....there is no way to go back in time..
1162111
Yes it would, but it would have to be going at approx 12% the speed of light. It would be "blue shifted" the opposite of the redshifting associated with cosmological expansion
442563
There's a number of ways to answer this.  Einstein's theory of Relativity says that all things are moving at the speed of light through spacetime, with stationary objects moving wholely in the time dimension.  As you start moving, some of your velocity is directed away from time and in a physical dimension.  When you approach the speed of light, you are traveling very little in the time dimension and mostly in the physical dimesions.  If you actually reached the speed of light you would experience no time whatsoever; your entire trip across the universe would be one instantaneous flash.  However, the faster you travel, the more difficult it is to travel even faster.  When you are traveling relativistically, Newton's second law of F=ma no longer applies.  You continue adding force, but rather than creating acceleration, you'll begin gaining mass.
621324
Around 105 light years, or 3x10^5 km/s * 365 * 24 * 3600s * 105 km, or 993 384 000 000 000 km, or 617 277 076 989 996 mi
50535
OK, first fo all Mr cliffx has it backwards.  As you continue to acellerate tworads the speed of light time will slow down for you and stay normal for everyone else.  Thus at that speeds you could travel 10000 lightyear in only 1 year, your lifetime, but thousands of years could pass on earth.\n\nIt has been theorized that time travel is posible but you could not simply accelerate to that speed.  Even if we could travel that fast the economical need would be currently beyond what any country has, even if they put all there funding into that one project.  but I am getting off the subject.\nOne theory is to travel into a black hole.  The gravetational field in a black hole is so strong that it has been theoryzed that even time cannot escape.  Thus if we were able to travel into a black hole we could use the captuered time there, so to speak, and transverse the timeline.\n\nThen there are ideas of actually traveling on light waves, lasers, to allow us to travel to the speeds necisary.  Of course then we could only travel to the time of how long that peice of machinery is on.  Also we would have to convert ourselvesinto an electrical signale, data (essicially transport), which would then bring up the promblum of measuring matter without moving it and blah blah blah.\n\nSummery, Yes it is possible to travel through time.  We just do not havet he knowledge and/or technology to do it yet.
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.
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.
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
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!
670589
Forever and ever.\nIt may get dimmer, but that is from the spreading of the light.  The photons will travel until they collide with something.
281751
Nothing will happen. THere is no sense of time when travelling at the speed of light. No time - nothing happens.\nYour clock is stopped cold.
359864
when u fire a rocket at high speed when u r moving at near speed of light relative to an observer, from the observer point of view, the rocket would never reach the speed of light due to relativistic effects of time dilation and length contraction. The observer would observe a flat rocket that is moving in slow motion.. the closer it is to the speed of light, the slower it moves, when it reach the speed of light, the observer would see the rocket as frozen and not moving. And from your point of view, u cannot accelerate the rocket to the speed of light RELATIVE to u.\n\nThe crucial point here is, RELATIVE. Everything has to be discussed relative to something else. There is no meaning in talking about ultimate speed since physical laws r invariant under translation and there is no prefered point of reference in the universe. When u talk about speed, u have to specify, with respect wo what.\n\nThere is no simultaneity in Einstein's relativity theory. The time u observe for a rocket to travel 1 mile is different from the time observed by the observer observing from somewhere else which is moving with some speed relative to u. This is relativity.\n\nAnd when u r moving near the speed of light, relative to an observer, u will not disintegrate and burst into some x-ray. As mentioned already, speed is relative. You are stationary with respect to your desk. But from the point of view of an alien observing from a planet a distance away, u r moving due to the motion of the Earth and sun and everything. Does that mean u or the alien would disintegrate and vanish into thin air???? no, of coz not. Pls do not think about friction.. that when u rub with air or other particles as u move thru space, u give off energy. no, that's not relativity.\n\nWe observe stars becoz they give off light from the nuclear reactions that is happening constantly in their core. We observe differing wavelengths due to the intensity of energy emitted, and also due to Doppler's effect due to expanding universe.\n\nThe centre idea of Einstein's relativity is that, there is no absolute space and time anymore. Space and time r different manisfestation of the same thing and they r interwoven into a connected flexible piece called the spacetime... instead of space and time in Newtonian physics. Relativity must not be understood in terms of theories of Newtonian physics. Relativity is not a new play on the stage of physics. Relativity is itself a new stage, literally.
219832
The speed of light is indeed a constant.  What's important is that it is a constant to every observer.  If you are traveling toward a light source at 1000 m/s, you will measure the light's velocity at 300,000 m/s.  If you are traveling AWAY from the light source, it will still measure 300,000 m/s.\n\nLight IS the absolute speed limit. (Of this universe anyway)
16422
A light year (or light-year), is defined as the distance that a photon would travel, in free space and infinitely distant from any gravitational or magnetic fields, in one Julian year (365.25 days of 86,400 seconds each). Since the speed of light in a vacuum is exactly 299,792,458 m/s by the definition of metre, one light year is exactly equal to 9,460,730,472,580,800 m, or about 5.879 × 10^12 (nearly six trillion) miles.
615996
You don't go 'back' because you can't get to that speed.  Time slows for you by the ratio of 1 over sqrt(1-v^2/c^2).\nYou have to get quite close to the speed of light before this is noticable at all.
360465
A light year is measured by the time on Earth not by your watch.  However, since one light year is the measurement of the distance that light travels in one Earth year, then one light year always equates to one year on Earth.  So, if you travel one light year, you should be one year older and the Earth would also be one year older (assuming no time anomalies, like a black hole, are encountered during the trip).  Keep in mind that a 'light year' actually measures distance (based on the speed of light).  \n\nHowever, time is always relative to where you are.  So, for you, time progresses at the same rate it always has (for the human body) no matter what's going on around you.  So, if you were gone for 3 minutes (clock time), you'd be three minutes older.  If you were gone for 24 hours, then you'd be 24 hours older.\n\nHowever, if you were to visit the proximity of a black hole, the theory is that time slows down.  So, while your watch may continue at the same rate as it always has (your time has actually slowed down).  So, time on Earth would be progressing at a much faster rate relative to you (even though Earth's progression is normal to them).  So, if you returned to Earth and your watch was only 12 hours later than when you left, time may have progressed days or weeks on Earth.  In which case, your body would have aged 12 hours instead of the days or weeks that it would have progressed if on Earth.