how fast is a clock moving if running half as fast with respect to an observer. (in terms of speed of light)?
958698
If t is the time that has been measured in the clock's reference frame, then t/2 is the time that has been measured by the observer.\n\nNow t = (t/2)[1-(v^2)/(c^2)]^(1/2)\n\nthe t's cancel and you are left with 1 = (1/2)[1-(v^2)/(c^2)]^(1/2)\nor [1-(v^2)/(c^2)]^(1/2) = 1/2\n\nsquare both sides to get 1 - (v^2)/(c^2) = 1/4\n\nsubtract one from each side to get -(v^2)/(c^2) = -3/4\n\nor (v^2)/(c^2) = 3/4\n\nthis means that v^2 = (3/4)(c^2)\n\ntaking the square root of both sides gives the final answer:\n\nv = [3^(1/2)]c/2.\n\nNot the most intuitive answer in the world.
671105
almost exactly, assuming someone on earth is doing the measurement. someone moving very fast would get a different result.
718668
Neglecting the fact that it would be imposible to accelate a train (non-zero rest mass) to the speed of light,\nif you did, an observer in the train would still see light moving away from them at the speed of light.\nThe speed of light is constant in all frames of reference.
426222
The speed of light is the same no matter where it is. It is 299,792,458 meters per second.
685470
the speed = distance/time
422440
the wavelength is half...\n\nvavelength and frequency are inversely proportional
263654
The speed of light is exactly 299,792,458 m/s.\nThe meter is defined in terms of the distance which light travels in a certain amount of time, that is how we know the EXACT speed of light....we defined it as so.
70622
Time does not exist.  Really.\n\nHey USHERFAN- light travels at 186,288 miles PER SECOND.   Just a LITTLE bit more than your guess.  Stick to the R-a&B.
11469
the speed of light = 299 792 458 m / s
846108
i dont know the exact speed but its faster than the light. want proof darkness is always been there before the light. " at first there was darkness then ...'let there be light" - genesis
52144
Here are the postulates:\n\n(1) The laws of physics are the same as viewed from the perspective of any observer moving at a constant speed.\n(2) The value of the speed of light (denoted "c") is the same in every reference frame.\n\nThe first condition isn't very strange: You'd expect physics to be the same if you were on a very smoothly moving train as you would if you were standing on the Earth.\n\nThe second condition is very strange: Suppose you have two people moving with respect to each other.  One of them is moving at 1/2 the speed of light and the other is moving at 1/4th the speed of light.  Now, a beam of light is passing by them.  They'll both measure the speed of that beam RELATIVE TO THEIR VELOCITY to be c.  \n\nNote that this is a big contrast between what we'd normally expect.  Suppose you were moving at 7 miles per hour and I threw a ball past you at 10 miles per hour.  You'd see the ball moving away from you (another way of saying "moving relative to you" at 3 miles/hour because 10 mph - 7 mph = 3 mph).\n\nIn our light example we just saw that both observers measure the velocity of light relative to their own velocity to be the same.  It'd be like if your friend was moving at 5 miles per hour and you were moving at 3 miles per hour and you both claimed the ball was moving away from you at the same rate.\n\nAt any rate, what this is meaning is that neither time nor space is an absolute quantity.  If you were to observe a rocketship moving near the speed of light (as measured with respect to you), you would observe:\n\n(a) That the rocket appears to contract (shrink) in it's direction of motion, and\n(b) Events aboard the spaceship would appear to occur more slowly.\n\nHowever, they would measure the same things happening to you and the events along the spaceship to be proceeding normally.\n\nThat is only a very brief introduction.  If you'd like a better, but still accessable to a non-scientist, account of this I suggest you consider reading http://casa.colorado.edu/~ajsh/sr/sr.shtml .
996962
The speed of light is a constant (186,000 mi per second) and does not change based on what it is travelling through.
1091562
Gravity.  Clocks run slower in a gravitational field. Plus whatever velocity difference there might be.
230716
Two observers with different frames of reference will measure time and distance differently in such a way that the speed of light is the same in all frames of reference.  Try this site and see if it helps.\n\nhttp://www.glenbrook.k12.il.us/gbssci/phys/Class/relativity/reltoc.html
49096
You can't go the speed of light, but even if you were going 99.9999999% the speed of light, yes, you could shine the beam forward, backwards, or sideways, and it would look normal in every direction.  That's the central idea behind relativty.\n\nAnd NO, the light would NOT be going twice the speed of light.  Anyone who says that is BSing you.
979220
Albert Einstein answered this question a long time ago.  He theorized (and every experiment since then has borne him out) that the speed of light is constant from ANY inertial (non-accelerating) frame of reference.  This includes the speed of light relative to your headlights.  \n\nLight speed is constant.  What changes is time and length.  Weird but true.
956950
The exact same as all light -- all wavelengths travel the same\n\n3 x 10 ^ 8 m/s or 186,000 miles per second