if any observer moving slower than the speed of light observes the speed of light to be a constant, does that imply that any observer moving at the speed of light observes anything moving slower than the speed of light to be moving at the speed of light, relative to itself?
i.e.: if light could measure, would it observe a car and a comet to be moving at the same speed?
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Anonymous2007-01-04 13:11
You can't move at the speed of light, unless you have a bucket of infinite energy, or you have no mass, and light can hardly observe. But someone moving close to the speed of light, relative to some other person, would observe that other person moving *slower* then they actually are, not faster.
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Anonymous2007-01-04 17:33
>>1
Flawed from the start. No observer can exist at the speed of light.
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Anonymous2007-01-04 18:56
>>3
flawed thinking, not relevant to the question, and a dumb way to go through life.
actually... in order to observe something, anything, there has to be a source of light bounce off from it and into the observer's eyes.
For example: If you are in a dark room, you can't observe anything, because you can't see. But when a flash light is turn on, light bounce off from surface, and allowing you to see.
Now... from the law of physic: Nothing can move faster than the speed of light. So therefore, if you are traveling at a speed of light, and you want to see something, light have to travel FASTER than you, and into your eyes for you to see. But that's not possible, becuase nothing can travel faster than you...
So basically, what that means is you will not be able to see... ...
... except for anything infront of you!
Any energy sources is going hit you (and your eyes) really hard coming directly infront of you...
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Anonymous2007-01-12 6:50
Can you not observe by feeling or hearing or even smelling?
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Anonymous2007-01-12 8:44
>>15
Well according to him, you cannot observe by observation.
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Anonymous2007-01-12 9:33
Ignoring the fact that travel at the speed of light is (currently thought of as) an imposibility, seeing anything wouldn't seeing anything as you normally would be imposible? Visible light from objects behind you would never reach you and light from objects ahead of you would double in frequency due to the dopler effect and fall outside of the visible spectrum. A small range of wavelegths lower than that of visible light sould be able to be percieved, but what that would look like I cannot imagine.
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Anonymous2007-01-12 12:45
this question never had anything to do with sending a human body at c, so visible spectrum doesn's matter. i think you're all misinterpretting his use of 'observer'.
looks like the question is just, if light moves at c relative to us, do we move at c relative to light. like, is the velocity the same both ways.
but i don't even know if the velocity is the same both ways between any two things moving at different speeds, in GR
i.e. if a spaceship left earth, would the velocity earth measured it to be traveling be equal in magnitude to the velocity the ship measured earth to be traveling
>>19
i have, i'd think one observer's measurement of the velocity would be different from the other because of time dilation? but im a mathematician not a physicist, so i'm not incredibly familiar with the actual workings of GR. :P
back to the op's question though, from what i've heard, light essentially doesn't experience time because its sort of, infinitely dilated at that speed. so i guess from light's "point of view", i'm not sure how that relates to the question but it sounds like it should!
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Yetti2007-01-13 0:01
Cannot achieve speed of light.
Light only moves at light speed because it has no mass.
Any mass would require an infinite amount of energy to accelerate.
Divide by zero sort of thing.
It is is impossible to got the speed of light. IN astronomy, this is because the equation needed to measure mass increase (moving mass= (rest mass)/Square root(1-(v/c)^2, c=speed of light) becomes (restmass)/0 if the object's speed= 3x10^8. In this sense, the result (#/0) translates to Moving mass=infinity. This means the object has infinate mass. To move infinte mass you would need infinate energy. THis is verified by tests in atom smashers. Subatomic particles have reached 0.9999c, but no further because to even reach these speeds simply requires too much power.