# Questions About Speed of Light & Time

• uk9999
In summary, the conversation revolves around questions about traveling at the speed of light and its effects on time and motion. The experts explain that nothing with mass can reach the speed of light, but it is possible to get close to it, causing time to slow down. The effects of gravity and motion on time dilation are also discussed. Lastly, the experts answer a hypothetical question about throwing a ball in a spaceship traveling at near-light speed and how it would behave.
uk9999
ok two question that kinda just have bugged me (im only 17 so this may all sound a bit basic!)

ok traveling at the speed of light time is 0... as all the 'speed' is used up in 1 of the 3 space dimensions
what would happen to someone traveling where the is no time?
would they simply be frozen or would it be (from there prespective instantanoues travel to the point where they stop traveling at the speed of light in that dimension?

my second question is a we are on the Earth we are moving so how far out would a persons 'clock' be on Earth compared to someone in no movement what so ever

uk9999 said:
what would happen to someone traveling where the is no time?
Nothing with mass can do the speed of light, so there is no answer to this question. It can't happen.
my second question is a we are on the Earth we are moving so how far out would a persons 'clock' be on Earth compared to someone in no movement what so ever
There is no such thing as a person with "no movement what so ever." The motion of one object can only be defined relative to some other object. There is no absolute standard of rest.

- Warren

well ok what i meant by no movement whatsoever was having (theorical) no gravitaional fields infact no forces acting on a person with a clock

thanks for ur replys neways just me wondering what would happen IF you could travel at the speed of light (with the infinite amount of energy required) i suppose its not worth thinking about

another question
say you were traveling at 5 miles less than light
and then you through a ball out of the side of your spaceship
what will happen to the ball?

would it just get heavier and larger n need more engery n infantly go up

uk9999 said:
well ok what i meant by no movement whatsoever was having (theorical) no gravitaional fields infact no forces acting on a person with a clock
An object with no forces applied to it is a quite different thing than an object with "no movement whatsoever." Forces produce accelerations, and they are directly measurable. Velocity itself, however, cannot be measured without reference to some other object.
another question
say you were traveling at 5 miles less than light
and then you through a ball out of the side of your spaceship
what will happen to the ball?
If you threw it in the direction of travel, the ball would be going faster than you, a little closer to the speed of light. From your perspective (in which the ball's velocity is not much different from your own), the ball will appear perfectly normal, and the physics it will seem to obey will be just like the familiar Newtonian physics you see on a baseball diamond.

Remember, there is no way to tell you're going "5 miles [per hour] less than the speed of light" without seeing something go past you.

- Warren

Nothing with mass can do the speed of light, so there is no answer to this question. It can't happen.
However, you can get arbitrarily close to the speed of light. As you do so, time slows to a crawl. If you were to extrapolate what you might see at the speed of light (say, if you were a photon), you would see the entire universe age and die in the blink of an eye.

DaveC426913 said:
However, you can get arbitrarily close to the speed of light. As you do so, time slows to a crawl. If you were to extrapolate what you might see at the speed of light (say, if you were a photon), you would see the entire universe age and die in the blink of an eye.
Such extrapolations are dangerous. Since it isn't possible, it's best just to say it isn't possible. Too many people in the world already have misconceptions about the speed of light.

- Warren

uk9999 said:
my second question is a we are on the Earth we are moving so how far out would a persons 'clock' be on Earth compared to someone in no movement what so ever

Gravity on the scale of the Earth doesn't have a dramatic effect on time dilation. But it's not negligible. They were able to detect the difference in time between two clocks at different altitudes - but it's, like, nanoseconds. The effect decreases with distance, so out where there's very little gravitational pull, the effect will be even smaller.

chroot said:
Such extrapolations are dangerous. Since it isn't possible, it's best just to say it isn't possible. Too many people in the world already have misconceptions about the speed of light.

I'm not here to manage the poster's use of the info.

Anyway, in this case, it's possible to answer his question without violating anything. We can examine speeds arbitrarily close to light, and see the effect. A 'short' blink of and eye at .99999c is pretty much the same as an almost zero-time blink of an eye at .99999999999999c. So the universe ages and dies in a nanosecond - or two.

uk9999 said:
another question
say you were traveling at 5 miles less than light
and then you through a ball out of the side of your spaceship
what will happen to the ball?

would it just get heavier and larger n need more engery n infantly go up

i really like this... so if you were traveling at 5 mph less than the speed of light (all theoritcal... hypothetically speaking... saying we know how fast we are going) and then threw the ball in front of you at 10 mph...? the ball is now traveling.. faster than the speed of light? or is the factor of speed of light now dismissed because you are inside of a spaceship with a controlled environment and you don't feel many G's... well not enough to make the ball go straight backwards when you threw it.

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TheUnknown said:
i really like this... so if you were traveling at 5 mph less than the speed of light (all theoritcal... hypothetically speaking... saying we know how fast we are going) and then threw the ball in front of you at 10 mph...? the ball is now traveling.. faster than the speed of light?
False. Velocities do not add linearly in special relativity.

You must use this relationship:

http://hyperphysics.phy-astr.gsu.edu/hbase/relativ/einvel.html

- Warren

chroot said:
False. Velocities do not add linearly in special relativity.

You must use this relationship:

http://hyperphysics.phy-astr.gsu.edu/hbase/relativ/einvel.html

- Warren

i read it... a couple times... But what you are saying is that velocity can exceed the speed of light.. but speed cannot? I am new to this area... sorry if my questions sound silly... but something is then exceeding the speed of light after the ball is thrown, what is it?

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TheUnknown said:
i read it... a couple times... But what you are saying is that velocity can exceed the speed of light.. but speed cannot? I am new to this area... sorry if my questions sound silly... but something is then exceeding the speed of light after the ball is thrown, what is it?
If I am moving at velocity u relative to you, and I throw a ball at velocity v relative to me (in the same direction that I am moving relative to you), then the velocity of the ball relative to you is $$(u + v)/(1 + uv/c^2)$$. For example, if you see me go by at 0.8c to the right, and I throw a ball to the right which moves at 0.5c relative to me, you will see the ball move at (0.8c + 0.5c)/(1 + 0.8*0.5) = 1.3c/1.4 = about 0.93c.

JesseM said:
If I am moving at velocity u relative to you, and I throw a ball at velocity v relative to me (in the same direction that I am moving relative to you), then the velocity of the ball relative to you is $$(u + v)/(1 + uv/c^2)$$. For example, if you see me go by at 0.8c to the right, and I throw a ball to the right which moves at 0.5c relative to me, you will see the ball move at (0.8c + 0.5c)/(1 + 0.8*0.5) = 1.3c/1.4 = about 0.93c.

ah... okay.. I'm not sure i totally understand this then... because to me, if i am traveling through space at .9999999999999999999% the speed of light... and i throw a ball at 30 mph... and it exceeds the speed of light... why does it "not" exceed it? something is exceeding the speed of light right? okay here's something that will make it a little bit different... thanks for the help by the way, i am just interested in learning more about what i don't know, and you guys know a lot. so say i am traveling in a huge spaceship (this is all extremely theoretical, and would probably never be possible... but isntead of dismissing it, i'd just like to hear sme opinions, i know most people don't like to talk about it if it can't be done with todays science) 5 mph slower than the speed of light, inside the space craft, the environment is "controlled" meaning there are no G forces, and no outside forces are felt inside the craft. A rocket is then launched from the back of the ship to the front, of course before exiting it would be pushed back inside since once the ship opens and the rocket or craft being propulsed tries to exit it would not be traveling faster than the environment passing it outside... so if this rocket reaches a speed of 7,000 MPH... it's obviously traveling 6,995 mph faster than the speed of light, or something is while it is still in the ship... so no matter what, no matter can travel faster than the speed of light in any circumstance? I've also heard some speculation.. that gravity can speed up the rate of travel for matter (black holes) and I've heard that supernova can cause matter to travel at .999999999% the seepd of light... what if a supernova exploded near a black hole? is the matter then alreday traveling to fast to be effected by the gravitational pull of the black hole? or is all of this jut impossible because it would seem unlikely to created a simulated environment inside a ship traveling so fast.

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TheUnknown said:
ah... okay.. I'm not sure i totally understand this then... because to me, if i am traveling through space at .9999999999999999999% the speed of light... and i throw a ball at 30 mph... and it exceeds the speed of light... why does it "not" exceed it?
It doesn't exceed it. In special relativity, velocities do not add the same way they do in normal Galilean relativity. It's a consequence of two postulates of special relativity: the speed of light is the same for all observers, and the physics of the universe is the same in all inertial reference frames.
A rocket is then launched from the back of the ship to the front, of course before exiting it would be pushed back inside since once the ship opens and the rocket or craft being propulsed tries to exit it would not be traveling faster than the environment passing it outside... so if this rocket reaches a speed of 7,000 MPH... it's obviously traveling 6,995 mph faster than the speed of light
To an observer inside the ship, the rocket's going 7,000 mph. To an observer outside the ship, you have to use the special relativistic velocity addition formula, and, again, the rocket will not be going faster than the speed of light. Keep in mind that, to an outside observer, events inside the ship, including the flight of the rocket, will appear to be happening in "slow motion."
so no matter what, no matter can travel faster than the speed of light in any circumstance?
No.
I've also heard some speculation.. that gravity can speed up the rate of travel for matter (black holes) and I've heard that supernova can cause matter to travel at .999999999% the seepd of light... what if a supernova exploded near a black hole? is the matter then alreday traveling to fast to be effected by the gravitational pull of the black hole? or is all of this jut impossible because it would seem unlikely to created a simulated environment inside a ship traveling so fast.
No matter what explodes next to what, the physics of this universe appears to preclude anything with matter from going the speed of light or faster.

- Warren

TheUnknown said:
ah... okay.. I'm not sure i totally understand this then... because to me, if i am traveling through space at .9999999999999999999% the speed of light... and i throw a ball at 30 mph... and it exceeds the speed of light... why does it "not" exceed it?
Because there is no reference frame where it is traveling faster than light. Keep in mind there is no such thing as absolute velocity in relativity, all velocities are measured relative to a particular reference frame. There may be some reference frame where you are traveling at .9999999999999999999c, but in your reference frame, you are at rest, by definition. So in your reference frame, the ball is only going at 30 mph. On the other hand, in this other reference frame that sees you going at .9999999999999999999c, the ball is not going 30 mph faster than you. This has to do with the fact that "speed" really means the distance an object travels in a given time, but each frame sees rulers in other frames shorter than their own, and each frame sees clocks in other frames ticking slower than their own, so different frames can disagree about how fast one object is moving away from another object.
TheUnknown said:
okay here's something that will make it a little bit different... thanks for the help by the way, i am just interested in learning more about what i don't know, and you guys know a lot. so say i am traveling in a huge spaceship (this is all extremely theoretical, and would probably never be possible... but isntead of dismissing it, i'd just like to hear sme opinions, i know most people don't like to talk about it if it can't be done with todays science) 5 mph slower than the speed of light
Again, there's no absolute truth about how much slower than the speed of light you're moving, all velocities are relative. There may be some frame where you are moving at the speed of light minus 5 mph (about 186282.397 miles per second - 0.0014 miles per second), but in your frame light is moving at the same speed it moves in every frame, about 186282.397 miles per second.
TheUnknown said:
inside the space craft, the environment is "controlled" meaning there are no G forces, and no outside forces are felt inside the craft. A rocket is then launched from the back of the ship to the front, of course before exiting it would be pushed back inside since once the ship opens and the rocket or craft being propulsed tries to exit it would not be traveling faster than the environment passing it outside... so if this rocket reaches a speed of 7,000 MPH... it's obviously traveling 6,995 mph faster than the speed of light, or something is while it is still in the ship...
No it isn't. In the ship's frame, the rocket may be traveling at 7000 MPH = 1.94 miles per second, but light is still traveling at 186282.397 miles per second in the ship's frame, so the rocket is moving much slower than the speed of light.
TheUnknown said:
I've also heard some speculation.. that gravity can speed up the rate of travel for matter (black holes)
According to the theory of general relativity, which is the theory that predicts black holes, every observer will see light moving locally at the same speed, where "locally" basically means in an arbitrarily small region of spacetime near him. This is just as true in the vicinity of black holes as anywhere else.

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so to an outside observer it would be happening in slow motion? so light IS time... and time is light? and the speed of light controls time and the way we percieve it? is this true? and is there anywhere where i can read more about this. sorry if i missed a link, i am just really excited, i have never been to a site like this, and i am fascinated with the universe and all physics, and i am goign crazy right now with exhilaration! lol this is great. I'm still very interested now... in why inside the ship the observer sees the rocket traveling at 7,000 mph, but outside it is not... what would happen if the outside observer could walk through the wall of the ship and witness the rocket in mid flight... would it go from slow motion to 7000 mph instantly? and is there any equation that could tell us how fast "slow motion" the rocket is moving from the outsiders perspective while it is in the ship?

TheUnknown said:
in why inside the ship the observer sees the rocket traveling at 7,000 mph, but outside it is not... what would happen if the outside observer could walk through the wall of the ship and witness the rocket in mid flight... would it go from slow motion to 7000 mph instantly?
If the observer stepped outside the ship, he'd be floating in space next to it. Everything in the ship, such as clocks would remain moving at a normal speed. But the universe would be whizzing by him at .999c.

The only way he could put himself at rest with respect to the universe would be to decelerate from .999c to 0 (with respect to the universe, say a nearby planet). But it is equivalent to saying he is accelerating himself to .999c wrt the spaceship. If he could then peer at the clock in spaceship, it would be moving slowly.

uk9999 said:
ok two question that kinda just have bugged me (im only 17 so this may all sound a bit basic!)

ok traveling at the speed of light time is 0... as all the 'speed' is used up in 1 of the 3 space dimensions
what would happen to someone traveling where the is no time?
would they simply be frozen or would it be (from there prespective instantanoues travel to the point where they stop traveling at the speed of light in that dimension?

my second question is a we are on the Earth we are moving so how far out would a persons 'clock' be on Earth compared to someone in no movement what so ever

1. If you were to violate relativity, and travel at the speed of light (v \ c) then from your frame of reference, time would stop around you. And from everybody else's frame of reference, time would stop for you. If you travel faster than light (v > c) then you will have negative time, length, and your mass will be beyond infinite. We cannot make mathematical sense out of this.

2. I cannot make sense out of your question. If you are talking about general relativity which says acceleration and gravity are the same, then this can be calculated. The escape velocity of the Earth is 11000 meters per second per second. So time for us will slow down by a factor of 0.999999999. So if you were on Earth for 1 hour, people in space would measure your time as 0.999999999 hours (and those are not significant numbers, it is less than that but google always rounds large numbers). Not much of a difference eh? But if your you are refereing to how the planets and galaxies are moving through the universe, those are great speeds so time would slow down significantly. But I do not know that velocity.

TheUnknown said:
so to an outside observer it would be happening in slow motion?
No, an outside observer also sees the light beam move at 186282.397 miles/sec in his frame. He would see clocks aboard the ship running slow, if that's what you mean.
TheUnknown said:
so light IS time... and time is light?
No, or at least I can't think of any way that statement would make sense.
TheUnknown said:
and the speed of light controls time and the way we percieve it? is this true?
In a way I guess this is true. The way spacetime works in relativity can be derived uniquely from two postulates--the first says that the laws of physics should look the same in every reference frame, the second says light should be measured to move the same speed in every reference frame. If these are true, then each frame must see other frame's rulers shrink and clocks slowed down in the way relativity predicts.
TheUnknown said:
Well, you probably want to start with learning about the "Lorentz transformation" which tells you how, if you know the coordinates of an event in one frame, you can figure out the coordinates of the same event in a different frame. You can play around with the Lorentz transformation equations and see for yourself that if the distance/time between two events is c in one frame, it will also be c in another frame. Once you are familiar with the Lorentz transformation then you can try to understand how it can be derived from Einstein's two postulates which I mentioned above. I'm not sure what good sites for these things would be, maybe someone else can offer a recommendation, or you can try looking around on google. This page is pretty good for learning the concepts of relativity, but it doesn't seem to talk about the details of the Lorentz transformation or how it is derived.

I can give you the equations of the Lorentz transform right now, though. Suppose you have two reference frames A and A', with A' moving at velocity v along the x-axis of A, and with the origins of each coordinate system matching at time zero in both frames (ie when t=0 in A and t'=0 in A', the point in space x=0, y=0, z=0 in A matches the point x'=0, y'=0, z'=0 in A'). In that case, if you know the space and time coordinates of some event x,y,z,t in A, and you want to know the coordinates x',y',z',t' of that same event in A', you'd use the Lorentz transformation:

$$x' = \gamma (x - vt)$$
$$y' = y$$
$$z' = z$$
$$t' = \gamma (t - vx/c^2)$$

where $$\gamma = 1/\sqrt{1 - v^2/c^2}$$

That's all there is to it, from this you can prove that each frame sees the other's clocks slowed down, that each sees the other's rulers shrunk, that if something is moving at velocity u along the x'-axis of A' then it will be moving at $$(u + v)/(1 + uv/c^2)$$ along the x-axis of A, and so on.
TheUnknown said:
I'm still very interested now... in why inside the ship the observer sees the rocket traveling at 7,000 mph, but outside it is not
If the outside observer is at rest relative to the ship, then he will see the rocket moving at 7,000 mph, but even in Newtonian physics, if the outside observer saw the ship moving at 3,000 mph in his frame, then he wouldn't see the rocket moving at 7,000 mph, he'd see it moving at 10,000 mph. But like I've said, velocities don't add in this simple way in relativity. If you like we could analyze this problem in terms of the Lorentz transformation, finding the coordinates that the rocket is launced and the coordinates it reaches the front end, as well as the coordinates a light beam is emitted from the back and the coordinates it hits the front end, in both the rocket's frame and another frame where the rocket is moving.

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Perhaps I caused some confusion -- when I used the phrase "outside observer," I did not mean an observer flying along with the same velocity right beside the ship. I meant instead an observer who sees the ship fly past with a velocity of nearly the speed of light.

- Warren

wow well that's kinda answered my question i was wondering about space battles at the speed of light which would include the 'going faster than light arguement' buts its all relative hehehe thanks for all ur posts

thanks guys, for all the information... I'm going to study all the equations and laws more, because i am still very interested in what would happen if the observer outside the ship was traveling at the same speed as the ship when the rocket was launched(watching it through a window), and then if he went straight into the ship how it would instantly chnge from slow motion to 7,000 mph... sounds kind of neat, and i want to get to the bottom of it, and find out what the rockets speed would be while he's watching it outside the ship. From reading all of this, i have got the interpretation that (the speed of) light propogates and controls the (speed of) time. Is this known? or is this true? or am i misinterpreting something. I'm glad I'm only 20 years old, i think i am going to make a profession of physics now, i have become obsessed instantly.

TheUnknown said:
thanks guys, for all the information... I'm going to study all the equations and laws more, because i am still very interested in what would happen if the observer outside the ship was traveling at the same speed as the ship when the rocket was launched(watching it through a window), and then if he went straight into the ship how it would instantly chnge from slow motion to 7,000 mph...
That wouldn't happen. If you were sitting inside the spaceship, or flying around right beside it watching through the window, you would see exactly the same thing, namely the rocket going 7,000 mph with respect to you. Being inside or outside the hull of the spacecraft is meaningless; what matters is your speed with respect to the spacecraft (and the rocket inside it).
From reading all of this, i have got the interpretation that (the speed of) light propogates and controls the (speed of) time. Is this known? or is this true? or am i misinterpreting something.
Light doesn't "control the speed of time." The speed of light is a universal speed limit -- the only absolute velocity -- and it just happens that light, having no mass, automatically travels at the maximum possible velocity. The best you can say is that the perception of time is in some way related to this speed limit.

- Warren

chroot said:
That wouldn't happen. If you were sitting inside the spaceship, or flying around right beside it watching through the window, you would see exactly the same thing, namely the rocket going 7,000 mph with respect to you. Being inside or outside the hull of the spacecraft is meaningless; what matters is your speed with respect to the spacecraft (and the rocket inside it).

Light doesn't "control the speed of time." The speed of light is a universal speed limit -- the only absolute velocity -- and it just happens that light, having no mass, automatically travels at the maximum possible velocity. The best you can say is that the perception of time is in some way related to this speed limit.

- Warren

ah, sorry i was told it would be going in slow motion.

TheUnknown said:
ah, sorry i was told it would be going in slow motion.
Again, it would be going in slow motion to an observer moving at high relative velocity to the spaceship. In other words, if someone was sitting on Earth while the spaceship moved away at 0.99c, the rocket inside the spaceship would appear to be moving in "slow-motion" to that observer.

An observer hovering just out the window is at rest with respect to the spaceship, so sees the same stuff as someone inside the ship would see.

- Warren

i see, i understand now, so standing still on a certain land/planet/sattelite... that objects speed that you are standing on, is not added to how fast something is traveling on the object(for instance the Earth is orbiting the sun at a speed, which i do not know, sorry, but we do not add that speed to anything traveling here on earth), instead it's speed is measured from earth, or the object in which you reside and are viewing another object from. It might not sounds like i understand it, but i do now lol. thanks

TheUnknown said:

For learning something from scratch, systematically, at least in physics, you should use a book, not the Web. What you'll find on the Web is lots of bits and pieces written by different people for different purposes. It hasn't been checked or reviewed or edited by anyone, and some of it is misleading or just plain wrong.

Someone writing a textbook at least tries to put things together into a coherent whole, and the publisher has editors proofread it, and has outside reviewers check the content. The result costs money (or you might be able to find it in a library), but you get some assurance that the product is reliable, if you stick with a company that specializes in textbooks.

The Web is good for looking for answers to specific questions, after you already know something about a subject and are able to figure out what is reliable and what is BS.

For relativity, my own two favorite introductory books are:

David Mermin, "Space and Time in Special Relativity" (a rigorous conceptual introduction to time dilation, length contraction, etc., with very little math; it's in paperback and not very expensive)

Taylor and Wheeler, "Spacetime Physics" (a more in-depth introduction, with math; somewhat expensive, but worth it IMHO).

Check a nearby library, or amazon.com.

thank you jtbell, i am getting most of my answers from these forums, i tend to learn better and remember stuff a lot more accurate when someone explains it and tells it to me :) I will read some stuff to, but i have trouble learning when i cannot ask questions, because i am full of them. and if i read something, and cannot question, then i don't understand in full detail,

I concur that a book is a much better way to learn this stuff. (You can always ask us questions as you read.)

See, we are giving you only bits and pieces, and we are pretty much starting in the middle, which is what leads to so many misunderstandings and false starts. You'll only get partial answers here, rather than understanding it from the ground up. Also, it's more efficient if you do the bulk of the work, rather than us. (Not that we mind, of course... ask away.)

TheUnknown said:
i see, i understand now, so standing still on a certain land/planet/sattelite... that objects speed that you are standing on, is not added to how fast something is traveling on the object(for instance the Earth is orbiting the sun at a speed, which i do not know, sorry, but we do not add that speed to anything traveling here on earth), instead it's speed is measured from earth, or the object in which you reside and are viewing another object from. It might not sounds like i understand it, but i do now lol. thanks
For the purposes of basic calculations, you can assume the Earth is at rest. Its velocity around the sun is not significant when compared to a spaceship going 0.99c with respect to it.

Since nothing in the universe is really "at rest," it's difficult to use real bodies in thought-experiments. The Sun is moving with respect to the galaxy, the galaxy with respect to other galaxies, and so on.

You could just label the start and end points A and B, and consider them both at rest with respect to each other. They're just two arbitrary points in space that are not moving with respect to each other. You can call one Earth and one Alpha Centauri to make the problem a bit more personable, but you have to neglect the slight (but very real) motion that the Earth and Alpha Centauri really have.

- Warren

chroot said:
Such extrapolations are dangerous. Since it isn't possible, it's best just to say it isn't possible.

The question was very good and I can't agree with your answer, Chroot. There are real, physical objects which are moving at speed of light: photons. So, the question "what would happen to someone traveling where the is no time?" is definitely not trivial, if "someone" means a photon. IMO the answer can tell us very fundamental things about the real nature of spacetime. What is a real role of space for a photon? How is it possible that we can create and observe objects which locally don't exist in time? How is it possible that things can happen with photons, if photons doesn't move in time? How can photons "detect" points of space and react on their existence if they are frozen in time?

I don't know the answers, but it looks like we can see here the more fundamental properties of our universe than our spacetime.

s3nn0c said:
The question was very good and I can't agree with your answer, Chroot. There are real, physical objects which are moving at speed of light: photons. So, the question "what would happen to someone traveling where the is no time?" is definitely not trivial, if "someone" means a photon. IMO the answer can tell us very fundamental things about the real nature of spacetime. What is a real role of space for a photon? How is it possible that we can create and observe objects which locally don't exist in time? How is it possible that things can happen with photons, if photons doesn't move in time? How can photons "detect" points of space and react on their existence if they are frozen in time?

I don't know the answers, but it looks like we can see here the more fundamental properties of our universe than our spacetime.

sorry if i don't understand, or sound like a fool.. but I've always wondered this too... why does traveling faster or equivelent than light always come up with cooky answers? why can it not be possible? is it just because we really don't have any answers yet? if me and the sun's light had a race, and i beat the sun's light to earth, what is so wrong with that? i could just look back and see the light coming? (does anyone know of gravity warp/ time distortion? I'd like to know if any of that can come into place when traveling close to or above the speed of light, like if you pulled space toward you, you would in fact beat light by not traveling faster than it, would that cause any problems?)

TheUnknown said:
sorry if i don't understand, or sound like a fool.. but I've always wondered this too... why does traveling faster or equivelent than light always come up with cooky answers? why can it not be possible? is it just because we really don't have any answers yet? if me and the sun's light had a race, and i beat the sun's light to earth, what is so wrong with that? i could just look back and see the light coming?
Imagining it to be so is not the same as it being possible. We DO have the answers, and the answers, demonstrated uncountable times over the last century, have shown that this is not the way the universe works.

"What would stop you", you might ask, "from getting in a spaceship and doing it?"
Well in a very small nutshell (and amongst many other things), as you approached the speed of light, your mass would increase, approaching infinity. It would take an infinite amount of energy to accelerate you further.

TheUnknown said:
(does anyone know of gravity warp/ time distortion? I'd like to know if any of that can come into place when traveling close to or above the speed of light, like if you pulled space toward you, you would in fact beat light by not traveling faster than it, would that cause any problems?)
No. This does not violate relativity, and is one of the speculative ways of crossing distances faster than light. (It, BTW, is the method that Star Trek uses.)

Wormholes are another way of shrinking the space between distances.

thank you.

<h2>1. What is the speed of light?</h2><p>The speed of light is a fundamental constant in physics, denoted by the symbol c. In a vacuum, it is approximately 299,792,458 meters per second (m/s). This means that light travels about 186,282 miles per second.</p><h2>2. How was the speed of light first measured?</h2><p>The first successful measurement of the speed of light was conducted by Danish astronomer Ole Rømer in 1676. He observed the eclipses of Jupiter's moon Io and noticed that the time between eclipses varied depending on the distance between Earth and Jupiter. By using this data, he estimated the speed of light to be about 220,000 km/s, which is close to the actual value.</p><h2>3. Can anything travel faster than the speed of light?</h2><p>According to Einstein's theory of relativity, the speed of light is the maximum speed at which all matter and information in the universe can travel. Therefore, nothing can travel faster than the speed of light.</p><h2>4. How does the speed of light affect time?</h2><p>According to Einstein's theory of relativity, time is relative and can be affected by the speed of light. As an object approaches the speed of light, time slows down for that object. This phenomenon is known as time dilation.</p><h2>5. Is it possible to travel through time by traveling at the speed of light?</h2><p>While time dilation does occur at high speeds, it is not possible to travel through time by traveling at the speed of light. This is because an object would need to reach the speed of light, which is impossible due to the infinite amount of energy required. Additionally, the laws of physics do not allow for time travel in this manner.</p>

## 1. What is the speed of light?

The speed of light is a fundamental constant in physics, denoted by the symbol c. In a vacuum, it is approximately 299,792,458 meters per second (m/s). This means that light travels about 186,282 miles per second.

## 2. How was the speed of light first measured?

The first successful measurement of the speed of light was conducted by Danish astronomer Ole Rømer in 1676. He observed the eclipses of Jupiter's moon Io and noticed that the time between eclipses varied depending on the distance between Earth and Jupiter. By using this data, he estimated the speed of light to be about 220,000 km/s, which is close to the actual value.

## 3. Can anything travel faster than the speed of light?

According to Einstein's theory of relativity, the speed of light is the maximum speed at which all matter and information in the universe can travel. Therefore, nothing can travel faster than the speed of light.

## 4. How does the speed of light affect time?

According to Einstein's theory of relativity, time is relative and can be affected by the speed of light. As an object approaches the speed of light, time slows down for that object. This phenomenon is known as time dilation.

## 5. Is it possible to travel through time by traveling at the speed of light?

While time dilation does occur at high speeds, it is not possible to travel through time by traveling at the speed of light. This is because an object would need to reach the speed of light, which is impossible due to the infinite amount of energy required. Additionally, the laws of physics do not allow for time travel in this manner.

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