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-- physics anyone?
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Originally posted by Jive_Turkey I thought as you approached the speed of light your mass increases such that when you reach the speed of light your mass would be infinite. Thats why its impossible to go the speed of light.

asymptotic. Yes. In theory. You would become a black hole of sorts. An object of infinite mass and infinitesmal size.

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Originally posted by HardTranceProd I thought, if you travelled at the speed of light, then time dilation would be so extreme that time would hold still. And then, if you exceeded the speed of light (impossible of course), you would go back in time (into the past).

If you were to travel at the speed of light time and space would become meaningless. In physics and to the eyes of a light particle the universe is an infinitesimally small space. In light's reference frame it is everywhere at once and everywhen at once. It is every"when" at once only because to light's refernce frame time has no meaning. The reason for all of this is the "dilation" that was mentioned before. The closer you get to the speed of light the more things change, distances get smaller, the rate of passing time changes, mass changes, etc. According to relativity the only two constants in the universe are the speed of light and the laws of physics.

If you think this all far out and a a bunch of bull, dont worry becuase no one really gets its either. In the words of my physics teacher:

"We are as confident in the validity of the theory of relativity, and our knowledge thereof, as we are confident in gravity. Wait that was a bad example because we dont really know that much about gravity..."

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Originally posted by NebulousQ If you were to travel at the speed of light time and space would become meaningless. In physics and to the eyes of a light particle the universe is an infinitesimally small space. In light's reference frame it is everywhere at once and everywhen at once. It is every"when" at once only because to light's refernce frame time has no meaning. The reason for all of this is the "dilation" that was mentioned before. The closer you get to the speed of light the more things change, distances get smaller, the rate of passing time changes, mass changes, etc. According to relativity the only two constants in the universe are the speed of light and the laws of physics.

As much as I know this statement is probably pretty correct, I find myself taking issue with the "everywhere at once and everywhen at once" simply because the speed of light is not infinite. Light travels a distance as it moves, hence "light years" (a fucking god awfully large amount distance no doubt!). If light were both here and there (being arbitrary points in space), then it would have to essentially be omnipresent and hence move at an infinite speed to be in both places at once. But the fact that we can observe light from the sun knowing that the light we see is actually "4 minutes old" tells me that the light does not move with infinite speed.

Then again, you did say from the frame of reference of the light. Oh if only I could be light!

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Originally posted by NebulousQ In light's reference frame it is everywhere at once and everywhen at once. It is every"when" at once only because to light's refernce frame time has no meaning.

i dont see how this is so. even light takes time, years, millions of years to rech us from distant stars and galaxies. heck we see galaxies as they were thousands of years ago because thats how long it takes the light to get here.

To both of you shakka and hiram, yes in our reference frame light can be pinpointed to a single location and time. But since light is travelling, well, at the speed of light, the time dilation basically becomes infinite and therefore time in the rest of the universe flows infinitely faster than it does for the beam. So the beam is everywhen (heh I like that term) because if viewed from its reference frame, at the very instant it is created the rest of the universe has already unveiled from beginning to end. Unless maybe if it gets sucked up into a black hole or something in the meanwhile.

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Originally posted by DrUg_Tit0 To both of you shakka and hiram, yes in our reference frame light can be pinpointed to a single location and time. But since light is travelling, well, at the speed of light, the time dilation basically becomes infinite and therefore time in the rest of the universe flows infinitely faster than it does for the beam. So the beam is everywhen (heh I like that term) because if viewed from its reference frame, at the very instant it is created the rest of the universe has already unveiled from beginning to end. Unless maybe if it gets sucked up into a black hole or something in the meanwhile.

sweeeeet.

That is pretty sweet....

One day we will visit life on other planets

At least, I hope.

^^No, we will all be dead whenever that may happen.

So if light is everywhen (like that too lol) how at the point light is created (from an energy conversion) from matter can it exist at all points in time? It surely can only exist from the point where it was "created"?

Actually re-read your post and you do say from the point it is created. But what happens when when it is converted into another form, for exmaple in plants? Where it is used.

Hmm think I'm confusing myself here.

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Originally posted by Dervish So if light is everywhen (like that too lol) how at the point light is created (from an energy conversion) from matter can it exist at all points in time? It surely can only exist from the point where it was "created"? Actually re-read your post and you do say from the point it is created. But what happens when when it is converted into another form, for exmaple in plants? Where it is used. Hmm think I'm confusing myself here.

Well, when it's absorbet, it's finished, nothing happens. I suppose photons don't really have a long lifespan in their own frame of reference

Ahh yeah supose if the time dilation is infinate it just means that the photons in the time frame of light only exist for an extremely brief period.

Just the word infinate tends to complicate things, silly stuff happens when it is involved... kinda like the alchol and drugs to the laws of physics and maths.

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Originally posted by metalgearsolid ^^No, we will all be dead whenever that may happen.

I don't care if I'm dead. As long as it happens, it will be sweet.

It'll be just like star trek.

wow after all this time cracking my skull trying to understand time dialation i finally got it. all i had to do was ask my pops lol

^^No, you did good. Drug Tito knows a lot about science asking him would be like asking Einstein. He is extremely intelligent when it comes to the sciences and math. He just lacks commen sense and the same sixth sense I have.

BTW DT: Can you help clarify something for me. My chemist teacher said that the light planet earth receives from a star(one you could see at night) the light takes four billion years to travel here. So he said that if we were to travel to one of these stars we could see into the past. how exactly does that happen? Does this have to do with the same subject(I certainly hope not this would make me look dumber than I actually am )

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Originally posted by metalgearsolid ^^No, you did good. Drug Tito knows a lot about science asking him would be like asking Einstein. He is extremely intelligent when it comes to the sciences and math. He just lacks commen sense and the same sixth sense I have. BTW DT: Can you help clarify something for me. My chemist teacher said that the light planet earth receives from a star(one you could see at night) the light takes four billion years to travel here. So he said that if we were to travel to one of these stars we could see into the past. how exactly does that happen? Does this have to do with the same subject(I certainly hope not this would make me look dumber than I actually am )

from what i understood that my dad told me and what ive read here...in our time reference frame yes, light does take millions of years to reach us in some cases, we are merely seeing the past. but in lights time reference frame there really is no time because time has basically stopped since it is already traveling at the speed of light. this is what i didnt get about the twin paradox. since the traveling twin is not traveling at the speed of light but almost at C time does not stop but passes by slower. i assume that if the traveling twin were actually hit the speed of light he would not age at all. someone please correct me if im wrong, ive never studied physics before.

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Originally posted by metalgearsolid BTW DT: Can you help clarify something for me. My chemist teacher said that the light planet earth receives from a star(one you could see at night) the light takes four billion years to travel here. So he said that if we were to travel to one of these stars we could see into the past. how exactly does that happen? Does this have to do with the same subject(I certainly hope not this would make me look dumber than I actually am )

If you were to travel to one of these stars at say close to the speed of light then the light from the earth would get there before you so I dunno how you'd be able to see into the past. Tho obviously when you looked at the earth you'd still have the same lag between what you see and what is actually happening. But I supose in your time reference you'd actually be looking into the future? Because earth would had a faster time frame than you while you were traveling.

So yes you would be seeing the earth past (the time lag ofthe light) but in your time frame it would actually be the earths future (as in if you had stayed on earth what youare now seeing would be the future). Because of the dilation experianced while traveling.

That right?

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Originally posted by metalgearsolid BTW DT: Can you help clarify something for me. My chemist teacher said that the light planet earth receives from a star(one you could see at night) the light takes four billion years to travel here. So he said that if we were to travel to one of these stars we could see into the past. how exactly does that happen? Does this have to do with the same subject(I certainly hope not this would make me look dumber than I actually am )

I have a feeling this one goes back to the point-of-reference.

I thought I heard a similar concept, that if you were looking through a telescope, you were essentially looking back in time--zooming in on light that is closer to the actual source. Or something odd like that...always seemed strange.

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Originally posted by metalgearsolid ^^No, you did good. Drug Tito knows a lot about science asking him would be like asking Einstein. He is extremely intelligent when it comes to the sciences and math. He just lacks commen sense and the same sixth sense I have.

Hm..whatever..

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BTW DT: Can you help clarify something for me. My chemist teacher said that the light planet earth receives from a star(one you could see at night) the light takes four billion years to travel here. So he said that if we were to travel to one of these stars we could see into the past. how exactly does that happen? Does this have to do with the same subject(I certainly hope not this would make me look dumber than I actually am )

Um I think you got him wrong. First of all it usually takes a couple of thousand years for light from other stars to reach the earth, so he basically meant that you're seeing stars now the way they were a couple of thousand years ago. I suppose if you'd get instantly transported to that star the light reaching you from earth would be a couple of thousand years old too, in other words, those stars see us the way we were couple of thousand years ago, same way we see them.

And hiram, yes, you got it right.

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Originally posted by DrUg_Tit0 And hiram, yes, you got it right.

::vitory dance::

Brian Greene uses a good analogy to explain this in his book "The Fabric of the Cosmos:"

Imagine that you are in a car in a big, wide, flat space. You have the option of either driving directly North, directly East, or anywhere in between (think between 12 o'clock and 3'o clock on your compass).

Now, compare this to Spacetime (that is, the physical universe we live in). You can either move directly through space, directly through time, or anywhere between.


So, imagine you are driving directly north. None of your movement is in any way going eastward at this moment. Now imagine you turn slightly to the right, and begin to go north-northeast. While you are still travelling primarily north, you are not traveling north at the rate at which you were previously, beacuse some of that motion is now going east. Now imagine you keep turning right until you are going directly northeast. You are now moving to the north and east and an equal rate. If you were to go directly east, you would no longer be moving north at all.

Think of spacetime in the same manner as your car going North and East. When you are completely motionless in space, you are moving through time at full speed. As you pick up motion, you begin to transfer some of your motion away from time and into space (just as you take some of your northward motions away as you turn slightly east). If you speed up (if you keep turning east), you are taking away more and more motion from your movement in time. Eventually, once you reach the speed of light (or very close to it), the fastest speed theoretically possible, you will no longer be moving through time (just as when you have turned due east, you are no longer moving north).

This explains the twins paradox. One twin stays on Earth while the other boards a ship that moves close to the speed of light. The one on the ship travels for only a year, but when he returns to earth, he finds his brother is now old, as many years have passed on Earth. Since the ship was moving so fast, it effectively slowed it's movement through time.


I'm pretty sure that's how it went. Sorry for the sloppy explanation, I'm running on no sleep.

Hm, there was one thing that kept troubling me here, but I just found the answer to it. Basically it means that some of our interpretations were wrong. Anyway, suppose we have 3 bodies, let's call them A, B, and C. Say A remains stationary and B and C start moving away from A, both at the speed of 0.6c in opposite directions. So considering that the clocks on B and C are ticking slower than those on A, if we put ourselves in the reference frame of C, it should seem that B is moving away from A at a speed greater than that of 1.2c, while in reality it should actually be slower than 1c.

So here is where we were partially wrong in our earlier conclusions. The real solution is that in all the systems time seems to flow slower for the rest of the universe than it does for the moving object, and that in all the moving systems there seems to be a contraction of space around them. Meaning that the object A would see objects B and C flattened and slowed down, but that the object B would also see the whole universe around it, including the objects A and C slowed down, flattened, and closer to each other.

Now, this may cause the astronaut paradox to seem impossible because both astronauts see the world around them slowed down. But what happens is that when the astronaut makes a U-turn, the time in the universe around him makes a sudden leap as the simultaineity plane between him and his twin make a shift. During his return trip, his time again seems to flow faster than the time of his eartly twin, as well as his earthly twin sees his time going faster than the astronaut's, but when he comes back, his deceleration makes the times resynchronize.

So coming back to the photon or an object moving at near light speed, the universe around it would actually seem to be in a temporal stasis, rather than a fast-forward motion. It would also seem to be flattened out into two dimensions, as the objects towards and away from which the photon or object is moving would seem to be extremely close. But, if the moving object would suddenly slow down to a halt, the universe would make a quick adjustment of its state, where objects around it would speed up in order to make up for the time lost. Additionally, the farther away those objects are, the more making-up they'll have to do, and during slowdown they will seem to be be more fast forwarded than those in the vicinity. Wikipedia rules

http://en.wikipedia.org/wiki/Twin_paradox

bringing this back from the dead.. but i was wondering if all color light travels at the same speed or does their speed vary? every color light has a diffrent wavelength so im guessing their speed varys not by much. also, when the speed of light is mentioned.. is that white light?

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Originally posted by hiram bringing this back from the dead.. but i was wondering if all color light travels at the same speed or does their speed vary? every color light has a diffrent wavelength so im guessing their speed varys not by much. also, when the speed of light is mentioned.. is that white light?

Through a vacuum same speed, through a medium different speeds (think prism). Speed of light is through a vacuum...doesn't matter what "color."

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Originally posted by NeoPhono Through a vacuum same speed, through a medium different speeds (think prism). Speed of light is through a vacuum...doesn't matter what "color."

does that also apply to other things like radio waves

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