Black Holes???

daguin said:

The main point I was trying to make is still valid here. It used to be also believed that the speed of light was "constant" no matter what medium it was in. The belief was that you could "bounce" it around in a medium (so that its exit would be delayed), but all of the bouncing light in the medium would still travel at the speed of light. Now we know that we can, indeed, slow it down. It is not "constant."

The experiments slowing down light have proven that it is not a "constant." Yet in most schools of thought it is still being treated as one. If we could be wrong about the speed being "constant," could we not also be wrong about the upper limit of travel being "the speed of light"? Also, if it can be violated in the quantum state, why not in the micro and/or macro states?

It is also generally accepted in cosmologic science that the particles escaping the "big bang" traveled in excess of the speed of light in the beginning. It is the only way to explain the distances achieved today. Physicists often explain this by saying that the physical laws had not "appeared" yet. This is the same argument that says it is useless to contemplate reality BEFORE the big bang because the laws of physics were different then.

If the laws could be different before and at the beginning, I ask, "Why can't they be different now?" It is the slavish adherence to the belief that the speed of light is inviolate, that stops much work being done. In order to move beyond it the assumption must be that we can exceed this limit. We only need to figure out how to do it.

Peace,
dave

Click to expand...

Light speed isn't constant. Its speed depends on the medium its passing through and gravitational fields.

However, in a total vacuum and in a negligible gravitational field it IS constant.

Also, speed of light has nothing to do with the speed of the actual fabric of time (assuming its moving, which it is, or was....)

I wonder if a 100 x10^99999999 mW laser beam focused in a point less than a micron can affect the fabric of time lolz

Well, anything is relative (again ) to the ambient ..... but light speed was never really considered a constant, if not in the void ..... light speed was always considered an absolute limit (also if i personally don't like "absolutes", cause all the times someone discover an "absolute", there's some other that spoil the party, damonstrating that it was wrong, LOL)

Physics don't say, being honest, that light speed is a constant, it just say that, in this continuum, nothing can travel faster than it, independently from the medium in which it travel ..... as far as i remember, speed of light depend from density of the medium ..... wondering about that crystals density, LOL

And also about this, i was wondering if someone discover a crystal structure dense enough for slow down the light, but, as example, less dense against other types of particles, imagine the faces of a lot of physic nobel prizes LOL ..... but, probably, this is just another almost impossible task



Edit: BTW, i just remembered an old science fiction book, where someone invented "slow glass", a substance that slow down the light that pass through it so much, that you can, as example, use it as lighting devices, just putting a glass plate with 12 hours of delay exposed at the sky ..... for the first 12 hours, the light that hit the upper face, just "pass through" it, accumulating in the delay structure of the glass, and when it start to come out from the other face, it passed 12 hours, so the light that was "delayed" inside it, flow out for the next 12 hours ..... zero cost street illumination, LOL (and, ofcourse, in the book, none was preoccupied to say you how the glass can manage all the trapped energy without just melt, LOL)

HIMNL9 said:

Well, anything is relative (again ) to the ambient ..... but light speed was never really considered a constant, if not in the void ..... light speed was always considered an absolute limit (also if i personally don't like "absolutes", cause all the times someone discover an "absolute", there's some other that spoil the party, damonstrating that it was wrong, LOL)

Physics don't say, being honest, that light speed is a constant, it just say that, in this continuum, nothing can travel faster than it, independently from the medium in which it travel ..... as far as i remember, speed of light depend from density of the medium ..... wondering about that crystals density, LOL

And also about this, i was wondering if someone discover a crystal structure dense enough for slow down the light, but, as example, less dense against other types of particles, imagine the faces of a lot of physic nobel prizes LOL ..... but, probably, this is just another almost impossible task



Edit: BTW, i just remembered an old science fiction book, where someone invented "slow glass", a substance that slow down the light that pass through it so much, that you can, as example, use it as lighting devices, just putting a glass plate with 12 hours of delay exposed at the sky ..... for the first 12 hours, the light that hit the upper face, just "pass through" it, accumulating in the delay structure of the glass, and when it start to come out from the other face, it passed 12 hours, so the light that was "delayed" inside it, flow out for the next 12 hours ..... zero cost street illumination, LOL (and, ofcourse, in the book, none was preoccupied to say you how the glass can manage all the trapped energy without just melt, LOL)

Click to expand...

Hmmm. What kinda glass is this lol. Post a link.

@ Tabish: as i said, it was a science fiction book, LOL.

Its not science fiction, they have slowed down light before and also sped up lol (Faster Than The Speed Of Light? - CBS News) and i learned that it is not that nothing can travel faster than the speed of light, only that information cannot be sent to travel faster than the speed of light.

No-one ever said that the speed of light is constant. It's the speed of light in a vacuum that's constant (and cannot be exceeded). Also, it's not a belief, it's an assumption (an axiom - like Euclids axioms of geometry) from which all the strange effects (which have been verified with a very high degree of precision) derive, thus assuring physicists that the initial assumption is a correct representation of physical reality.

Also in the expansion phase of the universe after the Big Bang, particles were NOT travelling faster than light. It was space itself which was expanding fast. Objects within that space were still traveling slower than light. Space expansion is not actual physical movement.

For example, it's very easy to devise an experiment where you can "exceed the speed of light": point your laser (this is LPF, after all) at the left edge of the sun. Then move it to the right edge in one second. Easy! But since the sun has a diameter of nearly 5 light-seconds, it means that the laser dot on the sun moves at about 5c, right? Yes, indeed. However, it's not an actual object that is doing the moving, so there's no contradiction (think about how the photons making up the spot move, and how the spot itself moves, and how one "instance" of the spot differs from another). Similarly, imagine a very gigantic pair of scissors, with blades millions of miles in length. If you close these scissors, the "cutting point" where the blades overlap may move with super-light speed - but again, this point doesn't have an independent existence, it's not an object in any sense. You can't exchange mass, energy or information by any of these super-c methods.

Don't become one of the gibbering old men who pay newspapers to run ads with "proofs" that the theory of relativity is wrong or that differential calculus can't work because it means dividing by zero or whatever.

dr-ebert said:

For example, it's very easy to devise an experiment where you can "exceed the speed of light": point your laser (this is LPF, after all) at the left edge of the sun. Then move it to the right edge in one second. Easy! But since the sun has a diameter of nearly 5 light-seconds, it means that the laser dot on the sun moves at about 5c, right? Yes, indeed. However, it's not an actual object that is doing the moving, so there's no contradiction (think about how the photons making up the spot move, and how the spot itself moves, and how one "instance" of the spot differs from another). Similarly, imagine a very gigantic pair of scissors, with blades millions of miles in length. If you close these scissors, the "cutting point" where the blades overlap may move with super-light speed - but again, this point doesn't have an independent existence, it's not an object in any sense. You can't exchange mass, energy or information by any of these super-c methods.

Click to expand...

I'm sorry ..... the examples cannot be considered right.

First, also if the diameter of the sun is 5 (4,64, IIRC) light-seconds, the point you shoot at it don't travel more fast of the light, cause the light itself already need 8 minutes and 20 seconds (medium, not considering usual variations) for reach the sun surface, so the light beam, when you move it in that way, just made a curve, where the curve add the difference of time due to the sun diameter (said in poor words, sorry) ..... the more correct consideration, about your example, is like if you shoot a water stream with an hydrant on a wall, where, as example, the water can flow from the hydrant only at 100km/h, and in no cases can move faster than so, in any directions (like photons), then consider the impact point as the spot ..... if you move the hydrant at 200km/h, the spot on the wall don't travel faster, the stream just make a curve, where the curve adds the difference of time, and reach gradually the wall at the usual 100 km/h.

The scissors, instead, the points cannot move faster than light, right for the "infinite mass, zero time" part of the equation ..... more you try to close it fast, more the mass of the tips increase, requiring also more energy from you for move them, and so on, until they reach the speed of the light (assuming theorically that you can do it), and at this point, having acquired infinite mass, you need infinite energy for move them, that means, you cannot move them faster than so in any way, except applying more than infinite energy (that, as far as i recall, is a bit impossible )

Oh, ok, ok, a supersymmetrical quantic bomb can reach a decent approximation of "more than infinite" energy, shifting part of it in some extra dimensions, but you think it worth the destruction of half of the galaxy just for confutate Einstein theory ?

Wrong on both counts. Assuming that you could observe the dot on the sun, you would see it travelling at 5c; and if that's all you can see, then you have no idea where the beam originated and how much time it spent to get there. So the fact that the light takes 8 mins to reach the sun in this somewhat contrived example (I just wanted to use familiar objects) is irrelevant.

Similar for the scissors. Substitute them with two large beams floating in space which are not quite parallel, and then move them at one another so that they just miss each other and observe the point where they overlap. The less the two beams deviate from parallel, the faster this will appear to "move". No energy needs to be applied at all, it's just a question of geometry.

Just to clarify, I'm not talking about the tips of the scissors, these indeed can't move faster than light (in vacuum).

dr-ebert said:

Assuming that you could observe the dot on the sun, you would see it travelling at 5c

.....

The less the two beams deviate from parallel, the faster this will appear to "move".

Click to expand...

Please, think better at what you've wrote here

Where's your problem?

here ya go read this

How to transmit information faster than light speed@Everything2.com

MY problem ? ..... LOL ! :crackup:

Ok, then .....

Assuming you can see the dot on the sun, or the end of the beams, you can "see" just nothing of that what you're saying, simply cause, also if your theories was right (thing that is NOT, if you really think about them with attention), you cannot "see" anything moving faster than the medium that you use for see it (it's just a law of physic, i don't have guilty in this), so, being the speed of the light an absolute, you can just see at this speed and no more.

And about the example itself, where the light need 8 minutes and 20 seconds for travel from here to the sun (and, BTW, you need others 8 minutes and 20 seconds, for see it back ), moving the targetting point (that is a very different thing of the beam spot) of the beam on the sun surface in the way that the apparent shifting become faster than light (assume 1 second), if you really had the possibilòity to "see" all the beam all in realtime (faster than light), the beam just appear to you "curved" of a proportional amount of degrees that is in report with distance, relative speed and differential speed (and i save you from the equations, cause i already have a discrete headache), that add to the lenght of the path just the amount that the light need for travel for other 3,64 seconds (proportionally, ofcourse), so, looking only at the spot, you just see the spot traveling on the sun surface at light speed, following your movement wit a proportional delay.

No need that you trust me, just calculate it yourself.

Edit: Please, don't turn this in a war, this is not our tread, and i don't have reasons for lie with you, i'm just stating physics laws

No, you don't know what you're talking about, and the gap seems to be too wide to bridge. Sorry.

ok guys can we at least agree on this:

no matter what speed light is going, slowed down, sped up, vacuum this, medium that.... the speed light is going is always Light Speed!


( i couldn't find a correct smilely to show that the above statement was a joke)

ROTFL

The main point I was trying to make is still valid here. It used to be also believed that the speed of light was "constant" no matter what medium it was in. The belief was that you could "bounce" it around in a medium (so that its exit would be delayed), but all of the bouncing light in the medium would still travel at the speed of light. Now we know that we can, indeed, slow it down. It is not "constant."

The experiments slowing down light have proven that it is not a "constant." Yet in most schools of thought it is still being treated as one. If we could be wrong about the speed being "constant," could we not also be wrong about the upper limit of travel being "the speed of light"? Also, if it can be violated in the quantum state, why not in the micro and/or macro states?

It is also generally accepted in cosmologic science that the particles escaping the "big bang" traveled in excess of the speed of light in the beginning. It is the only way to explain the distances achieved today. Physicists often explain this by saying that the physical laws had not "appeared" yet. This is the same argument that says it is useless to contemplate reality BEFORE the big bang because the laws of physics were different then.

If the laws could be different before and at the beginning, I ask, "Why can't they be different now?" It is the slavish adherence to the belief that the speed of light is inviolate, that stops much work being done. In order to move beyond it the assumption must be that we can exceed this limit. We only need to figure out how to do it.

Peace,
dave

Click to expand...

sorry i havent been kepping up with this thread but.. what you have said made me think.. well if light is passed through a differnet medium (very dense one) you will see a delay.. answer is yes.. BUT.. if you think of it as "packets" or photons.. it makes a bit more sense.. lets say one photon was shot through optical fibre, at the point it leaves the "gun" it is traveling at the speed of light.. it then enters the optical fibre.. is it really slowing down? or is it just percieved as slowing?

If we were the photon.. and we are moving through a dense medium, we will be bouncing off and being reflected in side the optical fibre.. but who is to say that im not still moving at the speed of light when im inside the optical fibre..

Basically im trying to say.. maybe (i could be wrong) its like having two identical cars traveling at the same speed.. but one keeps traveling in a straight line and the other goes around the world 5 times then to the finish line?? get it.. it seems as thought the first car was faster because it has reached the finish line first.. but in reality they were moving at the same speed.. only took a longer/diferent route..

So this makes me think that even thought it moves through a denser medium.. it is still moving at the speed of light.. but is rather taking a longer route due to "impurities" or "obsticales" in that medium.

ps: its just a thought please tell me if you agree or not!

-Adrian