# Lightspeed "barrier"

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3 things;

1. I havent finished school and therefore prosume others have not either (a small minority maybe...) and can also point out that to every teen (at 15 anyway) a very small percentage of us take the time to learn the theor(ies) of relativity.

2. I dont quite seem the point in that post and i prosume that as you appear to be new you havent got to 'learn the ropes' yet as it were. I suggest that people could get offended by such statements' date=' and you are suggesting that people such as saynora^3 with 7000+ posts are doing something wrong? Even with my humble effort of 302 i should suggest similar comments may by some people not be taken in the no offensive context in which they were intended.

But i am in no way telling you what to do mind, or being hot headed, just my opinion.

[/quote']

1. I say sorry again for (as i have already said i never ment to be rude or whatever). It is just that i am very disappointed in the level of modern education.

2. No matte how many posters a person had made - it doesn't mean a thing, actually - quality is more important than quantity.

3. And a little piece of advice - READ BOOKS, for i swear lots of the things u see here (about lightspeed and photons and so on) is not quite true (or misunderstood). Good luck!

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ironically; the things i have said have been based on such books.

is not quite true [/Quote] I dont want to dwell on your unconventional use of grammar but you have said is about a collective Again .

I am intrigued at why you are 'dissapointed', and how old are you.

And another thing; the point i was making about posts is that it appeared to me that you were telling people with 7000 times as many posts what they should be posting.

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Yes alot of what is posted here is not true

One of the most common mistakes is that time does not pass for a photon. You might as well say that a photon sees magic monkeys in it's frame as objects with null world lines do not have MCIFs.

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1. I say sorry again for (as i have already said i never ment to be rude or whatever). It is just that i am very disappointed in the level of modern education.

2. No matte how many posters a person had made - it doesn't mean a thing' date=' actually - quality is more important than quantity.

3. And a little piece of advice - READ BOOKS, for i swear lots of the things u see here (about lightspeed and photons and so on) is not quite true (or misunderstood). Good luck! [/quote']

I dont know if someone can come here without read a book, unless is a 5 years old genious.

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hehe, i seem to have come to a wrong place, but i was just curious

Simply speaking:

Travelling at a speed.gt.c is not forbidden (mathematically), but crossing the very barrier of c is impossible due to singularities. Though i must say some of modern theories (mostly raw and incomplete) keep trying to develop methods to 'avoid' this singularity. And again i must say - that is only maths, we never know what is real, for math is just a kinda language (and we often make mistakes and misprints in it, like i do for instance ))))

First of all, ppl have to make sure, that special relativity (u remember what it states, don't u. adbout the equality of masses ;-)))has a right to exist, for it has only been indirectly prooved in experiments. And that is what i would suggest you to think over, 4 it is interesting indeed.

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OK Iridium. Let's have a serious discussion. What is your opinion on Universal Extra Dimension models? Do you think they are reasonable or just a fad? What is the true value of the Planck scale?

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Pigs can fly.

No, they can't.

Why not?

They do not have the means to.

Prove it.

Pigs dont fly.

Maybe they will some day.

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hehe' date=' i seem to have come to a wrong place, but i was just curious

Simply speaking:

Travelling at a speed.gt.c is not forbidden (mathematically), but crossing the very barrier of c is impossible due to singularities. Though i must say some of modern theories (mostly raw and incomplete) keep trying to develop methods to 'avoid' this singularity. And again i must say - that is only maths, we never know what is real, for math is just a kinda language (and we often make mistakes and misprints in it, like i do for instance ))))

First of all, ppl have to make sure, that special relativity (u remember what it states, don't u. adbout the equality of masses ;-)))has a right to exist, for it has only been indirectly prooved in experiments. And that is what i would suggest you to think over, 4 it is interesting indeed.[/quote']

Singularities in what? Gravitational singularites? special relativty does not deal with gravity, so no gravitaional singularities occur in SR which is what we are discussing. What do you mean special relativty has only been 'indirectly proven'?

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how has it only been indirectly? ever hear of atomic clocks in aircraft and on ground?

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']Pigs can fly.

No' date=' they can't.

Why not?

They do not have the means to.

Prove it.

Pigs dont fly.

Maybe they will some day.[/quote']

Not aplicable here since you are comparing a well know facts about pigs anatomy based on biology with things know but with some aspects explained by theories.

Iridium, Im not saying that Relativity is wrong, just that one of its bases is that the lightspeed is taken as the most high speed available, and this is not highly prooved.

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OK Iridium. Let's have a serious discussion. What is your opinion on Universal Extra Dimension models? Do you think they are reasonable or just a fad? What is the true[/b'] value of the Planck scale?

That is not really a question... That is a kinda general statement.

For i doubt u have real idea of Extra Dimensional Models Be honest.

This model is surely nice, for it provides great freedom 4 developing new ideas and applying almost any method u invent (assuming u have enough fantasy and skill to build a good axiomatics for that) and so on, but again, i donno what to say for the question was very general.

if u wanna ask something more specific.....

but well, as for Planck scale,

it is supposed to be about 10^(-35)m, but these are just theories, because

strong, weak and electric interaction can somehow be combined (still there is no single point of view on that question), but the gravity stays 'untouched'. At least recent works seemed unconvincing.

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Singularities in what? Gravitational singularites? special relativty does not deal with gravity, so no gravitaional singularities occur in SR which is what we are discussing. What do you mean special relativty has only been 'indirectly proven'?

Sorry, i surely ment the geneal relativity :-D i say, i always make lots of misprints :-DD

sr is not what interests me much

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Sorry' date=' i surely ment the geneal relativity :-D i say, i always make lots of misprints :-DD

sr is not what interests me much[/quote']

If you want to know about GR you better make sure you know about SR first as SR really is just the degenerate case of GR.

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Exactly. The sound speed was a barrier to human technology and now it is not more a barrier. Light speed is a barrier aswell now and some day it wont be anymore.

Wrong. The sound "barrier" was never a barrier in any real sense of the word. No one ever said' date=' "It is not possible to exceed the speed of sound". In fact, we were propelling objects faster than sound for decades before the "sound barrier" was "broken". All the sound barrier consisted of was the problem involved with designing a plane that could acheive [i']controlled[/i] flight at super-sonic speeds.

The speed of light barrier is another animal all together, it is a consequence of how the universe, and reality itself, works at its most fundamental levels.

About the formula, ed84c, the Relativity is based with the light speed as a limit.

No, it is not. The light speed limit is a consequence of the postulates of Relativity, not a base starting point. There are a number of consequences of Relativity's postulates, and these are tested and shown to be correct everyday in high energy particle labs around the world. The postulates are shown to hold, and thus the light speed barrier holds, because it is an unescapable result of those very postulates.

The very fact that you would make such a statement shows that you have not thoroughly studied the subject.

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That is not really a question... That is a kinda general statement.

For i doubt u have real idea of Extra Dimensional Models Be honest.

Well' date=' which ED model would you prefer to discuss? The Randall-Sundrum model perhaps? Or maybe an ADD model?

if u wanna ask something more specific.....

Which fields do you think are restricted to the brane and which fields are allowed to propagate in the bulk? Do you think the SM brane should have a finite thickness, or by infinitely thin (ie. not project into the extra dimensions)?

but well, as for Planck scale,

it is supposed to be about 10^(-35)m, but these are just theories, because

strong, weak and electric interaction can somehow be combined (still there is no single point of view on that question), but the gravity stays 'untouched'. At least recent works seemed unconvincing.

That was why I asked. Do you feel that a UED model makes a reduction in the Plack scale reasonable, or do you feel that we would be better with a more traditional unification? Perhaps E8xE8'? What, to your mind, is the most convincing GUT scenario?

What is your view of E6 breaking via E6 -> SO(10) x U(1) -> SU(5) x U(1) x U(1) -> SU(3) x SU(2) x U(1)Y x U(1) x U(1)? If you think this is OK, which representations of the extra U(1)'s would you expect at low energies? In fact, if we restrict ourselves to one extra U(1) and the SM groups at low energies, can we build an anomaly free theory? How does this mesh with the LEP2 data on Z', or indeed the WMAP data?

Why do you find recent works 'unconvincing'?

I await with baited breath....

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Wrong. The sound "barrier" was never a barrier in any real sense of the word. No one ever said, "It is not possible to exceed the speed of sound". In fact, we were propelling objects faster than sound for decades before the "sound barrier" was "broken". All the sound barrier consisted of was the problem involved with designing a plane that could acheive controlled[/i'] flight at super-sonic speeds.

Yep, on that moment there was "exceptics" wich say that for a form of life inside or outside of a craft is not posible to do that.

The speed of light barrier is another animal all together,

No' date=' it is not. The light speed limit is a [i']consequence of the postulates of Relativity, not a base starting point. There are a number of consequences of Relativity's postulates, and these are tested and shown to be correct everyday in high energy particle labs around the world. The postulates are shown to hold, and thus the light speed barrier holds, because it is an unescapable result of those very postulates.

The very fact that you would make such a statement shows that you have not thoroughly studied the subject.

Einstein used the most fast speed available in the universe wich manifestate itself. You cannot use higher values of speed on the formula listed above, so that formula says that highert velocities of speedlight are not posible and that formula also said that the photon cant have mass. My point is that there is posible higher velocities, and by this the photon can have mass.

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Einstein used the most fast speed available in the universe wich manifestate itself. You cannot use higher values of speed on the formula listed above, so that formula says that highert velocities of speedlight are not posible and that formula also said that the photon cant have mass. My point is that there is posible higher velocities, and by this the photon can have mass.

Incorrect all EInstein assumed is:

1) the laws of physics are the same in all inertial frames (something that is true in Gallilean relativity).

2) the speed of light is constant in all inertial frames, strongly suggested by E&M and experimentally verifed many, many times.

Using these two postulates alone (tho' possibly having to postulate on the four momentum as the form we use is not the only one that gives the correct non-relativistic limit) you can derive the fact that:

a) anything with real non-zero mass must travel below the speed of light in any MCIF (momenatrily co-moving inertial frame)

b) that photons have no mass.

The formula I guess you are talking about is Einstein compostion of veolcites formula., this is a derived formula and you must look at the axioms and more fundamental formulas to find out why lightspeed is a 'barrier'.

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1. Thank you for all of you for posted many messages.

2. I'm an Industrial Engineering Student.

3. I'm interested at this topic, and Sorry for my bad English.

4. WIll somebody explain me simple things. Light is come from bulb or neon lamps, or anything emitted light. Then, many-many particle of lights is emmitted from those lamps to our room. Bounching-and bounching they make perfect and imperfect reflection in our room. and after that, where did they go? why when we turn off the lamp our room wil be dark, completely dark could be possible? (maybe silly but please explain).

5. According to Stephen H. , The Theory of Everything, Singularity happen before our universe is born and in a blackhole. Singularity is a kind of condition when things is compressed by infinite forces into infinitely small thing.

6. Blackhole can pull light. Stephen also said that there is a hypotetical "Worm Hole" by passing a line cutting light circular way caused by black hole's gravity.

7. Imaginative : Let say we have a brother in a star 90 years of lightspeed from earth. We call him, "I will go to your home.", then, we ride our hyperspace-enabled spacecraft. We will come before our call is heard by our brother. We are come there before EM waves, before light, BUT NOT BEFORE TIME isn't it like that? SO, time travelling is impossible.

8. Thanks a lot. I'm very happy with this forums.

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Not aplicable here since you are comparing a well know facts about pigs anatomy based on biology with things know but with some aspects explained by theories.

Iridium' date=' Im not saying that Relativity is wrong, just that one of its bases is that the lightspeed is taken as the most high speed available, and this is not highly prooved.[/quote']

It is applicable, since when trying to argue against someone who is

1) uneducated on the subject at hand and

2) not willing to do basic research on the subject,

the argument becomes totally meaningless. There are only so many ways you can prove that you are, in fact, incorrect. If you choose to ignore them, then there is nothing we can do about it.

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1. Thank you for all of you for posted many messages.

2. I'm an Industrial Engineering Student.

3. I'm interested at this topic' date=' and Sorry for my bad English.

4. WIll somebody explain me simple things. Light is come from bulb or neon lamps, or anything emitted light. Then, many-many particle of lights is emmitted from those lamps to our room. Bounching-and bounching they make perfect and imperfect reflection in our room. and after that, where did they go? why when we turn off the lamp our room wil be dark, completely dark could be possible? (maybe silly but please explain).

5. According to Stephen H. , The Theory of Everything, Singularity happen before our universe is born and in a blackhole. Singularity is a kind of condition when things is compressed by infinite forces into infinitely small thing.

6. Blackhole can pull light. Stephen also said that there is a hypotetical "Worm Hole" by passing a line cutting light circular way caused by black hole's gravity.

7. Imaginative : Let say we have a brother in a star 90 years of lightspeed from earth. We call him, "I will go to your home.", then, we ride our hyperspace-enabled spacecraft. We will come before our call is heard by our brother. We are come there before EM waves, before light, [b']BUT NOT BEFORE TIME[/b] isn't it like that? SO, time travelling is impossible.

8. Thanks a lot. I'm very happy with this forums.

These are good questions, but you might want to make a seperate thread for them, so more people will answer them.

Ill take a shot at the light thing. Yes, there are many many photons emitted, and they do reflect off surfaces. However, not all of them reflect. Many of them are also absorbed into the materiel. For example, a black fabric absorbs a lot of light, while white fabric does not absorb as much. A mirror reflects a very large amount. A room gets dark when you turn off the light because light moves at such a high speed, and large amounts of the light is absorbed compared to that reflected. There isn't enough light still bouncing around to be detected, if it exists at all.

A good question though to someone who knows more on the subject, if you have a very very good mirror, would you be able to keep the light bouncing around for a resonable amount of time?

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'']A good question though to someone who knows more on the subject, if you have a very very good mirror, would you be able to keep the light bouncing around for a resonable amount of time?

Yes, as long as you removed all the air between them (otherwise you would remove photons by collision with particles in the air). In fact, if it were an infinitely good mirror and you were in a perfect vacuum, they could bounce around forever.

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Here's one I came up with recently (not sure if it belongs here but there are several threads devoted to the speed of light so I thought here was as good a place as any and it does have implications for GR.).

The speed of a wave through a material is usually given as the sqrt of tension/density. Given the speed of light is constant and intergalactic space has such a low density, doesn't it hold the Einstiens rubber sheet does indeed need to be placed under a much higher tension in order to keep the speed of light constant. The origin of this tension could therefore be dark energy. That said the reverse would also be true, the comparitivly high density of galactic space would yield a much lower tension and therefore a much more 'relaxed' rubber sheet which would in turn be influenced by the presence of matter to a greater extent and therefore create the illusion of dark matter.

Explaining these two phenomena with exotic particles as opposed to simple geometry seems like overkill to me to say the least. Comments/suggestions welcome...

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']It is applicable' date=' since when trying to argue against someone who is

1) uneducated on the subject at hand and

2) not willing to do basic research on the subject,

the argument becomes totally meaningless. There are only so many ways you can prove that you are, in fact, incorrect. If you choose to ignore them, then there is nothing we can do about it.[/quote']

Uneducated on the subject.. please stop doing such coments, I`m not a kid and I asume there are no kids here (at least not much) so dont use this type of argument. Better come here and put your toughts about the subject, that will be more interesting.

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Going back to the subject, if photons are pure energy without mass:

1) Why when they got a massive object, like an star, they got deviated?

2) Why the photons got affected by gravity if they dont have mass?

On this last I want to talk about. I was researching by myself for explanations about and I got responses or info that dont convince me.

For example, the light got absorved by a black hole due of strong gravity, so it have to have any kind of mass for that. An interesting note: when light got absorved by a black hole it got invisible, the explanation is that the black hole dont let the light to go out. However if this is true there should be a manifestaion of light before get into the hole, some kind of "funnel".

Personally, due of strongs gravitational forces on the black hole, the photons near it got attracted at speeds higher than the lightspeed, for that it got invisible.

Comments, suggestions welcome (as soon it is not like the one exampled at start of this message)

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Photons travel in a straight line through curved space. The illusion that they are affected by gravity is created because gravity curves the space on which they travel. It is not a result of the photons themselves having mass or gravitational attraction.

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Photons travel in a straight line through curved space. The illusion that they are affected by gravity is created because gravity curves the space on which they travel. It is not a result of the photons themselves having mass or gravitational attraction.

Is a little contradictory, at least for me. Both may be affected by gravity.

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