speed of light?

[Corporate Thug]

i was reading this article, and i'm having trouble understanding the following:


"The light travels so fast that the main part of the light pulse exits the chamber even before it enters. Theoretically, this means that you could see a moment in time before it actually takes place."

anyone care to elaborate?

 

[Mickjc]

There are certain quantum events postulated where particles can can "travel" a finite distance in zero time.

1. Electron pair reactions:

Electron pairs are produce by certain particle collisions. One member of the pair will react similarly to the other with distance not being a factor. This is demonstrated by black hole theory. Electron pairs are generated by the high energy emissions of the black hole. The pairs will orbit the hole. Gravitiational (tidal) forces will tend to separate electron pairs and one of the pair may be pulled into the black hole as gravitational forces exceed those maintaining orbital velocity. Whatever happens to the electron in the black hole causes the one in orbit to emit light, visibly identifying the supposedly invisible black hole. This effect should happen over *any* distance in *zero* time and has been used by SF writers as a method of instantaneous communication.

2. Another quantum effect is proton tunnelling:

This one is pure maths, but under certain conditions protons "disappear" from one location and "reappear" in another in zero time. Mathematically speaking...

As to getting there before you started; it's a little more difficult to speculate. There is a theory that light modulation can travel faster than light. The analogy goes like this: You take a light wave and give it a shake to set up a standing wave or carrier. You then frequency modulate the wave so you have regions of compression and rarifaction. It appears the regions of compression move faster than the wave by about 1.3 times. You then have information moving faster than light.

As to light travelling faster than light, however...?

Mick.

PS. It's been sometime since I've worked in this area, so things change and I forget stuff.

 

[jswjimmy]

i would think that it enters and leaves at the same time(thats at 300times the speed of light not the speed of light). ps did you know i takes light 8 min to reach earth from the sun

 

[Mingon]

Sounds like rubbish, light has a finite speed, it cannot leave before it has entered it will always be an amount of time latter despite how small the amount of time is.

 

[Bleep]

light has a finite speed,

This is true it is just that we do not understand completly all the properties of light. We do not know wht the ultimate speed of light may be in some other enviroment.
Look at it this way light may cause a pressure wave in fromt of it and that pressure wave may be detectable someway. Math people sometimes try and prove stuff with numbers and start with a false premise and do their best to prove what they believe to be true but in real terms it is false.

Bleep

 

[Corporate Thug]

Originally posted by: Mingon
Sounds like rubbish, light has a finite speed, it cannot leave before it has entered it will always be an amount of time latter despite how small the amount of time is.

that is exactly what i was thinking

 

[PunDogg]

Originally posted by: Mickjc
There are certain quantum events postulated where particles can can "travel" a finite distance in zero time.

1. Electron pair reactions:

Electron pairs are produce by certain particle collisions. One member of the pair will react similarly to the other with distance not being a factor. This is demonstrated by black hole theory. Electron pairs are generated by the high energy emissions of the black hole. The pairs will orbit the hole. Gravitiational (tidal) forces will tend to separate electron pairs and one of the pair may be pulled into the black hole as gravitational forces exceed those maintaining orbital velocity. Whatever happens to the electron in the black hole causes the one in orbit to emit light, visibly identifying the supposedly invisible black hole. This effect should happen over *any* distance in *zero* time and has been used by SF writers as a method of instantaneous communication.

2. Another quantum effect is proton tunnelling:

This one is pure maths, but under certain conditions protons "disappear" from one location and "reappear" in another in zero time. Mathematically speaking...

As to getting there before you started; it's a little more difficult to speculate. There is a theory that light modulation can travel faster than light. The analogy goes like this: You take a light wave and give it a shake to set up a standing wave or carrier. You then frequency modulate the wave so you have regions of compression and rarifaction. It appears the regions of compression move faster than the wave by about 1.3 times. You then have information moving faster than light.

As to light travelling faster than light, however...?

Mick.

PS. It's been sometime since I've worked in this area, so things change and I forget stuff.

Interseting, how did you come across this info?? Do you work this stuff?

Dogg

 

[Mickjc]

The "information" was acquired as a by-product of three years of research into fuel cells. These operate efficently by moving protons and electrons (and probably a lot of other stuff as well) about very quickly. To begin to understand what's going on it's helpful to know a bit about how sub-atomic particles react with each other - quantum electrodynamics. There is some evidence to indicate that certain particles cover distance in zero time. All evidence *at this time* indicates that nothing with any mass travels faster since mass increases towards infinite values as speed approaches that of light and, therefore, would require infinite energy to push it.

There are particles with so little mass that they travel very fast: neutrinos go through the earth without slowing - it has been calculated that they have a range of over 10 light years in lead. Light is pure energy and you know how fast that goes. The problem is, at this level there is little to differentiate mass from energy or particles from waves, to the extent that researchers call these things "wavicles".

However, we are learning all the time and it's a dangerous assumption to say that something will never happen. For example there is a theory that certain particles - tachyons - have a slowest speed, which is that of light. Since we cannot detect anything travelling faster than light we cannot prove or disprove it. Yet.

Consider the words of the great man: "There are not only more things in heaven and earth Horatio than you know, but more than you can know."

Keep an open mind...

Mick.

 

[gururu]

the conclusions are misleading. The big problem with the experiment is that it does not account for the signature of the input light versus the output. That is, physically they may be similar (frequency, wavelength, velocity, etc), but are the photons injected the same photons ejected?

What I think: The matrix (cesium gas preparation) is absorbing the photons injected, and delivering newly generated photons at the other end. The photons expelled are the same velocity as the photons injected, but the time of delivery is far too rapid than the time necessary for the original photons to traverse the distance between input and output. Therefore, the conclusion is that the 'message' surpassed the speed of light.

Until they can prove that the same photons injected are those ejected, I wouldn't conclude that any subatomic particle or photon is capable of exceeding the velocity of light. The phenomenon just seems to be a special case in which the medium is capable of transducing an emission downstream upon excitation at a rate that would rival and/or surpass the time it took the input photons to reach the detected emission.

 

[Mingon]

The problem with getting somewhere before you have left is that eventually you go back to nothing i.e. the big bang, whilst it would be possible for things to move instantaneously, they would still exist in different place concurrently, but not simultaneously.

 

[NorthernSink23]

It should be noted that although the speed of light was intensified by a factor of 300, the time difference between the light pulse coming out before it entered was approximately 20ns. Hardly enough time to "see" anything.

 

[Georgeisdead]

Hey Mickjc, check out the thread Idea: Water Battery in the highly technical forum. This guy is talking about fuel cells and since you did some research on them, you might be able to contribute some good points to the discussion.

 

[rgwalt]

Originally posted by: gururu
the conclusions are misleading. The big problem with the experiment is that it does not account for the signature of the input light versus the output. That is, physically they may be similar (frequency, wavelength, velocity, etc), but are the photons injected the same photons ejected?

What I think: The matrix (cesium gas preparation) is absorbing the photons injected, and delivering newly generated photons at the other end. The photons expelled are the same velocity as the photons injected, but the time of delivery is far too rapid than the time necessary for the original photons to traverse the distance between input and output. Therefore, the conclusion is that the 'message' surpassed the speed of light.

Until they can prove that the same photons injected are those ejected, I wouldn't conclude that any subatomic particle or photon is capable of exceeding the velocity of light. The phenomenon just seems to be a special case in which the medium is capable of transducing an emission downstream upon excitation at a rate that would rival and/or surpass the time it took the input photons to reach the detected emission.

It is like having a very long hose, say New York to San Fransisco, filled with ball bearings stacked single file. If you push a ball bearing in one end, another will immediately pop out the other end. You could say that the ball bearing traveled extremely fast from NYC to SF, but in fact it was a different ball bearing that popped out. The trouble is that you can't distinguish between any of the ball bearings (or photons in this case) so you can't really say you are going faster than the speed of light.

Ryan

 

[Mookow]

Originally posted by: rgwalt

Originally posted by: gururu
the conclusions are misleading. The big problem with the experiment is that it does not account for the signature of the input light versus the output. That is, physically they may be similar (frequency, wavelength, velocity, etc), but are the photons injected the same photons ejected?

What I think: The matrix (cesium gas preparation) is absorbing the photons injected, and delivering newly generated photons at the other end. The photons expelled are the same velocity as the photons injected, but the time of delivery is far too rapid than the time necessary for the original photons to traverse the distance between input and output. Therefore, the conclusion is that the 'message' surpassed the speed of light.

Until they can prove that the same photons injected are those ejected, I wouldn't conclude that any subatomic particle or photon is capable of exceeding the velocity of light. The phenomenon just seems to be a special case in which the medium is capable of transducing an emission downstream upon excitation at a rate that would rival and/or surpass the time it took the input photons to reach the detected emission.

It is like having a very long hose, say New York to San Fransisco, filled with ball bearings stacked single file. If you push a ball bearing in one end, another will immediately pop out the other end. You could say that the ball bearing traveled extremely fast from NYC to SF, but in fact it was a different ball bearing that popped out. The trouble is that you can't distinguish between any of the ball bearings (or photons in this case) so you can't really say you are going faster than the speed of light.

Ryan

But couldnt you transmit information by varying how often you push on the ball bearings?

 

[FrenchTickler]

Light travels at the speed of the speed of light constant, C = 300,000,000 meters per second

Nother can travel faster than light, including time, which means if you could get your body traveling at the speed of light then you wouldn't age one second, and if you traveled faster then the speed of light you could theoreticly time travel.

You actualy slow down time everytime you move, you jsut can't notice it because it takes millions of miles to travel to even gain one second of youth back. It all had to do with displacement.

It is though impossible to travel at the speed of light, because light has no mass, and the only way you could travel at the speed of light is if you where massless, so it's impossible, unless you drop a few pounds.


Ryan

 

[stevennoland]

Dear French Tickler, light does have mass. Science has proved that you can bend it. If something can be manipulated, then it hass mass. Here is one. If you had a surface that absorbed all light, would you be able to see it?

 

[FrenchTickler]

Originally posted by: stevennoland
light does have mass. Science has proved that you can bend it.

Thats when it acts like a wave. A particle of light has been proved to have no mass there fore can not be effected by gravity. It's one of the biggest fudge factors of science next to the universal gravitational constant. Scientists where probably sitting around saying "see light isn't effected by gravity therefore it dosen't have mass and nothing can travel as fast as light. so it has to be a particle" Then another scientist says "well light has to have mass because in order to exist, you have to have mass, and light can be bent and minipulated. so it has to be a particle" Then they both said "duuuuuude lets just say that light can take the form of both particle and wave so we can both be right!" Pish posh


Ryan

 

[PowerMacG5]

Originally posted by: stevennoland
Dear French Tickler, light does have mass. Science has proved that you can bend it. If something can be manipulated, then it hass mass.

Wrong. I can manipulate an electro-magnetic wave, does it have mass?

Originally posted by: stevennoland
Here is one. If you had a surface that absorbed all light, would you be able to see it?

In a sense, yes, you would see something that you perceive as black. If it absorbed all light, than you will actually see nothing, but there is something behind it. Therefore, your brain would see black because it doesn't know what's on the other side of the object, but it knows that it cannot see whats on the side you are looking at. The theoretical object you speak of that absorbs all light would not be invisible because you would see a blank space. Basically, put a piece of black cardboard in front of a white wall. We will call the black cardboard the object that absorbs all visible light (although it really doesn't). Now, pretend it actually absorbed all the light, you would still see that there is something there.

 

[rjain]

Just correct the poor guy already! Light has zero rest mass. However, when it starts moving, it has a non-zero mass from the energy that is being transmitted.

This has nothing to do with "acting like a wave". Light acts like a wave and like a particle all the time, just like any other particle. Similarly, it has been said that atoms also act like a solar system. It's just a reasonable model which is accurate to within some tolerances or with respect to some measurements for some range of conditions.

 

[grant2]

Originally posted by: rgwalt
It is like having a very long hose, say New York to San Fransisco, filled with ball bearings stacked single file. If you push a ball bearing in one end, another will immediately pop out the other end. You could say that the ball bearing traveled extremely fast from NYC to SF, but in fact it was a different ball bearing that popped out. The trouble is that you can't distinguish between any of the ball bearings (or photons in this case) so you can't really say you are going faster than the speed of light.

This is an interesting anology but misses the point: According to the text of this article, A ball bearing would appear in San Fran 5 minutes before you released it in New York. Whether it's physically the same ball bearing or not, it's pretty amazing that the results of your action can be seen before you have taken it!!

That's what they are talking about: "Theoretically, this means that you could see a moment in time before it actually takes place. "

 

[grant2]

Originally posted by: shady06

Originally posted by: Mingon
Sounds like rubbish, light has a finite speed, it cannot leave before it has entered it will always be an amount of time latter despite how small the amount of time is.

that is exactly what i was thinking

And do you also think the world is flat & supported on the backs of elephants & that all matter is made up of 4 elements? Or do you only arbitrarily discount scientific study done AFTER your birth/adolescence?

 

[Mingon]

And do you also think the world is flat & supported on the backs of elephants & that all matter is made up of 4 elements? Or do you only arbitrarily discount scientific study done AFTER your birth/adolescence?

Wow your ignorant, perhaps we should have a P*ssing competition. I am 28, spent 9 years developing, designing and testing military equipement, and have spent the last 2 years teaching. I have studied engineering for 9years at various levels as well as business and project management. If you can match that then fair enough if not take your dumbarse comments elsewhere. :disgust:

 

[rjain]

Originally posted by: Mingon

And do you also think the world is flat & supported on the backs of elephants & that all matter is made up of 4 elements? Or do you only arbitrarily discount scientific study done AFTER your birth/adolescence?

Wow your ignorant, perhaps we should have a P*ssing competition. I am 28, spent 9 years developing, designing and testing military equipement, and have spent the last 2 years teaching. I have studied engineering for 9years at various levels as well as business and project management. If you can match that then fair enough if not take your dumbarse comments elsewhere. :disgust:

IME, engineers take science as a religion. They're told what's right and they have to believe it as dogma. Engineering isn't about discovering how things work, it's about building things that work better than what we have now. Scientific research progresses slowly enough that engineers can just take whatever current theories say when they're 20 and keep using that until they're 80. And I have NO clue how project management makes you a good physicist.

 

[Mingon]

IME, engineers take science as a religion. They're told what's right and they have to believe it as dogma. Engineering isn't about discovering how things work, it's about building things that work better than what we have now. Scientific research progresses slowly enough that engineers can just take whatever current theories say when they're 20 and keep using that until they're 80. And I have NO clue how project management makes you a good physicist.

Well your experience sounds very limited to say the least. A good engineer will use his experience in how things work with an imaginative view on improving or developing ideas be that new or improved - you can only re-develop the wheel so many times.
Project engineering gives an insight into the planning of a large scale task and informs the engineer of potential mistakes that can and do happen in development. The major difference between an engineer and a scientist is that the scientist can theorise how something can work - an engineer can make it work.

Couple of memories I have from work

I was working on a project involving the attachment of mines to ships using various methods. I was working with some colleagues on a silenced nail gun, whilst another branch was working on glue's. The person working on the glue's (epoxy style) was a young graduate chemist, whereas myself and my colleagues where engineers. When it came to the testing of a demonstration to the customer the chemist asked for a large vat of water and some plates of metal. This I supplied, her first reaction was that 'the metal has not been degreased' and followed by 'the water is very cold' - this was the UK in the middle of february. The point to the story is that as an engineer your develop an understanding of not just how things work, but also to understand where they are intended to work. The chemist had failed to understand that the hull of a ship would be both barnacle and in water likely to be less than 15c and as such the glues would not properly cure.

 

[rjain]

Originally posted by: Mingon

Well your experience sounds very limited to say the least. A good engineer will use his experience in how things work with an imaginative view on improving or developing ideas be that new or improved - you can only re-develop the wheel so many times.

Exactly. That doesn't mean you try to better understand what it is you're dealing with in the first place. You just try to build something that works better.

Project engineering gives an insight into the planning of a large scale task and informs the engineer of potential mistakes that can and do happen in development. The major difference between an engineer and a scientist is that the scientist can theorise how something can work - an engineer can make it work.

And engineers sometimes don't know how their products really work (that is, even the scientists can't explain them). That typically is the reason for the various factors of two and three that get thrown into the equations used.

Couple of memories I have from work

I was working on a project involving the attachment of mines to ships using various methods. I was working with some colleagues on a silenced nail gun, whilst another branch was working on glue's. The person working on the glue's (epoxy style) was a young graduate chemist, whereas myself and my colleagues where engineers. When it came to the testing of a demonstration to the customer the chemist asked for a large vat of water and some plates of metal. This I supplied, her first reaction was that 'the metal has not been degreased' and followed by 'the water is very cold' - this was the UK in the middle of february. The point to the story is that as an engineer your develop an understanding of not just how things work, but also to understand where they are intended to work. The chemist had failed to understand that the hull of a ship would be both barnacle and in water likely to be less than 15c and as such the glues would not properly cure.

Heh, you sound like my dad. And you, too, rant on about how scientists are stupid because they think about things that are different from what you think about. Since you're the engineer you should have explained to the chemist what the conditions were. That's your job. It's the chemist's job to design a glue to stick two things together, not to figure out what the people managing the project are not telling her about her design constraints.