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Light and its supposed speed.

Posted: Thu Aug 03, 2006 7:44 am
by Jbuza
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Posted: Thu Aug 03, 2006 7:58 am
by Jbuza
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Posted: Thu Aug 03, 2006 10:40 am
by Felgar
I only read through the first part of his lengthy discussion, but I'm not really sure what conclusions can be drawn from this. In essense he's saying that 'light' as we know it does not exist and that the concept of light being a physical entity is not relevant. Well, to some extent it's quite true; we know lots about what light does and how it behaves, but very very little about what it actually is. An evidence of this is seen in the behaviour of light and the results of which we see in quantum physics.

I think it should be pointed out that the seemingly erratic behaviour of light which is observed and then predicted through quantum physics is actually not unique to only light. Quantum physics also has a lot to say about electrons (according to quantum physics we can never know the exact position of electron) yet we do know that electrons have mass and therefore are actual physical objects. Because of these inconsistencies I feel the true failing here is on the part of Quantum Physics. Well, only in the sense that Quantum Physics does not explain *why* things happen, but only what will happen. As a predictor of behaviour the theory is extremely good but as an explanation of why, it is entirely void. In my opinion, Quantum Physics is destined to be replaced by an actual reasonable explanation that explains what light actually is, and explains why we see the results we see. It will likely validate the results of Quantum Physics by explaining the mechanism through which it works.

I view it the same as Relativity validating Netwonian Physics. Newton didn't understand why matter had gravity, only that it did. Einstein explained that gravity bends spacetime and this causes mutual attraction. Within the formulas of relativity are also the Newtonian Formulas. Now it should be noted that Relativity is also incomplete as it breaks down inside black holes, etc. Quantum Physics tells nothing about the reasons why these things happen. A better theory that holds under all conditions will explain why, and also further validate Relativity under the conditions where it yields correct predictions.

At the end of the day I'm not sure what your underlying point is Jbuza? Just food for thought?

PS: We know the speed of light definitively, but precious little about why that speed is what it is.

Posted: Thu Aug 03, 2006 1:00 pm
by Jbuza
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Posted: Thu Aug 03, 2006 1:19 pm
by Jbuza
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Posted: Thu Aug 03, 2006 1:21 pm
by Felgar
Jbuza wrote:My underlying point is that I don't understand about light.
Fair enough, and neither do any scientists, really. Until they can explain the reasons behind Quantum Phsyics.
Jbuza wrote:My question now becomes what if you observe it through the frame of reference of infinity? ... I would ask if we turn on a flashlight and God were standing on the boundary of space how long would it take him to see the light arrive?
Being bound by time and space it's inherently problematic to project our experiences into what God must experience. Having said that, I have always seen it kind of like Men in Black, where the whoel galaxy is inside a little ball. The whole universe can be seen at once and then God can 'zoom' in to any point. Then there's the time issue, and that becomes beyond comprehension because we simply cannot escape time. Like a ball with a slider below where it can be moved to show any time in all of history. Except then the slider must be infinitely long, so that doesn't work. LOL

But to answer your question let me first establish that when we turn on a flashlight on Mars, it takes about 8 minutes until we see it. From Saturn, a little over an hour. From the moon, about 1 1/4 seconds. So real-world results tell us the speed of light. If God choose to keep an 'eye' on that outer boundry of space, then it would take him a long time (13 billion years) to see the light. Of course he can also see you turn it on directly, so it's a little wierd. Here's an interesting article on some expirements they are doing to measure the distance from the Earth to the Moon, and the implications that it may have for Relativity and Quantum Physics. http://www.signonsandiego.com/news/scie ... laser.html

Posted: Thu Aug 03, 2006 2:19 pm
by Jbuza
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Posted: Thu Aug 03, 2006 2:47 pm
by sandy_mcd
I also only read the first part of the light article. I don't know enough or have the time to comprehend it but don't see anything of much scientific interest.
It seems that the author is trying to extend quantum mechanics to light. Just as electrons only exist as probability wavefunctions until there is some interaction, he seems to be trying to say something similar about light without explicitly making the connection.
Felgar wrote:Quantum physics also has a lot to say about electrons (according to quantum physics we can never know the exact position of electron) yet we do know that electrons have mass and therefore are actual physical objects. ... Well, only in the sense that Quantum Physics does not explain *why* things happen, but only what will happen. As a predictor of behaviour the theory is extremely good but as an explanation of why, it is entirely void.
I agree with a lot of what Felgar wrote, but science is never going to be able to answer the why question. Also, quantum mechanics only says what might happen, not what will happen.
Jim Walker wrote:"One might still like to ask: 'How does it work? What is the machinery behind the law?' ... -Richard Feynman

Perhaps we cannot find a basic mechanism of light for the simple possibility that it may not exist. ...
it holds atoms together, creates the properties of chemistry and of every element in the periodic chart. ... Scientifically, light has received the most scrutiny of any other force and provided physicists with its most acclaimed successes, with predictions within one part in millions. ... If it exists in space, what describes its shape, size, and boundary limits within space-time?
Feynman's quote was about quantum mechanics, not light.
Electromagnetism is more than just light (used here for electromagnetic radiation).
Electromagnetism does not hold atoms together (considered alone electromagnetic forces are more repulsive than attractive).
Photons do have physical size - when a photon diffracts (not defracts) it only interacts withpart of the diffracting material.

Posted: Thu Aug 03, 2006 2:50 pm
by BGoodForGoodSake
Jbuza wrote:
Felgar wrote:But to answer your question let me first establish that when we turn on a flashlight on Mars, it takes about 8 minutes until we see it. From Saturn, a little over an hour. From the moon, about 1 1/4 seconds. So real-world results tell us the speed of light.
How many of these things have actually been done? I'm not saying that for any reason other than curiosity.
All of these have been done, radio frequencies are electromagnetic emmisions just like visible light waves. The various probes which we have sent into space throughout the years have verified that radio waves take a certain amount of time to travel back and forth between the Earth and the space probe.

Re: Light and its supposed speed.

Posted: Thu Aug 03, 2006 2:52 pm
by BGoodForGoodSake
Jbuza wrote: If found this source to have kind of an interesting take on light

http://www.nobeliefs.com/light.htm

"Imagine that the phenomenon of light occurs only at the time of emission, reflection, defraction, and detection in matter, at the electron level, and nowhere else. Immediately, we eliminate the concept of light as discrete particles or waves traveling through space. Once you eliminate the concept of particles, waves and trajectories, the paradoxes, except for one (I'll explain later), completely disappear!"
I don't have time now to go through this article, but I will revisit this subject at a later time to rightfully tear apart the garbage that it is.

Posted: Thu Aug 03, 2006 3:41 pm
by Jbuza
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Posted: Thu Aug 03, 2006 3:56 pm
by Felgar
I read most of the rest of the article...
No one has yet proved that light can gravitate, regardless of how many descriptions say that it does. Beliefs, regardless of how many believers, do not equal proofs.
My understanding is that light can in fact bend spacetime, which is ultimately the creation of gravity. Expirements are being conducted to validate this fact, but it is predicted by General Relativity, if I am not mistaken. Dr. Mallet of the University of Conneticut is working to demonstrate that lasers can bend spacetime.
But wait! If nothing can escape, if everything gets dragged back, how can the gravitational force, itself, escape to influence other stars and matter? Gravity, according to quantum physicists also comes in the form of discrete particles called "gravitons" which can create waves and ripples through space at the speed of light. How do gravitons manage to escape black holes?
Quantum Physics only describes 3 force particles and NOT gravitons. There's currently no workable theory that introduces particles as force carriers of gravity (which would be called Gravitons). Well, there is String Theory, but from my (limited) understanding, that theory is still very well 'in development' and has by no means surpassed standard Quantum Theory as a usuable model. String Theory also has the issue of (maybe) being impossible to test with real expirements, and as such can be argued to be more of a philosophy and not a scientific theory. General Relativity is currently the only workable theory that allows us to calculate and predict gravity effects, AFAIK.
Jbuza wrote:Isn't the whole of creation a connected entity of God's design, and not amounts of matter x distance apart that influence other bits of matter in quantifiable delays? I say that my own reason and simple mind tell me that everything is connected in a way we do not comprehend.
You are right, things are connected, and simple fact is that we just don't know how these things are connected. We have no idea whatsoever how quantum entanglement works, only that is has worked so far. :)

I think the whole point the author makes about light not existing is entirely moot. He is arguing for adopting 'action at a distance' to light, so that really light transmission is just two electrons far apart affecting each other. In essence he takes the 'we can't tell where an electron is because it jumps around' from quantum physics and applies it to intergallactic scales instead of sub-atomic scales. Ultimately it's Quantum Physics' inablity to define these movements that causes me to doubt it. Yes it predicts results, but it does not explain why. Like Einstein, I hold to a belief in an orderred universe, not one where random events occur for no reason. The real truth and the explanations of why are likely very simple (really, all proven scientific facts are very simple and honestly in my opinion reveal an orderred creator) and hopefully one day someone will figure it out.

Taking a closer loook at what he said will demonstrate my point: "The difference in the analogy from the classical model comes with eliminating the concept of discrete particle entirely. In other words, light does not exist between events, but only at the events. ... It amounts to this: no one, throughout the history of science has ever seen or detected a photon in space! To this day, there has never existed a single scientific evidential experiment that has shown the existence of a wave or a particle of light between emission and detection."
You may have to read that a few times, but essentially what he says is this: "Photons don't actually exist, because no one has ever detected them without using a detector." Well, to me that's a tautology - of course, the only place we can detect them is where we have a detector! That will always be true, and as such all his conclusions are only vacously true and therefore meaningless.

Posted: Thu Aug 03, 2006 4:13 pm
by Felgar
Jbuza wrote:IS a radio transmission really the same as visible light emenated from a supernova? I know that visible light is on the chart of electro magnetic waves, but then what of a photon? Does a radio signal actually behave the same in all the clever tests men have devised to learn about light?

There are of models that say that light is a particle. Is a radio signal made up of photons?
Bgood is correct, they have all been done in practice on real spaceships and robots and that's why I chose those examples.

(Not withstanding the fact that Quantum Physics cannot determine whether light travelling through space is a photon or a wave, and that ultimately I believe the theory will be replaced with one that makes sense...) Radio waves and light waves are all electromagnetic waves and are all the exact same thing. They are all seen as photons with varying energy levels, and they all behave in same way...
sandy_mcd wrote: It seems that the author is trying to extend quantum mechanics to light. Just as electrons only exist as probability wavefunctions until there is some interaction, he seems to be trying to say something similar about light without explicitly making the connection.
...
I agree with a lot of what Felgar wrote, but science is never going to be able to answer the why question. Also, quantum mechanics only says what might happen, not what will happen.

Yes that's what he seems to be doing sandy; we both understand him the same way. Also, by saying "predict what will happen" I am speaking in terms of the probabilities provided by QT, so I agree with you here even if that wasn't clear. :)

Where I disagree is in your conclusion that science can't answer the question. I believe that one day we will be able to answer the question. Esspecially given that Quantum Physics leads to such utterly ridiculous notions of almost limitless numbers of universes being constantly created, I have faith that the theory is doomed to be replaced. :) Yes, it is faith and nothing more at this point. Oh, you did pick out the right question at hand, which is:
Jim Walker wrote:"One might still like to ask: 'How does it work? What is the machinery behind the law?' ... -Richard Feynman
The machinery behind the law is the key truth - we must find it eventually.

Posted: Thu Aug 03, 2006 4:15 pm
by Jbuza
gone.

Posted: Thu Aug 03, 2006 4:29 pm
by Felgar
Jbuza wrote:And the thinking from the same supposed law that only physical mass can act on the physical world, we propose that gravity has physical prescense.

The guys theory seems alittle far fetched when one supposes SR and GR to be true, and I think he deserves a lot of credit for trying to make sense out of light in a way that makes some sense.
You have to be really careful here. According to relativity, gravity has no physical presence and is just a manfestation of bending spacetime. The best example I know is that if you put a 10-pin bowling ball in the middle of a trampoline. The canvas curves toward the ball. Put a small marble on the trampoline and it will be attracted toward the bowling ball. In the same way, the 'gravity' is the result of the curvature of spacetime and is not, itself, an actual substance. That is, until they develop a theory for Gravitons, or somehow validate String Theory. :) The graviton is to gravity, what the photon is to light.

With respect to light having mass, it really doesn't. It is pure energy, which could be converted to mass, but as pure energy has no mass itself. Now, it does have momentum so when it hits something it will push against it, but still has no actual mass. These are all shown clearly in the formulas of Relativity. (if you're interested you can check out http://en.wikipedia.org/wiki/Mass#Equiv ... nal_masses ) The very formula that tells us that photons have momentum but no mass, also contains the very famous E = mc^2.