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Post by speakertoanimals on Jan 19, 2011 16:17:01 GMT 1
@sta Your #26 post raised a question for me; do you get a 'red shift' in emissions from an EM transmitter as it falls into a black hole? We get a redshift from ANYTHING that falls into a blackhole. The closer it appraoches the event horizon, the more red-shifted, and the more slowed the faller appears. So they never appear frozen at the event horizon, because the photons that leave them get red-shifted out of existence way before that.
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Post by abacus9900 on Jan 19, 2011 16:54:37 GMT 1
Except when I tell you you don't understand something, or have got something wrong, you accuse me of being insulting and belittling! This has happened OVER and OVER again. So, don't talk crap and try and teach me how to teach -- it's just a smokescreen, because you refuse to listen when I tell you you have misunderstood or got something wrong. Instead, we just have the pair of stock responses: 1) how dare you belittle us b y telling me I have got it wrong, I don't believe you understand it anyway....... 2) It's all your fault for being a crap teacher...................... WHat is still conspicuous by its almost total absence is ANY attempt on your part to actualy engage in a discussion, to ASK, to say -- I don't think I've quite got what you physicists mean by 'information'.............and so on. Stop wasting time berating me, and DISCUSS the actual physics for once................... Ok then, I will put this to the test. What do they mean when they (seem) to be saying that information about our universe may be stored at its edge?
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Post by speakertoanimals on Jan 19, 2011 17:30:08 GMT 1
Okay, we have the SHORT version of the holographic principle.
Physicists define the amount of information that could potentially be stored in a region. In simple terms, it's like asking how much you could store on your PC. So, if I had a system where each element could only have two states (0 or 1), then I could calculate the amount of information that could be stored if I had N such elements.
In the real world, the systems are a bit more complicated, but the principles are the same.
When they do this computation, including the possible effects of gravity (so, quantum gravity probably means that space should be treated as discrete, rather than continuous, and the associated scale is the Planck length. Gravity also places a limit on how much energy you can have in a given volume without it collapsing into a black hole through its own a gravity).
When you do that rough calculation, to try and place an upper bound on the information possible, you get a result that depends on the surface area, rather than the volume.
Which suggests that the correct fundamental theory should be a theory based on the surfaces surrounding a volume, rather than our current theories which describe states within the volume as the fundamental things of the universe.
Which is as simple as I can make it.
So, it's not really (as I understand it), that information about our universe is stored at its edge, but instead that the fundamental theory that describes our universe is a theory based on a surface (rather than a volume as we used to think), and that that fundamental theory can then be transformed mathematically to a theory on what we see as 3d space, but with the limited degrees of freedom that the upper limit on information content seems to be telling us.
But the transformation from surface to volume is, as far as I see, just maths. It doesn't mean that there is some magic interaction going on in our universe between the inside where we are, and the surface outside where the information lives. Nor is it the case that 3d is 'an illusion'.
It's actually a common situation in theoretical physics, where there are often various ways of writing down the same physics.
The use of the word hologram is because you can encode on a glass sheet (2D) information that gives the appearance of a 3D scene when you view it. Hence it seems as if the 3d information has been encoded in 2d.
You can compute that this is possible, but that doesn't, in the ordinary hologram case, say which is REAL -- and I really viewing this scene in 3d, or is it a 2d hologram?
Same for the holographic universe, it seems to me -- just because mathematically the fundamental theory may have to be written in terms of information on surfaces, doesn't necessarily mean that the surface is real and the 3d volume we see is 'the illusion'. Just means that the fundamnetal theory is a bit different from what we thought. But you can see how the 3d is an illusion, we are actually part of some cosmic hologram, appeals to the woo-woo element, just as the quantum theory, isn't it weird, appeals to them as well.
In physics terms, it's actually trying to investigate what quantum gravity might be and how quantum gravity interacts with the other quantum theories we have. We know there that we have to have a quantum theory of gravity (it is fundamentally inconsistent otherwise, a universe with quantum theories for some interactions,but classical gravity can be shown to make no sense -- it's not just fashion!), just that writing it down has proved rather hard. So, in effect, the holographic principle may be an indication why -- we were writing theories down as they applied to volumes, and we should have been writing down theories oin surfaces!
The hope seems to be that a successful quantum gravity theory will answer various problems -- like what about those nasty infinities with black holes, what about where did the bang in the big bang come from, and what about collapse of the wavefunction, is it real or what (Penrose thinks quantum gravity mediates the collapse).
So we know it is important, and frankly, I think theorists get a bit annoyed because it has taken us longer than we hoped!
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Post by abacus9900 on Jan 19, 2011 18:04:29 GMT 1
Okay, we have the SHORT version of the holographic principle. Physicists define the amount of information that could potentially be stored in a region. In simple terms, it's like asking how much you could store on your PC. So, if I had a system where each element could only have two states (0 or 1), then I could calculate the amount of information that could be stored if I had N such elements. In the real world, the systems are a bit more complicated, but the principles are the same. When they do this computation, including the possible effects of gravity (so, quantum gravity probably means that space should be treated as discrete, rather than continuous, and the associated scale is the Planck length. Gravity also places a limit on how much energy you can have in a given volume without it collapsing into a black hole through its own a gravity). When you do that rough calculation, to try and place an upper bound on the information possible, you get a result that depends on the surface area, rather than the volume. Which suggests that the correct fundamental theory should be a theory based on the surfaces surrounding a volume, rather than our current theories which describe states within the volume as the fundamental things of the universe. Which is as simple as I can make it. So, it's not really (as I understand it), that information about our universe is stored at its edge, but instead that the fundamental theory that describes our universe is a theory based on a surface (rather than a volume as we used to think), and that that fundamental theory can then be transformed mathematically to a theory on what we see as 3d space, but with the limited degrees of freedom that the upper limit on information content seems to be telling us. But the transformation from surface to volume is, as far as I see, just maths. It doesn't mean that there is some magic interaction going on in our universe between the inside where we are, and the surface outside where the information lives. Nor is it the case that 3d is 'an illusion'. It's actually a common situation in theoretical physics, where there are often various ways of writing down the same physics. The use of the word hologram is because you can encode on a glass sheet (2D) information that gives the appearance of a 3D scene when you view it. Hence it seems as if the 3d information has been encoded in 2d. You can compute that this is possible, but that doesn't, in the ordinary hologram case, say which is REAL -- and I really viewing this scene in 3d, or is it a 2d hologram? Same for the holographic universe, it seems to me -- just because mathematically the fundamental theory may have to be written in terms of information on surfaces, doesn't necessarily mean that the surface is real and the 3d volume we see is 'the illusion'. Just means that the fundamnetal theory is a bit different from what we thought. But you can see how the 3d is an illusion, we are actually part of some cosmic hologram, appeals to the woo-woo element, just as the quantum theory, isn't it weird, appeals to them as well. In physics terms, it's actually trying to investigate what quantum gravity might be and how quantum gravity interacts with the other quantum theories we have. We know there that we have to have a quantum theory of gravity (it is fundamentally inconsistent otherwise, a universe with quantum theories for some interactions,but classical gravity can be shown to make no sense -- it's not just fashion!), just that writing it down has proved rather hard. So, in effect, the holographic principle may be an indication why -- we were writing theories down as they applied to volumes, and we should have been writing down theories oin surfaces! The hope seems to be that a successful quantum gravity theory will answer various problems -- like what about those nasty infinities with black holes, what about where did the bang in the big bang come from, and what about collapse of the wavefunction, is it real or what (Penrose thinks quantum gravity mediates the collapse). So we know it is important, and frankly, I think theorists get a bit annoyed because it has taken us longer than we hoped!
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Post by speakertoanimals on Jan 19, 2011 18:13:23 GMT 1
And?
Don't just cut and paste, and add a smilie -- SAY something! Or perhaps I was right all along, and you don't actually want to learn, or aren't willing to TRY to learn..............................
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Post by carnyx on Jan 19, 2011 18:20:42 GMT 1
Things are moving apace!
(As an aside, my take on 'information' is that fundamentally it is a scalar quantity .. like the number of 'bits' in the binary quantification of a property. Interestingly it can be increased and reduced by addition and subtraction, and in odd ways by multiplication, division, integration, etc. )
(And .... I am going to watch that video again .. it seemed to be a bit of a farrago covering very different fields, each needing a brief summary of WTF it was about .. and not necessaily connected at all. Rather, in the event of not finding the Higgs Boson it seemed to be making the plea that these kind of sciences should be indulged as forms of Art.)
However, the Swiss Two-Slit bloke talked about nobody knowing what was really happening to the light between the source and the screen. His remark, plus the stuff in the hologram sequences, reminded me of puzzles I had as a kid when messing about with lenses.
With a slide projector, if you get a perfectly focussed picture on a screen, then move the screen closer and closer to the lens, eventually you just get a blob .. that must contain all of the information required to make the picture, which then must coexist without interference in all places in the 'blob' ...and in the lens, the same time .. Very Curious? You can see this effect with a lens that has broken, and by using just a tiny part of it, it will still be possible to focus the image on the screen, but it will be dimmer. You can of course simulate this by blanking off any large part of the lens with a bit of tape.
Now the 2D image information seems to be progressively transformed in some way on it's journey to the lens, and then progressively de-transformed on it's way to the 2D screen image. The 'transform' at the lens must be into a very different kind of spatial coordinate set, than the 2D area image ...... which I never fathomed.
And, there was another weird effect I noticed when making telescopes, where if you put a strip of tape across the Objective lens, effectively making two separate semicircular lenses. If you looked out at the 3D landscape, then you would get two fuzzy images that would become one, and focussed, at a particular eyepiece setting. But, nearer and further objects would still appear as dual, and fuzzy... and could be pulled into focus A crude rangefinder? Later, I saw it in SLR cameras as a focussing aid. .
Now to the two-slit experiment. I would have to be convinced that each photon started from exactly the same optical plane, and position, in order to rule out this split-lens/split-image effect. I suspect that this may be difficult with the average laser.
Also, why the slit? Why not use two pinholes?
So, STA, I'd be grateful if you could ask around among your optical colleagues to check out the two-slit apparatus
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Post by Progenitor A on Jan 19, 2011 18:47:00 GMT 1
Okay, we have the SHORT version of the holographic principle. Physicists define the amount of information that could potentially be stored in a region. In simple terms, it's like asking how much you could store on your PC. So, if I had a system where each element could only have two states (0 or 1), then I could calculate the amount of information that could be stored if I had N such elements. In the real world, the systems are a bit more complicated, but the principles are the same. When they do this computation, including the possible effects of gravity (so, quantum gravity probably means that space should be treated as discrete, rather than continuous, and the associated scale is the Planck length. Gravity also places a limit on how much energy you can have in a given volume without it collapsing into a black hole through its own a gravity). When you do that rough calculation, to try and place an upper bound on the information possible, you get a result that depends on the surface area, rather than the volume. Which suggests that the correct fundamental theory should be a theory based on the surfaces surrounding a volume, rather than our current theories which describe states within the volume as the fundamental things of the universe. Which is as simple as I can make it. So, it's not really (as I understand it), that information about our universe is stored at its edge, but instead that the fundamental theory that describes our universe is a theory based on a surface (rather than a volume as we used to think), and that that fundamental theory can then be transformed mathematically to a theory on what we see as 3d space, but with the limited degrees of freedom that the upper limit on information content seems to be telling us. But the transformation from surface to volume is, as far as I see, just maths. It doesn't mean that there is some magic interaction going on in our universe between the inside where we are, and the surface outside where the information lives. Nor is it the case that 3d is 'an illusion'. It's actually a common situation in theoretical physics, where there are often various ways of writing down the same physics. The use of the word hologram is because you can encode on a glass sheet (2D) information that gives the appearance of a 3D scene when you view it. Hence it seems as if the 3d information has been encoded in 2d. You can compute that this is possible, but that doesn't, in the ordinary hologram case, say which is REAL -- and I really viewing this scene in 3d, or is it a 2d hologram? Same for the holographic universe, it seems to me -- just because mathematically the fundamental theory may have to be written in terms of information on surfaces, doesn't necessarily mean that the surface is real and the 3d volume we see is 'the illusion'. Just means that the fundamnetal theory is a bit different from what we thought. But you can see how the 3d is an illusion, we are actually part of some cosmic hologram, appeals to the woo-woo element, just as the quantum theory, isn't it weird, appeals to them as well. In physics terms, it's actually trying to investigate what quantum gravity might be and how quantum gravity interacts with the other quantum theories we have. We know there that we have to have a quantum theory of gravity (it is fundamentally inconsistent otherwise, a universe with quantum theories for some interactions,but classical gravity can be shown to make no sense -- it's not just fashion!), just that writing it down has proved rather hard. So, in effect, the holographic principle may be an indication why -- we were writing theories down as they applied to volumes, and we should have been writing down theories oin surfaces! The hope seems to be that a successful quantum gravity theory will answer various problems -- like what about those nasty infinities with black holes, what about where did the bang in the big bang come from, and what about collapse of the wavefunction, is it real or what (Penrose thinks quantum gravity mediates the collapse). So we know it is important, and frankly, I think theorists get a bit annoyed because it has taken us longer than we hoped! ;D ;D ;DhAHAHAHAHAHAHAHAH!
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Post by Progenitor A on Jan 19, 2011 18:56:49 GMT 1
Okay, we have the SHORT version of the holographic principle. Physicists define the amount of information that could potentially be stored in a region. In simple terms, it's like asking how much you could store on your PC. So, if I had a system where each element could only have two states (0 or 1), then I could calculate the amount of information that could be stored if I had N such elements. In the real world, the systems are a bit more complicated, but the principles are the same. When they do this computation, including the possible effects of gravity (so, quantum gravity probably means that space should be treated as discrete, rather than continuous, and the associated scale is the Planck length. Gravity also places a limit on how much energy you can have in a given volume without it collapsing into a black hole through its own a gravity). When you do that rough calculation, to try and place an upper bound on the information possible, you get a result that depends on the surface area, rather than the volume. Which suggests that the correct fundamental theory should be a theory based on the surfaces surrounding a volume, rather than our current theories which describe states within the volume as the fundamental things of the universe. Which is as simple as I can make it. So, it's not really (as I understand it), that information about our universe is stored at its edge, but instead that the fundamental theory that describes our universe is a theory based on a surface (rather than a volume as we used to think), and that that fundamental theory can then be transformed mathematically to a theory on what we see as 3d space, but with the limited degrees of freedom that the upper limit on information content seems to be telling us. But the transformation from surface to volume is, as far as I see, just maths. It doesn't mean that there is some magic interaction going on in our universe between the inside where we are, and the surface outside where the information lives. Nor is it the case that 3d is 'an illusion'. It's actually a common situation in theoretical physics, where there are often various ways of writing down the same physics. The use of the word hologram is because you can encode on a glass sheet (2D) information that gives the appearance of a 3D scene when you view it. Hence it seems as if the 3d information has been encoded in 2d. You can compute that this is possible, but that doesn't, in the ordinary hologram case, say which is REAL -- and I really viewing this scene in 3d, or is it a 2d hologram? Same for the holographic universe, it seems to me -- just because mathematically the fundamental theory may have to be written in terms of information on surfaces, doesn't necessarily mean that the surface is real and the 3d volume we see is 'the illusion'. Just means that the fundamnetal theory is a bit different from what we thought. But you can see how the 3d is an illusion, we are actually part of some cosmic hologram, appeals to the woo-woo element, just as the quantum theory, isn't it weird, appeals to them as well. In physics terms, it's actually trying to investigate what quantum gravity might be and how quantum gravity interacts with the other quantum theories we have. We know there that we have to have a quantum theory of gravity (it is fundamentally inconsistent otherwise, a universe with quantum theories for some interactions,but classical gravity can be shown to make no sense -- it's not just fashion!), just that writing it down has proved rather hard. So, in effect, the holographic principle may be an indication why -- we were writing theories down as they applied to volumes, and we should have been writing down theories oin surfaces! The hope seems to be that a successful quantum gravity theory will answer various problems -- like what about those nasty infinities with black holes, what about where did the bang in the big bang come from, and what about collapse of the wavefunction, is it real or what (Penrose thinks quantum gravity mediates the collapse). So we know it is important, and frankly, I think theorists get a bit annoyed because it has taken us longer than we hoped! I did warn you (not being smug!) that if STA could nor explain such a simple concept as differentiation properly then ther was no chance she could explain more complex things. She does not appear to understand anything on thei topic. Still neither do we!. Never mind Abacus It can truly be said, that never in any field of human endeavour has so much misunderstood garbage been spewed out by so few Would you like STA to teach your child either at school of College?
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Post by abacus9900 on Jan 19, 2011 19:07:12 GMT 1
And? Don't just cut and paste, and add a smilie -- SAY something! Or perhaps I was right all along, and you don't actually want to learn, or aren't willing to TRY to learn.............................. I'm just lost for words STA. You say you made it as simple as possible. Really? STA, dumb down, remember? You would not be any good on Horizon. Why can't you be more like that nice Mr. Tegmark?
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Post by abacus9900 on Jan 19, 2011 19:09:15 GMT 1
Well, only on condition that I had a child who had the combined talents of Copernicus, Einstein, Newton....
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Post by Progenitor A on Jan 19, 2011 19:19:10 GMT 1
Things are moving apace! (As an aside, my take on 'information' is that fundamentally it is a scalar quantity .. like the number of 'bits' in the binary quantification of a property. Interestingly it can be increased and reduced by addition and subtraction, and in odd ways by multiplication, division, integration, etc. ) Well, yes, in that numbers are scalar and all information can be digitised into strings of 0's an 1's , then yes information is scalar (And .... I am going to watch that video again .. it seemed to be a bit of a farrago covering very different fields, each needing a brief summary of WTF it was about .. and not necessaily connected at all. Rather, in the event of not finding the Higgs Boson it seemed to be making the plea that these kind of sciences should be indulged as forms of Art.) ;DQuite I got the impression that looking for the t Quark was a sort of interlude, like the Potters wheel of old, where thay had run out of things to say, or entertain us with However, the Swiss Two-Slit bloke talked about nobody knowing what was really happening to the light between the source and the screen. His remark, plus the stuff in the hologram sequences, reminded me of puzzles I had as a kid when messing about with lenses. Not only him, the emeinent Professor from Stanford (I think)said the same about QM generally With a slide projector, if you get a perfectly focussed picture on a screen, then move the screen closer and closer to the lens, eventually you just get a blob .. that must contain all of the information required to make the picture, which then must coexist without interference in all places in the 'blob' ...and in the lens, the same time .. Very Curious? You can see this effect with a lens that has broken, and by using just a tiny part of it, it will still be possible to focus the image on the screen, but it will be dimmer. You can of course simulate this by blanking off any large part of the lens with a bit of tape. Now the 2D image information seems to be progressively transformed in some way on it's journey to the lens, and then progressively de-transformed on it's way to the 2D screen image. The 'transform' at the lens must be into a very different kind of spatial coordinate set, than the 2D area image ...... which I never fathomed. And, there was another weird effect I noticed when making telescopes, where if you put a strip of tape across the Objective lens, effectively making two separate semicircular lenses. If you looked out at the 3D landscape, then you would get two fuzzy images that would become one, and focussed, at a particular eyepiece setting. But, nearer and further objects would still appear as dual, and fuzzy... and could be pulled into focus A crude rangefinder? Later, I saw it in SLR cameras as a focussing aid. This is a bit difficult for me, but at least I can follow what you are saying Now to the two-slit experiment. I would have to be convinced that each photon started from exactly the same optical plane, and position, in order to rule out this split-lens/split-image effect. I suspect that this may be difficult with the average laser. A good point, but I think we must place some trust in the integrity of the University Professors in this respect (especially ven dey spik mit heavy German accents hah!) Also, why the slit? Why not use two pinholes? Probably because the diffraction and hence interference acts only over a limited range (well a large range but with the human eyeball that can only detect a limited light energy, the 'spread' of difffracted waves is limited); thus with a pinhole only a fraction of the diffracted ring would actually caise intefernce. So far better to incease the range of interference using vertical slits?[/quote]
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Post by Progenitor A on Jan 19, 2011 19:22:12 GMT 1
Well, only on condition that I had a child who had the combined talents of Copernicus, Einstein, Newton.... Ah! If they were so clever, then they would soon see right through such 'teachers' as STA and do something useful, such as skip her lessons and look at the dolly-birds in the canteen!
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Post by speakertoanimals on Jan 19, 2011 19:38:21 GMT 1
So, abacus and naymissus both show that they know how to use the quote button, and smilies, but nowt else................
TO go back to a proper question:
The point about the two slits is that classically, you can understand it in terms of waves. No problemo.
Except the problem comes when we discover that light isn't exactly a continuous wave, but can act like particles as well. So, what happens when we have ONE particle in our apparatus?
It's not just light, we can do the same trick with electrons as well, and have one electron falling on two slits (except the wavelength of electrons is smaller, so we can't rule two slits for them in the same way, so we usually use a different technique, but the principle is the same).
We have ONE particle, we send it out as one particle, it passes through the apparatus, and is detected as a single particle that arrives at one particular point at the other end. Yet we find that we can't, for the apparatus in between identify a single path for that particle. In the slits case, if we put try to detect where the particle is in between the source and screen, we find that the pattern we get out at the other end is different.
So, the pattern we get on the screen for two slits is different to the pattern we get if it definitely passes through the top slit, or definitely passes through the bottom slit, and it isn't even a simple combination of the two patterns. We are forced to the conclusion that the single particle somehow manages to act like a wave in between, not a particle.
And using analogies from classical optics doesn't help, because the problem is not waves per se, but how something that acts like a particle at the start and at the end can act like a wave as well in the middle! We are forced to the conclusion that a single particle can also be a wave, that we can't split stuff into stuff that is waves and stuff that is particles, but instead that stuff is somehow both, and neither!
To return to the two slits -- why not two dots? Well, the simple answer is that two slits gives the simplest pattern, and we usually compute the slit pattern on the basis that the slits are much longer than they are wide. But we get some sort of interference and diffraction whatever holes we have in our screen! One simple example is where you have more than two slits, and if you increase the number of slits, you end up with a diffraction grating.
And to link back to holograms -- a hologram is, in effect a VERY complicated screen, and the pattern you get back out when you pass light through it is the image of the 3d scene that you made the hologram from!
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Post by speakertoanimals on Jan 19, 2011 19:44:29 GMT 1
Except I don't think it is possible for anyone with a brain to dumb it down as far as your level -- even if I did believe than you would actually listen if I did!
Don't go thinking that I was posting any of that explanation for your benefit, there are others on here reading this stuff, even if they don't stick their heads about the parapet and enter the discussion.
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Post by abacus9900 on Jan 19, 2011 20:02:47 GMT 1
Except I don't think it is possible for anyone with a brain to dumb it down as far as your level -- even if I did believe than you would actually listen if I did! Don't go thinking that I was posting any of that explanation for your benefit, there are others on here reading this stuff, even if they don't stick their heads about the parapet and enter the discussion. Perhaps in that case STA I should just give up asking you questions and ask someone else who is closer to my 'level.' I bet Max Tegmark could lower himself enough to provide me with something I could use.
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