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Post by carnyx on Jan 20, 2011 23:14:53 GMT 1
Re the double slit experiment, it seems to me that any attempt to detect a wave at a slit, will cause it to lose energy, and it will then lose coherence with the wave at the other slit. The effect will be a disappearance of the interference pattern, and the screen image will revert to be typical of particles, rather than waves.
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Post by Progenitor A on Jan 21, 2011 8:59:35 GMT 1
Re the double slit experiment, it seems to me that any attempt to detect a wave at a slit, will cause it to lose energy, and it will then lose coherence with the wave at the other slit. The effect will be a disappearance of the interference pattern, and the screen image will revert to be typical of particles, rather than waves. At the slit? Do you mean before the slit? And surely the only way energy could be lost is for the photon to drop down in enrrgy by ssome amount of quanta, that is to drop to a lower frequency? Now coming back to yor information ideas in the respect that information is a scalar quntity. First I agreed but then I thought a bit more and decided that as well as magnitude, much information also has a clearly defined direction. Therefore,it would seem, information can be both scalar or vector, but I am not sure where this is getting us. Note that in all the waffle and BS (the original sources are probably sound but refracted through an a dim lens become absurd) that has been put forward, no attempt has been made to define information. Nor was it in the Horizon programme I just did not understand why a black hole (aapparently uniquely) destroys information (that so far undefined quality) For if a body were to fall into the sun is not similar 'information' lost? When an object is near to a nuclear blast is not similar 'information' lost? Inded if I chuck a letter on the fire, is not 'information' lost? Now one of the major planks of information theory is I believe, entropy; as physcial systems advance further and further into an entropic state, so more and more 'information' is lost. Note that all this begs the question already asked; what is information. Undoubtedly information must be defined partly (if not wholly) by change; constant unchanging things give us no information (I think). Its a long time sice I studied information theory and that central plank of telecommunications, Shannon. (Why name an Irish airport after him - it seems quite empty to me (the airport) - I just couldn't find the flight information I needed?).
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Post by carnyx on Jan 21, 2011 11:55:54 GMT 1
NM, before the slit.
And, you say:
And I guess it would not take much of a change of frequency to obliterate the interference pattern altogether, which is a vernier effect after all and so is incredibly sensitive.
And on the question of information, I guess we can reduce it down to two scalars, one being simply a binary 'there/not there' state, and the other scalar being the address, which could be expresses as a string of 'bits' So, what is interesting is that within an element of 'information' there will be more bits ( aka energy) taken up with the location than the bit of information itself.
I suspect this wil be true even for even for temporal ( time-stored) information .. ( i.e strings)
So I don't see the significance of the black-hole stuff per-se, as the idea that information is essentially a 2D affair seems to be obvious, and so the question of 3D volumes to store information is maybe redundant.
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Post by abacus9900 on Jan 21, 2011 13:26:44 GMT 1
This video lecture by Dr. Leonard Susskind makes things clearer about black holes, information and the holographic universe. He was one of the experts appearing in Horizon the other night. It's important to watch the question section following his lecture to gain a full understanding: fora.tv/2008/07/23/Leonard_Susskind_-_The_Black_Hole_War(There's a short add before the video starts.)
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Post by speakertoanimals on Jan 21, 2011 14:17:14 GMT 1
As regards the double slit, the point is that IF the photon lost energy, that would be detectable, and it isn't what is seen. Because we have ONE photon passing through both slits, and ONE photon detected on the screen.
Doesn't happen -- photons have ONE energy, which is determined by their wavelength/frequency. Hence the phrase 'a photondropping down by some amount of quanta' makes no sense -- the photon IS the quantum (of em radiation).
So, a photon has a definite frequency (and hence a definite energy). If a photon of a different frequency is detected, that is a DIFFERENT photon, not the earlier one somehow changing its frequency. You can't ADD energy to a photon, all you can do is interact with the orginal one, destroy it, and create a new photon with more energy than the first one.
Otherwise it makes it sound as if A photon can exist in various energy states, which is not the case.
Nope information is SCALAR by definition. So, if encoding a vector, we have two parts to the information, the magnitude (a single number), and the direction (a single number in 2D, two numbers in 3D).
So, the information in a set of numbers is just the sum of the information in each single number (provided the numbers are independant, as they are in this case).
Because, as I explained earlier, a black hole is a one-way street -- the information about the exact make-up of the matter faling into it is lost, since to the universe outside, all the defines a black hole is the MASS, angular momentum, and the charge.
Why don't you bother reading what I post before claiming it is rubbish?
Wrong. Let's take simple digital storage, we have a set of bits, each can be 0 or 1. So for N bits, we can store any number between 0 and 2^{N}.
If we have maximum storage capacity scaling as the volume, then for a memory store of volume V, doubling the volume doubles the memory capacity -- twice as many bits.
However, if the bits reside on the surface, then doubling the volume (for a sphere say), doesn't double the memory capacity, but only increases it by a factor of 2^(2/3).
I think you are confusing the number which gives you the amount of information, the dimensionality of that, with then dimensionality of the storage system.
Change? Utter rubbish! Are you SURE you have actually read Shannon.
Information is very simple. I have a system (a string of bits in a message, an array of bits that forms an image, an array of pixels that forms a digitised colour image).
For each system, there is the total number of possible configurations. So, for N bits, there are 2^{N} possible distinct states of those bits. Hence for N bits, you can store any whole number between 0 and 2^{N}. Doesn't matter whether or not you CHANGE what is written in that memory, the information is there once you have written it, stored for as long as the memory lasts.
Nope. The value at the location is all that matters. As regards location, it is assumed (as in a digital photograph), that we already know what order the bits are being used in. Pre-agreed beforehand. So all someone has to do if they want to send me a new image is send me the N bits in the correct order, because we have already agreed what size images we are dealing with, and the fact that we will beusing a raster scan.
We just need to count the number of locations (the number of bits in this case, the number of little Plnack length cells in the physics case), and the number of possible states at each location (2 in the binary case, more in the RGB colour image case, and everything up to the collapse into a black hole limit in the physics case).
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Post by carnyx on Jan 21, 2011 14:31:43 GMT 1
Which dimensions are you talking about? MLT or LWH?
If LWH ( i.e. cartersian geometry) then you agree that information is basically scalar i.) e., 1D ( and a second D for the presence/absence value, I suppose ..... ..... So why complicate it with 3D (volume) considerations?
I suspect that a lot of stuff about modern 'physics' is really instrumental, and has no meaning or utility except for the purpose they were shaped to do.
...But the practitioners seem to need to create metaphysics, metaphors, and the like ... to amaze and mystify the laymen who are expected to go 'woo'!
And a lot of these analogies are pretty terrible .. and some just stink! But, the practitioners really don't like to see laymen and amateurs criticising the crappy metaphors, or fooling around with the underlying concepts either. As long as we keep the cheques flowing ....
(Look at the branch of physics called 'Climate Science' .. to see how it all works)
So, in reality, we on this board are in the main fooling around with the metaphors, for recreational purposes e.g. as exercises for their ingenuity and thought processes. But what I find interesting is the fact that the practitioners too seem to have fun fooling around with concepts, hypotheses and so on .. but keep the fun among themselves.
Anyway, I'm off to look at the Abacus link ..
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Post by speakertoanimals on Jan 21, 2011 14:59:58 GMT 1
Information is DEFINED as being a scalar way of measuring the amount of information stored -- doesn't mean that the thing storing the information has to be one dimensional (or two, or three, or ten!).
So the amount of information stored in a photo, or in a movie, is a scalar, even though that information only makes sense as a 2d thing (image), or as a 3d thing (movie).
no stranger than the fact that you can take your ipod, with maximum storage indicated (20GB for my very old one), and store pictures, movies, music whatever.
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Post by Progenitor A on Jan 21, 2011 15:35:26 GMT 1
Hi Carnyx When I say that some information (most of it in fact) is vectorial what I mean is this A vector has magnitude (the scalar bit) and direction. If we wish to access the information that the Voyager satellite is sending back to earth, we must access the scalar information and the direction that it is coming from. Now I know that you have posited that information has two parts, an address and the information stored in that address and I can see the logic in that position. But as far as addresses are concerned, some addresses surely point to scalar locations (as in a memory) store, and others point to a physical vector (celestial co-ordinates for Voyager)? I find yout points about the relationship of information to energy fascinating too. JC Maxwell considered that was true, and just as in absolute entropy there can be no energy exchange, so in information absolute entropy ther is no information exchange - just a terrible sameness everywhere (oddly, as in the Great Socialist States that suppressed information there was an awful dull sameness about everything) And if information does exist on the 'edges of the univers' then why doe it take much longer to access some information that it does others (e.g. my mobile phone received information from a base station in less than a microsecond, but it takes about 90s for the voyager information to reach earth
(I see that the board's resident 'physicist' does not have a clue about the relationship between 'change' and 'information content'. Now why am I not the slightest bit surprised?)
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Post by abacus9900 on Jan 21, 2011 15:38:40 GMT 1
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Post by buckleymanor1 on Jan 21, 2011 16:10:55 GMT 1
So if you destroyed the original photon and created a new one with more energy by interaction. Why is it not possible to interact with the new photon by takeing away energy, and create another new photon with less energy similar to the first.
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Post by speakertoanimals on Jan 21, 2011 16:54:33 GMT 1
Sorry, yes, you can go that way as well! But it still isn't the original photon.
I'm trying to stop people getting the wrong idea -- that A photon can have various energy states, or that you can ADD energy to a photon and increase its energy.
Although sometimes usage gets a bit confusing, such as when we talk about a photon scattering off a charged particle, and loosing energy (hence changing frequency), and changing momentum.
I supose I'm just trying to stop the idea of CHANGING the energy state of a photon, or talking about the possible energy states of A photon (as opposed to the possible photon energies). The first sounds as if A single photon, THIS photon, can occupy various energy states. Which isn't quite the case, it's NOT the same case as when an electron in an atom can have various energy states, be excited from one level to a higher one.
Whereas for a photon, the thing that CAN have various energy states is the em quantum field, but those energy states are usually described as (for example)
no photons
1 photon with energy E
2 photons each with energy E
3 photons each with energy E
and so on (supposing we had a set-up where possible photon energy was only E, rather than the continuous set of energies and frequencies we can have).
Which probably doesn't help much -- but I could just detect an unusual and non-standard usage that I think was giving people the wrong ideas.
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Post by speakertoanimals on Jan 21, 2011 17:02:38 GMT 1
Nope, this is just totally wrong!
You are confusing the amount of information (which is a measure of the amount of content), and the actual content, and the format of that content.
So, I can have a 1MB image:
which may be colour -- RGB vector at each pixel of grayscale, brightness value at each pixel
Or I can have a 1MB sound file.
BOTH contain the same amount of information, but the content and format of that content is different in each case.
So, naymissus has used information in the common sense, NOT information in the sense in which it is being used in information theory
Because you're talking nonsense, as usual!
Now I think you are probably confused by the link between information and entropy. Entropy (via the secone law) is associated with change, in that it tells us about the direction of change (entropy increases). Similarly (which was the whole point about black holes), quantum evolution says no information is LOST. But information content can be totally static, and is defined as such.
Your 60GB hard drive is a 60GB hard drive, even if you haven't read or written anything on it for a year -- it's still 60GB. And when you change the content, it's still a 60GB hard drive.
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Post by speakertoanimals on Jan 21, 2011 17:15:49 GMT 1
It's not that information is stored at the edge of OUR universe, but instead that OUR universe is really of lower dimensionality (the surface of a sphere rather than the whole interior, if you like), and physics happens there, it just APPEARS as if it is physics is happening in the inside.
Our 3D physical universe is then, supposedly, an 'image' cast by the physics happening on the surface, but that isn't to say that we can stretch the analogy, and ask how long whatever it is that casts the hologram takes to get from the surface to us in the interior.
So, when I look at a white-light hologram, I see a box, and another box that appears to be six feet behind it. Yet the information that is both is actually on the small piece of glass in my hand, no more than a few inches away from each other. The scene with 3D objects far apart is just one interpretation of the information encoded in the hologram.
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Post by carnyx on Jan 21, 2011 17:47:52 GMT 1
Re the Abacus link on Len Wossname.
Seems to me he reckons that we are all living on the inside of a black hole ..with the 'edge of the Universe' being the inside face of the event horizon.
I was quite pleased when he said that 'black holes' gave off huge amounts of stuff .. so won't they be directly detectable?
Now to ask STA a question; how do you get to a point where the increasing gravitational force on an object orbiting a singularity overcomes the increasing outward force due to the consevation of angular momentum?
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Post by Progenitor A on Jan 21, 2011 19:29:09 GMT 1
Re the Abacus link on Len Wossname. Seems to me he reckons that we are all living on the inside of a black hole ..with the 'edge of the Universe' being the inside face of the event horizon. These guys, it seems to me, are following through where their mathematics leads them and erecting a fantasy world that cannot be proved or disproved by the 'scientific method' In other words (at this stage anyway), it ain't science but it's metaphyisical kite- flying
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