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Post by speakertoanimals on Jan 19, 2011 20:14:03 GMT 1
I wasn't aware that you'd started!
Let's face it, you've been a TEENY bit rude -- I spend (a little) time and effort writing fairly long posts about the holographic universe, and the only response you can come up with is just copying the whole thing, and laughing.
I don't see that anyone else has attempted to answer your query, so if you really want the right sort of answer, maybe you should just go somewhere else, and allow these boards to host some discussions, rather than your interminable 'let's try and insult STA' troll-fest.
Or perhaps I should try and descend to your level as well, and just copy, paste, and laugh a lot. Naw, I'm afraid that's too infantile to hold my interest for more than a few seconds. I'll take up more intellectual pursuits (like dribbling and picking my nose........).
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Post by abacus9900 on Jan 19, 2011 21:09:08 GMT 1
I wasn't aware that you'd started! Let's face it, you've been a TEENY bit rude -- I spend (a little) time and effort writing fairly long posts about the holographic universe, and the only response you can come up with is just copying the whole thing, and laughing. I don't see that anyone else has attempted to answer your query, so if you really want the right sort of answer, maybe you should just go somewhere else, and allow these boards to host some discussions, rather than your interminable 'let's try and insult STA' troll-fest. Or perhaps I should try and descend to your level as well, and just copy, paste, and laugh a lot. Naw, I'm afraid that's too infantile to hold my interest for more than a few seconds. I'll take up more intellectual pursuits (like dribbling and picking my nose........). You're just teasing now. STA, in a nutshell, you do not seem to be able to summarize. Perhaps you should try to develop this skill.
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Post by speakertoanimals on Jan 20, 2011 14:06:17 GMT 1
And still no actual debate..........................
Which is a damn shame, since the Holographic universe stuff is actually very interesting! But since no one (even those who started the topic) seem to want to actually DISCUSS it................
What a waste!
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Post by abacus9900 on Jan 20, 2011 15:03:15 GMT 1
And still no actual debate.......................... Which is a damn shame, since the Holographic universe stuff is actually very interesting! But since no one (even those who started the topic) seem to want to actually DISCUSS it................ What a waste! STA, it shouldn't be a debate. It should be you teaching us stuff. If I went on a course at college I would not expect to have a debate with the instructor; I would expect to sit quietly and listen and take notes and, perhaps, ask the odd question about something that was not clear to me.
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Post by carnyx on Jan 20, 2011 15:57:47 GMT 1
Hold on!
I'm working up questions about the nature of holograms, images, and the two-slit experiment.
In the meantime, here is a query. if you had a pinhole camera, but with two pinholes, what extra properties would it have?
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Post by speakertoanimals on Jan 20, 2011 16:41:22 GMT 1
Except I'm not paid to teach you! And anyway, much teaching nowadays isn't the simple sit there and takes notes, you are expected to participate in the learning process. Whereas you just sit at the back sniggering and throwing paper planes at the lecturer, and shout out 'it's all rubbish!' at every opportunity.
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Post by speakertoanimals on Jan 20, 2011 16:55:44 GMT 1
Hold on! I'm working up questions about the nature of holograms, images, and the two-slit experiment. In the meantime, here is a query. if you had a pinhole camera, but with two pinholes, what extra properties would it have? A pin-hole camera with two pin-holes? Well, ignoring interference effects, you'd just get two images superimposed, one from each pinhole, and end up with a blurry image. It's kind of like the classic experiemnt with a home made pin-hole camera -- with a small pinhole you get a sharp image, but it's dim. If you make the pinhole larger (or have a multiplicity of pinholes), it is brighter, but blurred. Hence why putting a lens over a large pinhole is the logical progression -- you have the light-gathering advantages of a large pinhole, but you also need the lens to get a sharp image. If you wanted to demonstrate interference effects with two pinholes, first you'd need them close together, as close as the slits in the double slit. Then you'd need the correct source -- the simple calculations imagine a plane wave incident on the slits, which you usually approximate by a distant point source. If you just point it out the window, then each point in the sceen generates its own interference fringes, but each in slightly different places. which isn't what you want. Hence the point source. With double slits, the pattern is going to be the SAME as you move in a direction on the observing screen parallel to the slit length -- hence you can deduce that you are going to get a stripy interference pattern. But with two pin-holes instead, you apparently get something called hyperbolic fringes (the bright and dark bands are no longer stripes, but curved strips in the shapes of hyperbolae).
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Post by abacus9900 on Jan 20, 2011 17:45:04 GMT 1
Except I'm not paid to teach you! And anyway, much teaching nowadays isn't the simple sit there and takes notes, you are expected to participate in the learning process. Whereas you just sit at the back sniggering and throwing paper planes at the lecturer, and shout out 'it's all rubbish!' at every opportunity. So you want to get paid for teaching here do you? No wonder we don't learn anything.
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Post by speakertoanimals on Jan 20, 2011 18:23:15 GMT 1
If you want to learn, you have to engage (which is this case means a sensible interaction and debate, and a willingness to admit that you might be wrong. You've not been doing any of this.
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Post by abacus9900 on Jan 20, 2011 18:48:08 GMT 1
If you want to learn, you have to engage (which is this case means a sensible interaction and debate, and a willingness to admit that you might be wrong. You've not been doing any of this. I'm sorry, STA, but it's hopeless because you begin teaching stuff at an advanced level instead of at a more basic level so not much gets learnt. It's like trying to teach algebra to someone who has yet to grasp arithmetic. You also seem to try to put across too much information at once, where (in my humble opinion) you should be trying to whet appetites for more knowledge. Maybe you think it's below you to do this, I don't know. Would it not be better to make slow but steady progress instead of trying to make people digest too much information at once? It all ends up as just a waste of time and effort.
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Post by speakertoanimals on Jan 20, 2011 19:15:03 GMT 1
Yeah, yeah, heard it all before. Except if I tell you that you have not understood something basic, you get all miffed and refuse to believe me, so there is no point. And (as the response to my intial posts showed), you don't actually TRY to read what I have written and ask about what you got stuck on -- if I recall correctly, you just pasted the whole thing and laughed. Hardly a productive or mature response, or the sort of response you would expect from anyone who did seriously want to learn something.
Let's face it, it the usual response of the troublesome kid at the back of the class, who just heckles, then when confronted claims none of it is his fault, it's just that the whole lesson is beyond him, so it's all the fault of teacher really.
When it comes to the holographic principle, ANY of it seems beyond your level anyway, so why bother asking? After all, you didn't do what any sensible person would have done, like asking what quantum gravity means, or what the Planck length is, or anything like that. instead, paste and giggle (I really could do with coming up with a shorthand for that, seems to be your main mode of interaction at the moment.................).
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Post by abacus9900 on Jan 20, 2011 19:25:17 GMT 1
Yeah, yeah, heard it all before. Except if I tell you that you have not understood something basic, you get all miffed and refuse to believe me, so there is no point. And (as the response to my intial posts showed), you don't actually TRY to read what I have written and ask about what you got stuck on -- if I recall correctly, you just pasted the whole thing and laughed. Hardly a productive or mature response, or the sort of response you would expect from anyone who did seriously want to learn something. Let's face it, it the usual response of the troublesome kid at the back of the class, who just heckles, then when confronted claims none of it is his fault, it's just that the whole lesson is beyond him, so it's all the fault of teacher really. When it comes to the holographic principle, ANY of it seems beyond your level anyway, so why bother asking? After all, you didn't do what any sensible person would have done, like asking what quantum gravity means, or what the Planck length is, or anything like that. instead, paste and giggle (I really could do with coming up with a shorthand for that, seems to be your main mode of interaction at the moment.................). STA, I have come to the conclusion that the only motivation you have to post here on this MB is to bust balls, and that is all. Sorry to be so direct, but there it is.
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Post by abacus9900 on Jan 20, 2011 19:28:49 GMT 1
Very well, what is the Planck length?
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Post by speakertoanimals on Jan 20, 2011 19:44:52 GMT 1
FINALLY, an actual question!
Okay, in quantum theory, we have Plancks constant. This is what relates the frequency or wavelength of light to the energy of a photon (remember the photoelectric effect thread).
It also relates the energy of a particle like the electron to the wavelength of the associated waves, when we are doing stuff like electron diffraction.
In quantum theory in general, it sets the scale. The same number crops up all over quantum theory.
Now think about gravity. From relativity, we have the speed of light (in vacuum) as a fundamental constant. For gravity, we have the gravitational constant, the 'G' in GmM/r^2 (the newtonian gravitational force between objects).
If you put these together, you get a length (the Planck length). The actual value turns out to be 1.616252(81)×10−35 meters, so its pretty small.
The MEANING of it is that since it involves Plancks constant (which sets the scale in quantum theory), the speed of light (which sets the scale for speed), and the gravitational constant (which says how strong gravity is), it should be a length that has something to do with the scale associated with quantum effects in gravity.
The point to note is that this expected scale of quantum gravity effects is rather small -- about 10^-20 of the diameter of a proton! So, if spacetime stops being the smooth, continous thing that it is in general relativity, it is predicted that these effects only occur right down at the Planck length scale.
Which is why (as a lengthscale for quantum gravity effects), it comes into the information theory calculations, since it says that rather than being continuous, we should think of spacetime as instead like a 3d sheet of squared paper, with the size of the squares (actually cubes, but I don't have a 3d cubed pad to hand!) being the Planck length.
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Post by abacus9900 on Jan 20, 2011 20:15:20 GMT 1
FINALLY, an actual question! Okay, in quantum theory, we have Plancks constant. This is what relates the frequency or wavelength of light to the energy of a photon (remember the photoelectric effect thread). It also relates the energy of a particle like the electron to the wavelength of the associated waves, when we are doing stuff like electron diffraction. In quantum theory in general, it sets the scale. The same number crops up all over quantum theory. Now think about gravity. From relativity, we have the speed of light (in vacuum) as a fundamental constant. For gravity, we have the gravitational constant, the 'G' in GmM/r^2 (the newtonian gravitational force between objects). If you put these together, you get a length (the Planck length). The actual value turns out to be 1.616252(81)×10−35 meters, so its pretty small. The MEANING of it is that since it involves Plancks constant (which sets the scale in quantum theory), the speed of light (which sets the scale for speed), and the gravitational constant (which says how strong gravity is), it should be a length that has something to do with the scale associated with quantum effects in gravity. The point to note is that this expected scale of quantum gravity effects is rather small -- about 10^-20 of the diameter of a proton! So, if spacetime stops being the smooth, continous thing that it is in general relativity, it is predicted that these effects only occur right down at the Planck length scale. Which is why (as a lengthscale for quantum gravity effects), it comes into the information theory calculations, since it says that rather than being continuous, we should think of spacetime as instead like a 3d sheet of squared paper, with the size of the squares (actually cubes, but I don't have a 3d cubed pad to hand!) being the Planck length. OK, I've got the gist of this, thank you (although diagrams would be nice too). What else do I need to know?
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