I Essence of Holography

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How do you understand the world "holographic"?

Is it not it is about every part is included in other part and vice versa. If you take a piece of image of holography, the part of the entire thing is within any other part.

How best to phrase the above?

There is another definition that holographic is about the Information about the volume is encoded on a surface.

Is this what laser holograms do? Does it has a surface only and nothing beneath it?
 

davenn

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How do you understand the world "holographic"?

Is it not it is about every part is included in other part and vice versa. If you take a piece of image of holography, the part of the entire thing is within any other part.

How best to phrase the above?

There is another definition that holographic is about the Information about the volume is encoded on a surface.

Is this what laser holograms do? Does it has a surface only and nothing beneath it?

looks like you haven't done any google research on the subject yet
how about going and doing that, then come back with specific questions on what you didn't understand
in your readings ... include links to those things you were reading
 
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looks like you haven't done any google research on the subject yet
how about going and doing that, then come back with specific questions on what you didn't understand
in your readings ... include links to those things you were reading
Yes, I have googled this.. I just wondered why holography is mentioned in the Holographic Principle for example or popular articles writing is our universe a hologram (Sci-Am). What principle of laser holography that other concepts can use. I read:

"A hologram is an image that appears to be three dimensional and which can be seen with the naked eye. Holography is the science and practice of making holograms. Typically, a hologram is a photographic recording of a light field, rather than an image formed by a lens. The holographic medium, i.e., the object produced by a holographic process (which itself may be referred to as a hologram) is usually unintelligible when viewed under diffuse ambient light. It is an encoding of the light field as an interference pattern of variations in the opacity, density, or surface profile of the photographic medium. When suitably lit, the interference pattern diffracts the light into an accurate reproduction of the original light field, and the objects that were in it exhibit visual depth cues such as parallax and perspective that change realistically with the relative position of the observer. That is, the view of the image from different angles represents the subject viewed from similar angles. "
 

davenn

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well that quote from Wiki pretty much answers your questions, particularly the last Q

so what parts of that do you not understand ?
 
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well that quote from Wiki pretty much answers your questions, particularly the last Q

so what parts of that do you not understand ?
"That is, the view of the image from different angles represents the subject viewed from similar angles. "

What has this got to do with the universe being a hologram?

 

davenn

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What has this got to do with the universe being a hologram?

So now you are introducing a totally new subject unrelated to your first queries

a nice theory but as the last line on that link says .... Probably Not

Don't state something as factual when it hasn't been proven ... that link doesn't say that it is

 
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So now you are introducing a totally new subject unrelated to your first queries

a nice theory but as the last line on that link says .... Probably Not

Don't state something as factual when it hasn't been proven ... that link doesn't say that it is

It's related. When I ask others if they believed the universe was a hologram as sci-am mentioned. They said "Do you know what is a hologram"? It's as if it's not related.

So I am asking, what does the concept of holograms which came from laser holography got to do with the universe as hologram?

What is the definition of hologram that makes both possible?
 

anorlunda

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So now you are introducing a totally new subject unrelated to your first queries
I don't think so. I think he has been asking all along what "The Holographic Principle" has to do with actual holograms.
 

davenn

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I don't think so. I think he has been asking all along what "The Holographic Principle" has to do with actual holograms.

really ??
His Op had nothing to do with the universe being a hologram

he was asking about holograms and how they work
 

davenn

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So I am asking, what does the concept of holograms which came from laser holography got to do with the universe as hologram?

What is the definition of hologram that makes both possible?

the universe is unlikely to be a hologram as stated at the end of your link
 
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really ??
His Op had nothing to do with the universe being a hologram

he was asking about holograms and how they work
I had it in mind when I mentioned regarding Information about the volume is encoded on a surface, which is the holographic principle in black hole.

Anyway in the article in the middle:

"This is also how a hologram works, which takes 3 dimensions of information, and stores it on a 2D surface. For example, when “holographic Tupac” performed at Coachella in 2012, all three dimensions were represented in the image, but it was still a just 2D projection. Susskind and ‘t Hooft reconciled that even though objects are physically consumed by black holes, all of their information remains imprinted on the event horizon as a hologram.".

But there is another feature of holography, in that if you take a tiny piece, all the information is also encoded or stored there.

So is this a second meaning of holography and if the universe is a hologram. Any tiny piece has information of all the rest (automatically explaining the non-locality in QM?)
 
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Hi @lucas_ ,
I had it in mind when I mentioned regarding Information about the volume is encoded on a surface, which is the holographic principle in black hole.
The holographic principle is an idea/hypothesis in theoretical physics.
Here is a nice introductory lecture about it:

Leonard Susskind on The World As Hologram
 

Ibix

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An ordinary photo records only the intensity of incoming radiation, and throws away any information encoded in the relative phase of the incoming light. A hologram records the phase information as well (hence hologram, meaning something like "all picture"), which turns out to produce apparently 3d images. The "every piece contains the whole image" thing is a bit misleading (I think it's from William Gibson's Fragments of a Hologram Rose - that's certainly the first place I read it). Because what's encoded on the hologram plate is a Fourier transformed representation of the image, detail is stored on large scales and the "big picture" is stored on small scales. So a small section of a hologram of a rose will indeed display something that looks rather like a rose, but blurrier and less detailed than the whole hologram.

I don't think this really relates to the usage of hologram by Susskind. To the very limited extent that I understand it, I think he's arguing that the universe is governed by differential equations, and the solution of differential equations follows from the boundary conditions. Thus everything in the 3+1 dimensional universe is in principle encoded (or encodable, anyway) on a 2+1 dimensional boundary such as the event horizons of black holes - analogous to a 3d image stored on the 2d surface of a hologram. At least, that's what I recall from @PeterDonis' description of it. My understanding is that Susskind is convinced, but more or less everyone else's jury is still out.
 
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Thus everything in the 3+1 dimensional universe is in principle encoded (or encodable, anyway) on a 2+1 dimensional boundary such as the event horizons of black holes - analogous to a 3d image stored on the 2d surface of a hologram. At least, that's what I recall from @PeterDonis' description of it. My understanding is that Susskind is convinced, but more or less everyone else's jury is still out
That is my understanding of it too.
 

pinball1970

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Hi @lucas_ ,

The holographic principle is an idea/hypothesis in theoretical physics.
Here is a nice introductory lecture about it:

Leonard Susskind on The World As Hologram
I watched all of it as I find Susskind easy to listen to. Interesting video.
 
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I watched all of it as I find Susskind easy to listen to. Interesting video.
I'm glad you liked it :smile:. I like Susskind too. As for the holographic principle itself, I think it's a bold, maybe even wild idea, but nevertheless I like to watch some bold theorethical physics because I find it stimulating and challenging. And sometimes it makes my thoughts go in new, unexpected directions :smile:.
 
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An ordinary photo records only the intensity of incoming radiation, and throws away any information encoded in the relative phase of the incoming light. A hologram records the phase information as well (hence hologram, meaning something like "all picture"), which turns out to produce apparently 3d images. The "every piece contains the whole image" thing is a bit misleading (I think it's from William Gibson's Fragments of a Hologram Rose - that's certainly the first place I read it). Because what's encoded on the hologram plate is a Fourier transformed representation of the image, detail is stored on large scales and the "big picture" is stored on small scales. So a small section of a hologram of a rose will indeed display something that looks rather like a rose, but blurrier and less detailed than the whole hologram.
Any good video about how this encoding where "detail is stored on large scales and the "big picture" is stored on small scales" in laser holography?

I don't think this really relates to the usage of hologram by Susskind. To the very limited extent that I understand it, I think he's arguing that the universe is governed by differential equations, and the solution of differential equations follows from the boundary conditions. Thus everything in the 3+1 dimensional universe is in principle encoded (or encodable, anyway) on a 2+1 dimensional boundary such as the event horizons of black holes - analogous to a 3d image stored on the 2d surface of a hologram. At least, that's what I recall from @PeterDonis' description of it. My understanding is that Susskind is convinced, but more or less everyone else's jury is still out.
If the universe is a hologram. Is it not still possible this feature of "detail is stored on large scales and the "big picture" is stored on small scales" can also be true explaining quantum correlations even light years away? Didn't Susskind talk about quantum nonlocality?

Remember these lines from William Blake:

To see a World in a Grain of Sand
And a Heaven in a Wild Flower
Hold Infinity in the palm of your hand
And Eternity in an hour
 

Ibix

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Any good video about how this encoding where "detail is stored on large scales and the "big picture" is stored on small scales" in laser holography?
No idea. I learned about them in lectures. A hologram plate is essentially a diffraction grating, though, so the principle is simply that the output is the Fourier transform of the plate multiplied by the distribution of the incident radiation. If you keep just part of the plate, you lose the high frequency information and keep only the low frequencies. This means that the resulting image can't have rapid changes in it - i.e. it cannot have large changes over short lengths (like sharp boundaries) and must look blurry and lacking well-defined small-scale structure.
Is it not still possible this feature of "detail is stored on large scales and the "big picture" is stored on small scales" can also be true explaining quantum correlations even light years away?
Above my pay grade, I'm afraid.
William Blake
I don't think this is a valid reference for physics.
 
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anorlunda

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If the universe is a hologram
Be careful with your verb choice. The word is in that context makes it absolute and not nuanced. Much better to say, "we can describe the universe as ...."
 
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I watched some videos at youtube about holography principles and more familiar with it.

Then I read about Bohm Implicate Order which is akin to the 2D photographic plate. Didn't Susskind mention about Bohm Implicate Order in his Holographic principle? Are there no connections?


"Holograms and implicate order

In a holographic reconstruction, each region of a photographic plate contains the whole image
Bohm employed the hologram as a means of characterising implicate order, noting that each region of a photographic plate in which a hologram is observable contains within it the whole three-dimensional image, which can be viewed from a range of perspectives. That is, each region contains a whole and undivided image. In Bohm's words:
"There is the germ of a new notion of order here. This order is not to be understood solely in terms of a regular arrangement of objects (e.g., in rows) or as a regular arrangement of events (e.g. in a series). Rather, a total order is contained, in some implicit sense, in each region of space and time. Now, the word 'implicit' is based on the verb 'to implicate'. This means 'to fold inward' ... so we may be led to explore the notion that in some sense each region contains a total structure 'enfolded' within it".

Bohm noted that although the hologram conveys undivided wholeness, it is nevertheless static.

In this view of order, laws represent invariant relationships between explicate entities and structures, and thus Bohm maintained that in physics, the explicate order generally reveals itself within well-constructed experimental contexts as, for example, in the sensibly observable results of instruments. With respect to implicate order, however, Bohm asked us to consider the possibility instead "that physical law should refer primarily to an order of undivided wholeness of the content of description similar to that indicated by the hologram rather than to an order of analysis of such content into separate parts ..."
 

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