Starship Asterisk*

APOD Robot wrote: ↑Sun Oct 03, 2021 4:05 am The Holographic Principle and a Teapot

Explanation: Sure, you can see the 2D rectangle of colors, but can you see deeper? Counting color patches in the featured image, you might estimate that the most information that this 2D digital image can hold is about 60 (horizontal) x 50(vertical) x 256 (possible colors) = 768,000 bits. However, the yet-unproven Holographic Principle states that, counter-intuitively, the information in a 2D panel can include all of the information in a 3D room that can be enclosed by the panel. The principle derives from the idea that the Planck length, the length scale where quantum mechanics begins to dominate classical gravity, is one side of an area that can hold only about one bit of information. The limit was first postulated by physicist Gerard 't Hooft in 1993. It can arise from generalizations from seemingly distant speculation that the information held by a black hole is determined not by its enclosed volume but by the surface area of its event horizon. The term "holographic" arises from a hologram analogy where three-dimension images are created by projecting light through a flat screen. Beware, some people staring at the featured image may not think it encodes just 768,000 bits -- nor even 256^3,000 bit permutations -- rather they might claim it encodes a three-dimensional teapot.

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Tekija wrote: ↑Sun Oct 03, 2021 5:51 am It is a three dimensional image of a teapot suspended in the air in front of a vertical backdrop and a slanting base.

Because we are binocular, we can see three dimensions. This is called ”single binocular vision”. It has three ”steps”. The first is simultaneous vision. Both eyes independently see the same image. The second is fusion. When our brain detects the two similar (not identical, see below) images - the sensory part of fusion - it will automatically and uncosciously precisely align the images into a single one by adjusting the direction of the eyes - the motor part of the fusion. We do not want to see double. Once the images of the two eyes are aligned, our brain notices that they are not in fact identical. This is because right eye sees it slightly from the right side and our left eye from the left - this is called disparity. Within half a second or so after aligning the two images, our brain calculates from this disparity a three dimensional view - the third step of single binocular vision called stereopsis.

But this three dimensionality is limited to a relatively narrow field, narrowest directly in front of us and a but wide in our peripheral visual field, called Panum’s space. Outside this space we continuously see double. This does not bother us because our brain is accustomed to these physiological diplopic images (but out a Finger in front of you and focus to it, puting it thus inside Panum’s space and everything behind your finger will be seen double. Now focus to the obects behind your finger, thus moving Panum’s space there, and you will see your finger doubled).

The APOD of today plays with single binocular vision. It has a repeating vertical motif that is there to stimulate fusion. Then there are the two disparate images that, once fusion is activated, within the half second or so will be spotted by our brain. It will find them different and will calculate the three dimensional image to us. Once ready, fusion keeps it visible and fixed even if we tilt the screen or look at it sideways. The third component is the random ”noise” added to confuse us so to hide the two disparate images. The three dimensional view emanates from the fact that the two images are slightly at dirrerent distances from the margin of the repeating vertical motif.

There are two ways of getting the stereoscopiv view. If you have latent outward squint like many of us have (almost all shortsighted myopic individuals have this exophoria) you can just let your eyes wander a bit so that one vertical motif moves approximately on top of the next one. The brain will notice they are similar, but not identical, fusion will align them perfectly and the brain will calculate the stereopsis. If you let your eyes wander two much so that they will skip on vertical motif and align the next one, your stereopsis will produce an abstract three dimensional image - a Salvador Dali teapot if you wish.

If you are not blessed with exophoria, it will be more difficult. You will need to look somewhat beyond Panum’s space and then out your screen within it. If you have latent inward squint, esophoria, or you align your eye on the wrong side of Panum’s space, the three dimensionality will reverse as the eyes are crossed the unintended way.

zendae1 wrote: ↑Sun Oct 03, 2021 4:52 am I can see these things pretty easily, but always inside out. Real clear 3D, but convex becomes concave and vv. For me, the teapot is more like a mold for a teapot.

You've merged too far. Straighten out your eyes even more and you can get a stack of three.

As for the theory that "a surface can encode all the info in a 3D space", I call BS.

Joe6666 wrote: ↑Sun Oct 03, 2021 6:52 pm

rochelimit wrote: ↑Sun Oct 03, 2021 9:30 am

zendae1 wrote: ↑Sun Oct 03, 2021 4:52 am I can see these things pretty easily, but always inside out. Real clear 3D, but convex becomes concave and vv. For me, the teapot is more like a mold for a teapot.

It's the 3DSmax teapot! this image is really old!

I can see both hollowed version and flying out version! It looks really cool when you see it as it should be as you can see the vertical background going down all the way, while the horizontal plane stops, so there's a "cliff" hidden behind the teapot, so cool

I see two teapots - a small one in front of a larger one.

I see two teapots - a small one in front of a larger one.

Mr Hull wrote: ↑Mon Oct 04, 2021 2:12 pm

johnnydeep wrote: ↑Sun Oct 03, 2021 5:51 pm

zendae1 wrote: ↑Sun Oct 03, 2021 3:44 pm

Thank you for that. It explains why I've seen both ways.
When these images first came out - I saw them at Spencer Gifts many moons ago - they all performed 'correctly' for me. The other way ended up being more favored I suppose.

I can easily see images such as these, but never in the convex view. But I have never been able to see those double image cross-eyed stereograms that Chris posts from time to time to help those not possessing red/blue 3D glasses.

As for the theory that "a surface can encode all the info in a 3D space", I call BS. Even assuming the volume and surface subdivisions are limited to Planck length granularity, the number of Planck volumes (i.e. the maximum bits of information) increases faster than the number of Planck faces enclosing it. So, if we must map Planck volumes one-to-one to Planck areas on the enclosing surface, in order to be able to represent all of them, we will run out. Hmm...unless...the number of possible volume bits can be encoded using 2^{number of faces}, where each face encodes a 0 or 1, allowing 2^{number of faces} permutations to encode whether each enclosed volume is a 0 or 1. In which case, 2^{number of faces} will increase MUCH faster than the number of volume bits. But this feels a lot like cheating and is therefore probably wrong.

On the other hand, the math is beyond me, and I'm sure the smarter people have it all rationally explained to the satisfaction of many.

I found this quite interesting and related to encoding information of a larger 3D volume with a 2D surface, and all sorts of stuff I didn't really understand

https://www.quantamagazine.org/how-spac ... -20190103/

johnnydeep wrote: ↑Sun Oct 03, 2021 5:51 pm

zendae1 wrote: ↑Sun Oct 03, 2021 3:44 pm

Chris Peterson wrote: ↑Sun Oct 03, 2021 1:58 pm
There are two ways you can merge an image like this. You can let your eyes drift apart (like looking through the image to something behind it), or you can cross your eyes a bit (like looking at something just in front of the image). And these images can be designed to use either method. This one is designed for the first way. That will show the teapot normally. Do it the second way (with crossed eyes) and your brain will still merge them, but now each eye is getting the wrong image, and you get that odd inverted look- as you say, more like a mold, concave instead of convex.

Thank you for that. It explains why I've seen both ways.
When these images first came out - I saw them at Spencer Gifts many moons ago - they all performed 'correctly' for me. The other way ended up being more favored I suppose.

I can easily see images such as these, but never in the convex view. But I have never been able to see those double image cross-eyed stereograms that Chris posts from time to time to help those not possessing red/blue 3D glasses.

As for the theory that "a surface can encode all the info in a 3D space", I call BS. Even assuming the volume and surface subdivisions are limited to Planck length granularity, the number of Planck volumes (i.e. the maximum bits of information) increases faster than the number of Planck faces enclosing it. So, if we must map Planck volumes one-to-one to Planck areas on the enclosing surface, in order to be able to represent all of them, we will run out. Hmm...unless...the number of possible volume bits can be encoded using 2^{number of faces}, where each face encodes a 0 or 1, allowing 2^{number of faces} permutations to encode whether each enclosed volume is a 0 or 1. In which case, 2^{number of faces} will increase MUCH faster than the number of volume bits. But this feels a lot like cheating and is therefore probably wrong.

On the other hand, the math is beyond me, and I'm sure the smarter people have it all rationally explained to the satisfaction of many.

rochelimit wrote: ↑Sun Oct 03, 2021 9:30 am

zendae1 wrote: ↑Sun Oct 03, 2021 4:52 am I can see these things pretty easily, but always inside out. Real clear 3D, but convex becomes concave and vv. For me, the teapot is more like a mold for a teapot.

It's the 3DSmax teapot! this image is really old!

I can see both hollowed version and flying out version! It looks really cool when you see it as it should be as you can see the vertical background going down all the way, while the horizontal plane stops, so there's a "cliff" hidden behind the teapot, so cool

zendae1 wrote: ↑Sun Oct 03, 2021 3:44 pm

Chris Peterson wrote: ↑Sun Oct 03, 2021 1:58 pm

zendae1 wrote: ↑Sun Oct 03, 2021 4:52 am I can see these things pretty easily, but always inside out. Real clear 3D, but convex becomes concave and vv. For me, the teapot is more like a mold for a teapot.

There are two ways you can merge an image like this. You can let your eyes drift apart (like looking through the image to something behind it), or you can cross your eyes a bit (like looking at something just in front of the image). And these images can be designed to use either method. This one is designed for the first way. That will show the teapot normally. Do it the second way (with crossed eyes) and your brain will still merge them, but now each eye is getting the wrong image, and you get that odd inverted look- as you say, more like a mold, concave instead of convex.

Thank you for that. It explains why I've seen both ways.
When these images first came out - I saw them at Spencer Gifts many moons ago - they all performed 'correctly' for me. The other way ended up being more favored I suppose.

Chris Peterson wrote: ↑Sun Oct 03, 2021 1:58 pm

zendae1 wrote: ↑Sun Oct 03, 2021 4:52 am I can see these things pretty easily, but always inside out. Real clear 3D, but convex becomes concave and vv. For me, the teapot is more like a mold for a teapot.

There are two ways you can merge an image like this. You can let your eyes drift apart (like looking through the image to something behind it), or you can cross your eyes a bit (like looking at something just in front of the image). And these images can be designed to use either method. This one is designed for the first way. That will show the teapot normally. Do it the second way (with crossed eyes) and your brain will still merge them, but now each eye is getting the wrong image, and you get that odd inverted look- as you say, more like a mold, concave instead of convex.

rochelimit wrote: ↑Sun Oct 03, 2021 9:30 am

zendae1 wrote: ↑Sun Oct 03, 2021 4:52 am I can see these things pretty easily, but always inside out. Real clear 3D, but convex becomes concave and vv. For me, the teapot is more like a mold for a teapot.

It's the 3DSmax teapot! this image is really old!

I can see both hollowed version and flying out version! It looks really cool when you see it as it should be as you can see the vertical background going down all the way, while the horizontal plane stops, so there's a "cliff" hidden behind the teapot, so cool

zendae1 wrote: ↑Sun Oct 03, 2021 4:52 am I can see these things pretty easily, but always inside out. Real clear 3D, but convex becomes concave and vv. For me, the teapot is more like a mold for a teapot.

“ We suggest and motivate a precise equivalence between uncompactified 11-dimensional M theory and the N=∞ limit of the supersymmetric matrix quantum mechanics describing D0 branes. The evidence for the conjecture consists of several correspondences between the two theories. As a consequence of supersymmetry the simple matrix model is rich enough to describe the properties of the entire Fock space of massless well separated particles of the supergravity theory. In one particular kinematic situation the leading large distance interaction of these particles is exactly described by supergravity. The model appears to be a nonperturbative realization of the holographic principle. The membrane states required by M theory are contained as excitations of the matrix model. The membrane world volume is a noncommutative geometry embedded in a noncommutative spacetime.”