Comments on: 175. Holographic principle for dummies

By: cad

cad — Wed, 09 Nov 2011 20:34:45 +0000

The presentation can be found in several formats at

By: Leo

Leo — Tue, 05 Jul 2011 17:34:38 +0000

Ok I have a question:

if a black hole is supermassive, say 100 billion solar mass, let’s suppose Alice fells into it and Bob watches it from a spaceship. According to today’s physics, Bob will see Alice slowing down and becoming red and freezed on the event horizon. While Alice will feel nothing special when passing the event horizon, for a while, she will feel nothing special and will be alive.

If this is true the we have a statement an information about Alice BEHIND the event horizon. But we cannot have this info.

By: kelvin

kelvin — Sat, 05 Feb 2011 05:41:05 +0000

The link for the vid appears broken

By: Raphael

Raphael — Wed, 13 Jan 2010 17:43:51 +0000

What is the radius of a black hole? Is that the radius of its event horizon? Does a black hole have a radius? I thought that a black hole is pointlike object with infinite density? Emphasis on ‘pointlike’.

Interesting food for thought.

Thanks.

By: Lubos Motl

Lubos Motl — Mon, 12 Jan 2009 22:36:01 +0000

Priv?t Dmitrij,

it’s actually only one sentence later in the text – saying that the additional, radial, holographic dimension is encoded in the scale of the stereogram patterns (the periodicity in the x-direction), much like the information about the r-position in AdS is encoded in the scale in quantum gravity, too.

Best wishes
Lubos

By: Dmitry

Dmitry — Mon, 12 Jan 2009 20:51:39 +0000

Nice! Updated the post to link to yours. But you did not explain why stereograms are good as example of holographic principle

Cheers,
Dmitry.

By: Lubos Motl

Lubos Motl — Mon, 12 Jan 2009 18:13:24 +0000

Hi Dmitry, here is an TRF article with a Mathematica notebook

http://motls.blogspot.com/2009.....grams.html

By: Dmitry

Dmitry — Mon, 12 Jan 2009 14:56:15 +0000

Eventually, I will sink you in traffic, Motl

By: Lubos Motl

Lubos Motl — Mon, 12 Jan 2009 12:36:56 +0000

Incidentally, in advance, the technical “Wikipedia” name for these particular stereographs are

http://en.wikipedia.org/wiki/Autostereogram

By: Lubos Motl

Lubos Motl — Mon, 12 Jan 2009 12:34:18 +0000

Hi Dmitry, I still maintain some kind of Turbo Pascal on my desktop PC but I don’t think that it is really an up-to-date software. So it would be better to rewrite the program into something more modern, including Mathematica, despite a possible slowdown.

I can write an English version of the explanation why the “dinograms”, as I called it, work, but your indication that it would boost the traffic sounds unlikely, unless you count roughly 3.1415926 visits added as clicks from your blog!

By: Dmitry

Dmitry — Mon, 12 Jan 2009 11:51:15 +0000

Hoho, I can have some fun with your program Would you want to translate the page to English and put it on your blog? I believe, you would have some serious boost of traffic.

Cheers,
Dmitry.

By: Lubos Motl

Lubos Motl — Sun, 11 Jan 2009 21:58:16 +0000

The stereogram is a fun picture for this topic. When we were undergrads in Prague, we had so much fun with it. My friends saw it at an exhibition. I couldn’t really see it well, with my fuzzy vision, but after some time, I cracked how it worked and wrote some elementary programs that converted a function z(x,y) into this colorful picture.

http://www.kolej.mff.cuni.cz/~.....node2.html

In fact, I should recreate it now for Mathematica, even though it might be slower than a compiled program in Turbo Pascal. We’ll see. It should be fast today even if interpreted.