
Hologram Within a Hologram Hints at Fate of Black Holes - furcyd
http://nautil.us/blog/hologram-within-a-hologram-hints-at-fate-of-black-holes
======
allovernow
I feel like articles like this quickly devolve into pseudo physics nonsense in
attempting to explain such higher level, poorly understood, abstract ideas to
laymen, as they're barely just skimming the surface of ideas that only really
exist as high level math.

Not necessarily a fault of the journalist, it's just that words really cannot
capture the breadth of information or the inquisitive power of what the
physicists derived without some understanding of the symbolic system involved.

~~~
raducu
As a layman, it makes me wonder what a hologram within a hologram within a
hologram can explain.

~~~
peter_d_sherman
You can think of it as information within other information within still other
information...

Simple 2D example (for programmers) -- you have a binary string, which can be
looked at as a series of 1's and 0's, or as a series of 8-bit bytes.

Well if we look at it as a series of bytes (think of that as the first
"holographic" dimension, because the bytes don't really exist -- that is, all
they really are is repeated groupings of 8-bits -- CPU's and programs and
memory might work with data of that length and "see" them, but in essence, the
string is is just 1's and 0's.

So that's the first "holographic" dimension... bytes. But now, inside of that
string are substrings -- discrete runs of shorter information. Let's think of
those substrings as "holographic" dimension 2.

From here, there could be even higher "holographic" dimensions, that is, let's
say we observe only some substrings relative to a mathematical pattern, f(x).

Well, you can think of f(x) -- and the resulting data it produces as a result
of reading specific substrings in a specific order -- as living in a higher
dimension, a "higher dimensional" "observer", if you will...

Whenever you see the word "black hole" or "hologram" \-- replace that with the
word "information", and think about it from that perspective... usually
there's something there...

(It's also equally-and-oppositely possible that I'm a crackpot and don't know
what I'm talking about -- take this explanation with the proverbial grain of
salt... <g>)

~~~
QuanticSausage
I beg to differ on the proposition that you're a crackpot. That seems to me a
perfectly mathematical way of thinking. If you're a crackpot, it's because all
mathematicians are.

------
YayamiOmate
It the paragraph setting the premise correct?

"The problem is this: The laws of quantum mechanics insist that information
about the past is never lost, including the record of whatever fell into a
black hole. But Hawking’s calculation contradicted this. He applied both
quantum mechanics and Albert Einstein’s theory of gravity to the space around
a black hole and found that quantum jitters cause the black hole to emit
radiation that’s perfectly random, carrying no information. " I always thought
that amount of information about current description of it must be conserved.
It's differet than history of the state evolution. IMO simplest QM experiment
contradicts this statement: if you pass a linearly polarized filter on a
rotated filter you get a random result. You can't infer original state. It's
like mas conservation in box of eggs. If you shake it, the amount of eggs is
the same, it's state is different and untrackable.

So in my understanding the blackhole was a perfect scrambler. It carries the
same amount of information is distribution random. Or the number of bits must
stay the same but their distribution changes. That might be slightly different
from amount information definition in Shannon sense.

Was my understanding wrong all along?

~~~
usgroup
I'd hazard to guess that "information" implies "not uniformly random", and
"uniformly random" implies "no information". That the black hole ripples
random implies that the input is in part "converted" to uniformly random and
thus by the implications above that information is lost.

At least that's how I'd interpret your paragraph.

~~~
saagarjha
> "uniformly random" implies "no information"

You can have something that when observed appears to be uniformly random but
can be transformed into something that is not. Consider a Hadamard transform
applied to |+>.

~~~
jacobush
Or decryption?

~~~
cbzbc
Possibly - though decryption relies on other information held elsewhere (the
keys), so I imagine within physics it then turns into a hidden variable
problem.

------
bentona
Here's a video that made me feel like I almost half-way understood one of the
main underlying principles (AdS/CFT correspondence)
[https://www.youtube.com/watch?v=klpDHn8viX8](https://www.youtube.com/watch?v=klpDHn8viX8)

re: "Following the discovery of this duality by Juan Maldacena"

Semi-unrelated: If you like articles like this, I bet you'll love that whole
channel.

------
lbj
"They found that at first, as the black hole gobbles up matter and gets
bigger, its information content increases. But then, in its old age, as
radiation starts spitting data back out, its information content decreases,
diverging from Hawking’s description."

How does this differ from Hawkings conclusions?

~~~
ymolodtsov
It doesn't, really, I guess they were trying to say that Hawking's predictions
don't give us a clue what's going on with the information – if the black hole
radiates like a black body it can't really push the information out through
it.

------
krzat
That 2D approach sounds interesting, I'm wondering if a game could be created
to give people better intuitive understanding of this stuff.

------
peter_d_sherman
Excerpt:

"The problem is this: The laws of quantum mechanics insist that information
about the past is never lost, including the record of whatever fell into a
black hole. But Hawking’s calculation contradicted this. He applied both
quantum mechanics and Albert Einstein’s theory of gravity to the space around
a black hole and found that quantum jitters cause the black hole to emit
radiation that’s perfectly random, carrying no information."

IF Hawking was wrong (remember, I said "if"), then the following identity
would hold:

Radiation = Information

Also... There's an interesting philosophical question brought up by this...
what is randonimity? How does one mathematically determine that something is
random? Perhaps "random" is just a human word we use to explain/label a
pattern that we as-of-yet don't understand... The history of mathematics is a
history of patterns that were not understood at certain points in time, that
became well understood at later points in time... So I ask the mathematical
community: "define random". If "random" is just a series of numbers which have
no apparent pattern, yet fall into a statistical distribution, then I'll bet
that a future mathematician will show that the digits of Pi (or groupings
thereof) to fall into the same statistical distribution as a "random" sequence
of numbers... In other words, if this were proven, then if someone looked at
Pi as that statistical distribution (without knowing anything else about Pi),
they'd assert that the number series was random, when in fact it was not, that
is, it was generated by an algorithm, the algorithm for Pi... which can be
thought of as _Information_ , whether you look at that information in
algorithm form or outputted digits form...

~~~
balfirevic
It is widely believed, but not proven [0], that Pi is normal. Nobody who knows
what they're talking about would confuse this with it being random.

[0] -
[https://en.wikipedia.org/wiki/Normal_number](https://en.wikipedia.org/wiki/Normal_number)

