### Holographic Principle

Continuing the theme

**Xenophanes' Cosmos:**

"Being one, it is like all over, seeing and hearing and having the other senses all over"

Pondering the holographic principle, in Leonard Susskind "The Black Hole Wars" 2008

In 1976 Stephen Hawking proposed that information gets lost in Black Holes.

Gerald 't Hooft and Leonard S were aghast, since this meant that physics would not now be reversible.

Of course with quantum effects, events are only reversible if they are not observed...

Personally I am not perturbed by the non-reversibility of making omelettes.

In 1983 at an EST conference (Walter Erhard liked to spend his cash on parties for physicists, and why not?]

Gell-Mann,Glashow, Wilczek Hawkings all there... , 't Hooft & LS had to suffer again

SH saying "Information is lost in Black Hole Evaporation"

The controversy or "War" took a while to heat up...

motls

Penrose Diagrams: can fit infinity onto a page. Wish I understood them.

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Some History: 1908 Minkowski spacetime "proper time" (?)

Some numbers:

protons & neutrons on earth 5E51 (using HP-35 calculator 'exponential' notation = 5 * 10^51)

proton diameter 1.724E-15m

Planck length E-35 m

time E-42 sec

mass 2.17644E-8kg = 10 million bacteria

1.956E9 Joule

Schwarzschild radius equals the Planck length.

57.2 L of gasoline at 34.2 MJ/L

KE of Lear Jet?

(cf cosmic rays 1991 ..50 joules )

In 1972 LS had a chat with Dick Feynman, where they proposed small buds breaking off black holes...

Definition Entropy S = log of 'number of arrangements'

Information: Ptolemy's Library at 8E5 ft³ could contain 1.7E14 bits in books

E109 bits in Planck cells

but the exterior area Ptolemy's library is only E74 Planck squares;

LS maintains that is all the information that the library could contain.

I missed the bit where this was proved.

But something about Black Holes having their entropy/information on the surface, BHoles are the most dense, so a volume can only contain information proportional to its area.

This is the "Holographicic principle" 3d Spacetime is merely the projection from a 2D Holograph somewhere on the surface...

Somehow we are back at Xenophanes' Sphere where the "sense all over" are now a 2D Holograph of the 3D cosmos.

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Burkenstein proposed dropping one bit (E-45kg) onto a Black Hole with a radius of 3000 m.

the increase in the Horizon area would be E-70m² = Planck square

1972: Entropy of Black Hole ~= Horizon Area (Planck units) but note that 'approximately'

Denni Sciama "Stephen says" BH are Black Bodies

"Temperature is increase in energy of a system when you add one bit of entropy"

eg

5 ◎ Black Hole M=E31 T=E-8°K (◎ = solar mass) ie so cold it is not currently evaporating

Planck Mass BHole E32°K

finally evaporates in a "pop" roughly equivalent to "an artillary shell"

(actually 2E9 Joules is a pretty large round)

Loss of I ⇨ S ⇨ Heat ⇨ "causes an increase in "

Evaporation of 10 ◎ Black Hole takes E68 years

Entropy probably increases

from 1983 to 1991 LS had nothing to Say on this

**CMB photons are 1 cm apart**

Black Hole Horizon:

If you are suspended just above the Horizon (by a very strong cable?) you feel a very High Temperature

Whereas if you freefall through, you feel nothing unusual

- this I dont understand...

Amanda Peet from NZ joined LS in 1993

pbs

- If you ruin into Amanda in Auckland, get her to explain the holographic principle - she is an expert...

LS launched "Black Hole Complementarity" theory for a layer above the BH Horizon 1 Planck Thick

every bit is "scrambled and emitted" (??) so information is not lost? - I dont get this...

electron is a point - because you cant increase its spin... (?) (Schwartchild radius is E-56m or so ??)

nucleons spin as strings

a meson is tough

**: "you could lift a good sized truck on the end of a meson"**

"fundamental" strings are E19 times smaller

you could lift E40 Tons from a fundamental string ... high tensile -> Planck Length...

electron

**emits & absorbs E19 photons per second**

on average, >; age of the universe for an electron to emit a graviton (E18sec)

Gravity : loss of P.E. ▽ Mass (▽" Leads to a decrease in ")

Wrapping a String around a compact dimension gives it an electric charge

Joe Polchinski D-Branes 1995

D5 branes + D1 branes + open strings -> extremal BH with classical horizon (?)

Extremal BH : electric repulsion balances Gravitational attraction?

Strominger-Volta calculation: Horizon Area = Entropy (exactly. no more 'aproximately')

Callan Maldacena

Some guys from Mumbai Tata institute Strings on the Horizon, so NO info loss??

anti-DeSitter Space (aDS)

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Maldacena& Witten QFT description (so no info loss because its QFT )

(2+1) with QCD ~= (3+1) with gravity (actually (3+1) ~= (4+1)

if we imagine an antiDeSitterSpace in time, as a soup can with the above Escher as a slice through the can...

Black Hole in the Soup ? ordinary hot fluid of gluons ?

Quantum Gravity in aDS <-> QCD

so QCD in one realm implies information conservation in the other? "dual"

" implications for nuclear physics" - [ nuclear physics is a backwater as theory, but might get $ from Federal Bomb fanatics]

So thus ends the War

Oddly Stephen Hawkings didnt pay off his bets until 2004 & 2007

and Roger Penrose Still doesnt accept it. ie he still reckons that Information is lost, and he doesnt mind../

Out of every E10 bits of information in the universe, 1 is

**Not**associated with BHHorizons

Cosmic Constant ? E-123 (Planck units) why so small?

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Next Installment: Roger Penrose "Cycles of Time" (which apparently has been trounced)

Roger proposes a smooth transition from one eon to the next through the big bang(s)

Just like Stephen H. smoothed off the pointy bit at the beginning, hence exeunt deus

Roger now smooths off the transition from one eon to the next.

As usual I get lost in the maths.

One of the great sadnesses in life, to be too stupid to do Tensors....

Anyway praise to Roger for at least discussing tensors.

Its sort of scalars -> Vectors -> Tensors And theres

20 numbers at every point of the Ricci Tensor (Ricci dont lose that number)

and 10 in the Einstein tensor. And

pressure is energy is mass so its all self-reflective...

I returned Rogers book to the library, hence this sketchy summary.

Otherwise it wold sit around, gathering overdue fines, while I tell myself I'll read it and understanf Tensors one day

Roger says it all works if mass disappears.

Well Super-Kamiokande did a 300 day run on 3000 Tons of water and

no protons decayed, so its gonna be a long time

Roger, rather blithely says E100 years, and mass will somehow wither away.

The best part is that

**unusual circles**should be found in the CMB - that old 'face of god' black body remnant of 370,000 years post big bang

Super-Kamiokande embarrassingly decayed itself... i

in November 12, 2001, about 6,600 of the photomultiplier tubes (costing about $3000 each [8]) in the Super-Kamiokande detector imploded, apparently in a chain reaction as the shock wave from the concussion of each imploding tube ...

Anyway some young astrophysicist has said there are

**no circles in the CMB**so thanks Roger, for proposing a falsifiable hypothesis.

I still dont get how the BBang was super-low Entropy, something about Gravitational potential energy increasing... guess I'll never understand Entropy

Physicists get disturbed by breaking eggs. Birds (life) somehow is affronting.

Anyway its somehow cheering that Roger still maintains that Information is lost in Black Holes, even after Stephen has paid off on his bets to that effect.

Coming Soon

**Dante's inferno**as a projection into 3D space of higher dimensional SpaceTime (a neat little book on cosmology, which I wish I could find again).

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