Example of a scientific poster

The Info-Computation Turn in Physics A Hacking-Type Revolution Israel Belfer Bar Ilan University, Israel

“Ask anybody what the physical world is made of, and you are likely to be told “matter and energy.” Yet if we have learned anything from engineering, biology and physics, Information is just as crucial an ingredient... a century of developments in physics has taught us that Information is a crucial player in physical systems and processes. Indeed, a current trend, initiated by John A. Wheeler of Princeton University, is to regard the physical world as made of Information, with energy and matter as incidentals.” Jakob D. Bekenstein (2003)

Information is Physical – Maxwell’s Demon The physics of work (Szilard), computing (Bennett) and forgetting (Landauer)

The Generalized Second Law: ∆𝑺𝟎 + ∆𝑺𝑩𝑯 ≥ 𝟎 Shannon Entropy – 𝑯 𝒙 =−

𝑷(𝒙𝒊 ) 𝒍𝒏(𝑷(𝒙𝒊 )) 𝒊

Bolzmann’s H-Theorem: 𝑺 = −𝒌

𝑷𝒊 𝒍𝒏(𝑷𝒊 ) 𝒊

Black Hole entropy represents Missing Information (state configurations; transcended baryon number). Proportional to the BH surface area A:

𝑆𝐵𝐻

Larry Gonic – (quoted by Bennett), ‘Science Classics: Maxwell’s Demon’ , Discover 12, 82–83 (July 1991)

From Information-Bound to the Holographic Universe

[Planck's length : 𝑙𝑝 =

𝐴 = 2 4𝑙𝑝

−33 𝐺ħ 𝑐 3 = 1.61 × 10𝑐𝑚 ]

THE ENTROPY OF A BLACK HOLE is proportional to the area of its event horizon, the surface within which even light cannot escape the gravity of the hole. Specifically, a hole with a horizon spanning A Planck areas has A/4 units of entropy. (The Planck area, approximately 10-66 square centimeter, is the fundamental quantum unit of area determined by the strength of gravity, the speed of light and the size of quanta.) Considered as information, it is as if the entropy were written on the event horizon, with each bit (each digital 1 or 0) corresponding to four Planck areas. (Bekenstein, 2003)

Information Enthusiasm: It From Bit

• Information Paradox • Black Hole Wars • Informational Bound: 2𝜋𝑅𝐸 𝑆≤ ħ𝑐 • Holographic Principle

Finite Information Capacity ~𝟏𝟎𝟏𝟐𝟐 𝐁𝐢𝐭𝐬

Quantum Information Theory (QIT) Physical-Informational properties: • Superposition • Entanglement (teleportation, computation) • Reversibility • Decoherence (new Information)

• Pan-computationalism “Its all just Bit-Flipping”(Lloyd) • Digital Physics • Extreme Physical Information David Deutsch (1985)- “Quantum theory, the Church-Turing principle and the universal quantum computer” [first example of a QM Turing machine] Lov Grover (1996)- “A fast quantum mechanical algorithm for database search” - O(√N) complexity Peter Shor (1997) - "Polynomial-Time Algorithms for Prime Factorization and Discrete Logarithms on a Quantum Computer" – O(log N) complexity

“Otherwise put, every ‘it’ – every particle, every field of force, even the space-time continuum itself – derives its function, its meaning, its very existence entirely – even if in some contexts indirectly – from the apparatus-elicited answers to yes-or-no questions, binary choices, bits. ‘It from bit’ symbolizes the idea that every item of the physical world has at bottom – a very deep bottom, in most instances – an immaterial source and explanation; that which we call reality arises in the last analysis from the posing of yes–no questions and the registering of equipment-evoked responses; in short, that all things physical are Information-Theoretic in origin and that this is a participatory universe.” (Wheeler, 1990, p.5)

A New Scientific Style : Ramifications Physics defining Information Processing Information-Processing defining Physics

“should the ‘NP Hardness Assumption’ -- loosely speaking, that NP-complete problems are intractable in the physical world -- eventually be seen as a principle of physics?” (Aaronson, 2005) • The Church-Turing Thesis limiting physically realizable structures (Tegmark, 2005)? • Physicality of quantum computation expanding complexity classes? • Separate physical dynamics from Information processing (Timpson, 2004)?

Curiouser and curoiuser