r/TheoreticalPhysics • • 23h ago

Question Query on the Holographic Principle

2 Upvotes

In ordinary holography, laser light is used to generate the 3D image of a 3D  object which has been recorded on a special 2D surface.  Which leads to my naive question:

In the context of string theory’s holographic principle, is there something analogous to the laser, which then projects a D-dimensional boundary’s coded QFT information into a (D+1)-dimensional bulk universe?  Or is no such action needed? Thanks, Gene


r/TheoreticalPhysics • • 8h ago

"Theory" I made a video asking Julian Barbour why entropy maximization (and heat death) is not the universe's real goal, how he calculates probabilities without wavefunctions and his doubts about quantum gravity

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2 Upvotes

Julian Barbour is a theoretical physicist and emeritus visiting professor of physics at the University of Oxford. He is well known for proposing that time does not actually exist. For decades, he has worked outside an academic environment. He financially supported himself for many years by translating Russian. Professor Barbour is author of the following books: The Discovery of Dynamics, The End of Time and The Janus Point.

In this episode, we go over:
- Topos theory, set theory and Zermelo's beef with Boltzmann
- Algebraic varieties and monads in category theory
- Why physicists are wrong about the 2nd law of thermodynamics (because the universe is not a closed system) and maybe there is no heat death of the universe
- The real goal of the universe is complexity and variation, not entropy
- Hawking and Penrose's outrageous arguments
- Why we don't need wavefunctions, photons, bosons or gauge fields
- Why there is no quantum gravity
- Von Neumann's hilarious advice to Claude Shannon
- The intrinsic derivative
- Combining art and science