How Our Universe Could Emerge as a Hologram

Sugarman

Making Sugar
Joined
Feb 24, 2016
Messages
23,539
#1
The fabric of space and time is widely believed by physicists to be emergent, stitched out of quantum threads according to an unknown pattern. And for 22 years, they’ve had a toy model of how emergent space-time can work: a theoretical “universe in a bottle,” as its discoverer, Juan Maldacena, has described it.

The space-time filling the region inside the bottle — a continuum that bends and undulates, producing the force called gravity — exactly maps to a network of quantum particles living on the bottle’s rigid, gravity-free surface. The interior “universe” projects from the lower-dimensional boundary system like a hologram. Maldacena’s discovery of this hologram has given physicists a working example of a quantum theory of gravity.

But that doesn’t necessarily mean the toy universe shows how space-time and gravity emerge in our universe. The bottle’s interior is a dynamic, Escheresque place called anti–de Sitter (AdS) space that is negatively curved like a saddle. Different directions on the saddle curve in opposite ways, with one direction curving up and the other curving down. The curves tend toward vertical as you move away from the center, ultimately giving AdS space its outer boundary — a surface where quantum particles can interact to create the holographic universe inside. However, in reality, we inhabit a positively curved “de Sitter (dS) space,” which resembles the surface of a sphere that’s expanding without bounds.
More At: https://www.quantamagazine.org/how-our-universe-could-emerge-as-a-hologram-20190221/
 

saor

Honorary Master
Joined
Feb 3, 2012
Messages
19,210
#2
Some of these ideas are like reading Gren Egan.

(^ link is to a greg egan site with sciencey stuff to help explain parts of the book, Diaspora - which I haven't read yet, but Permutation City is one of my favorite books about mind uploads and the difference in subjective speed etc._
 
Top