Is Our Universe a Hologram? Physicists Debate Famous Idea on Its 25th Anniversary

I have previously speculated here that the universe is perhaps a gigantic aquarium that came into being with the Big Bang!

"... Twenty-five years ago this month, a conjecture shook the world of theoretical physics. It had the aura of revelation. “At first, we had a magical statement ... almost out of nowhere,” says Mark Van Raamsdonk, a theoretical physicist at the University of British Columbia, Vancouver. The idea, put forth by Juan Maldacena of the Institute for Advanced Study in Princeton, N.J., hinted at something profound: that our universe could be a hologram. Much like a 3-D hologram emerges from the information encoded on a 2-D surface, our universe’s 4-D spacetime could be a holographic projection of a lower-dimensional reality.

Specifically, Maldacena showed that a five-dimensional theory of a type of imaginary spacetime called anti–de Sitter space (AdS) that included gravity could describe the same system as a lower-dimensional quantum field theory of particles and fields in the absence of gravity, called a conformal field theory (CFT). ..."

Is Our Universe a Hologram? Physicists Debate Famous Idea on Its 25th Anniversary - Scientific American The Ads/CFT duality conjecture suggests our universe is a hologram, enabling significant discoveries in the 25 years since it was first proposed