Like the universe as a hologram:
Today, I want to tell you why some scientists believe that our universe is really a 3-dimensional projection of a 2-dimensional space. They call it the “holographic principle” and the key idea is this.
Usually, the number of different things you can imagine happening inside a part of space increases with the volume. Think of a bag of particles. The larger the bag, the more particles, and the more details you need to describe what the particles do. These details that you need to describe what happens are what physicists call the “degrees of freedom,” and the number of these degrees of freedom is proportional to the number of particles, which is proportional to the volume.
At least that’s how it normally works. The holographic principle, in contrast, says that you can describe what happens inside the bag by encoding it on the surface of that bag, at the same resolution. …
Personally I think that the motivations for the holographic principle are not particularly strong and in any case we’ll not be able to test this hypothesis in the coming centuries. Therefore writing papers about it is a waste of time. But it’s an interesting idea and at least you now know what physicists are talking about when they say the universe is a hologram.Sabine Hossenfelder, “Why do some scientists believe that our universe is a hologram?” at BackRe(Action)
And in our next post, experimental physicist Rob Sheldon replies.
Further reading on the hologram universe:
Sabine Hossenfelder: Can gravitational wave interferometers tell us if we live in a hologram universe? It’s actually a good thing if theses in physics don’t gain currency just because they make good TED talks. That could be part of their problem.
How is the hologram universe coming?
Astrophysicist Niayesh Afshordi Explains The Holograph Universe To Suzan Mazur At Oscillations
“Substantial evidence” claimed for universe as a hologram