Neil Degrasse has been quoted speaking of the Universe as concieveably being a simulation. Is such a notion plausibly possible?

Replies to This Discussion

Permalink Reply by Unseen on January 7, 2017 at 11:35pm

Notice I said "machine." You are not addressing that. You are using the word "program" in place of "machine." A program controls a machine, but imagine now a machine controlling a hydrogen atom. Could such a machine be less complex than a hydrogen atom? How? Now imagine a machine (not a program) that can control every subatomic particle, nay every quark, as well as every interaction, and is less complicated than the universe. Once again, I don't see how it's possible.

▶ Reply

Permalink Reply by Michael on January 10, 2017 at 6:08pm

Already in Holographic universe theory what happens in 3-space is a hologram of that determined on the 2D event horizon which captures this universe. Thus reality is a 3D simulation of what is happening on the event horizon with no intervening mechanisms nor complexity. This correlates with the mathematics of the error correcting algorithm already noted governing the data on the event horizon.

▶ Reply

Permalink Reply by Michael on January 11, 2017 at 6:23pm

The idea of expressing spacetime as a quantum code is so amazing that deserves at least a brief non-technical presentation. It relies on two relatively recent ideas in physics: the holographic principle and quantum error-correction. The holographic principle asserts that all the information contained in a region of space is encoded on the boundary of the region. Quantum error correction is the foundation of building large-scale quantum computers that can be operated to solve hard problems. Based on these two ideas, Fernando Pastawski, Beni Yoshida, Daniel Harlow and John Preskill have constructed quantum codes that realize the holographic principle.

▶ Reply

Permalink Reply by Unseen on January 11, 2017 at 6:49pm

if quantum computers become practical, suddenly the uncrackable crypography of today will be worthless. Some new, currently inconceivable, way of protecting data transfers will need to be developed or there will no longer be any such thing as secure data transference.

Permalink Reply by Michael on January 12, 2017 at 6:47am

@unseen,
Quantum codes are slated to make unbreakable ciphers not using a quantum computer, for all that's worth.

Permalink Reply by Dr. Bob on January 10, 2017 at 3:39pm

A simulator would have to be in control of everything every motion of every subatomic particle, in control of particles coming into and going out of existence.

No, a simulator would only have to be in control of every observation made by a sentient player-character. It wouldn't need to generate particles until a sentient player-character actually made an observation looking for particles.

Then it would only need the equations necessary to generate the observations.

▶ Reply

Permalink Reply by Unseen on January 10, 2017 at 9:44pm

That does not sound like the kind of simulation that could keep an entire universe going, and it certainly doesn't sound like the kind of simulation some physicists seem to be thinking about,

▶ Reply

Permalink Reply by Gregg RThomas on January 6, 2017 at 9:55am

At Bob:

"...putting a VR headset on every human on the planet would..."

Bad idea Bob, the Planet would never get past PORN.

▶ Reply

Permalink Reply by Dr. Bob on January 11, 2017 at 4:43pm

LOL. That's probably true. Why didn't the Matrix think of that? Then Neo and the rest wouldn't have tried to escape!

▶ Reply

Permalink Reply by matt.clerke on January 2, 2017 at 5:34pm

The machines which generate simulations are more complex than the simulations they generate. Thus, no machine could simulate the universe.

That's a good point, except that it need not simulate the universe... merely a universe. I can simulate a universe anytime I like. With enough computing power, it could even be as complex as our universe, but a fraction of the size. Maybe our universe is merely a scaled down simulation of another universe?

▶ Reply

Permalink Reply by Unseen on January 2, 2017 at 9:16pm

I'm not sure where you went with that.

In the world of aesthetics, some answer the question "What is art?" by saying "Art is what someone says is art," which is a nod to the subjectivity of questions involving evaluation.

I suppose if you want to say "A universe is what someone says is a universe," then you may have a point.

However, I am talking about the kind of universe we mean when we talk about our own. I suppose you could define a hydrogen atom as a universe and run a simple program to model it which is more complex than the atom by some standard (ignoring the fact that subatomic particles aren't as simple as we once thought them to be),

Could a program that controls a simulation of our universe with everything in it and every event in it in real time actually be less complex than the universe itself? I don't see how.