Space

Open Board
· 3 followers
RC YuWilliam Fan
Lee Johnson6 months ago
cosmology

How Our Universe Being a Simulation Could Explain Quantum Mechanics

The most recent post over on the StarTalk board delves into the simulation hypothesis, what it means and how philosophers and physicists have tried to untangle the puzzle.

But one thought stuck with me: doesn’t the simulation hypothesis kind of explain the weird stuff about quantum mechanics?

This wasn’t an original idea – in fact, there’s a great paper that covers these issues and even proposes some tests.

The Problems with Simulating a Universe

Bostrom's original paper introduces the concepts of the simulation hypothesis, but brushes over a key issue. He speaks of “posthuman” societies with planet-sized computers, but later authors generally pay more attention to the limitations. No matter how big the computer, the processing power is still finite.

Campbell et. al. [2] compare this to rendering a computer game. Most designers don’t render the whole map all the time – you really only need it to render what the player can see. Taking this shortcut maximizes the usable output from your limited computing capability. It’s efficient.

And if you were simulating a universe – especially ones that could contain simulations themselves – efficiency would be crucial. You’re unlikely to have a definitive plan for every electron, through the whole history of the universe.

What This Could Explain About Quantum Mechanics

  • The program “plays dice”: Why is quantum mechanics probabilistic? Because like No Man’s Sky or the Binding of Isaac, the generation of the universe is procedural. Simply calculating as needed based on some probabilities would save computing power.

  • Wavefunction collapse: When we make an observation of the quantum world, we’re taught that the many possibilities of the initial wavefunction “collapse” to a single result, but nobody knows why. The simulation hypothesis explains this easily: the precise value would only be “rendered” when we look at it. The strange behaviour is because the simulation finally settles on one possibility when we look.

  • Quantum entanglement: How do we get “spooky action at a distance” aka quantum entanglement? It’s weird that information can apparently travel faster than light, unless it’s a simulation. Then the information may not travel that far at all – it’s all in the same computer, after all.

But, as Terence Tao pointed out on the podcast, if reality is a simulation, it’s incredibly – suspiciously – consistent. 

2
RC Yu6 months ago

Crazy thought. Are we living in a black hole?

StarTalk Show Notes7 months ago
StarTalkcosmology

Season 17, Episode 3: Are We Living Inside a Black Hole?

Hey StarTalkians! Season 17, Episode 3’s collection of “Cosmic Queries” saw Neil and Chuck tackle a lot of questions about black holes, and this question in particular stood out:

Alcubierre Drives, Antimatter Multiverses & More! | Cosmic Queries #103

Neil’s answer is solid. But lurking underneath that question is something they didn’t address in the episode: why would we be living in a black hole at all? This post takes a brief look at one recent paper making this argument as an example, but there are others .

Black Hole Universe: The Bounce Model

The paper investigated what happens when a cloud of matter collapses in on itself in curved space, taking into account quantum mechanics.

Quantum mechanics matters because of the Pauli Exclusion Principle, which says that no two fermions in the same system can occupy the same quantum state. There are two key parts to this definition:

  • Fermions include electrons, as well as composite particles like protons and neutrons. Basically, it includes all the “regular” matter we’re most familiar with.

  • Quantum states are defined by some key values. For example, in an atom, electrons occupy discrete “energy levels,” denoted by an integer physicists label n. So n = 1 is the lowest energy level. Other quantum numbers relate to magnetic properties and “spin.”

It’s like there are set seats for the particles, and if someone else has seat n = 1, = 1, m = 0 and s = 1/2, then the next fermion has to sit somewhere else.

So when all of the quantum numbers fill up, this limits how much the matter can be squashed. Some particles have to move to a different “seat.” This creates a kind of pressure that pushes the matter back outwards.

This bounce is what the paper investigates. While from the “outside,” an observer would see a black hole form, on the inside there would be a big bang. This is illustrated in the attached image.

  • The good news: It would explain the initial inflation phase of the universe and dark energy.

  • The bad news: It requires a curved universe, but most evidence says ours is flat.

So do we live in a black hole? Maybe! But probably not.

0

Join the social media for nerds.

Where sources matter.

Continue with Email

Have an account? Log in