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What Is Spacetime, Really?

blog.stephenwolfram.com

21–30 of 122 posts

Re: What Is Spacetime, Really?

#21
post #16

If you want a second opinion, Cosma Shalizi reviews A New Kind of Science by Stephen Wolfram: http://bactra.org/reviews/wolfram/

Subtitle: "A Rare Blend of Monster Raving Egomania and Utter Batshit Insanity."

This is a classic that everyone should read, utterly destroying a shameless self-promoter gifted with some intelligence and a grasp of jargon.

Re: What Is Spacetime, Really?

#22
Things like this always leave me feeling stupid. How is one supposed to wrap their mind around the idea of space emerging from an underlying "network"?

What exactly is being networked; what is the "stuff" of the network? He describes the network in terms of connections, which in my mind requires a topology, or space within which to exist; yet space does not apparently exist at this level. If there is no space, then what separates the nodes in the network? If no space separates the nodes, what defines the distinct connections between them?

Yes, i'm completely lost.

Re: What Is Spacetime, Really?

#23
post #7

Maybe a physicist could help me out: the idea here of treating space as a simple discrete network, and particles just being emergent behavior sounds very interesting. But doesn't this violate Bell's Theorem, that no local hidden variables could completely explain quantum mechanics?

I am not a physicist, but Wolfram covers this. "Because there’s a theorem (Bell’s Theorem) that says that unless there’s instantaneous non-local propagation of information, no such “hidden variables” model can reproduce the quantum mechanical results that are observed experimentally." Wolfram's continues by saying he is allowing instantaneous non-local propogation because network nodes have no coordinates; coordinate…

So quantum effects like entanglement are distortions in the structure of the network. So basically quantum effects are due to distortions in space-time, i.e. there is a 'worm hole' type structure connecting entangled particles?

This is getting out of my depth, but isn't that basically what Loop Quantum Gravity proposes?

Re: What Is Spacetime, Really?

#24
post #17

Earlier quoted context omitted.

It's written in the first person, and he's describing the findings. How else should he have written it?

Wolfram is known for this. He's clearly a bright fellow but he is not even close to being the only or the first person to work on stuff like cellular automata, computational theories of physics, or complexity. He did not invent everything he claims to have invented and while he does footnote he's definitely not drawing attention to any of the others in the area. It's tragic really. A New Kind of Science is full of br…

That is exactly the reason I stopped reading halfway through. I couldn't take any more of his narcissism.

Re: What Is Spacetime, Really?

#25

I found this incredibly hard to read, due to Wolfram's constant need to self-aggrandize. The entire tone of the piece is, "I discovered this, then I discovered that". In reality, most of his "revelations" were discussed by others long before he arrived on set.

I really appreciated his tone. I'm incredibly fascinated by ideas like quantum physics and basic building blocks of the universe, but am often left behind when I read articles about them due to a lack of understanding of the core mathematics. His tone makes this complicated subject understandable.

Re: What Is Spacetime, Really?

#27
post #15

Maybe a physicist could help me out: the idea here of treating space as a simple discrete network, and particles just being emergent behavior sounds very interesting. But doesn't this violate Bell's Theorem, that no local hidden variables could completely explain quantum mechanics?

IANAP either, but wasn't the hidden variable problem resolved by the pilot wave theory?

It wasn't resolved. Pilot Waves have nonlocality, which contradicts Relativity. (I don't know, it may be correct that quantum mechanics is non-local, but Relativity-minded folk are rightfully suspicious of such a model.)

Re: What Is Spacetime, Really?

#28

I found this incredibly hard to read, due to Wolfram's constant need to self-aggrandize. The entire tone of the piece is, "I discovered this, then I discovered that". In reality, most of his "revelations" were discussed by others long before he arrived on set.

The article would certainly be less awkward and more interesting if he involved other people than just himself and Einstein.

Even if he's exclusively describing the evolution of his own thought and linking to his own articles, each discovery and theoretical advancement would better be presented in terms of upstream research that brought it along and predated it, crediting others whenever possible. Science is a network, too!

Re: What Is Spacetime, Really?

#30
post #22

Things like this always leave me feeling stupid. How is one supposed to wrap their mind around the idea of space emerging from an underlying "network"? What exactly is being networked; what is the "stuff" of the network? He describes the network in terms of connections, which in my mind requires a topology, or space within which to exist; yet space does not apparently exist at this level. If there is no space, then w…

What is matter made of? The answer, whatever it is, cannot be matter. From what fundamental thing does 'space' arise? The answer, whatever it is, cannot be anything that would exist in a 'space' as such. And so we creep towards the idea that at a low enough level, everything is just information.
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