What Is Spacetime, Really?
blog.stephenwolfram.com
What Is Spacetime, Really?
1–10 of 122 posts
Re: What Is Spacetime, Really?
#2This is a very well done piece. I love how many links and additional paths it leads to in thinking.
It's a constant challenge for scientists to realize that nearly _everything_ we know is an approximation or only true in certain circumstances. It also takes an amazing amount of humility to work knowing that you may be proving yourself, your heroes and all many people have worked for wrong.
Thank you Mr Wolfram for your thoughts.
Re: What Is Spacetime, Really?
#3Maybe 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?
Re: What Is Spacetime, Really?
#4I 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.
Re: What Is Spacetime, Really?
#5Maybe 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, but if the values of the cells are real-world values like charge, momentum, or higgs field strength, then I don't think they are hidden variables. They are the same variables described by the standard model, but calculated discretely instead of continuously.
Re: What Is Spacetime, Really?
#6> I mostly just assumed Einstein’s whole mathematical setup of Special and General Relativity—and got on with my work in quantum field theory, cosmology, etc. on that basis.
I like the way he nonchalantly throws that "etc" in there, as though to indicate that working in these areas is no big deal, really.
Re: What Is Spacetime, Really?
#7Maybe 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; coordinates (and dimensions themselves) arise as a result of how nodes are connected.
"And even though the network may mostly correspond on a large scale to 3D space, it’s perfectly possible for there to be 'threads' that join what would otherwise be quite separated regions."
He has changed the definition of locality.
Re: What Is Spacetime, Really?
#8I 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.
It's written in the first person, and he's describing the findings. How else should he have written it?
Re: What Is Spacetime, Really?
#9Err... is Wolfram now taking credit for this idea, which began circulating back in 2009?
http://www.nature.com/news/the-quantum-source-of-space-time-...
Because I don't see his name in the citations...
Re: What Is Spacetime, Really?
#10In the beginning was a graph, more like diamond than graphite. Every node in this graph was tetravalent: connected by four edges to four other nodes. By a count of edges, the shortest path from any node back to itself was a loop six edges long. Every node belonged to twenty-four such loops, as well as forty-eight loops eight edges long, and four hundred eighty that were ten edges long. The edges had no length or shape, the nodes no position; the graph consisted only of the fact that some nodes were connected to others. This pattern of connections, repeated endlessly, was all there was.
Intro to Schild's Ladder by Greg Egan. He was obviously thinking along similar lines.