Nope, being bounded or not is irrelevant re: whether it is discrete or continuous. For example there are infinite real numbers between 0 and 1. The function f(x) = x with domain f:[0,1] -> R over that interval is bounded and continuous.
Nope, being bounded or not is irrelevant re: whether it is discrete or continuous. For example there are infinite real numbers between 0 and 1. The function f(x) = x with domain f:[0,1] -> R over that interval is bounded and continuous.
Erm.... you mean like like quantum field theory, one example of which is quantum electrodynamics that has proved to agree with experiment to an accuracy of 8 (and more) decimal places?
Soldato
I'm talking about a ToE, which would be a merger of GR and QFT (yeah, I meant QFT).
GR and QFT are incompatible theories, particularly when we get to the big bang and black holes.
Ah, a bit of a language barrier then: for me GR = relativity + gravity, whereas QFT = quantum mechanics + relativity.
There are actually some quite nice results when you try to use both GR and QFT, particularly with black holes. There's a great set of notes here -- Chapter 10 outlines how to derive the laws of black hole thermodynamics by doing some QFT on a curved spacetime near the event horizon of a black hole. It's been a very long time since I worked with this stuff, but I remember there was a book by Fulling that did a good job of trying to formulate quantum field theories on curved backgrounds, pointing out the problems/inconsistencies along the way.
Soldato
This seems to be conflating the meaning of discrete as in separate, with the sense of discrete being an antonym of continuous. Unless I'm missing something. I don't see how you make the step from boundable = none continuous. That said, haven't we cited that current thought believes Time ISN'T continuous? I.e. there are planck seconds?
Soldato
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If you're talking about a cyclical universe you're right I don't support that.
Vacuum fluctuation. And it probably will and has, but that'll be another universe (multiverse model)
Ah, Douglas Adams, we miss you.
Soldato
I was thinking of the Continuous Creation model, actually. But why not support the possibility that the Big Bang could happen multiple times? Doesn't it seem improbable that this is a one-time event? I don't refer to a cycle of Big Crunch-Big-Bang-Repeat. But of this happening multiple times, possibly overlapping.
So you do!
If you can bound something continuous surely you've then got something discrete? In your example of numbers it works. But if space is continuous but has boundaries i.e. "the edge of the universe" surely now I have something discrete? if the boundaries can be exactly pinpointed, then you now have an absolute distance between the boundaries. Like in your numbers example you've managed to exactly pinpoint 0 and 1. But on a 'physical number line' you couldn't pinpoint 0 and 1 exactly if the number line is continuous. Because even if you had the most infinitely accurate measuring device you could still add another recurring 9 and never be at the point 1. Therefore it's impossible to bound it. I'm talking about space here (as in physical space) not numbers.
The point is, if the world were one dimensional. And it was your function of f(x), and it was a continuous dimension, it would be impossible to physically (as in physical space) erect a boundary at 0 and 1. Because if you had a boundary on them you now have the discrete length of 1 defined in physical space.
See this is where engineers and scientists diverge.
Scientist: "How can I reconcile Relativity with Quantum Mechanics? There must be a solution."
Engineer: "If(project == 'rockets' ) { $system = RELATIVITY } elseif(project == 'microprocessors') { $system = QM } [...]"
You lot do the Whys. We'll do the How's.
Very true.
It works, I can use the concept to build a working machine. Beyond that I dont give a ****!
(Doesn't mean I am not interested, simply, that in practice, it doesn't matter!
)
Soldato
Hawking wasn't a pop physicist.
I was having a chat with a physicist yesterday and went down the entanglement route, string theory etc. Very interesting stuff. We also discussed black holes and the stuff Cox is saying isn't an absolute there. For example there is a lot of theoreticals and hypotheses about the instance and outcome of black holes. Some theories explain only very small physical aspects of them based on what we know, others what we think or evidence 'suggests', some is guesswork and other stuff is as OP has said so varied or by way of scale so beyond our current understanding.
I'm not a fan of Brian Cox in all honesty. I could listen to him and have a chat, although I ascribe more with regard to something Weinstein (not H) said that at the moment around the world there are maybe just fifty physicists who are at the centre of all the important REAL discovery and formulaic hypotheses.
We also only ever go from T=0 before that guesses are supersymmetry or a singularity or a divine creator. Make of that what you will.
Well I've not proposed erecting any physical boundaries but rather was just highlighting that something being bounded doesn't infer that it is either discrete or continuous. I don't see why the expansion of the universe automatically means that time is discrete, AFAIK it isn't known for sure either way.
Actually, I always though that we went from T+(5.39 × 10 ⁻⁴⁴ s).
That is the problem. what happened during this unimaginably small period of time is the second most puzzling thing in all of cosmology.
(The other being what happened before T=0. something that realistically our monkey brains are incapable of comprehending)
Soldato
Its ok jesus is coming back before that.
Time does not exist, go figure its a human concept.
Time, as a remarkably astute lady of my acquaintance, who has absolutely no physics education at all, put it, Is Gods way of allowing causes to have effects.
As she put it "Without Time, there is no action!"
Frankly, I cant really think of a better way of putting it.
Similar to my thinking that a few great scientists made the big discoveries, Faradays, Rutherfords, Einsteins, Bohrs, Heinsbergs etc. iIf you go onto the physics forum though there are a range of people of all ages discussing at the level of Hawkings, string theory etc, but he didn't really come up with anything, he's just restating what others have said before him but his fame if you like elevates him to a genius level but is he..
Hawking radiation? lol
Wild guess: you’ve never followed any of Stephen Hawking’s research, have you?
Well taken from wiki.
So you see the point, his ideas are much a collection of others' ideas and work already done. You could say that for anyone though. Anyway.