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thetaobums
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How could something possibly come from nothing? He reminds me of the Sokal Affair.
thetaobums said:How could something possibly come from nothing? He reminds me of the Sokal Affair.
Mark M said:There are many, many cosmological models that attempt to explain the origin of the universe. Most recently, models from quantum gravity have grown in popularity, such as loop quantum cosmology's 'bounce' models (marcus is the expert on this, I don't know enough about LQG to comment on them). There are various cyclic models, and loads of models where the universe can fluctuate out of a vacuum.
If you're asking if Krauss's ideas are accepted to be possible, then yes. That may be how the universe began. However, there is no consensus. There are dozens of non-singular cosmologies that are researched by many people.
BTW, as pointed out by skydivephil, these aren't Krauss's ideas. Actually, Edward Tyron was the first to start taking seriously a zero-energy universe.
What does the zero energy universe mean though? From what I've read on this there seem to be some formidable obstacles:Mark M said:Edward Tyron was the first to start taking seriously a zero-energy universe.
Krauss basically presents the mainstream view of theoretical physics within academia to the public.thetaobums said:How could something possibly come from nothing? He reminds me of the Sokal Affair.
thetaobums said:How could something possibly come from nothing? He reminds me of the Sokal .
thetaobums said:How could something possibly come from nothing? He reminds me of the Sokal Affair.
skydivephil said:To be fair to Krauss he's not arguing anything more than the idea is plausible, not correct.
A fascinating antidote to outmoded philosophical and religious thinking, A Universe from Nothing is a provocative, game-changing entry into the debate about the existence of God and everything that exists. “Forget Jesus,” Krauss has argued, “the stars died so you could be born.”
I just noticed this. What do you have in mind for a finite flat universe? Wouldn't it either have to be a manifold with boundary or else be an infinite flat manifold with the mass energy all lying within a bounded region (which would not be consistent with the cosmological principle, not that that's necessarily a show-stopper).Mark M said:And of course, these only apply for a finite universe (closed or flat). If the universe has negative curvature, or an infinite flat topology, then of course there is no consistent way you can integrate the energy density over an infinite space and receive sensible results.
skydivephil said:Nevertheless those caveats are there and I guess perhaps people read into what they want to, ignoring them or noticing them depending on what they want to see.
What I think Krauss is saying is that a quantum nucleation event from "nothing" has to have undergone inflation to get the unvierse we see.
You can't disntinguish Vilenkin model form say LQC bounce by confirming inflation happened. I am not sure why, but popular accounts of cosmology seem to like inflation, like the brane clash model, but LQC bounce seemes to be ignored by many popularisers. Krauss is guilty of this, but he's far from the only one.
I don't see why Krauss can't promote his religious beliefs, there's plenty of religious people claiming cosmology supports their religious position.
I think its better to say we don't know the origin of the unvierse and the religious often imply we do, rather than - hey it might have come from nothing.
andrewkirk said:I just noticed this. What do you have in mind for a finite flat universe? Wouldn't it either have to be a manifold with boundary or else be an infinite flat manifold with the mass energy all lying within a bounded region (which would not be consistent with the cosmological principle, not that that's necessarily a show-stopper).
skydivephil said:Having thought about it a bit more, I wonder if the reason LQC bounce scenarios are "boring" is that they are less of an ultimate answer. Why do you think?
Now that's a lot closer to some ultimate answer than our universe bounced from another one that collapsed, where did that unvierse come from? Answer : no idea.
Doesnt it depend what you mean by atheist? There are postive and negative atheists. Positive atheism asserts god does not exist. Negative atheism is the rejection of belief in god usually on the grounds of insufficient evidence.
andrewkirk said:I just noticed this. What do you have in mind for a finite flat universe? Wouldn't it either have to be a manifold with boundary or else be an infinite flat manifold with the mass energy all lying within a bounded region (which would not be consistent with the cosmological principle, not that that's necessarily a show-stopper).
But that would be lying.twofish-quant said:Part of getting them to accept scientific evidence, was to assure them that scientists weren't trying to "abolish God."
Counter-productive to what, precisely?Chronos said:Inciting or fueling public sentiment that science is anti-theistic is distracting and counter productive.
twofish-quant said:It's also that the LQC approach is "worry about gravity and don't try to come up with a theory of everything."
On the other hand, the quantum fluctuation models tend to posit that the universe "dropped" out of an expanding field.
If someone thinks that God is unnecessary, I don't have a problem with that. I do have a problem with someone calling me "delusional" because I happen to believe in God, which is the position that Richard Dawkins takes, and part of the reason that Krauss has gotten a lot of press is that Dawkins wrote a section of Krauss's book.
It's odd but I have some young Earth creationists that I have to apologize to. Way back when when I was arguing with young Earth creationists, I found that they really didn't care that much about the age of the universe. The thing that worried them was the idea that scientists had this agenda of "getting rid of God everywhere" and so they were resistant to accepting scientific evidence because "first you get us to accept that the universe is 13.6 years old, then next you get rid of the crosses and Bibles from our houses and tell us that how to raise our kids." Part of getting them to accept scientific evidence, was to assure them that scientists weren't trying to "abolish God."
It turns out that I wasn't, but Dawkins clearly is, and since Krauss has Dawkins write a section in his book, I don't think it is opposed to Dawkin's agenda. I wish Stephen Jay Gould was still around.
Part of this is a US/UK thing. Religion is very strong in the United States, whereas in the UK, I'm told that it's sort of dying out.
skydivephil said:To be fair to Krauss he's not arguing anything more than the idea is plausible, not correct.
Does this prove that our universe arose from nothing? Of course not. But it does take us one rather large step closer to the plausibility of such a scenario.
When project funding is cut or denied due to political friction, I would call that counter-productive.Chalnoth said:Counter-productive to what, precisely?
skydivephil said:Having thought about it a bit more, I wonder if the reason LQC bounce scenarios are "boring" is that they are less of an ultimate answer. Why do you think? Suppose we found the universe was eternal say like in the Caroll/Chen model or something like that or suppose we found it did come from nothing. Now that's a lot closer to some ultimate answer than our universe bounced from another one that collapsed, where did that unvierse come from? Answer : no idea.
The latter I personally find v exciting becuase it means there's more to learn. But perhaps others dont... But whilst LQC may be less satisfying it seems more liklely to get into a testable format and let's hope someone should be making more noise about that.
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skydivephil said:I think there is a great divide between the Us and the Uk . In the Us I think polls are around 85-95% of the population believe in god. A recent poll in the Uk found only 17% of the populaiton belived that god created the unvierse. Churches in the Uk are turned into aprtments and nightclubs.
I can understand a science educator in the USA wanting to promote Gould's NOMA for diplomatic/tactical reasons. If you are going to admit there's a conflict between science and religion and 90% of the populatin is religious, you are likely to lose.
Not so in the UK.
The question that follows then is forgetting tactical/diplomatic reaosn, is NOMA valid? I think the problem is Gould was just wrong to presume they don't overlap. Religions are extremley interested in origins and any science that deals with origins is going to arouse the interest of religion. In some context some of the religious wing will deny the science ie evolution and sometimes climate change . In others they will hijack it and pretend it proves god ie mono theists with cosmology or new age mystics with QM. The truth is NOMA doesn't work becuase the magisterium do overlap. If atheists cosmologists like Krauss don't talk about comsology you can be damm sure theolgians and mystics will.
And I would call it counter-productive to pollute science with money from religious institutions, such as the Templeton Foundation.Chronos said:When project funding is cut or denied due to political friction, I would call that counter-productive.
Great! I hadn't thought of that. Certainly the flat torus is a compact 2D space without boundary. I suppose the flat 3D torus is what you get when you take a cube and identify the three pairs of opposing faces, with the correct sense. That would certainly meet the requirements of a completely flat space that is compact.Mark M said:A universe with the topology of a 3-torus would have Euclidean geometry, but no boundary.
Essentially, a 2-torus is the familiar surface of a doughnut. This may seem to curved, but it is still Euclidean. Parallel lines stay parallel, the angles of a triangle added up to 180 degrees, etc.
A 3-torus would be the higher dimensional generalization.
I believe you have to embed the 2D torus in four dimensions in order for it to be flat everywhere (note: you don't have to embed the torus at all). In three dimensions, there is some negative curvature on the inner side, and some positive curvature on the outer side.andrewkirk said:Are you sure about the regular torus being flat though?
Greg Bernhardt said:Religious Discussion: Discussions that assert the a priori truth or falsity of religious dogmas and belief systems, or value judgments stemming from such religious belief systems, will not be tolerated.
Lawrence Krauss is a theoretical physicist who has proposed various theories in cosmology, particle physics, and astrophysics. Some of his notable theories include the "anthropic principle" and the "vacuum energy hypothesis."
While some of Krauss' theories have gained traction and are widely accepted, others have been met with criticism and skepticism within the physics community. The acceptance of his theories varies depending on the evidence and support for them.
Krauss' theories are typically based on mathematical models and observations from experiments and observations. Some of his theories, such as the "inflationary universe" model, have also received support from other physicists and researchers in the field.
The scientific process involves constant testing and refinement of theories, so it is not uncommon for theories to be modified or even disproven as new evidence and data emerge. Some of Krauss' theories have been supported by evidence, while others have been challenged or modified based on new research.
Krauss' work has made significant contributions to our understanding of the universe and has sparked important discussions and debates within the physics community. His research has also inspired new experiments and observations that have furthered our understanding of the cosmos.