Good science talks

[GQgeek]

Lawrence Krauss: The Universe From Nothing



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I figured people would watch the first few minutes and figure out whether they wanted to watch, but at teh virg33n's request:

He talks about the current view of cosmology. The title of the talk is a reference to the importance dark matter/energy in our current understanding and the fact that this makes it possible to have a universe with a total energy of 0. If the total energy is 0, then it could have been created from nothing, hence the title of the talk.

He talks about general relativity, some of the early problems with it, how they were resolved, how we know the universe is expanding, the difficulties in observing that it is, quantum theory and how that fits in with relativity, and ultimately why we're all fucked.

He makes some really interesting comments at the end (actually throughout) such as that in the future, all evidence of the big bang will be erased (or more precisely obscured from view), and that if those future people have to develop an understanding of their own view of the universe, they might come up with an explanation, but it will be the wrong one.

Anyway, he's a very engaging speaker and I highly recommend it.

 

[imageWIS]

That's not good. Not good at all. ******* awesome would be a far better description of Krauss' lecture. As much as I love Feynman, Krauss is so much more approchable, especially for people that aren't used to exploring advanced physics / mathematics.

 

[Tck13]

Thanks for posting that! Mind blown...

 

[tagutcow]

Long story short: We can explain how the something of the Universe could have come from nothing by accepting as given a set of timeless, immutable physical laws that have just sort of always been around.

WHERE IS YOU"RE GOD NOW BWAHAHAHAHA!!!!11!

 

[indesertum]

^i dont get it.

the laws of physics have not always been around. they began when time began when the universe began

 

[Nereis]

My understanding is that there could conceivably have been a universe of 'nothing', yet still governed by the same laws. That's because we cannot observe anything from before the big bang.

Someone please correct me if that's wrong. My understanding is pretty limited after all.

 

[tagutcow]



^i dont get it.
the laws of physics have not always been around. they began when time began when the universe began

The Big Bang created the laws that, in turn, created the Big Bang!?! If this whole idea of the Universe springing forth unbidden from the quantum foam is correct, the physical laws that govern that quantum foam would have to have some sort of precedence- causal precedence, if not temporal precedence- to the Big Bang itself. If the Universe came into being because of these laws, it is not true creatio ex nihilo. So until the theory can explain why these laws exist, and why they are immutable, it doesn't really live up to its advertised goal of explaining why there is something rather than nothing.

The facetious tagline was a reference to the fact that Krauss' book of the same name was packaged as a thinly-disguised apologetic for atheism (and in fact, the video that Geek linked to is peppered with various needling remarks throughout its length, eagerly lapped up by his sycophantic audience, which just goes to show that blasphemy has become banal these days.) I remember thinking when reading the reviews that it could have been valuable simply as a popular science book, but instead it was packaged as another new-atheist broadside, replete with an introduction by Dawkins (who, as a biologist, would have otherwise been speaking outside of his expertise.)

 

[indesertum]

no. the laws of physics as we understand it dont apply before the big bang. there's no such thing as temporal precedence to the big bang because time began with the big bang. i dont think anybody knows what the causal precedence is or even if that's within our ability to figure out.

 

[Pliny]

Lawrence Krauss: The Universe From Nothing
I figured people would watch the first few minutes and figure out whether they wanted to watch, but at teh virg33n's request:
He talks about the current view of cosmology. The title of the talk is a reference to the importance dark matter/energy in our current understanding and the fact that this makes it possible to have a universe with a total energy of 0. If the total energy is 0, then it could have been created from nothing, hence the title of the talk.
He talks about general relativity, some of the early problems with it, how they were resolved, how we know the universe is expanding, the difficulties in observing that it is, quantum theory and how that fits in with relativity, and ultimately why we're all fucked.
He makes some really interesting comments at the end (actually throughout) such as that in the future, all evidence of the big bang will be erased (or more precisely obscured from view), and that if those future people have to develop an understanding of their own view of the universe, they might come up with an explanation, but it will be the wrong one.
Anyway, he's a very engaging speaker and I highly recommend it.

Krauss writes for New Scientist and I love his The Physics of Star Trek - great fun if u ever wondered how the Enterprise can in theory travel faster than light speed or how a replicator (might) work.

 

[tagutcow]



no. the laws of physics as we understand it dont apply before the big bang. there's no such thing as temporal precedence to the big bang because time began with the big bang. i dont think anybody knows what the causal precedence is or even if that's within our ability to figure out.

I don't think there is by any means a scientific consensus that there was no time before the Big Bang (for instance, there are several models of an oscillating Universe,) although we are agreed on the latter point.

Krauss intended his book (which I'm assuming he outlined in this speech) as a refutation to the claim that the Universe requires a First Cause outside of itself to exist. The very title, A Universe from Nothing: Why There is Something Rather than Nothing, announces that he has found a scientific solution for a philosophical/theological problem. In fact, the theory only explains why something could be created by a vacuum (and in 2011, virtual particles are hardly groundbreaking,) the theory doesn't explain how something can be created by no thing.