Blog Tags: 

A Universe from nothing? Lawrence Krauss

I highly recommend watching the following lecture when you have about an hour of spare time:

How is this related to TurnKey? Good question. Well, the origins of the Universe relate to everything in the Universe right? TurnKey is in the universe, hence the relation. QED.

Seriously, the lecture is not only incredibly deep and educational, it is also entertaining. Richard Dawkins introduces his friend Lawrence Krauss, a physicist, who he later dubs the Woody Allen of physics.

Here are my main takeaways from the lecture:

  • There is observational proof that the net energy of the universe is zero.

  • zero net energy means it is possible for a universe to bubble into existence from random fluctuations in the quantum foam.

  • Most of the energy of the universe (70%) is actually in space itself. Empty space weighs something (this is called dark energy). The other 30% is a type of matter we can't see but can prove is there due to gravitational effects. But wait, 70% + 30% is 100%! What about all the stuff we can see? Yeah, that's just a rounding error. Pollution.

  • The peculiarities of our observable universe's laws of physics (e.g., ratio of dark energy to matter) can be explained by cosmological natural selection. Only universes that have exactly the right physics will lead to the creation of life, evolution and eventually astronomers that can make observations.

  • The "ugly" implication for physics is that it may be impossible to find a theory of everything which explains why the laws of nature are the way they are (e.g., ratio of different forces). Impossible because they're arbitrary. Instead of a "theory of everything", the holy of grail of physics this last century, we may end up with a "theory of anything". In fact, string theory is just such a theory, and it implies a landscape of possible types of universes 10^500 large.

  • We live in a very special time where it is possible to prove all of this, by making empirical, scientific observations.

    The kicker is that the universe is expanding greater than the speed of light. This means scientists in the far future (e.g., 100 billions years from now), will not be able to observe the evidence for any of this so they will have to either come to the wrong conclusions (e.g., that the universe is static and consists of only 1 galaxy), or take our word for it - if we or anyone/anything else manages to pass the knowledge along that far into the future.

Your takeaways may be different, depending on how much you already know about physics and cosmology.

2014/08/07 Update: debate between Dr. Lawrence Krauss vs William Lane Craig

For those interested in the counter-arguments to Krauss's viewpoints, a friend sent me an intelligent debate on the subject. I hadn't seen this before or I would have posted both from the get go. Good stuff.

An ineffable loving nothingness?

Thinking about this some more, I think there's something deeply inherently problematic about using human language to describe something as removed from day to day intuition as the origins of the universe. 

We all use the same words but by using the same words we do not always mean the same things.

That's why we use mathematics to describe physics, but even mathematics breaks down at some point. Mathematics is the language of quantitative relations between different entities. How do you use mathematics to say anything useful about the state that preceded the emergence of a physical system that can express those relationships?

It's really quite a deep philosophical question. In the above debate Craig makes a valid counter-argument I think that Kraus's definition of nothingness is problematic because it merely pushes the question back to another level. The universe originated from "nothing" in another system that has certain properties. Where did that other system come from?

Or as Hawking puts it:

what breathe fires into the equations?

My favorite concept of nothing is the Zen Budhhist version. An ineffable loving nothingness.


Liraz Siri's picture

I updated the post to embed the debate between William Craig and Krauss in the above. I hadn't come across it before. I haven't seen the whole thing yet (will watch it over the weekend) but from the snippets that I did see it looks very good.

Chris Musty's picture

I was seriously hoping I would not read Liraz or Alon as the author of this garbage (or Jeremy for that matter).

I would like to watch it just to shoot holes in his arguments but seriously dont have time nor the will to do it.

Chris Musty


Specialised Technologies

Liraz Siri's picture

I must not have fully woken up when I posted that in the morning because it didn't cross my mind that Lawrence was controversial or that I was stepping into a religious debate. Yikes!

Anyhow, I updated the blog post with the debate. Good to hear both sides of the argument.

Liraz Siri's picture

Just a quick afterthought: I feel very lucky to be alive at a time when we are discovering so much so quickly about the universe. What a privilege! I doubt we'll get to the ultimate truth in my lifetime but who knows?
BenL's picture

Really enjoyed the talk by Kraus! Thanks for that link.

Just a note on your comment "The universe originated from "nothing" in another system that has certain properties. Where did that other system come from?" 

Kraus mentioned this in other talks: from a Physics point of view, "nothing" is really nothing, no energy, no matter, no time, no space. In other words, it is not in another system. It really is nothing.


Liraz Siri's picture

To be honest I don't really get how physics can describe nothing. I think I'll try reading the book version of his argument, which I imagine is more detailed.

I think there are several potential limitations with how far we can speculate on the origins of the universe using modern physics.

First, we know that modern physics is incomplete. For example, the best mathematical models we have for describing nature at the macro scale (relativity) and the really small scale (quantum mechanics) are fundamentally incompatible. We don't have an empirically validated unified theory of everything yet.

Second, even when physics is "complete", We'll never have a model that we know is absolutely true. The best we can hope for is a model we can't falsify with an conflicting experiment or observation. But that was true for Newtonian physics as well. For a while.

Finally, by definition, science is limited to approaching the truth through experiments and observations in our universe. It seems a bit of a stretch to imagine we can use science to verify what is true outside (or "under") our universe.

I admit this isn't at all my area of expertise so I might be missing something. I'll add Kraus's book to my reading list.


Add new comment