The Physics of Nothing; The Philosophy of Everything

[n2doc]

Category: Gravity • Physics • big bang
Posted on: August 16, 2011 4:17 PM, by Ethan Siegel

"Men occasionally stumble over the truth, but most of them pick themselves up and hurry off as if nothing had happened." -Winston Churchill
It's often said that you can't get something from nothing. And while this may be true for most practical applications of your life, it isn't true for our physical Universe.

And I don't just mean some tiny part of it; I mean all of it. When you take a look at the Universe out there, whether you're looking at the wonders of this world or all that we can see for billions of light years, it's hard not to wonder -- at some point -- where it all came from.

And so we try to answer it scientifically. In order to do that, we want to start with a scientific definition of nothing. In our nearby Universe, nothing is hard to come by. We are surrounded by matter, radiation, and energy everywhere we look. Even if we blocked it all out -- creating a perfect, cold, isolated vacuum -- we still wouldn't have nothing.

more (interesting read)

http://scienceblogs.com/startswithabang/2011/08/the_physics_of_nothing_the_phi.php?utm_source=mostactive&utm_medium=link

[Tuesday Afternoon]

1. k and r and bkmrkd. thanks.

[snagglepuss]

2. Very interesting. Thanks for posting. K & R nt

[GeorgeGist]

3. One large flaw.

Nothingness would have no dimensions. Ipso facto it never existed.

[DetlefK]

4. How would know? Have you ever seen nothingness?

As the article says: A (3+1)-spacetime without curvature and without real energy/matter, but with virtual energy/matter.

Though I doubt that vacuum fluctuations shaped our universe. The plasma oscillations of early universe (approx. age 5 minutes (electron-freeze-out) to 380.000 years (photon freeze-out)) have a much larger amplitude.

And of course it depends on the time-scale. Sure, you can get such a non-empty vacuum with electromagnetism and with Strong Interaction. But the question is, whether the unified laws of nature back then had a similar uncertainty principle.

[sudopod]

5. Wow.

Have you ever even solved a differential equation before?

[tama]

6. Dimensions

are mathematical forms.

You can't make physical theories without mathematics, and physical theories grow in complexity as mathematicians dream up new mathematical forms.

[Hawkowl]

7. Isn't

Isn't "never existing" equivalent to nothingness? How else are you going to define nothingness?

[tama]

8. No-form?

Time - which you imply by "never" - is tricky concept.

First, there is psychologically experienced time, usually in the linear unidirectional form 'past-now-future'.
Second, there is what is usually calle "geometric time" that is certain mathematical form depending from the theory in question: 4D-spacetime of general relativity ("Minkowski space"), geometric times in quantum theories, and of course geometric times in attempts to combine relativity and quantum theories.

So for example, quantum states do not *exist* in 4D-spacetime, but 4D-spacetime decoheres from quantum state. Yet quantum state has form, which is (or at least can be described as) mathematic expressions.

A question to think about, does number theory, for example natural numbers, exist time dependently or independenty from time?