Q & A: is nothing something?

Space is a vacuum. So that means it is filled with nothing. It might sound dumb but what is nothing? Could the nothing be a something?
- Draken-Korin (age 4)

You can't expect a simple answer to a semi-philosophical question like this. It touches directly some very deep issues that people have argued about for a long time, and still argue about.

The 'nothing' of space means what's left when all the removable stuff (atoms, etc.) is removed. So I guess the question could be whether the un-removable part still does something. Right now, it looks like it does. The expansion of the universe looks very much like it's accelerating, the way it would if space were filled with some un-removable energy density.

Is that something? Or is it just another choice of words to describe an acceleration which could just as well be taken as an independent law of nature, without saying that 'something' in space caused it?

There's very much evidence that the acceleration from the background of energy in space was once much larger. That means that it can't always be ascribed to some fixed law, and might best be thought of as due to somethingness of space.

Of course that raises another possibility. Could there someday be another change in that background? Could there someday be truly nothing in 'empty' space? We don't know.

Mike W.

There are other good indications that the vacuum plays an active role in physical processes that can be measured. All the elementary particles we know of have zero size (that is, particles whose sizes we have been able to measure have been found to be themselves made up of constituent pieces.

For the particles with "zero" size, we can ask what the space is like nearby these little points. It turns out that this space is seething with particles and antiparticles, popping into and out of existence (in particle-antiparticle pairs) according to the laws of quantum mechanics. These particle-antiparticle pairs do have a net observable effect on the strength of the electric field around a real particle. In each pair, the particle that's oppositely charged to the real particle is pulled inwards, towards the real particle, while the other half of the pair is repelled. This effect amounts to a "screening" of the charge of the real particle. We can tell that this is going on by asking what the strength of the electric field is very close to a particle, and finding that it is in fact bigger than might be expected if the vacuum were "empty". There are other observable effects, such as on how strong the magnetic field is around a spinning particle.

These measurements lead us to believe that these particle-antiparticle pairs are constantly being produced and destroyed everywhere, including in every bit of vacuum. You cannot remove them, so by the definition above, they are part of the vacuum.

Here's another interesting consequence of this: Nothing can escape from inside the event horizon of a block hole. However, particles and antiparticles are constantly being created and destroyed, even near the event horizon of a black hole. One of the pair can fall in, leaving the other half of the pair to fly away. This phenomenon is called "Hawking radiation," after Steven Hawking, who predicted it in the 1970's. Black holes, if they just sit in space with no real matter to fall in (that is, they are surrounded only by vacuum), will gradually "evaporate" because of all the Hawking radiation escaping.

Tom

(published on 10/22/2007)

This is very funny to me because i have always asked myself the opposite to this question. Can something be nothing. Since all particles that have been measured are made up of other pieces i think that as we explore even smaller particles this trend would have to continue. Because even if a particle is found that is just a single fabric, how would that fabric exist? So i guess the two questions could be linked to get an answer, nothing can be something because everything is nothing. Does that make sense?
- Michael Bolt (age 18)
Canada

I see what you're driving at, but at some point these philosophical questions start to feel like mere words bouncing around. Nature doesn't care what our answer is.

Mike W.

(published on 07/27/09)

could that something that's nothing be the dark matter scientists be talking about?
- Joshua (age 13)
kennesaw

No, so far as we can tell dark matter is removable. It clusters in galaxies, near more familiar matter.

The "dark energy" which is also much discussed is part of what might be meant by "the something that is nothing" or some such phrase. Dark energy seems to be, at least for the time being, an unremovable property of space.

Mike W.

(published on 08/27/10)

Actually, vacuum is filled up with space. 'Nothing' is exctly what was before the Big Bang....which is nothing! What's hard to understand about nothingness?
- Anonymous

What does "Actually, vacuum is filled up with space" mean? Does it have any implications for anything that can be observed?

As for "before the Big Bang", many modern cosmological theories have a great deal going on before the Big Bang. For an interesting take on that, you might read Sean Carroll's "From Eternity to Here".

Mike W.

(published on 08/29/10)

I feel when we use 'nothing' in our daily life we actually use it in a context, like nothing there, nothing in the bottle, etc. I want to ask: what is the universal meaning of nothing? I will use an inference to prove that the universal meaning of nothing cannot be understood by anyone: Nothing means no anything. So if there is nothing, there is no people. If there is no people, how can one thinks about the meaning of nothing. In other words, we cannot find an instance of a universal nothing.
- Xiaogang (age 30)
Enschede, Netherlands

These philosophy arguments puzzle me. What's at stake?

Mike W.

(published on 05/24/11)

IF there is nothing in a space then there has to be something there in order for that space to be there right so there is never nothing. i could take all the atoms out of a space but something has to be there for them to take that space, so im all that space is something right?
- Toy (age 17)
heshey PA USA

This question is close to others that have been asked. I still don't really understand them. Say I answered "right, there's something in space" or "no, there's nothing in space". What would that tell you about the world? Would you expect to see anything act any different either way?

Thinking about it, I guess that saying that space "is something" (besides boosting its self-esteem) might suggest that someday a theory (string theory?) about that something might be developed. Then once the theory is developed, it could tell us something about what to expect to see.  Based on pretty much pure guess, I'd the say that space is something. Or maybe not.

Mike W.

(published on 06/20/11)

This isn't exactly a question more of an answer than anything, but nothing is in fact something, because nothing exists even as an idea of something that is missing, or void as an not there; But even if it is only an idea, it exists, and because there was nothing before there was what we call "something" there was in fact already something there being, "nothing" And because this is how the universe works, the Red Shift Theory, means that we are expanding into "something" new, something untouched by the KNOWN universe. We always fear what we don't know anything about, but why should we fear something that is so obvious? Everything has to stop and start before something else can do the same thing, its like a never ending relay race. So i guess my question is: Can you find anything wrong with what i have just explained?
- Ray Robertson (age 15)
Rancho Cucamonga, CA, United States

I can't really comment since I didn't follow what it meant.

Mike W.

(published on 08/30/11)