Isn't nothing still something?

Lensman

Just watched Stephen Hawkings "The Story of Everything". Maybe it's outdated by now, maybe not. Still beautiful to watch.
Anyway.....Isn't Nothing still considered to be Something?

phinds

You need to be more specific in defining what you mean.

For example, for the sentence "there is nothing outside the universe", then NO, the word "something" could not be meaningfully substituted for the word "nothing".

alexg

But if you're talking about inside the universe, (since that's all there is), then nothing is filled with lots of somethings.

salvestrom

Vacuum energy essentilly removes the possibility of an actual "nothing" existing within the universe. If you stand with your hands apart and put yourself anywhere in the universe, you would never find a situation where you can accurately declare "there is nothing between my hands". The only solution is to put your hands together. ;)

Lensman

Thank you all. I was curious as to what kind of comments I might get on my not-very-specific question. The comments in themselves are welcome. I envy those of you who do understand the math associated with physics, the equations and all. My talents lie elsewhere.
I will be more direct now with my question. In "The Story of Everything" Stephen Hawking showed the beginning of the Big Bang. Do I understand this right? Before the BB there was nothing, correct? The Big Bang started expanding and still is expanding. What is the Big Bang expanding into?

phinds

"big bang" really has two totally distinct meanings

1) the singularity / t=0 --- this is TOTALLY a mystery to everyone including Hawking. The most meaningful way to descirbe it is "the place where current theories totally break down and give meaningless answers"

2) the evolution of the universe starting at one Plank time after the singularity --- this is reasonably well understood in many aspects. I commend to your reading "The First Three Minutes" by Weinberg

as to what it is expanding "into", there is no such thing. The thing that is expanding is everything.

Lensman

Thanks! It's really a challenge trying to wrap my mind around a concept such as "as to what it is expanding "into", there is no such thing. The thing that is expanding is everything."
It only natural, for me, to try to understand such descriptions based on how I perceive everything around me. I have to get out of my comfort zone.

Drakkith

Perhaps instead of imagining the universe expanding, just realize that what we actually see is that everything in the observable universe is moving away from everything else. Whether the universe is expanding into nothing or something is beyond our capabilities to determine at the moment, and possible forever. Our model doesn't REQUIRE that anything be outside the universe for it to expand into, but it really doesn't care if there is or isn't, it simply doesn't go there.

ynot1

Ergo nothing would be the absence of a vacuum energy. Finally an answer with a physical interpretation. It would seem at the big bang all the vacuum energy in the universe was compressed into a small volume.

phinds

No, that is complete speculation on your part. It is not known whether the unverse was infinite at the beginning. All we know for sure is that it was a lot smaller than it is now and a lot denser. That does NOT imply that it was small or finite.

ynot1

Ergo the universe was a lot smaller and a lot denser than it is now, not small, not infinite. Sorry for the speculation.

Drakkith

No problem. Someone forgot to refill Phind's food bowl and he's irritable at the moment.
Down Phinds down! *swats with newspaper* Off the couch!

Radrook

Deleted

phinds

Nah, I'm just permanently irritable. It's my mission in life to tell other people when they are wrong. It's a public service I perform.

ynot1

Wrong? Could that be worse than being speculative?;)

sigurdW

Is what we think of as our universe , the universe that contains everything?

Where is the proof? I think you treat an assumption as a fact!

phinds

No, he is treating a DEFINTION as a fact. The word "universe" in physics is genearlly taken to mean "all that there is". Yes, there ARE theories (that have no basis in fact) that there are "multiple universes" and so forth, but that doesn't change the basic definition.