A question from an eight year old

S

Scott Myers

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OK, I was driving my daughter to a local skatepark.. we were listening to music, loudly, and she had a question, that deserves some pondering. Maybe it's philosophy, maybe a little science, but still...

She said, "When I'm drinking my water from this bottle, air cannot get back into the bottle, so it collapses. So, how big is the universe?"

What are you talking about? "We'll the universe is not made of air or water, so why doesn't it collapse?"

HMMM????

So.. What of the vacuum??? Did she prove the universe is infinite, or did she prove that it has rigid borders, that keep it from collapse???

What do you all think? Does it prove anything?

I told her I would think on it. I didn't tell her I would be consulting a bunch of folks with brains, but that is what I am doing.

So, please help me be smarter than she is, just for a couple more years!!
 
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Scott Myers said:
What are you talking about? "We'll the universe is not made of air or water, so why doesn't it collapse?"
Click to expand...
Expanding space and dark energy I believe...
 
May be so, but expanding nothingness?

Space can be compressed no?

Water cannot be compressed, and air can be.

The way I see it, it is infinite, or structurally sound by your dark matter, or what about something of a shell????

Very strange ideas, but I want to continue to explore this. Can a vacume expand or contract???
 
Scott Myers said:
She said, "When I'm drinking my water from this bottle, air cannot get back into the bottle, so it collapses. So, how big is the universe?"

What are you talking about? "We'll the universe is not made of air or water, so why doesn't it collapse?"

HMMM????

So.. What of the vacume??? Did she prove the universe is infinite, or did she prove that it has rigid borders, that keep it from collapse???

What do you all think? Does it prove anything?
Click to expand...
The force that crushes the bottle is not caused by the vacuum, it is the air pressure outside the bottle that crushes it.

Relevant link:
http://science.howstuffworks.com/question200.htm

~Raithere
 
"When I'm drinking my water from this bottle, air cannot get back into the bottle, so it collapses. So, how big is the universe?"

-- It would be interesting to know more about her reasoning that led her to the question.


"We'll the universe is not made of air or water, so why doesn't it collapse?"

The implicit assumption here is that the universe is empty -- which it is not.
 
Scott space is not a vaccum, we might not totally understand the makeup of space but it cannot be a vaccum.

Firstly the Universe is held together by Gravity but there is not enough matter in the Universe for this to happen. Therefore you get the Theory of Dark Matter which would account for the Gravity needed to stop the Universe tearing apart.

Secondly another force is also effecting the Universe because it is expanding, this is called Dark Energy. Again we can't see or even prove that Dark Energy exists but we know it must be there because the Universe is expanding.

It was a very clever observation from your daughter but the thing to remember here is just because we can't see something does not mean it is not there. I believe that Dark Matter should account for twice the amount of matter that we can see. So most of the content of the Universe is invisible.
 
Scott Myers:

If (and you know I don't assert this) there exists nothing around the universe and the universe is expanding into nothing, that nothing could not exert pressure. If there is something around the universe, the universe is still hurtling forward from the inertia of the big bang, which is enough, apparently, to fight against whatever force (if there is any force) pushing it back. Of course, I would assert that space is infinite (even if the universe may be finite) and that one can never "collapse the water bottle of the universe" as energy cannot be destroyed.
 
Keep in mind that we are trying to find an explanation an 8-year old will have enough knowledge to understand.
 
ok imagine this black holes and white holes, hold the universe together so it dosent collapse just like if you poke a few holes in the bottle and drink from it then infact it wouldent collapse because of the flow of air circulating between the "holes"

that came off the top off my head by the way
 
the mighty hand of Hekki (may she be praised above all others) holds the universe together and guides our every action. we are but pawns in the intricate webs that her divine wisdom weaves.
 
Don't forget: PV=nRT. First of all n (number of moles) is static. Drinking a bottle of water reduces the moles of both water and gases above it. As n goes down, then V (volume) must go down as well. Of course, pressure (P) could also go down, but then the pressure of the surrounding air would overcome the bottle's ability to maintain its shape, hence the volume would descrease eventually anyways. Her example was a vacuum surrounded by air pressure. What is the near vacuum of the universe surrounded by?
 
Scott Myers said:
OK, I was driving my daughter to a local skatepark.. we were listening to music, loudly, and she had a question, that deserves some pondering. Maybe it's philosophy, maybe a little science, but still...

She said, "When I'm drinking my water from this bottle, air cannot get back into the bottle, so it collapses. So, how big is the universe?"

What are you talking about? "We'll the universe is not made of air or water, so why doesn't it collapse?"

HMMM????

So.. What of the vacuum??? Did she prove the universe is infinite, or did she prove that it has rigid borders, that keep it from collapse???

What do you all think? Does it prove anything?

I told her I would think on it. I didn't tell her I would be consulting a bunch of folks with brains, but that is what I am doing.

So, please help me be smarter than she is, just for a couple more years!!
Click to expand...
What does she read? Do you ever talk with her about those things?

Maybe you have an indigo child in your hands....
http://en.wikipedia.org/wiki/Indigo_Children

Yaba Daba :m:
 
The Little Prince is a good book for young, inquisitve minds that also helps children think outside-the-box. It's seems like she's very intelligent and would enjoy it.
 
Wings said:
Don't forget: PV=nRT. First of all n (number of moles) is static. Drinking a bottle of water reduces the moles of both water and gases above it. As n goes down, then V (volume) must go down as well. Of course, pressure (P) could also go down, but then the pressure of the surrounding air would overcome the bottle's ability to maintain its shape, hence the volume would descrease eventually anyways. Her example was a vacuum surrounded by air pressure. What is the near vacuum of the universe surrounded by?
Click to expand...
But the universe is not collapsing....
Or is it?
*Bethoven's 5th symphony*

Yaba Daba :m:
 
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