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Hazel1220 · Oct 22, 2008, 01:49 AM

Ok I love science but I usually need it broken down into small bites for me to fully grasp. NO sound in space because of a vacuum. Why and what creates the vacuum? I understand no water or air to create sound waves and what not but what is this vacuum everyone speaks of? Am I just trying to understand it to literally? I just imagine space and then whoosh... everything being sucked away somewhere.:o:D Sorry if this is a dumb question but I was just curious.

ebaines · Oct 22, 2008, 05:44 AM

A vacuum is the absence of material. It's not that in space "everything" is sucked away somewhere, but rather that there was never anything there in the first place. Space is a very big place, and while there is lots of material that clumps together under gravity to make up everything we see (stars, planets, moons, etc) the volume of space is so vast that the average density of material across space is very very low - almost (but not quite) zero. We call space a vacuum because compared to places like the earth's atmosphere at sea level the density of material in space is negligible.

Capuchin · Oct 22, 2008, 05:55 AM

Don't associate a "vacuum" with a "vacuum cleaner", the two are only tenuously linked.

andrewc24301 · Jan 10, 2009, 07:10 PM

Originally Posted by Capuchin

Don't associate a "vacuum" with a "vacuum cleaner", the two are only tenuously linked.

Although if you were in a space craft, and someone punched a hole clear through it, you would notice everything would pull towards the hole, much like a vacuum.

You can not breathe in "a vacuum", to the contrary, the vacuum would suck all the air out of your lungs, and your hole body would collapse.

MaryJS · Jan 11, 2009, 04:42 AM

Ebaines gave a very good definition. In practical, there is no vacuum in space, because we have so many different particles flying around there, but density is much less there, than here on Earth, so we call it "vacuum".

A real, theoretical vacuum, does not have any kind of particles at all in it: you have no protons, no neutrons, no electrons, and no "force mediators" like photons (light) in it at all. However,
You can have a vacuum energy and fields in the vacuum, which will be needed to create particles later.