MadSci Network: Earth Sciences |
Indeed, there are spaces between the molecules of air we breathe. In fact, most of what we think of air is actually vacuum. Air is composed of about 78% Nitrogen (N2), 21% Oxygen (O2), and 1% other stuff (mostly water vapor and CO2). If you were to somehow condense all this air (at standard temperature and pressure) into a pure solid, a liter of "Air" would take up only about 15 ml, or 1.5% it's original volume (estimating a typical "air" molecule radius of about .18 nanometers). The reason we don't notice the vacuum (or spaces) between the molecules of air is that all of these air molecules are zipping around at the speed of sound, pushing against our bodies, and inducing a force we experience as air pressure. So you see, there are spaces between air molecules. But on average, we don't notice the lack of what is there because air molecules are bouncing around, filling those spaces with their speedy paths, and pushing against their containers. Bonus: As for the quarks question and that there must be something there... if you look very very closely at a bit of vacuum, you'll find that there really is no such thing as a pure vacuum (or complete emptiness). I'll refer you to a book called The Elegant Universe by Brian Green. In short, if you somehow had a microscope that could see things on the order of 10^-33 cm (sub-Panck length), you'd see that due to the Uncertainty principle, space becomes roiling foam of particles popping in and out of existence. And while you're at it, read Richard Feynmann's QED and you'll find that light can travel faster than the speed of light and in curling, zigzag paths. But you see, all this is hypothesis. Still, it's fun to think about ;)
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