5 ms·
I used to think of space as big and empty - and indeed, this map invokes that feeling a little. But since reading "Out of the Silent Planet" I have come to see
by Thorentis 7y ago
I used to think of space as big and empty - and indeed, this map invokes that feeling a little. But since reading "Out of the Silent Planet" I have come to see it a different way.
He had read of 'Space': at the back of his thinking for years had lurked the dismal fancy of the black, cold vacuity, the utter deadness, which was supposed to separate the worlds. He had not known how much it affected him till now-now that the very name 'Space' seemed a blasphemous libel for this empyrean ocean of radiance in which they swam. He could not call it 'dead'; he felt life pouring into him from it every moment. How indeed should it be otherwise, since out of this ocean all the worlds and all their life had come? He had thought it barren: he now saw that it was the womb of worlds, whose blazing and innumerable offspring looked down nightly even upon the earth with so many eyes-and here, with how many more! No: Space was the wrong name.
> Out of the Silence Planet (C.S. Lewis)
- Arbalest 7y agoAtoms are mostly empty space too. Distance between electrons and the nucleus is substantially larger than the "size" of the nucleus.
- arethuza 7y agoA "fly in a cathedral" being the analogy that stuck in my memory.
- pmilot 7y agoIt's a beautiful excerpt, thanks for sharing. Though I can't help but feel that the author's allegory fits a nebula better than "plain" space.
- kijin 7y agoEven a nebula is absurdly empty. A particularly dense nebula might have ~10k particles per cubic centimeter floating around in it. Even that is vastly more empty than the vacuum we create inside particle accelerators and such.
- john_minsk 7y agoWow. Really? I would have thought that our artificial vacuum is pretty empty... Any good read on the topic?
- kijin 7y agoI'm not an expert in this area at all, so I pulled that comparison out of a few different articles and wikipedia. According to [1], the pressure inside the LHC is somewhere between 10^-11 and 10^-10 mbar. That's between 10^-9 and 10^-8 Pascals. CERN also says that it's "a vacuum almost as rarefied as that found on the surface of the Moon." According to [2], pressure on the surface of the moon is between 4x10^-11 and 8x10^-10 Pa. The upper limit is quite close to 10^-9 Pa, so let's say that CERN can manage 10^-9 Pa on a good day. According to [3], the inside of a nebula is 100-10k times more dense than general interstellar medium. (The "10k particles per cubic cm" figure also comes from the same page.) According to [2], interstellar medium in the Milky Way averages between 10^-15 and 10^-14 Pa. So the pressure inside a nebula should be between 10^-13 and 10^-10 Pa. Another comparison using the number of particles per cubic cm [3] yields a figure between 10^-14 and 10^-12 Pa. The difference is probably due to temperature, but anyway both results are significantly less than the LHC. We can probably make better vacuums on a smaller scale, though. [1] https://home.cern/science/engineering/vacuum-empty-interstellar-space https://home.cern/science/engineering/vacuum-empty-interstel... [2] https://en.wikipedia.org/wiki/Orders_of_magnitude_(pressure) https://en.wikipedia.org/wiki/Orders_of_magnitude_(pressure) [3] https://physics.stackexchange.com/questions/26326/how-dense-are-nebulae https://physics.stackexchange.com/questions/26326/how-dense-...
- rytill 7y agoAbsolutely beautiful, thank you for sharing. Are there functions which would map space to relatively smaller regions that could give us a different perspective on our universe? For instance, what would a starmap look like with each region of space scaled by its gravitational flux?
- Pigo 7y agoOften I think the study and exploration of space should be the primary focus of our entire civilization, or species even. It makes most everything we focus on seem trivial to me. But then I think maybe that's just because I liked Star Trek: TNG so much.