4 ms·
There’s around 10^25 atoms per cubic meter of air at sea level, so talking about a 10^5 density, a 10^20 reduction in density, is pushing the definition of “the
by FakeComments 8y ago
There’s around 10^25 atoms per cubic meter of air at sea level, so talking about a 10^5 density, a 10^20 reduction in density, is pushing the definition of “there”. (This also makes it closer to space, at 1 particle per cubic meter, than Earth atmosphere, by a dozen orders of magnitude.)
For reference, lead in drinking water is actionable at a 10^8 factor, but beyond that — say 10^12 — we largely talk about it not being there.
There’s basically no case we refer to something attenuated by twenty orders of magnitude as qualitatively the same.
Edit:
For fun, I looked up what it meant as energy differences — twenty orders of magnitude is the difference between you jumping and the total energy from the sun that strikes the face of the Earth each day.
https://en.m.wikipedia.org/wiki/Orders_of_magnitude_(energy) https://en.m.wikipedia.org/wiki/Orders_of_magnitude_(energy)
- EForEndeavour 8y agoYour comment is consistent with why the parent replied to the grandparent: 2e5 is orders of magnitude greater than "dozens." That's still closer to space than to sea-level atmosphere, but it's not nearly as close as the grandparent comment stated.
- FakeComments 8y agoA density of 10^5 is eight orders of magnitude beyond “ultra high vacuum”, which is about 10^13 particles per cubic meter — or 10^-12 times normal. Poster is more correct to say “dozens” (four orders of magnitude) than that it’s not a vacuum (eight orders before the edge of ultra high). https://en.m.wikipedia.org/wiki/Vacuum https://en.m.wikipedia.org/wiki/Vacuum Poster was completely correct that this accounts for only minuscule interactions such as surface oxidation and teensy drag over prolonged interactions, and nothing like the “atmosphere” behaves.
- DoctorOetker 8y agoat what point exactly did I compare with sea level?