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cevn
on Nov 21, 2018
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Silent and Simple Ion Engine Powers a Plane with N...
Is it true that there's no such thing as a perfect vacuum? How much 'stuff' is in vacuum on average to make it impure? Sorry if these are stupid questions.
NikolaeVarius
on Nov 21, 2018
[–]
http://adsabs.harvard.edu/abs/1968PASJ...20..230T
A few atoms per cubic meter, but yeah, no real thing as a perfect vacuum.
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