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" Dear Merlin, How empty is empty space? ARTHUR LEVY HOUSTON, TEXAS When a rabbit disappears into “thin air” at a magic show nobody tells you the thin air already contains over 10,000,000,000,000,000,000 (ten quintillion) atoms per cubic centimeter. The very best laboratory vacuum chambers have as few as 10,000 atoms per cubic centimeter. Interplanetary space gets down to about 10 atoms per cubic centimeter while interstellar space is as low as 0.5 atoms per cubic centimeter. The award for nothingness, however, must be given to intergalactic space. There it is difficult to find more than 0.0000001 atoms per cubic centimeter. It has been postulated that outside the universe, where there is no space, there is no nothing. We might call this hypothetical region (where we are certain to find multitudes of rabbits) nothing-nothing "
― Neil deGrasse Tyson , Merlin's Tour of the Universe