So here’s an odd one – today is “Create a Vacuum Day“!
Here’s what nationalwhateverday.com has to say:
Create a Vacuum Day is celebrated on February 4th of each year. In everyday usage, vacuum is a volume of space that is essentially empty of matter, such that its gaseous pressure is much less than atmospheric pressure. The word comes from the Latin term for “empty”. A perfect vacuum would be one with no particles in it at all, which is impossible to achieve in practice. Physicists often discuss ideal test results that would occur in a perfect vacuum, which they simply call “vacuum” or “free space”, and use the term partial vacuum to refer to real vacuum.
I have a particle-filled take on what “a perfect vacuum” is: