There is only supposed to be one space after a period. Maybe back in the days of typewriters two was okay, but today, with computers typesetting things so beautifully, one is enough, thank you. Even worse is when people send you blurbs to upload to websites you manage, and there are two spaces after each period. While it’s not really technically hard to fix, it’s something that I don’t want to have to deal with on principle.
I repeat, only one space should follow a period.