Great Moments in Jr. High SCIENCE
He patiently explained that there really isn't anything that actually sucks stuff up. It doesn't matter if you are drinking a milk shake or pumping water out of a swimming pool, what you are really doing is creating a vacuum and the atmospheric pressure forces the shake, or water, or whatever into that vacuum, giving the impression it's being sucked in, when actually it's being pushed.
"So," he concluded, "Nothing really sucks up anything. It only happens when you create a vacuum."
One of the guys on the football team raised his hand. I swear this is true...
"Oh yeah?" He said belligerently, "What about a VACUUM cleaner?"
I think he was a lineman.