Hello all Never occured to me until a friend made fun of me for not knowing how a TAP and a vaccum cleaner works. And even I was surprised! How can I not know!? Question 1. I know that turning on the tap means increasing the pressure so water flows out, and the more you turn, the more pressure you make (so more water comes out)... but... why? What has my turning the handle got anything to do with increasing pressure? And where is this "pressure" coming from? And then I thought of VACUUMS (house chores) and how that is also related to pressure. Question 2. Empty space sucks things. So the cleaner works. Why exactly does it suck things though? (anything to do with the mercury rising up to the top of a long thin tube?) I have a feeling that maybe question 2 demands a long answer. But I am ready for it! Anyways, thank you everyone, any help will be greatly appreciated.