RE: Boyles law1 Jul 2021 15:47
Probably the best way I can think of explaining it (I don't want to teach granny to suck eggs, it is not my intention to do so) is:
Get a syringe which is half full of air. Stick your finger over it and push the plunger. Assuming the temperature stays the same, the total quantity of air hasn't changed, but the reduced volume has meant an increase in pressure, hence why it feels like the syringe wants to blow your finger off the end. Conversely, if you pull the plunger, again the total quantity of air hasn't changed but the pressure has dropped, hence feeling like there is a vacuum wanting to pull the end of your finger into the syringe. This is Boyle's law.
There are various other gas laws (e.g. Avogadro) which, when combined, result in the Ideal Gas Law (PV = nRT), but that's for another post!