I know that it’s possible to buy hourglasses that run out after a set amount of time, like 30 mins/an hour/2 hours etc., and even water-drippers that measure every 30 minutes. How do they do that?
In: 2
maths.
you create a opening between the two halves of the hourglass this is going to let a known about of sand though a minute (worked out by experiments with previous hourglasses). you can then just add however much sand is needed to get to the wanted time (say 1 hour).
its not PERFECTLY accurate, but a lot of the time, you dont need extreme accuracy. your food cooking for a hour is not going to be burnt if it stays in 61 minutes or be raw after only 59 mintues, for example
Latest Answers