Recent content by DrDavy

Thank you very much, bob012345, for the definitive answer!

Before I look at the spoiler, I want to say that I think the one that is running would be lighter, because at any given moment, there would be grains of sand in the air. I guess that's the point of the first part of Erobz's answer. I'm not smart enough to grasp the second part of that answer.

Here's my question: Two spent hourglasses that weigh exactly the same on a balance scale. You flip one over so that it's running. What happens to the balance?

My doctorate is in humanities. But I ran across an interesting topic on your site: Two people on a frictionless surface pulling on a rope. The center of gravity would remain the same. I have a question I would like a serious answer to, so I joined.