how stuff works

During my interview this past Wednesday, I was asked this question: "how is water pumped up in a coffee maker?"

Of course, I did not know the answer and I was totally honest about it. Although I have used coffee maker for a long time, not even once did that question come across my mind. Probably vaguely, and I thought it was simply the condensation of the steam.

After coming back to Michigan, I asked my fellow PhD students this question. No one seemed very sure about it either. So I looked up the web "how stuff works" and got the answer. It actually has something to do with a one-way valve, a heating tube with certain diameter and surface tension of bubbles.

Yesterday I was washing my face with some self-foaming cleanser. Then I suddenly realized that I didn't know how this self-foaming thing worked either. I know it has something to do with the pressure, but where is this foam coming from?

Luckily the website has answers for everything. But I am still fascinated by how many years of study I took in school and how little I know about real-life products.

Hmm...another reason not to go academic.