The Churn

"Dad, are you taking a nap?"

"No sweetie, I am just trying to meditate while lying down."

"Can I ask you a question?"

"Sure!"

"What is a churn?"

"I think you are asking me about the arrangement that makes butter. It's an earthen pot with a lid that has a stick fitted to it. The stick has a rope coiled around it. If you put cream in the pot and churn it by pulling on the rope, the butter in the cream floats up. And then, you put it on a toast, and eat it."

"Wow! That sounds like the story about the gods and the demons that I read in Amar Chitra Katha.  Only, that they churned the ocean waters, and they used a giant snake for the rope and a mountain for the stick."

"Yes, that's the one."

"And dad, do you know that after they churned the ocean, nectar and deadly poison came out. Lord Shiva drank the poison to save the universe, and the gods and the demons fought over the nectar, which would make them immortal."

"Yeah. But you have to remember that with cream, what comes out, is not so good for you. When you grow up, you will find that having too much butter can clog your arteries and  make you very sick. Buttermilk, or the stuff that is left over, is actually much better for you. It can make you healthy."

"Does that mean that what was left over when the gods and the demons were done churning, could also be much better?"

"You mean the sea water? Well, I don't know about that. You know, you can't even drink it because it has too many salts in it."

"Dad, is it possible to remove the salts from the sea water?"

"Yes. But it is a complicated process. You need large machines for desalination, which is what removing salt from sea water is called."

"What type of machines?"

"Well, there are many types. The idea is to heat up the water and convert it to steam. Some people believe that if you pass the steam through a giant machine called a centrifuge, you can remove all the salt from it. And then, if you cool it down, you get pure drinking water."

"Dad, what is a centrifuge?"

"Uh, let's see.  A centrifuge is a machine that can spin something around very rapidly and separate the things that are in it. Like water and salt."

"You mean this machine is something like a churn?"

"Yes sweetie, something like a churn."