** How much power does it take?** That's today's topic here at

**THE MAIN THING.**Scientifically speaking,

**is a measurement of how much energy is transferred per unit of time. Energy is often measured in**

*power***, and 1 joule per second is a**

*joules***named after James Watt, the inventor of the steam engine.**

*watt,** "A what?"* my editor asks.

*"Yes, that's correct. A watt."* I reply.

*"No, **'what.' **I'm asking **'what.'**"* She is being patient with me.

*"Why would you ask Watt? He's been dead almost 200 years."*

*"No! **'What' **is the question I'm asking."* She's annoyed, I can tell.

*"How can I possibly give you a correct answer if you don't even know the question you're asking?"*

My editor leaves the room muttering under her breath. Weird.

Heating 1 kilogram of water 1° Celsius uses 1 kilocalorie, or 4184 joules of energy. Confusingly, 1 kilocalorie is also 1 nutritional calorie. So for example, a bowl of chocolate ice cream contains 430 nutritional calories, or 1,799,120 joules of energy. That's a lot of nutrition! If I eat that bowl of chocolate ice cream in 3 minutes (trust me, I can do it), I'm transferring almost 10,000 watts. That's impressively powerful.

Especially in terms of ** horsepower, **a unit of power equal to 550 foot-pounds per second, or 745.7 watts. During the 3-minute ice cream energy transfer described above, I'm doing the work of 13.4 horses. I begin to understand the origin of the expression "eating like a horse." That's really powerful.

In the movie *Back to the Future*, the time-traveling DeLorean requires 1.21 ** gigawatts** of power when traveling at 88 miles per hour to overcome the constraints of normal space-time. That's a lot of power! That's like me and 121,000 of my closest buddies simultaneously eating bowls of chocolate ice cream in 3 minutes! Can you even imagine?

To overcome Earth's gravitational pull requires an ** escape velocity** of 11.2 kilometers per second. That's really fast! It doesn't actually have anything to do with the power thing we're talking about today, but I think it's interesting, don't you?