### The Return of Fermi Problem Friday: Catching Some Zzzzz's

Newton's first law of motion says that at object at rest tends to stay at rest until acted upon by an outside force - like an alarm clock.

In case you missed it, a group of napping advocates, called the National Association of Friends of the Siesta, hosted a nine-day competition in Madrid, Spain, this October to see who could make the most of a 20-minute nap.

The contest was organized to revitalize the tradition of taking an afternoon siesta - a tradition that is dying out in Spain. Taking afternoon naps is not an uncommon practice around the world, but thanks to today's 24-hour-a-day, 7-day-a-week work lifestyle, fewer people are given the opportunity for a nap.

A 62-year old Ecuadoran man, named Pedro Soria Lopez, beat out 359 other contestants to take home the prize - \$1400!!!

Lopez napped for 17 minutes. Though one of the runners-up napped for 18 minutes, Lopez scored extra points during his snooze for snoring at a peak of 70 decibels. (As loud as a vacuum cleaner!)

Contestants earned points for the amount of time they spent asleep - a maximum 20,000 points for a full 20 minutes - and also for flamboyant pajamas, unique sleeping positions (eh?) and, of course, snoring.

So, here's the Fermi problem:

Nearly 30 percent of the contestants actually fell asleep during the contest. Knowing that, how much energy did they conserve by sleeping and not working during the contest? (Math hint: Keep in mind that the Calories we see on our food labels are actually kilocalories.)

We'll have the answer on Monday, so stay tuned!

1. Doesn't seem if snoring were a problem with these guys, but snoring is a problem

### How 4,000 Physicists Gave a Vegas Casino its Worst Week Ever

What happens when several thousand distinguished physicists, researchers, and students descend on the nation’s gambling capital for a conference? The answer is "a bad week for the casino"—but you'd never guess why.

### Ask a Physicist: Phone Flash Sharpie Shock!

Lexie and Xavier, from Orlando, FL want to know:
"What's going on in this video? Our science teacher claims that the pain comes from a small electrical shock, but we believe that this is due to the absorption of light. Please help us resolve this dispute!"

### The Science of Ice Cream: Part One

Even though it's been a warm couple of months already, it's officially summer. A delicious, science-filled way to beat the heat? Making homemade ice cream.

(We've since updated this article to include the science behind vegan ice cream. To learn more about ice cream science, check out The Science of Ice Cream, Redux)

Over at Physics@Home there's an easy recipe for homemade ice cream. But what kind of milk should you use to make ice cream? And do you really need to chill the ice cream base before making it? Why do ice cream recipes always call for salt on ice?