Built on Facts

Ok, so this isn’t really physics as such, but it’s pretty fascinating. There’s a very large online community called Reddit in which users submit links which interest them. These links come with two little arrows beside them, and the users can vote the link up or down. Here’s a screenshot of how the website looks…

In which I argue against gun control.

Less Than Absolute Zero

I’m sitting in a hotel in Utah at the PQE 2013 conference.¬† As I write this, the temperature is a rather brisk 19F. (For everyone else in the world, -7.2C) That’s not cold at all to some of you, but some of you didn’t grow up in south Louisiana. Either way, on the Kelvin scale…

Why calories can be complicated.

The Shadow Knows

On shadows, when they work, and when they don’t.

The shootings in Connecticut are a monstrous act of incomprehensible horror. For all the atrocities visited upon the world in the last hundred years, this is still without doubt among the most appallingly evil acts ever performed by a single person. And he is dead, and beyond the reach of human justice. Normally I’d wait…

Interference – on the moon!

Wow, lots of moon posts these days.¬† This one is going to talk about a question left by commenter ppnl a couple posts back: ppnl: So could you use a pair of one meter telescopes a kilometer apart to create a point of constructive interference on the moon as small as what would have been…

This wonderful headline showed up in my Facebook feed: U.S. ‘planned to blow up Moon’ with nuke during Cold War era to show Soviets might. This was a bit eyebrow-raising. Dr. Strangelove was a slightly unfair caricature, but the Cold War really did have a better-than-average share of nuttiness. Still – blowing up the moon?…

How to keep a laser beam small.

My post about seeing a laser from the moon mentioned¬† the fact that the beam from a laser spreads as it propagates. We’re used to seeing this from a flashlight – the beam from a flashlight across a room is much smaller than the beam from a flashlight across an open field. Lasers spread too,…

If you’re one of the probably four people who haven’t heard about Nate Silver, you’ve missed out. He’s a statistics guy who runs the always interesting 538 Blog at the New York Times. He made his name in baseball statistics, Moneyball style, and moved into politics where he made state-by-state statistical forecasts of the last…