Mark your Calendar

March 20th is Wear Your Favorite Sweater Day, in honor of what would have been Mr Roger's 80th birthday.

The real lords of the Underground

An abandoned 1850 clock in Paris began running again, and was discovered to have been completely and secretly restored by the Untergunther.
Compared to them, the 1980's collegate fad of running about in steam tunnels was nothing.

Geek explosion over at xkcd

First, Randy sucks you in with the Friday comic, a geeky riff on the Drake Equation which calculates the probability of extraterrestrial life. There's even more discussion in the blag.

But then you come upon a newer posting which starts out with a straightforward-seeming explanation of solar sails and why their efficiency is so low (He did, after all, work for NASA.)  But somehow that description mutates from an illustration of that inefficiency (1.21 gigawatts needed to levatate a squirrel by shooting a laser at a mirrored surface) to discussions of how to increase the efficiency with more mirrors, to a suggestion of how the lasers should be solar powered, and how we'd need a Dyson sphere around the sun to capture all the power, and how the sphere would need a hole in it........   you'll see.

Oh, and among the comments to that post is this one:

A lasing medium between the Sun and your sail, you say?  http://laserstars.org/history/mars.html

That URL goes to a rather interesting academic paper describing how the anomalously high levels of long-IR radiation coming from Mars are due to natural lasing effects going on as solar radiation impinges on the CO2 atmosphere.   Hmmm..... Some had wondered if the surprisingly high failure rate of Martian space probes had a common cause, and now we know.  Not only are there Martians, but they're shooting at our incoming missiles with lasers!

The Grammy in Mathematics

Real-world story right out of NUMB3RS --  mathematician's algorithms used to reconstruct the only known recording of Woodie Guthrie.

Basic market economics, explained with Smurfs

http://www.scq.ubc.ca/tragedy-of-the-commons-explained-with-smurfs/

More pretty pictures

That is, if you like the dramatic "illustration-like" quality of "High Dynamic Range" digital images.
Here's a bunch, scaled for wallpaper use on a bunch of standard computer display sizes.

photo of the day

Nothing particularly timely, but good to know it's there.

Rocketboom

Pi Song