I've noticed over the years that different numbers have their own "personalities". If you're a mathematician doing a calculation and you get the answer 248, it means something completely different than if you get 247 — because the number 248 shows up in all sorts of amazing places, while 247 is just dull. So when I was invited to give the Rankin Lectures in Glasgow, I thought it would be fun to explain this idea with some examples. I decided to give separate talks on three of my favorite numbers: 5, 8, and 24.

The first one should be quite easy for everyone. After that they get harder, but they're still meant to be expository and fun, Here you can see streaming videos of my talks — and also my slides, which have links to references that fill in the details.

youtube-dl is a small command-line program to download videos from YouTube.com and a few more sites. It requires the Python interpreter, version 2.x (x being at least 5), and it is not platform specific. It should work in your Unix box, in Windows or in Mac OS X. It is released to the public domain, which means you can modify it, redistribute it or use it however you like.

Tom Guilmette spent a productive evening locked in a Las Vegas hotel room with a Phantom Flex high-speed/high-def video camera, taking high-speed footage of water, breaking glasses, himself jumping on the bed, and other everyday phenomena that become amazing and dramatic when slowed down to wachowskiian speeds and cleverly edited.

Tepco's photos and video clips from inside the Fukushima Daiichi nuclear power plant.

As the 25th anniversary of the Chernobyl nuclear disaster approaches, the BBC's Daniel Sandford has been given rare access to the contaminated reactor block.

Considered the worst nuclear power plant accident in history, the site in Ukraine is still a dangerous place to visit.

The disaster occured on 26 April 1986 at reactor number four when a power outage surge led to a series of explosions and a plume of radioactive smoke.

We do not know their names, their faces, their families or their personal stories. Nobody really does. They are strangers, in a faraway land, doing the unthinkable. In Japan they have a name: The Fukushima 50. A coterie of nuclear plant employees - some reports indicate 50, others suggest four working rotations of 50 - who stayed behind while 700 of their co-workers were evacuated from the stricken Fukushima-Daiichi facility on the Japanese coast.

Five have been killed. Two are missing. Twenty-one have been injured in a struggle where, in the words of Japan's Prime Minister Naoto Kan, "retreat is unthinkable." The men understand the stakes. They know there is no turning back. One worker told a departing colleague he was prepared to die - that it was his job. Another informed his wife he wouldn't be coming home anytime soon.

Follow the YokosoNews (in English), NHK World TV (also in English), and NHK GTV (in Japanese) Ustream channels on a single page. (Cacophony of audio? Use the mute button, Luke!)

TBS TV live on Ustream.

NHK live on Ustream.

Billionaires, even low on the Forbes list, have more money than they can spend. Lex's Sarah O'Connor and Edward Hadas discuss why they still strive to increase their fortunes.