Friday links

On July 20, 1969, man first landed on the moon. Here's NASA's Original Mission Video (over 3 hours - if you just want to see the first step, start at 3:15), Photographs Taken By NASA's Apollo Mission Astronauts and a gallery of photos from the mission, memories of Plucking NASA's Moonmen From the Sea, and the speech prepared for Nixon in the event of a disaster.

The Pentagon has a laser that can identify people from a distance—by their heartbeat.

Hollywood’s Doom Book and other Tales of Blacklisting in American Cinema.

Tomorrow is the anniversary of the 20th of July plot, the unsuccessful bomb attempt to kill Hitler in 1944.

Why did we wait so long for the bicycle?

How the Escalator Forever Changed Our Sense of Space.

ICYMI, most recent links are here, and include a 19th century experimental pneumatic subway, lawn mower physics (in slow motion), treadmill history, why red M&Ms disappeared for a decade, and the anniversary of the beginning of the atomic age (the 1945 Trinity test and related links).

Friday links

It's the anniversary of the 20th of July plot, the unsuccessful bomb attempt to kill Hitler in 1944.

A brief history of prosthetic limbs.

The Bayeux Tapestry with knobs on: what do the tapestry’s 93 penises tell us?

On July 20, 1969, Neil Armstrong walked on the moon. 

The Scientific Quest For the Perfect S'more.

Ye Oldest Public Library in the English Speaking World.

ICYMI, Monday's links are here, and include the physics of how lawn mower blades cut grass (at 50K frames per second), spiders flying by using electricity, and the anniversary of the beginning of the atomic age (the 1945 Trinity nuclear test).

Friday links

Apocalypse alert: supermoon, solar eclipse and Friday the 13th. Paraskavedekatriaphobia: Why is Friday the 13th Considered Unlucky?

July 14 is Bastille Day. Here's Jonah Goldberg's classic article on the subject: The French are Revolting.

A Brief History of Trial by Combat.

Supercut: 100 Greatest One-Liners Before The Kill.

Mozart’s Much Less Family Friendly Works (Some NSFW language - apparently his sense of humor had a scatological component).

Secret Policing: How Local Authorities Surveil Americans.

ICYMI, Thursday's links are here, and include the 19th century fight over Sunday mail delivery, the art and science of creating ice in the desert 2,000 years ago, sporting pastimes from the Georgian era, and some male contraceptive advice (just wear a polyester sling, and let the heat and electrostatics do all the work), with bonus Monty Python.

Great "teachable moment" for the kids - tonight's total lunar eclipse/super blood moon

These come along quite rarely, and the next opportunity to see one will be in 2033. It's also nice (and not easy!) to find things that will give kids a better understanding of, and hopefully interest in, the mechanics of astronomy.

More on tonight's lunar eclipse:

What's actually happening is a confluence of three things. The moon will be full and in its closest point in its orbit around the Earth, making it a so-called supermoon. In addition to this, a lunar eclipse will occur. In other words, the Earth will line up directly with the sun and moon, directly between the two, Wolf said. So the "moon will completely fall in the shadow of the Earth," he said.

Click here to embiggen.

Because a lot of light scatters off the Earth's atmosphere, the moon will not look completely dark but have a coppery red color — hence the blood moon moniker.

Atlas Obscura:

The moon will be at its closest orbital point to Earth as well as in its brightest phase, so it will appear bigger and more brilliant than usual—30% brighter and 14% larger than when it's at its farthest point (apogee), a difference of 31,000 miles. Sunlight sifting through the outer bounds of Earth’s atmosphere en route to the moon will cast that signature gory glow, making it both a blood moon and a super moon.

West coast kids will be have the best view  - totality is between 10:11 and 11:23 eastern time, so just after sunset Pacific time, plus the kids will still be awake and the weather tonight looks as though it will be much clearer out there.

Lots more is available at EarthSky.org, and here's Space.com's full viewing guide: 'Supermoon' Lunar Eclipse: When and Where to See It.

NASA has a brief explanatory video: