It’s Thursday, and time for another retro science video! This time around, a brief (three-minute) explanation of Pi, that mischievous, irrational number. The following video explains visually how to calculate pi, and thus where formulae like pi * r-squared come from. (I can still remember my geometry teacher making the corny joke for the thousandth time: “Pie aren’t square. It are round!”).

Did you know that NOVA has a YouTube Channel? Well, surprise! Not all the episodes are there, but here are some of my favorites.

Cracking the Maya Code

About the decipherment of Mayan hieroglyphs. This episode includes several appearances by my former FSU professor, Kathryn Josserand (she was a linguist and Mayan language expert; there’s nice remembrance of her here).

Secrets of the Parthenon

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This is weird and mesmerizing: ultra slow-motion video of bullets impacting various materials (glass, wood, metal, hollow-points on ballistics gel, and so on). The soundtrack adds nothing to the experience, so you might as well mute it (unless you want to have a rave while watching the video). But from a scientific perspective, there’s a lot of interesting stuff going on here…what was most interesting to me was watching the bullets instantly liquify when they hit hard surfaces (like harder metals). There are also several shots in which the bullets are impacted by other projectiles in mid-flight.

The best news: there’s nothing gross here, just very cleanly photographed bullet impacts on non-gross objects.

(Via Kottke.org.)

How do beekeepers get honey out of honeycombs? Would you believe it involves a gigantic centrifuge and some 90’s rap? (Well, the latter is just edutainment, not technically part of the extraction process.) Anyway, this vintage Reading Rainbow clip explains the process a beekeeper goes through to harvest the honey, then there’s a segment with a hilarious rap explaining why bees are important, and finally we see a new beehive being transferred into a new hive box. (That last part is really surprising and fun — you get to see how beekeepers pack and unpack a bee colony for mailing via US Post.)

Enjoy, and particularly keep an eye out for Levar Burton’s bee-related puns (FWIW, apparently the clip in which kids picked out some books has been edited out to fit the YouTube 10-minute time limit):

So this is real. Seriously. A group of researchers have put together a system called PhotoSketch which allows the user to literally sketch a desired scene (see above for an example), label each part of the scene with keywords, then PhotoSketch searches the web for photos and assembles a photographic version of the sketch. Um. Wow?

If you’ll recall, Skynet (the killer computer “defense” system from Terminator) became self-aware at 2:14am EDT August 29, 1997. So it’s taken Skynet twelve years to learn how to draw. I think we’re safe for a bit longer. But sketch while you can, people. There is no fate but what we make.

Here’s a video of PhotoSketch in action:

PhotoSketch: Internet Image Montage from tao chen on Vimeo.

(Note: you can watch in HD at the Vimeo site.)

Also for what it’s worth, many commenters have been insisting that this is a hoax. How could a computer possibly do such a thing? Well, the creators have released the source code binaries (Windows only, link updated), presented a paper at SIGGRAPH Asia 2009 on the technology, and even made that paper available for download.

(Via Kottke.org.)

In 1971, astronaut David Scott conducted Galileo’s famous hammer/feather drop experiment on the moon, during the Apollo 15 mission. Galileo had concluded that all objects, regardless of mass, fall at the same speed — however, the resistance caused by the air (as in the case of the feather in Earth’s atmosphere) can cause the feather to drop slower. Well, on the moon there is no atmosphere (a vacuum), so the objects should drop at the same speed. See for yourself how the experiment turned out in the video below.

As Mission Controller Joe Allen wrote in the Apollo 15 Preliminary Science Report:

During the final minutes of the third extravehicular activity, a short demonstration experiment was conducted. A heavy object (a 1.32-kg aluminum geological hammer) and a light object (a 0.03-kg falcon feather) were released simultaneously from approximately the same height (approximately 1.6 m) and were allowed to fall to the surface. Within the accuracy of the simultaneous release, the objects were observed to undergo the same acceleration and strike the lunar surface simultaneously, which was a result predicted by well-established theory, but a result nonetheless reassuring considering both the number of viewers that witnessed the experiment and the fact that the homeward journey was based critically on the validity of the particular theory being tested.

Joe Allen, NASA SP-289, Apollo 15 Preliminary Science Report, Summary of Scientific Results, p. 2-11

Here’s video of the experiment:

Ever since the hammer/feather drop in 1971, moon-hoax conspiracy theorists have been trying to prove that this footage was faked. Here’s one video that claims to disprove NASA’s experiment. I encourage you to read the YouTube comments on that hoax video for an entertaining nerd-fight. See also: high-resolution video of the experiment from NASA, and a mathematical discussion of the physics involved.

(Via Kottke.org.)

“We see with the eyes, but we see with the brain as well, and seeing with the brain is often called ‘imagination,’ and we are familiar with the landscapes of our own imagination, our ‘inscapes,’ we’ve lived with them all our lives. But there are also hallucinations as well, and hallucinations are completely different…they seem to come from the outside, and to mimic perception.” With those words, world-famous neurologist Oliver Sacks begins a fascinating twenty-minute talk on hallucination, which you can watch in its entirety below. Sacks is well-known for his work in neurology, and you’ve probably seen the movie Awakenings (starring Robin WIlliams as a character based on Sacks) — that film was based on the true story of how Sacks discovered how to revive catatonic patients with a new drug called L-Dopa. Anyway, back to today’s Sacks talk.

Discussed: visual hallucinations among the visually impaired, hallucinations as “a rather boring movie,” Charles Bonnett syndrome, handsome young men who disappear in a flash, hallucinations of Kermit the Frog, why Kermit?, temporal lobe epilepsy (”time travel” style hallucinations), the special part of the brain activated by cartoons, how the mind may treat hallucinations as dreams, and finally, “Kermit means nothing to me!”

If your computer is up to the task, you may want to watch the talk in high-resolution MP4 — much bigger and shinier.

The New Yorker brings us an important message from extraterrestrials, translated by writer Paul Simms. I’m just gonna start this dialog by emphasizing that everything’s cool. They just want to, you know, check out our planet and hang out. There are some details and stuff to work out, but nobody’s gonna get eaten by huge laser-wielding death monsters. The message begins (emphasis added):

We are on our way to your planet. We will be there shortly. But in this, our first contact with you, our “headline” is: We do not want your gravel.

We are coming to Earth, first of all, just to see if we can actually do it. Second, we hope to learn about you and your culture(s). Third–if we end up having some free time–we wouldn’t mind taking a firsthand look at your almost ridiculously bountiful stores of gravel. But all we want to do is look.

Personally, I welcome our new gravel-interested (but not TOO interested) overlords. As they continue, “[A]s far as protocol goes, we’re a pretty informal species. If you want to put together a welcoming ceremony with all your kings and queens and Presidents and Prime Ministers and leading gravel-owners, that’s fine. But please don’t feel like you have to.” So it’s cool. Read the rest and keep close hold of your precious gravel, people.

What if you finished reading this article and remembered every detail of it for the rest of your life? That’s the problem people with super-autobiographical memory face—and yes, it’s often referred to as a problem, not a gift. Their minds are like a computer hard drive that retains everything: dates, middle names, license plate numbers, even what they eat for lunch on a daily basis There are only four confirmed super memory cases, a disorder experts say is somewhat related to OCD, though no doubt there are plenty others who haven’t been identified yet.

So who are the four individuals who’ve all recently been the subject of a study at the Center for the Neurobiology of Learning and Memory at the University of California, Irvine? Let’s meet them and find out…

1. Bob Petrella

A Los Angeles based producer for the Tennis Channel, Bob Petrella may remember every number in his cell phone, but it’s his ability to recall sporting events that’s most remarkable. Give him a date, like March 30, 1981, and he could tell you not only that it was the day Reagan was shot, but also that Indiana beat North Carolina for the NCAA championship that evening. Even more impressive: when it comes to the Pittsburgh Steelers, his favorite team, you can show him a single freeze frame from most any game that he’s seen, and he can tell you not only the date of the game, but the final score.

According to a piece on ABC news, Patrella “remembers all but two of his birthdays since he turned 5. He recalls where he was and what he did with high school buddies. Grainy images of the 1970s are vivid pictures in his head. ‘I remember all my ATM codes,’ he said. ‘I remember people’s numbers. [I] lost my cell phone Sept. 24, 2006. A lot of people, if they lost their cell phone, they would panic because they have all these numbers. I didn’t have any numbers in my cell phone because I know everybody’s numbers up here [in my head].’

2. Jill Price

Probably the best known of the four, Jill Price has described her ‘gift’ as “nonstop, uncontrollable and totally exhausting.” She was the first to be diagnosed with the condition, and recently published a memoir, The Woman Who Can’t Forget. Price remembers most details of nearly every day she’s been alive since she was 14 and compares her super memory to walking around with a video camera on her shoulder. “If you throw a date out at me, it’s as if I pulled a videotape out, put in a VCR and just watched the day,” she has said.

Like Bob Petrella, Price calls California home, though working as an assistant at a Jewish religious day-school, she’s about as far from Hollywood as you can get. And although people she meets at parties are impressed with her ability to remember everything from the date of the Lockerbie plane bombing (December 21, 1988) to the last episode of Dallas, (May 3, 1991), in her memoir, she describes super memory as a nuisance, partly because she can’t seem to forget painful events, like when someone she was crushing on rejected her.

3. Brad Williams

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After yesterday’s link to an Ignite Talk, Scrabble: How to Confuse and Destroy Your Opponents, I thought I’d take this opportunity to feature a few more great five-minute talks. Remember, the Ignite format is very strict: five minutes per talk, twenty slides total, and slides auto-advance every fifteen seconds. So each of these talks is sort of a bite-sized lecture. Some are delivered by experts, others by people who just know interesting stuff. Enjoy!

Will Noel, “Restoring The Archimedes Palimpsest”

The Archimedes Palimpsest is a 10th century manuscript of the mathematician’s work. Unfortunately it was turned into a prayer book in the 13th century. Will Noel explains how he helped rescue the text in this week’s Ignite talk.

Note: you can also check out the palimpsest online at ArchimedesPalimpsest.org.

Vanessa Holfeltz, “Boiling Water in 5 Easy Steps” (Using a Nuclear Reactor)

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