24 Strange Scientific Studies

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1. Hi, I'm John Green. Welcome to my salon. This is mental_floss on YouTube, and did you know that in 2010 a researcher trained pigeons to tell the difference between good and bad paintings made by children? The pigeons were positively reinforced when they pecked at good paintings and after a while, they were able to determine which ones were good, even observing color and pattern cues in paintings they'd never seen before!

And that's the first of many odd scientific studies I'm going to share with you today.

2. A study was conducted at the Babraham Institute to determine whether sheep were capable of recognizing the faces of other sheep. When the study concluded in 2001, the researchers had discovered that sheep could recognize the faces of fifty sheep about 80% of the time, and they remembered them for over two years, which is much better than my own sheep facial-recognition.

3. In 2011, researchers at Albany Medical College played songs by Beethoven and Miles Davis to rats, learning that the rats preferred silence, but would rather hear Beethoven than Miles Davis. Then the researchers injected some rats with cocaine while the rats were listening to Miles Davis because, y'know, why not? At this point they weren't even conducting a study, they were just enjoying some jazz, and dosing rats with cocaine, as you do. But anyway, they learned that those rats preferred the jazz music, even after the cocaine was out of their systems.

4. Dr. Allan Walker Blair, an assistant professor of pathology and bacteriology at the University of Alabama, allowed a black widow spider to bite him in the 1930s. There was little research on the spider at the time, so he wanted to document his experience with the bite. Unsurprisingly, he discovered that it caused what he described as "excruciating pain". For the record, he lived, but he died of cardiac arrest a decade later, which was probably related to the experience.

5. Speaking of horrible experiments performed on oneself, in the '90s, veterinarian Robert Lopez took ear mites from a cat's ear and placed them in his own ear. He was trying to determine whether humans can get mites from cats. Turns out that we can, but he still repeated the experiment twice, and then got it published in the journal of American Veterinary Medical Association.

6. In the 1960s at Penn State University, an experiment was conducted on a male turkey to see how minimal a stimuli had to be for it to be considered a mate. The researchers kept removing components of a turkey until it was just a turkey head on a stick, and the male turkey still tried to mate with it.

7. A 2012 study found that human male athletes experienced increases in testosterone in their saliva while doing squats after watching short videos containing either erotic, humorous, or aggressive content.

8. In 1976, a group of researchers did a study to determine whether the speed and flow of men's urination was affected by people being too near them. And I can just tell you—yes. But anyway, in order to do this, they left an observer with a periscope in a public restroom for extended periods of time. He found that the closer a man had to pee next to another man, the longer it took for him to start urinating. He also peed, on average, less if someone was standing next to him.

9. Speaking of urine-related studies, Peter Snider, a professor of Neurology at Brown University, discovered that people who have to pee really badly actually have increased levels of cognitive impairment. That study, by the way, cost him a total of $1.25 to complete.

10. In 2012, a group of psychologists found that, quote, "leaning to the left makes the Eiffel Tower seem smaller." Basically, when people are leaning, their ability to estimate things like quantity and size is affected because we tend to assume that smaller things go on the left and larger things go on the right. It may be a result of bias among people who read from left to right. Which we should follow up a study with people who read right to left and see what happens when they lean right—I just gave you an idea for a study, science!

11. A paper published in 2004 out of the Zoology Institution of Stockholm University is well summed up by its title, "Chickens Prefer Beautiful Humans." It turns out that chickens tend to peck at faces that humans also prefer and consider beautiful. It's a good thing that all those chickens live in Sweden because Swedish people are very beautiful. I'm sure the chickens just enjoy pecking their faces constantly.

12. Dr. Anna Wilkinson of the University of Lincoln in the UK trained a red-footed tortoise to yawn in order to research social cognition in tortoises. Over the course of six months in 2011, Wilkinson and her team taught the tortoise to yawn on command, but they didn't observe contagious yawning when they had the tortoise around other members of its species.

13. In 2003 the journal Polar Biology published a paper on the trajectory of penguins' projectile poop. Apparently penguins poop that way because of gastrointestinal pressure, and in case you're wondering, the poop lands an average of 40 cm away from the penguin. So watch out, Wonder Woman!

14. In the early 1900s, Romanian scientist Nicolae Minovici hung himself 12 times for up to 25 seconds with an assistant nearby. He survived and was able to observe first-hand a lot of the symptoms of hanging, like vision problems, and ringing in the ears.

15. At the University of Minnesota, in 2004, scientists discovered that it is just as easy to swim in syrup as it is to swim in water. In order to conduct the experiment, they filled a 25 meter swimming pool with a liquid made of guar gum, a liquid that is twice as thick as water, and it turns out that you can swim in it just fine!

Why did we need to know this? Well, why do we need to know anything, really?

16. In 1986, eleven Russian men spent 370 days lying down in bed. The experiment was to help with future space expeditions, because a year in bed simulated weightlessness.

17. The U.S. has conducted some dubious sleep experiments, too. In the early 1900s, Dr. Nathaniel Kleitman had six men stay awake for days to see the symptoms, but he stayed awake for longer that any of them when he forced himself to stay awake for 115 hours, causing hallucinations. He also once lived underground for six weeks trying to adjust to a 28-hour day, so y'know, he was a fun guy to hang out with I bet.

18. During the early 2000s, an argument over whether the actor Steve Buscemi was cool prompted researchers Ilan Dar-Nimrod and Ian Hansen to research what characteristics make a person cool. They surveyed 353 college students and determined some of the qualities, like being good-looking, friendly, and successful, or being the star of the HBO series Boardwalk Empire.

19. In 2013 a group of researchers joined forces and asked people at bars to rate their own attractiveness. They found that the higher the blood alcohol content of people, the higher they rated themselves on attractiveness.

20. The study "Patient Preference for Waxed or Unwaxed Dental Floss" was published in 1990. And since I know that you're wondering, around 79% of subjects preferred waxed dental floss and around 21% unwaxed.

21. At the National University of Quilmes in 2007, scientists found that hamsters recovered 50% faster from shifts in their daily time cycles when they were given Viagra. That means that Viagra could potentially help people with jet lag.

22. In the '70s and '80s professors at Florida State University studied the reactions of men and women when a stranger approached them and asked, "Would you go to bed with me?" The majority of men said yes, whereas every single woman said no. Because, y'know, they aren't crazy. Who would say yes to that question? Like, did you ask, "Do you have chlamydia?" first?!

23. There have been multiple studies on whether owners looked like their dogs, although we all know that they do. Like in 2004, Michael Roy and Nicholas Christenfeld had participants match pictures of owners with pictures of their dogs, and the participants were right 64% of the time. Also, Roy and Christenfeld found that people had a much easier time matching purebreds with their owners, rather than mixed breeds. But if I can just make a personal comment here, both mental_floss director, Mark, and mental_floss writer, Meredith, look exactly like their dogs. I, on the other hand, in no way resemble mine.

24. And finally, I return to my salon to tell you about a similar study. During the '80s, psychologist Robert Zions discovered that married couples start to look like each other over time. To prove this, he gave participants a bunch of photographs of single faces. Twenty-four were pictures of individuals in a couple when they first got married, and twenty-four were of the same people, but 25 years later. Then he asked participants to match up pictures of men with the women who most looked like them. There was significantly more resemblance in the couples after 25 years, and participants could match them much easier. Which is good news for me because it means that I'm going to get much cuter in the next 15 years.

Anyway, thanks for watching this episode of mental_floss on YouTube which was brought to you by our friends at Geico and made with the help of all of these nice people who work so hard on the show every week so thanks to them, thanks to you for watching, and as we say in my hometown, don't forget to be awesome.

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iStock // Ekaterina Minaeva
Man Buys Two Metric Tons of LEGO Bricks; Sorts Them Via Machine Learning
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iStock // Ekaterina Minaeva

Jacques Mattheij made a small, but awesome, mistake. He went on eBay one evening and bid on a bunch of bulk LEGO brick auctions, then went to sleep. Upon waking, he discovered that he was the high bidder on many, and was now the proud owner of two tons of LEGO bricks. (This is about 4400 pounds.) He wrote, "[L]esson 1: if you win almost all bids you are bidding too high."

Mattheij had noticed that bulk, unsorted bricks sell for something like €10/kilogram, whereas sets are roughly €40/kg and rare parts go for up to €100/kg. Much of the value of the bricks is in their sorting. If he could reduce the entropy of these bins of unsorted bricks, he could make a tidy profit. While many people do this work by hand, the problem is enormous—just the kind of challenge for a computer. Mattheij writes:

There are 38000+ shapes and there are 100+ possible shades of color (you can roughly tell how old someone is by asking them what lego colors they remember from their youth).

In the following months, Mattheij built a proof-of-concept sorting system using, of course, LEGO. He broke the problem down into a series of sub-problems (including "feeding LEGO reliably from a hopper is surprisingly hard," one of those facts of nature that will stymie even the best system design). After tinkering with the prototype at length, he expanded the system to a surprisingly complex system of conveyer belts (powered by a home treadmill), various pieces of cabinetry, and "copious quantities of crazy glue."

Here's a video showing the current system running at low speed:

The key part of the system was running the bricks past a camera paired with a computer running a neural net-based image classifier. That allows the computer (when sufficiently trained on brick images) to recognize bricks and thus categorize them by color, shape, or other parameters. Remember that as bricks pass by, they can be in any orientation, can be dirty, can even be stuck to other pieces. So having a flexible software system is key to recognizing—in a fraction of a second—what a given brick is, in order to sort it out. When a match is found, a jet of compressed air pops the piece off the conveyer belt and into a waiting bin.

After much experimentation, Mattheij rewrote the software (several times in fact) to accomplish a variety of basic tasks. At its core, the system takes images from a webcam and feeds them to a neural network to do the classification. Of course, the neural net needs to be "trained" by showing it lots of images, and telling it what those images represent. Mattheij's breakthrough was allowing the machine to effectively train itself, with guidance: Running pieces through allows the system to take its own photos, make a guess, and build on that guess. As long as Mattheij corrects the incorrect guesses, he ends up with a decent (and self-reinforcing) corpus of training data. As the machine continues running, it can rack up more training, allowing it to recognize a broad variety of pieces on the fly.

Here's another video, focusing on how the pieces move on conveyer belts (running at slow speed so puny humans can follow). You can also see the air jets in action:

In an email interview, Mattheij told Mental Floss that the system currently sorts LEGO bricks into more than 50 categories. It can also be run in a color-sorting mode to bin the parts across 12 color groups. (Thus at present you'd likely do a two-pass sort on the bricks: once for shape, then a separate pass for color.) He continues to refine the system, with a focus on making its recognition abilities faster. At some point down the line, he plans to make the software portion open source. You're on your own as far as building conveyer belts, bins, and so forth.

Check out Mattheij's writeup in two parts for more information. It starts with an overview of the story, followed up with a deep dive on the software. He's also tweeting about the project (among other things). And if you look around a bit, you'll find bulk LEGO brick auctions online—it's definitely a thing!

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Why Your iPhone Doesn't Always Show You the 'Decline Call' Button
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When you get an incoming call to your iPhone, the options that light up your screen aren't always the same. Sometimes you have the option to decline a call, and sometimes you only see a slider that allows you to answer, without an option to send the caller straight to voicemail. Why the difference?

A while back, Business Insider tracked down the answer to this conundrum of modern communication, and the answer turns out to be fairly simple.

If you get a call while your phone is locked, you’ll see the "slide to answer" button. In order to decline the call, you have to double-tap the power button on the top of the phone.

If your phone is unlocked, however, the screen that appears during an incoming call is different. You’ll see the two buttons, "accept" or "decline."

Either way, you get the options to set a reminder to call that person back or to immediately send them a text message. ("Dad, stop calling me at work, it’s 9 a.m.!")

[h/t Business Insider]