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Why reCAPTCHA is Good for Humanity

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Last week we talked about KittenAuth, a novel CAPTCHA system used to differentiate between humans and spambots -- by using pictures of kittens. Today let's take a look at reCAPTCHA, the system in use by this very blog. What does it do, and why is it good for humanity?

What's a CAPTCHA?

First let's review the term CAPTCHA. It's a loose acronym for "Completely Automated Public Turing test to tell Computers and Humans Apart." The idea is to force humans to do a (relatively) simple task like read a few words presented in an image, then type them into the form -- but this trick only works if the task is hard for computers (ahem, spambots) to do.

CAPTCHA systems are used on forms all over the web in order to cut down on spam form submissions. If you've ever run a blog, you'll know that legions of spambots are crawling the web, submitting every form they find -- so having a CAPTCHA on the form drastically reduces form spam. However, in most CAPTCHA systems the text you type in is meaningless, purposely scrambled text. reCAPTCHA is different.

What's Different About reCAPTCHA?

reCAPTCHA was born when Luis von Ahn, an assistant professor at Carnegie Mellon, realized that millions of people were spending time typing meaningless words into forms. Why not turn this word-decipherment into useful work that helped with some common goal? What if there was a set of words (as images) that needed to be viewed and deciphered by humans? It turns out that book scanning projects (including the Internet Archive) have just this problem: when scanning a print book into a computer -- particularly an old book in poor condition -- some words can't be deciphered automatically by Optical Character Recognition (OCR) software, and need a human to figure them out. In order to get a good text-only copy of a scanned book, lots of human attention is needed.

So reCAPTCHA is conceptually simple: take the words the OCR software can't read and put them in front of human users. If multiple users decipher the same hard-to-read word using the same text, reCAPTCHA can safely assume that it has been properly deciphered, and feed that word back into the book scanning project, slotting it into its associated book. Thus, text that is by definition difficult or impossible for a computer to accurately scan has been deciphered by humans -- and the humans doing the work generally don't even know it!

Yeah, But...

There's one technical catch -- what's to stop people from typing in random gibberish as "decipherment" of the words? Given that reCAPTCHA by definition doesn't know the correct decipherment of its subject words, how can it judge whether you've gotten it right? To solve this problem, reCAPTCHA presents two words together: one unknown and one known (the latter meaning a word for which reCAPTCHA already has a good decipherment). You have to get the known word correct, and the unknown word is (as described above) compared with other users' decipherments to eventually determine whether it's correct. There's also an audio variant for users with visual impairment, in which they listen to spoken language and convert it to written text.

So next time you fill out a reCAPTCHA form when commenting on a Mental Floss blog post, remember: you're helping to digitize books!

Further reading: Carnegie Mellon press release, Wikipedia page, reCAPTCHA project site.

Shhh...super secret special for blog readers.

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Live Smarter
This 'Smokeless' Fire Pit Promises a More Efficient Burn
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BioLite

For thousands of years, people have gathered around open flames to cook food, find warmth, and share stories deep into the night. Campfires have been around since the dawn of humanity, but what if there was a way to use modern technology to make them even better? The people at BioLite believe they've found one.

The FirePit is the outdoor gadget startup's answer to the recreational, backyard fire. It offers the same benefits as a more conventional product: a space for building wood or charcoal fires, a removable grate for grilling, and metal screens on each side to protect onlookers from embers. But the yellow battery pack is what sets it apart from anything else on the market. With the press of a button, a fan inside the FirePit stokes a hotter, more efficient blaze without producing all of the smoke and soot people are used to.

Couple sitting by a firepit on the beach.
BioLite

"Air injection makes the fire burn more completely," Ryan Gist, one of the lead engineers on the project, told Mental Floss. "So you basically get all the energy out of your fuel." The result is a fire you can enjoy without worrying about your eyes and throat burning, moving your chair every five minutes to avoid a gust of smoke, or having your clothes stink for weeks.

It also makes for a fire capable of burning longer and brighter with less wood. Smoke is made of tiny fuel particles that haven't fully burned up. Using a fan, the FirePit can draw that runaway fuel back into the fire before it has a chance to escape. "It's like when you're stuck on the highway behind a truck and it's got black stuff coming out of the tailpipe," BioLite marketing director Erica Rosen told Mental Floss. "When you see black stuff coming out of a fire, it's the same thing. So what we've done is, we've given fire a tuneup."

FirePit's built-in fan makes the fire easy to control. If campfire gazers want to see big, roaring flames through the box's X-ray mesh, they can turn the air down low. The higher fan setting produces a smaller, more intense burn, which is perfect for chilly autumn nights. Adjusting the blaze can be done remotely with the BioLite Energy app or manually from the control panel on top of the battery pack.

People sitting by a fire.
BioLite

BioLite designed the FirePit for backyards, but its foldable legs make it convenient to carry to the beach, a campsite, or anywhere else where you might bring a cooler of the same size. Once it's cooled down after an evening of grilling hot dogs and toasting marshmallows, the pit fits neatly into its solar panel case, where it can recharge in time for the following night (the battery also features a USB plug for charging indoors).

The FirePit recently debuted on Kickstarter, where it's available along with its solar carrying case for a special deal of $169 (once the first 300 FirePits go, it will be sold for the regular price of $199). To help the campaign reach its $100,000 funding goal, you can reserve yours today with shipping estimated for May of next year.

Skewers cooking on a grill.
BioLite

All images courtesy of BioLite.

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ABBA Is Going on Tour—As Holograms
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AFP/Stringer/Getty Images

Missed your chance to watch ABBA perform live at the peak of their popularity? You’re in luck: Fans will soon be able to see the group in concert in all their chart-topping, 1970s glory—or rather, they’ll be able to see their holograms. As Mashable reports, a virtual version of the Swedish pop band is getting ready to go on tour.

ABBA split up in 1982, and the band hasn't been on tour since. (Though they did get together for a surprise reunion performance in 2016.) All four members of ABBA are still alive, but apparently not up for reentering the concert circuit when they can earn money on a holographic tour from the comfort of their homes.

The musicians of ABBA have already had the necessary measurements taken to bring their digital selves to life. The final holograms will resemble the band in the late 1970s, with their images projected in front of physical performers. Part of the show will be played live, but the main vocals will be lifted from original ABBA records and recordings of their 1977 Australian tour.

ABBA won’t be the first musical act to perform via hologram. Tupac Shakur, Michael Jackson, and Dean Martin have all been revived using the technology, but this may be one of the first times computerized avatars are standing in for big-name performers who are still around. ABBA super-fans will find out if “SOS” still sounds as catchy from the mouths of holograms when the tour launches in 2019.

[h/t Mashable]

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