Why Are Bots Unable to Check "I Am Not a Robot" Checkboxes?

iStock.com/Oleksandr Hruts
iStock.com/Oleksandr Hruts

Oliver Emberton:

How complicated can one little checkbox be? You can't even imagine!

For starters, Google invented an entire virtual machine—essentially a simulated computer inside a computer—just to run that checkbox.

That virtual machine uses Google's own language, which they then encrypt. Twice.

But this is no simple encryption. Normally, when you password protect something, you might use a key to decode it. Google’s invented language is decoded with a key that is changed by the process of reading the language, and the language also changes as it is read.

Google combines (or hashes) that key with the web address you’re visiting, so you can’t use a CAPTCHA from one website to bypass another. It further combines that with “fingerprints” from your browser, catching microscopic variations in your computer that a bot would struggle to replicate (such as CSS rules).

All of this is done just to make it hard for you to understand what Google is even doing. You need to write tools just to analyze it. (Fortunately people did just that).

It turns out that these checkboxes record and analyze a lot of data, including: Your computer’s timezone and time; your IP address and rough location; your screen size and resolution; the browser you’re using; the plugins you’re using; how long the page took to display; how many key presses, mouse clicks, and tap/scrolls were made; and ... some other stuff we don’t quite understand.

We also know that these boxes ask your browser to draw an invisible image [PDF] and send it to Google for verification. The image contains things like a nonsense font, which (depending on your computer) will fall back to a system font and be drawn very differently. They then add to this a 3D image with a special texture, which is drawn in such a way that the result varies between computers.

Finally, these seemingly simple little checkboxes combine all of this data with their knowledge of the person using the computer. Almost everyone on the Internet uses something owned by Google—search, mail, ads, maps—and as you know, Google Tracks All Of Your Things™️. When you click that checkbox, Google reviews your browser history to see if it looks convincingly human.

This is easy for them, because they’re constantly observing the behavior of billions of real people.

How exactly they check all this information is impossible to know, but they’re almost certainly using machine learning (or AI) on their private servers, which is impossible for an outsider to replicate. I wouldn’t be surprised if they also built an adversarial AI to try to beat their own AI, and have both learn from each other.

So why is all this hard for a bot to beat? Because now you’ve got a ridiculous amount of messy human behaviors to simulate, and they’re almost unknowable, and they keep changing, and you can’t tell when. Your bot might have to sign up for a Google service and use it convincingly on a single computer, which should look different from the computers of other bots, in ways you don’t understand. It might need convincing delays and stumbles between key presses, scrolling and mouse movements. This is all incredibly difficult to crack and teach a computer, and complexity comes at a financial cost for the spammer. They might break it for a while, but if it costs them (say) $1 per successful attempt, it’s usually not worth them bothering.

Still, people do break Google’s protection [PDF]. CAPTCHAs are an ongoing arms race that neither side will ever win. The AI technology that makes Google’s approach so hard to fool is the same technology that is adapted to fool it.

Just wait until that AI is convincing enough to fool you.

Sweet dreams, human.

This post originally appeared on Quora. Click here to view.

Why Are Barns Often Painted Red?

iStock/Ron and Patty Thomas
iStock/Ron and Patty Thomas

Beginning with the earliest American settlements and continuing into the 18th century, most barns weren't painted at all. Early American barn builders took sun exposure, temperature, moisture, wind, and water drainage patterns into account when placing and building barns, and they seasoned the wood (that is, they reduced the moisture content) accordingly. The right type of wood in the right environment held up fine without any paint.

Toward the end of the 1700s, these old-school methods of barn planning and building fell by the wayside. People sought a quicker, easier fix for preserving their barns—a way to coat and seal the wood to protect it from sunlight and moisture damage. Farmers began making their own coating from a mix of linseed oil (a tawny oil derived from the flax seeds), milk, and lime. It dried quickly and lasted a long time, but it didn't really protect the wood from mold and wasn't quite like the "barn red"we know today—it was more of a burnt orange, really.

Turning Red

The problem with mold is that it decays wood and, in large quantities, can pose health risks to people and animals. Rust, it turns out, kills mold and other types of fungi, so farmers began adding ferrous oxide (rusted iron) to the linseed oil mix. A little bit of rust went a long way in protecting the wood, and it gave the barn a nice red hue.

By the late 19th century, mass-produced paints made with chemical pigments became available to most people. Red was the least expensive color, so it remained the most popular for use on barns, except for a brief period when whitewash became cheaper and white barns started popping up. (White barns were also common on dairy farms in some parts of Pennsylvania, central Maryland, and the Shenandoah Valley, possibly because of the color's association with cleanliness and purity.)

Throughout Appalachia (a historically poorer region), many barns went unpainted for lack of money. In the tobacco regions of Kentucky and North Carolina, black and brown barns were the norm, since the dark colors helped heat the barn and cure tobacco.

Today, many barns are still painted the color traditionally used in a given region, with red still dominating the Northeast and Midwest.

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This story was updated in 2019.

Is There An International Standard Governing Scientific Naming Conventions?


Jelle Zijlstra:

There are lots of different systems of scientific names with different conventions or rules governing them: chemicals, genes, stars, archeological cultures, and so on. But the one I'm familiar with is the naming system for animals.

The modern naming system for animals derives from the works of the 18th-century Swedish naturalist Carl von Linné (Latinized to Carolus Linnaeus). Linnaeus introduced the system of binominal nomenclature, where animals have names composed of two parts, like Homo sapiens. Linnaeus wrote in Latin and most his names were of Latin origin, although a few were derived from Greek, like Rhinoceros for rhinos, or from other languages, like Sus babyrussa for the babirusa (from Malay).

Other people also started using Linnaeus's system, and a system of rules was developed and eventually codified into what is now called the International Code of Zoological Nomenclature (ICZN). In this case, therefore, there is indeed an international standard governing naming conventions. However, it does not put very strict requirements on the derivation of names: they are merely required to be in the Latin alphabet.

In practice a lot of well-known scientific names are derived from Greek. This is especially true for genus names: Tyrannosaurus, Macropus (kangaroos), Drosophila (fruit flies), Caenorhabditis (nematode worms), Peromyscus (deermice), and so on. Species names are more likely to be derived from Latin (e.g., T. rex, C. elegans, P. maniculatus, but Drosophila melanogaster is Greek again).

One interesting pattern I've noticed in mammals is that even when Linnaeus named the first genus in a group by a Latin name, usually most later names for related genera use Greek roots instead. For example, Linnaeus gave the name Mus to mice, and that is still the genus name for the house mouse, but most related genera use compounds of the Greek-derived root -mys (from μῦς), which also means "mouse." Similarly, bats for Linnaeus were Vespertilio, but there are many more compounds of the Greek root -nycteris (νυκτερίς); pigs are Sus, but compounds usually use Greek -choerus (χοῖρος) or -hys/-hyus (ὗς); weasels are Mustela but compounds usually use -gale or -galea (γαλέη); horses are Equus but compounds use -hippus (ἵππος).

This post originally appeared on Quora. Click here to view.