How Does CAPTCHA Know That I'm Not A Robot?

I know that I am not a robot. You know that I am not a robot. So why is it that every time I try to login to a website, I get a CAPTCHA popup testing me to prove I’m not a robot?

CAPTCHA stands for “Computer Automated Turing Test to Tell Computers and Humans Apart.” A mouthful, I know. It’s an elaborate form of the Turing Test designed by the famous British mathematician and codebreaker Alan Turing.

The test examines a machine’s ability to emulate human thinking by exhibiting intelligent behavior. The test works like this: ask a question to both a human and a computer, and if the questioner can distinguish the two based on the answer, then the computer has failed the Turing test.

Identifying CAPTCHA visuals are easy enough for humans but extremely difficult for the pesky spambots and trolls. The Turing test has passed the test of time. Since it originated in 1950, no computer has ever passed the Turing Test. Not one. Not Siri, Alexa, Watson, or any other complex Artificial Intelligence Technically, there was a case of success in 2014, but that is still highly debated and inconclusive. As artificial intelligence becomes even more advanced, it becomes more probable that one day there will be a computer that is indistinguishable from humans.

But if artificial intelligence is truly going to kickstart the robot revolution to end humanity, it’s going to have to be able to pick out the stop sign photos first.

SOURCES: 

http://www.captcha.net/

https://plato.stanford.edu/entries/turing-test/

https://www.britannica.com/technology/Turing-test