![Submerged submarine.](https://cdn.primetimetale.com/wp-content/uploads/2020/11/submarine-5.jpg)
The Submarine
The first electrical submarine was launched in 1888. The man behind it? Spanish inventor Isaac Peral! Though he was the first to come up with the idea, many countries around the world attempted to duplicate his results.
Funny thought, right? Since today underwater travel is so commonplace, you can even book a room at underwater hotels!
It was called the Peral submarine and it used an electric battery. Holding a crew of 12 people it could travel at a maximum speed of eight knots. That may not sound too impressive today but for the world’s first, we think it deserves more recognition!
CAPTCHA Codes
The Completely Automated Public Turing test to tell Computers and Humans Apart, also known as CAPTCHA may give you headaches when trying to access various parts of the internet, but they’re actually super-useful!
They were invented in part by Guatemalan professor of Computer Science Luis Von Ahn in 2000. Nowadays, reCAPTCHA require us to pick specific images from a list, such as those containing fire hydrants or bicycles. But the earlier versions offered users jumbled letters instead.
Both words were taken from various, old scanned documents. Only one of the words was unknown by the algorithm behind the CAPTCHA. When enough people agreed on what that word said, it would get sent back to a database.
The best part? They would actually use those words to digitize documents that would have taken far too long for humans to leaf through and digitize, not to mention a lot of money! CAPTCHA and ReCAPTCHA are still used today to keep hackers at bay.
In addition to this nifty piece of technology, Von Ahm also brought us Duolingo!