It’s interesting when world’s collide. In this case, we’re taking people whose names you know and matching them with inventions you probably use (or at the very least are familiar with), because most people probably have no idea the two of them go together.

Here are 7 famous people who created some very useful products!

7. Ophthalmoscope – Charles Babbage

Charles Babbage, one of the earliest computer pioneers, suffered from double vision. He invented a device that used a mirror to reflect light into a patient’s eye, and that also had an opening a doctor could look through to see the inner eye.

A version of his ophthalmoscope is still used today.

6. Mock Trial Card Game – Elizabeth Magie

Elizabeth is the woman who invented Monopoly (she called it The Landlord’s Game) before it was stolen by Charles Darrow and Parker Brothers – and she had worked with the latter before, when they published her game Mock Trial in 1910.

5. Airplane Wing De-Icer – Katharine Burr Blodgett

Her most famous invention might be non-reflective glass (it prevents glare and distortion), but her invention that helped de-ice the wings of airplanes was instrumental during WWII.

4. Copier – James Watt

Watt is best known for his work on the steam engine, but he patented a copier in 1780, a technique that involved writing on the top page, then using his device to press it against a thinner, see-through page.

The ink transferred to the second page in reverse, but since it was translucent, you could read it from the other side.

3. Bicycle – The Wright Brothers

You know about their airplane, but did you know they invented the St. Clair and Van Cleve bicycles as well?

The used the St. Clair to innovate their airplane ideas, adding wing-like parts to the sides.

2. Air Conditioner – Maria Telkes

Maria Telkes was a Hungarian chemist who immigrated to the U.S. in the 1920s, where she went on to innovate in the world of solar energy power in the 1940s.

In the 1970s she imagined an air conditioner that used calts to store cool air at night, then used that cooler air the next day to conserve power.

1. Molecular Knife – Dr. Flossie Wong-Staal

Wong-Staal was the first person to clone and genetically map HIV, work that undoubtedly saved hundreds of thousands of lives, and in doing so invented a “molecular knife” that cuts through the genetic information in cells.

Wow, I honestly had no idea – I hope you learned something today, too!