Thursday, October 19, 2006

Did you know?

Sir Isaac Newton (1642 - 1727) invented the cat flap. Today gravity, tomorrow the cat flap. And which really has proved to be the most useful?

Coincidentally the cat flap demonstrates Newton’s third law of motion – for every reaction there is an equal and opposite reaction – taking the same amount of time to swing from one side to the other side.


And from the Very Squashed Version of Mathematical Principles of Natural Philosophy by Sir Isaac Newton, 1687
"I do not know what gravity is. But it seems to be the case that every body in the universe attracts every other body with a force called gravity, which is proportional to the masses of the bodies, and diminishes by the square of the distance between them. No doubt God causes all this."

For a slightly less squashed version go here.

4 comments:

Serena said...

Liz, you are a veritable fount of information. I had no idea about Newton's cat flap.:)

Elsie said...

Is a cat flap the thing in the door? Sometimes I swear I don't understand English!

Clare said...

I need more sleep. I read that as Isaac Newton invented the flat cap...

Liz Hinds said...

It's possible; he was a very inventive man.