Birthday: 15 February

Famous story of dropping things off the tower of Pisa, probably apocryphal; didn't do it in reality, only talked about it as a thought experiment. 350 years later, astronauts replicated Galileo's experiment on the Moon (they brought two balls to drop them on the lunar ground), you can see it on YouTube.

Rolled balls of varying mass down inclined planes. Noted that the distance travelled grows with time squared (acceleration). These experiments took him many years for some reason.

There were no stopwatches in that time, so how did Galileo time it? With his lute as an incline, he put bells as gates for the ball to break through. Then spacing the bells increasingly distant so that the chiming sounds became equidistant.

Measuring the acceleration: differences in length increased according to some constant.

The constant varied, it wasn't always 10 as you see above. Galileo couldn't understand it, but we know it was measuring error.

Aristotelian idea: All objects have a natural state that they want to reach. Heavy objects want to go down, heavier objects even more so.

Galileo thought experiment: basket containing ten stones, and a single stone separate. Which of these two objects falls faster? The basket, if heavier, supposedly falls faster. What happens if you tie the eleventh stone to the basket? He arrived to the conclusion that all objects must fall at the same speed.

Existentialism. Surname means graveyard; I wonder if he picked this intentionally?

Ludwig Wittgenstein once stated that Kierkgaard was "by far the most profound thinker of the [nineteenth] century. Kierkegaard was a saint."

"Kierkegaard predicted his posthumous fame, and foresaw that his work would become the subject of intense study and research."

Birthday: 10 December

The first programmer. Long before there was anything like a computer, only Charles Babbage's theory which she translated to French (with extra notes), she got it – how it would work. This is hard to do when you don't grow up around computers, the idea of computation which surrounds us today and seems obvious had not occurred to anyone. Even Babbage wasn't able to envision it. That's why we say she was the first programmer.

After Babbage refused her offer to work with him, she spent ten years abusing opiates and alcohol (given by her mother who thought she should less cerebral and more ladylike), then died.