The cosmologist Carl Sagan once speculated that if aliens were observing Earth from orbit, they would come to the conclusion that the dominant life-form had wheels.  Human beings are their lesser symbionts who do everything for their wheeled masters; cleaning them, feeding them, maintaining them, and at great time and labour, constructing their massive migration pathways to render their going smooth.

Newton's Third Law of Shipping

Gravity, pale and dark-haired, somehow managed to draw people in without trying.  There was a magnetic force to him; something hypnotizing, attractive.  Most elements said “he’s an enigma,” but that, of course, was only an excuse.  Nobody knew what drew them to him.  Metals like Gold and Iron and Bismuth were closer to him than elements like Hydrogen or Helium – of course, Helium was distant because that was just what his family was like. (That, however, seemed to be changing; he’d accompany Iron along to Gravity’s place, and might put in a word or two.)

Normal Force, on the other hand, was energetic, wild.  With a bright smile and an acute sense of humor, he made friends with the freer elements; Carbon and Oxygen were two of his closest ones.  Sometimes, he even palled around with Hydrogen, and Hydrogen would convince him to – for one night, or one week – separate some of Gravity’s friends from him for parties.  But he always had to try to make friends.  He always had to make an effort.

Gravity was jealous of Normal Force’s ability to do or say anything; Normal Force envied Gravity’s unconscious attraction to people.  Gravity resented Normal Force, because of how often he took his friends; Normal Force disliked Gravity because of how easily he drew them back.

Some say hate is the counterpart to love.

Of course, others say hate is just that – hate.

The Most Joy a Math Professor Can Have

I remember back when I was studying linear algebra, one of the first things we got taught was the Cholesky factorisation.

Later in the course we got taught the LDL’ factorisation, and suddenly the lecturer gets a weird little smile on his face like he’s holding back the secrets of the universe.

He drew our attention to the ability to split the D into sqrt(D) matrices and with a few flicks of his pen and a girlish giggle, had shown how LDL’ was really the Cholesky factorisation the whole time.

Seeing his face, like he’d just told us who River Song was, made me remember that Math really means something to some people… And that I was one of them.