Analogies Analogies

  As I was going over the equations of motion, I switched from using 'x' for position to 'd' for displacement in the middle of a problem.  This caused a few students to become confused. After explaining that the equations should be read for content and not just followed to the letter, I berated them unfairly by saying "If you are reading a book and the parlor in chapter one becomes a living room in chapter 2, do you stop reading?"
  Later the same day, in a different class, I was warning them that we were going to vectorize our equations of motion and start solving the equations in x and y direction simultaneously...as they all groaned in dismay I quickly interjected "Hey - if you are learning French, you might as well learn German too."  Then we all looked at each other and started to pick apart just how terrible that analogy was, so I quickly modified it to "Hey - once you learn to speak French..." I tilted my head 90 degrees and spoke to them sideways "...you can speak French like this too!"

Inspiried by a Typo

A student in Astronomy accidentally typed the "loves of stars" instead of the "lives of stars".  I thought to myself, Hmmmm....

So here is my response:

We met at first, dispersed and cold

With gravity's love, our fates foretold

We drew together tight and bold

Fusing together, two became one

For 10 billion years, we were the Sun

But eventually our love was undone

We separate: one grew bigger, redder, and colder

Into itself the rest contracted and started to smolder

Alpha alpha alpha, the core grew older and older

Dwarf-like and tiny, merely a carbon sack

I spin and recall when we began to contract

As memories of love fade, white into black