Excuses courtesy of Joachim Verhagen's collection of science jokes.
- I accidentally divided by zero and my paper burst into flames.
- Isaac Newton's birthday.
- I could only get arbitrarily close to my textbook. I couldn't actually reach it.
- I have the proof, but there isn't room to write it in this margin.
- I was watching the World Series and got tied up trying to prove that it converged.
- I have a solar powered calculator and it was cloudy.
- I locked the paper in my trunk but a four-dimensional dog got in and ate it.
- I couldn't figure out whether i am the square of negative one or i is the square root of negative one.
- I took time out to snack on a doughnut and a cup of coffee. I spent the rest of the night trying to figure which one to dunk.
- I could have sworn I put the homework inside a Klein bottle, but this morning I couldn't find it.