If you can't articulate (off the top of your head) the units of energy, the units of power, or the difference between energy and power, the judge just might exclude you.

If you allege a fire started with a propane torch and can't articulate the chemical formula for propane,the judge just might exclude you.

If you don't know that the air we breathe contains 20.95% oxygen (or if you say it is 92% or 11%), the judge just might exclude you.

If you base your determination on negative corpus logic, the judge just might exclude you.

It is up to the Judge. I don't think one has to memorize NFPA 921 but if you don't know what a watt is, the judge just might exclude you.


The very last example in Sidebar 2 has the Judge excluding a witness who could not describe thecombusion of hydrogen to form water. I was in the courtroom when he said, “I’m sorry. If you don’t know H2O, you will not be rendering opinion testimony in my courtroom.”