And finally, keep in mind that audiences need a bit of extra
time to assimilate mathematics, so try to make their job as easy
for them as possible. It’s particularly important to define any
unfamiliar symbols and to avoid cumbersome notation. If you’re
only going to use the scalar form of an equation, then write it out
using that notation and leave the generalized tensor version for
the textbooks. And don’t just plunk down the equation and then
stand there like a tombstone for 60 seconds while your audience
studies it. You should always talk through any equation you
show your audience. For example, as you’re writing out E = mc2
on the blackboard, you should say something like, “And so now
we see that the energy E is equal to the mass of the object
multiplied by the square of the speed of light.”