From a reader (I could do without the “even your columns” comment):

Positrons and antielectrons are the same thing. Good Job S.F.
Chronicle, and to the careful readers at www.defensetech.org. Should I
go into my spiel now about how really, really, really, really, really
awful journalism about science is these days? I’m a non-practicing
chemist (currently typing with one hand, holding baby #2 with the
other), and it ticks me off.
Thanks for the corner, and even for your columns!