David, who is clearly one of the world's most patient physicists, writes:

"Jim:

Once again you don't get it."

Like Jim, David appears to have two choices:

(1) To continue trying to teach the unteachable Mr. Arnold
(2) To recognize that Mr. Arnold is unteachable and perhaps use his talents to enlighten other Science Blog threads, such as those begun recently by aerospace watchdog Scruffy

This bite of realism brought to you by "Gadfly."