From the oral argument transcript today in Briscoe v. Virginia, a funny moment in the argument of University of Michigan law professor Richard Friedman:

MR. FRIEDMAN: I think that issue is entirely orthogonal to the issue here because the Commonwealth is acknowledging –

CHIEF JUSTICE ROBERTS: I’m sorry. Entirely what?

MR. FRIEDMAN: Orthogonal. Right angle. Unrelated. Irrelevant.

CHIEF JUSTICE ROBERTS: Oh.

JUSTICE SCALIA: What was that adjective? I liked that.

MR. FRIEDMAN: Orthogonal.

CHIEF JUSTICE ROBERTS: Orthogonal.

MR. FRIEDMAN: Right, right.

JUSTICE SCALIA: Orthogonal, ooh.

(Laughter.)

JUSTICE KENNEDY: I knew this case presented us a problem.

(Laughter.)

MR. FRIEDMAN: I should have — I probably should have said –

JUSTICE SCALIA: I think we should use that in the opinion.

(Laughter.)

MR. FRIEDMAN: I thought — I thought I had seen it before.

JUSTICE SCALIA: Or the dissent.

(Laughter.)

MR. FRIEDMAN: That is a bit of professorship creeping in, I suppose.

I think Friedman should have explained “vectors with a dot product of zero,” but I guess that would have been overly technical.

If you’re curious, the Supreme Court has never used the word “orthogonal” in a written opinion. It has usually appeared in the federal reports in patent cases, although it occasionally surfaces elsewhere. See, e.g., United States v. Harris, 491 F.3d 440 (DC Cir. 2007) (“This test is fact-intensive, and the facts at issue are often orthogonal to those explored at trial.”).