No, the Iranians haven’t discovered a kind of radio wave that the rest of us just missed. The “almost” in almost invisible means something, and there’s a variety of situations that can dramatically increase the radar signature, or that can make radar not the important consideration at all.

Modern “stealth” aircraft like the F35 uses split-ring resonator patterns in the skin of the aircraft. This is much more durable than the iron spheres suspended in a top coat that the F-22 and older aircraft use. (There’s a reason why the F-22 can’t be left out in the rain). The problem is that the resonator pattern is highly dependent on radar frequency. So yeah, the Iranians may very well have found radar frequencies that aren’t absorbed very well by the F-35.

The details are classified, but just a look at the visible design and common sense about how smart they are will tell you they didn’t only pay attention to a few frequencies. The coating isn’t only split-ring resonators either, there is a chemical component of some kind.

From what I’ve heard, any frequencies where they’re weak will be very low ones, which both require bigger, more obvious equipment and are less precise. And even then it might be a matter of a basketball-sized signature rather than a golf ball-sized one, and will be somewhat directional.

All of which is to say “Let’s continue with the American myth that the F-35 is ‘almost’ invisible”. The way to detect, at a great distance, an ‘undetectable’ object is to look for what is NOT there, the ‘shadow’ that invisibility leaves behind. The same myth that you ‘heard’ about the frequencies. Actually, it is entirely invisible if you believe in magic. The Iranians, obviously, do not believe in magic.

I don’t think that the Canadian government should believe in the American ‘magic’ either. Can we really trust what the Americans say about anything?

After all, Boeing keeps having their planes drop out of the sky.