> Can you tell me the thickness of a U.S. Postage stamp with the glue on it?

A: Get a pile of stamp sheets, measure the height, and do a calculation. (You did go to school, didn't you.)

Thanks, 'j'. You got the point of this discovery. It jumped out at me in the same way. The report makes the point that the covering of the shell would have probably been green so the marking down into the white shell underneath would have made the scoring stand out. If it had only been one scratch then it would be called an incidental mark, but it went well beyond that to be a deliberate pattern.

I notice from the diagram (per the linked story) that I only need to fit a spiral phase plate (no, not a flux capacitor) to my Tardis and it all works automagically...

... via "orbital angular momentum" and "OAM multiplexing".

Frankly, I am still confused as to why it's not (more simply) "circular polarisation" that has been known about since the early days of radio.

True! "This call may be recorded..." is a bi-directional statement. I love the logic.

Also, if in doubt, as you hear the 'statement', repeat their exact words into the phone.

And, if in further doubt, when a real human comes on the line, ask, "Do you agree?" If the answer is a spluttering 'Yes' then.... or if 'No' then say "Please review your recording of his call, and I'll wait on the line as you do that." And, listen to what happens; It's likely to be hilarious! ;-)

It is a dark room and I do not touch-type.

I do not presume that the satellits has been the other ageny of the USA government. ;-)

:-) I've been there, too. My first computer was an IBM 1130, with 8kB of 'ram'. From what I can tell, here, we have 0kB and all hard-wired to the devices attached to the receivers and transmitters. The satellite just 'talks' via the transmitter and Earth has to listen, or lose the data. That is "how it was" in 1978 (earlier for the finalisation of the design, and the satellite's set-up of the NSA Deep Space Network ground stations).