In reply to Richard McBrooom.
Anagram of “RICH RAD NEW SETI”:
“WIDEN THEIR ARCS”
https://wist.info/einstein-albert/5229/
As in “Hello” and “Welcome.”
Shadowing the two greetings:
Dark: “ELO”
Light: “WHELM C (as in speed of light)”
Sphinx O: “W (is) HELM CO”