Richard Clark wrote:
"Well, given the tremendous correspondence that attended the other
threads, dare I pause to offer something from the realm of the real?"

If you don`t want an EM reflection in space, the possible reflecting
object must be indistinguishable from space. It must have a resistive
characteristic impedance of 377 ohms.

377 ohms per square material spaced 1/4-wave from a reflective surface
for the purpose of completely absorbing a normally incident wave was
invented by Stanfield Salisbury at the Harvard Radio Research Laboratory
during WW-2, according to the 3rd edition of Kraus` "Antennas" on page
909, attenuation is at least 20 dB for the reflection and the bandwidth
is 1.3 to 1. Kraus gives a transmission line equivalent diagram on page
910.

Kraus derives the 377 ohms of free space on page 131. The reflecting
surface does not need to be zero or infinity ohms. The exposed surface
must be transformed to 377 ohms from whatever the underlaying surface
is.

The 377-ohm carbin cloth shown by Kraus is named Salisbury screen for
its inventor. It is placed 1/4-wavelength from the reflective surface.
The small amount of energy penetrating the screen undergoes 180-degrees
of delay in makind a round trip to the reflective surface and back to
the carbon screen. It undergoes an additional 180-degrees of delay in
peflection. The 360-degree total puts the reflected energy back in-phase
with the penetrating energy. This makes a high impedance.

A high impedance in parallel with 377 ohms leaves the 377 ohms
unchanged. It continues to match the incident energy and continues to
take a bite out of the reflected energy between the two surfaces.

Stealth aircraft, antenna laboratory. or non-reflective glass must look
like 377 ohms.

Best regards, Richard Harrison, KB5WZI