RE: ATM secondary holder

["Andersen, Clark R." <clanders@utmb.edu>]

As it appears that my notion of using wires to suspend the secondary was old
news, how about something a little more far out.  Since any obstruction
messes with the image, how about electromagnetically suspending & aligning
the secondary?  If this has been attempted, I'd be interested to hear about
it.  It seems to be feasible in terms of engineering, but may not be
practical.

Even more radical would be to use a network of intersecting infrared lasers
to generate a virtual secondary by distorting the refractive index of the
air in the tube... unfortunately, this would undoubtedly cause undesireable
image distortions.

I recall reading in Astronomy or S&T years ago about a group who used
differential heating of the air in a tube to create a refractive objective
... the pictures were a bit blurry around the the edges, but it worked.