From: "Geo" 

How do you get interference patterns with a disk shield?

Geo.

"Phil Payne"  wrote in
message news:44acbe29$1{at}w3.nls.net...
> > If the shade is any distance at all from the telescope it wouldn't need
to
> > be much larger than the lense on the scope.
>
> It's a shitload cleverer than that.  A distant enough object produces
light
> that can be treated in some ways as coherent.  The suggested bafflle lets
> the star's light through, but creates interference patterns.  The
> plant-seeking sensors are placed in an interference "trough".
>
> If my slipstick is correct, you could even tune for star diameter.  That
> would back up a whole load of other measurements.
>
> I haven't messed with interference patterns since I was the first person
in
> my school's history to show the split in the sodium line.
>
>

--- BBBS/NT v4.01 Flag-5