Re: [ATM] Telescope could focus light without a mirror or lens

["David Harbour" <stainless_steel@suddenlink.net>]

Mel wrote:

> This came up in an article reporting a proposal for an exoplanet resolving
> space telescope.
>
> In reviewing a couple of articles behind the zone plate, it looks like one
> needs millimeter control of the holes and rings.  The plate needs to be 
> held
> flat to the same magnitude as the critical focus zone: millimeter 
> resolution
> for longer focal ratios.  And for planets, solar and lunar imaging, 
> dumping
> 90% of the light is a blessing.
>
> There are examples of zonal plate photography on the web.
>
> Mel Bartels

My question for you, Mel, is how will we ever get one of those orbiting 
instruments up there, now- now that we are going to retire the shuttle 
operations right away, and the Lockheed Martin design for the next 
generation space transportation system will never be built? Their design is 
brilliant. I guess maybe we can hire the Chinese to put it up. ?!?!

Send them some more dollars, I guess. They have a major chunk of our 
dollars, I understand (oh, no- they sent them back for treasury bills)-

R-101


----- Original Message ----- 
From: "Mel Bartels" <mbartels@bbastrodesigns.com>
To: <atm@atmlist.net>
Sent: Saturday, May 03, 2008 12:45 AM
Subject: Re: [ATM] Telescope could focus light without a mirror or lens


>> Bob May wrote:
>> >
>> > All in all, something that is neat for doing crude optics with
>> > but not going to be used for astronomical purposes as it is not
>> > going to do the job.
>> The fine print I read had me thinking that the results were
>> strongly dependent on wavelength, perhaps as much as a singlet.
>
>
>
> This came up in an article reporting a proposal for an exoplanet resolving
> space telescope.
>
> In reviewing a couple of articles behind the zone plate, it looks like one
> needs millimeter control of the holes and rings.  The plate needs to be 
> held
> flat to the same magnitude as the critical focus zone: millimeter 
> resolution
> for longer focal ratios.  And for planets, solar and lunar imaging, 
> dumping
> 90% of the light is a blessing.
>
> There are examples of zonal plate photography on the web.
>
> Mel Bartels
>
>
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
> 


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