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Re: problems with beaming

To Lee,

>>In this case something like far ultra violet or Rontgen waves may decrease
>>the size of the aperture by a thousandfold (compared to visible light). 
>>Do you know if there are lasers that can transmit EM-radiation with these
>Yes, we have produced lasing reactions all the way up and into the x-ray bands.

Then that would decrease the problems significantly, the only thing that may
be more difficult is the reflection (I'm not sure which materials can
reflect X-rays well).

Why is it necessary for the beam to be in phase? Does that have to do with
interference in the beam?

>Besides the obvious advantage of not needing to build HUGE single antennas,
>there are other benefits. For instance, a phase array is "steerable". That
>is, the beam can be moved several degrees in any direction without physical
>movement of the antenna itself.

Steering, now I'm really interested, how is that done?

>For instance, Kelly's problem with beam
>"jitter" may be solved by coupling a feedback loop from the starship,
>intelligent prediction software and beam steering on a phased array to
>reduce or remove the problem.

The problem is that the feedback may take upto 10 ly (for deceleration), any
prediction would probably be meaningless.

>Actually it is 2 of these ~ above each other and is normally taken to mean
>"approximate", unfortuneately, there is no way to write this in ASCII unless
>you write ~~ which I believe has a different meaning.

Ah, now it makes sense.