Rich <someone@somewhere.com> writes:

Am I to understand that Berkely will pay for it's operation
and staffing? Do you know what they plan to use it for?

As I understand it, Berkeley will use it for radio astronomy,
to basically replace another radio telescope they had on the
site (which is moving away).

I understand that together Paul Allen and Nathan Myhrvold are
donating 12.5 million. That seems to be about half the $25 million
dollars you say it will cost. Where does the rest come from?

Paul Allen recently gave the other half, too (it was dependent
on meeting a bunch of milestones).  However, the costs have
increased somewhat (normal for big projects as you note) and the
SETI Institute has to cover the rest.

The total cost,
spread over about 5 years, is in the range of $25M. 
The next big public radio telescope (ALMA) is costing taxpayers 
about $50 million this year alone, and will take many years 
to complete, and will end up at least on order of magnitude 
more expensive.

And don't think I don't question these costs as well. But Alma
is partly funded by the the ESO and partly by the NSF. I've not
found what the split is.

The USA contribution for 2004 alone is 50.8 million dollars.

It seems very similar to the Allen Telescope.

There are a few differences, though they are both arrays.  
ALMA runs at higher frequencies (where
water vapor is a big problem) and hence requires a high, dry site.
It is following the conventional approach of big, hand-built
antennas (this makes some sense, since the high frequency
receivers of ALMA are expensive, so you want to minimize the
number).

The Allen array will end up costing less 
than 1/4 of the cost of the last radio telescope (Greenbank), 
which was built entirely with public funds.

We shall see. I've not noted that large projects tend to finish
on time and at the estimated cost. Perhaps SETI is immune from
this aspect of large projects, we shall see.

Very true.  But the initial cost of the Allen array was $26M, and
ALMA $552M.  So it starts at less than 5% of the cost of *one*
other publically funded radio telescope.  And they may both go
over budget by equal amounts - we'll see.

The total cost of the Allen Array will be less than 1/4 of
what NSF spends on new astronomy facilites *every year*.  
It is less than 1% of NASAs yearly expenditure on astronomy.
SETI is not a big project, even in the astronomy world.

NASA is another money pit.  

Note that the whole Allen array is about 1/5 the cost of the
smallest NASA mission (discovery mission).

And every once in a while, someone gets a brilliant idea 
and everything changes for the better.

The Allen telecope array, in many people's minds, is exactly
such an idea.  It's MUCH cheaper than any comparable telescope,
and for many purposes much more useful.

How does it compare to the ALMA? 

They run in different frequency ranges.  ALMA needs a high dry site,
the Allen array does not.  ALMA is a more or less conventional
design, optimized for high frequencies.  Allen is a radical design
running at lower frequencies, aiming for lower costs and higher
productivity.  It is trying 3 major departures from
existing radio telescopes:
  1) Dishes stamped out using an extension of satellite TV dish
     technology.
  2) Wideband feeds with low-cost, wide bandwidth pre-amps
  3) Full bandwidth transmission to the control center on 
     fiber optics.
Note that all these things make it cheap, and all of them make it
more useful.  Small dishes give a wide field of view.  Wideband
feeds and pre-amps, and full bandwidth transmission, allow
simultaneous observations at all frequencies, something no other
telescope can offer.

They say that the view is much better there. How is the situation
in Hat Creek WRT interference?

It looks OK.  The reason for Chile is high-and-dry, not low interference.
Since much of the interference is from satellites, Chile won't help
much in this regard anyway.

And who is driving this?
The SETI Institute, with private funds.

Well, you've already mentioned Berkeley, which is not a private
orginization. So unless I misunderstand something, this cannot be
totally true.

True, but Berkeley is already running a radio telescope on this site,
which they are closing down.  (It's a high frequency design and will
be moved to a high dry site, like ALMA, and combined with a similar
array from Caltech).  So Berkeley, a public institution, gets to use
a new radio telescope, paid for by private interests, to do radio
astronomy (which they are already using public money for). If you
believe it's OK to use public money for radio astronomy at all, this
is a very good deal for the taxpayer.  SETI money is helping a 
public institution do what it is already doing, only better.

    Lou Scheffer