[LEAPSECS] Schedule for success
seaman at noao.edu
Wed Dec 31 18:55:04 EST 2008
Just sitting here watching the Nixie tube page ticking along:
I have Hard Day's Night on the HD for a sound track. Somehow seemed
Dropped by our sysadmin's office earlier. He didn't look too
frantic. One reason (no irony intended) is that we rely on FreeBSD
for various critical infrastructure at the observatory.
On Dec 31, 2008, at 4:20 AM, Poul-Henning Kamp wrote:
> The FreeBSD kernel Warner and I have worked on for 15 years approaches
> 5 million lines of code.
Good job boys!
We do have systems in astronomy of that level of complexity,
including, for instance our widely distributed image processing
system, layered on a virtual operating system of complexity similar to
BSD. Its kernel has networking built in down to the bedrock - any
resource can be either local or remote. The exact same high level
source code runs not only on a wide swath of both BSD and Sys V
unixes, but also back in the day ran verbatim on VMS and Data General
OSes. There are very tricky bits in the VOS as well as vast numbers
of applications with clever algorithms.
Of more recent vintage, you might peruse various "virtual observatory"
projects around the globe. Just to point to something completely
different, I heartily recommend the Microsoft Research World Wide
Telescope and Google Sky.
> For comparison, the US navy touted the complexity of the Air
> craft carrier Ronald Reagan (CVN-76), by boasting that it was
> built from "more than one million individually tracked pieces".
Yes indeed. Management never quite seems to get the complexity of
software. You might query on "ALMA" and "LSST" for a sense for the
scale of some current projects.
On the other hand, note that those aircraft carrier pieces each have
equivalent complexity of much greater than the 5 lines of code implied
by an assertion of parity. (And of course, presumably include
hundreds or thousands of onboard computers.)
> Back when computers had just broken the 32 kilowords barrier, one
> of the greatest thinkers in computer science wrote:
Another appropriate quote from Dijkstra:
"Computer science is no more about computers than astronomy is about
> We have no way to upgrade our programmers, we can only make the
> task in front of them simpler.
One might reference the Mythical Man Month here, too.
> The fact that you cannot see the problem, does not make it a non-
> people like Warner and me have seen the problems, we know they are
Well, perhaps we haven't been clear enough that we do understand what
problem you are talking about. We just disagree about the solution.
> If you don't trust us, how about this:
> Judah Levine of the National Institute of Standards and
> Technology in Boulder, Colorado, which provides the time
> standard and technical support for most commercial activities
> in the US is braced for New Year's Eve. "On December 31,
> I'll be waiting with a cup of coffee for the problems to
> roll in," he sighs.
Yeah, I didn't think much of that article.
For those that dig back to the depths of the archives of this list and
prior discussions, I should mention that it was Levine who kickstarted
the interest of the astronomical software community in this issue. JL
contacted an astronomer in northern Arizona, who contacted the
National Observatory in southern Arizona. It naturally wended its way
to my desk. I believe this was the first public message:
Just a reminiscence as we close out another year.
Happy New Year!
Back to watching the clock.
More information about the LEAPSECS