What's New Robert L. Park 6 Aug 2010

WHAT=92S NEW   Robert L. Park   Friday, 6 Aug 10   Washington, DC

1. KEPLER MISSION:  MANY PLANETS -- STILL ONLY ONE EARTH.
As the 20th century approached its end, the age-old speculation that=20
planets must orbit other suns was confirmed by wobble in the position of=20
Gamma Cephi.  Whose pulse did not quicken at the discovery?  Any doubts=20
about the interpretation were swept away in 1999 when HD 209458 d was=20
directly observed transiting the disc of its parent star.  It was time fo=
r=20
the Discovery Program, Dan Goldin's vision of "faster, cheaper, better"=20
missions focused on specific goals.   Kepler uses a photometer to=20
continuously monitor the brightness of over 145,000 main sequence stars i=
n=20
a fixed field of view. The data is analyzed to detect periodic fluctuatio=
ns=20
from planets transiting the disc of the star. So what have they found?=20
According to an essay by Dennis Overbye in the New York Times on Tuesday,=
=20
there was great excitement a couple of weeks ago when Dimitar Sasselov of=
=20
Harvard announced at a TED conference in Oxford, UK that 140 earthlike=20
planets have been found in one small patch of sky. In fact, many planets=20
have been found, but so far not one is earthlike.  Of course, it was all=20
over the web. The Web puts all of the world's knowledge at our fingertips=
;=20
unfortunately it=92s mixed with all of the world=92s bullshit. =20

2. FERMI PARADOX: WHERE ARE ALL THE SPACE ALIENS?
The question of whether we are alone gnaws at us.  In 1950, in a discussi=
on=20
of whether advanced civilizations might exist elsewhere in the Milky Way=20
galaxy, Enrico Fermi famously asked, "Where are they?" This has come to b=
e=20
known as the Fermi paradox.  If planets are a common feature of stars, th=
e=20
naturalistic assumption would be that life exists throughout the Milky Wa=
y=20
galaxy.  Sentient beings with the capacity to develop advanced technologi=
es=20
would be expected to evolve.  Implicit in Fermi=92s question was an=20
assumption that advanced technologies would be capable of interstellar=20
travel.  Where are they?  At home, as we are.  Interstellar distances are=
=20
too great.  Travel time is not the principal obstacle.  The barrier is th=
e=20
energy it would take to accelerate a spacecraft to a reasonable fraction =
of=20
the speed of light.  I hope that's the end of the Fermi paradox, and the=20
Dyson sphere, and all that science fiction crap.

3. GLOBAL WARMING: ARCTIC THAW GENERATES POSITIVE FEEDBACK.
Stable systems all rely on negative feedback to keep them that way. As th=
e=20
Arctic Ocean warms, however, methane produced by organic decay bubbles up=
=20
from the seabed. Vast areas of permafrost will release large amounts of=20
methane as they thaw (WN 4 Sep 09). Methane is a powerful greenhouse gas,=
=20
25 times more powerful than CO2.  This is positive feedback, like putting=
 a=20
microphone in front of the speaker. It can be unpleasant.

4. FEEDING THE WORLD:  CAN THERE BE ANOTHER GREEN REVOLUTION?=20
No!  Norman Borlaug was not some organic farmer. High-yield agriculture=20
demands more machinery, fossil fuel, fertilizer, and water, as well as=20
transportation from where food is produced to where it's needed. =20

THE UNIVERSITY OF MARYLAND.
Opinions are the author's and not necessarily shared by the
University of Maryland, but they should be.
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