| Thursday,
August 26, 2010 Musing
on science
It continues hot in Los Angeles. There's a dinner tonight, and some other
stuff so it's taking a while to catch up.
Meanwhile, one of the more interesting things to think about is the
possible relationship of radiation decay rates to the Sun. From Rutherford's
decrees on we have "known" that radiation decay rates are constant. For any
given isotope there is a probability that it will decay and emit radiation.
There are several kinds of radioactive decay. It's a bit more complicated
now than it was when I was in high school physics, but the essentials are
the same. The major kinds of radiation are alpha particles -- which are
helium nuclei, two protons and two neutrons; beta decay, in which a neutron
breaks up into a proton and an electron (and an anti-neutrino); and gamma
decay in which things break up and emit x-rays. There are other kinds of
radiation discovered more recently. In all cases, though, Rutherford's
dictum was that the amount of radiation is dependent only on the number of
atoms of the radiating stuff. Over time more atoms pop and do their
emissions, so there are fewer of them left to pop, so the total radiation
decreases.
We generally express this in "half life": the time it takes for half the
radiation in a sample to be emitted, which is to say the time it takes for
half the atoms to pop. There are a lot of theories on why a given atom pops
when it does, but none I know of that "explains" it, and certainly none that
will let you predict when a given atom will pop; that's a random process.
This is mostly confirmed by observation, but there are exceptions. Long
term observations of the emissions of some substances like silicon-32 (half
life 172 years) show something very strange: the radiation emitted certainly
adds up to that expected by a half life of 172 years, but there is seasonal
cycle, a wobble, with radioactive output peaking when the Earth is at
perihelion and at minimum when the Earth is as aphelion. The closer we are
to the Sun, the more radioactive output. The variation is fairly small, but
it's there. There are observations of other periodic radiation, some in
periods of 7 seconds. Since no one has been looking for any such thing,
there's no predicting what else may be found on closer observation.
Understand that it's not easy to observe this. The variations are fairly
small compared to the total radiation (which continues to conform to what's
predicted by Rutherford's uniform decay rate if you look at longer time
periods). You can't study this in stuff with half lives in the millions of
years because the total decay is tiny and the variations would be invisible.
It's hard to study it in stuff with short half lives because it doesn't last
long enough to go through the cycles. You need stuff with half lives in the
order of a century, it needs to be pure, and you need to look at it and
record the output continuously. Until recently that hasn't much been done.
If proximity to the Sun affects radioactive decay, then presumably so
does solar activity. A lot of the Earth's interior is radioactive stuff and
its decay is what heats the Earth's interior. Apparently this is another
possible coupling of the Sun to Earth temperature. How powerful this
influence can be isn't known to me, and so far I haven't found anyone
studying it. Perhaps it is not a large enough variation to put into the
climate models. On the other hand, we know that climate seemed to be
different during the Maunder Minimum (1645 - 1750) when there was very
little solar activity (few to no sunspots). We don't have much of a sunspot
count before that when the Little Ice Age was forming; but the Maunder
Minimum happened during the middle of the Little Ice Age. In 1709 the Rhine
froze and wasn't navigable until Summer. Many in Europe starved. After about
1715 sunspot counts rose, and so did temperatures. Whether that has any
causal relationship is a matter of debate.
The acceptance of ignorance over what causes radioactive decay has
annoyed a number of theoretical physicists. "It just happens that way" isn't
very good theory, but our understanding of nuclear forces doesn't really
give a better hypothesis. Attempts to quantify and understand nuclear forces
including the "strong nuclear" force have resulted in a number of theories,
and as I understand it are being revised again in terms of field theories.
Let me hasten to say that my understanding is minimal. I wasn't all that
interested in nuclear forces in my undergraduate physics courses. and the
theory wasn't all that good in those days anyway. What I did learn was that
we can't predict when a given atom will pop because we don't really know why
it pops. I don't think that has changed much.
It does seem to me that if something as fundamental as nuclear decay can
be influenced by solar radiation, this is a significant discovery. Whether
it has implications for climate science I don't know, but since climate
science has no real predictive power and doesn't seem able to explain things
like the Ice Ages in any detail, it may be interesting. Ben Franklin
postulated volcanoes shading the Earth could have great cooling effects and
cause it to be cold. I'm not sure we have got a lot further than that, and I
doubt that's the explanation for the 200,000 year Ice Age cycles. Note that
we are in a temporary warm period in the middle of a big Ice Age. Our
temporary warming period is about to run out; the best prediction from past
cycles is that the ice will come back. That fear was all the rage when I
first began writing science fact columns back in the last millennium.
The significance here is that the Rutherford dictum was about as accepted
as anything in science ever can be. Now it appears to be in doubt. Science
remains exciting, because there's so much we don't know -- but we could find
out. If we keep looking.
===============
I have several messages critical of the Space Access
Society because it doesn't want to abolish NASA. That seems naive. There is
a case for public investment in space; the question is how that should be
done. I have always been in favor of X=Projects and Prizes, both of which
NASA can do. Space research facilities are expensive; NASA has them; we have
a model of governent cooperation with airplane companies during the
development of the aviation industry.
NASA has been a good part of the problem and the Standing Army has been
one of the major factors; but NASA has done some wonders. It has good people
as well as bureaucrats. I'd rather money went to NASA than the Department of
Education. In 1980 Larry Niven and Art Dula wrote a paper called "How to
Save Civilization and Make a Little Money" for the first Citizen's Advisory
Council report. It got critiqued by everyone at the meeting and was
rewritten and was part of the Council Report. It gave a good basis for a
commercial space policy (Mr. Heinlein was one of those in attendance) and
parts of that paper were incorporated into the Commercial Space Act. There
are many ways that NASA can be of great benefit to the nation. We need real
climate observation data. We need weather observations.
I've been one of NASA's most stringent critics -- I am told that when the
rumor went around that I was going to be appointed Administrator there was
sheer terror at NASA headquarters -- but I am no advocate of leaving
research and development vital to the future of the human race entirely to
commercial forces. It is the duty of government to look into the far future
long past the time when you can predict return on investments.
I've explained all this in two papers; they are quite old, but the
principles have not changed. See
Why Have NASA?, and
How To Get To Space.
=============
I found this interesting:
http://news.cnet.com/8301-11128_3-
20014393-54.html?tag=nl.e703 It's a tour of the electric grid and I
found it informative.
==============
Two moons on 27th August 2010
cid:1.183102900@web51001.mail.re2.yahoo.com
27th Aug the Whole World is waiting
for......... ....
Planet Mars will be the brightest in the
night sky starting August.
It will look as large as the full moon to the
naked eye.
This will cultivate on Aug. 27 when Mars
comes within
34.65M miles off earth. Be sure to watch the
sky on
Aug. 27 12:30 am.
It will look like the earth has 2 moons.
(I suppose I ought to have explained: nothing can possibly
be brighter than the full moon except the Sun. Mars doesn't get brighter
than about magnitude -2.9, while Venus gets to about -4. The full Moon is
about -13 at it's brightest. I don't know why included this other than
whim. Please don't go out looking for two full moons...)
I think I must have been distracted by a phone call while I
was looking for stuff to put up here and this didn't register.
====================
The newer GSM-based Kindles *do in fact* have a
telephone number - that's how they work on the 3G network.
Go to a GSM-based Kindle's Settings screen, and
then type '611' - you'll get all kinds of information (four pages of it),
including the telephone number of the GSM Kindle.
You can try and register it on the MicroCell
and see if it works . . . AT&T may disallow the phone number ranges they've
allocated for the GSM Kindles, but it's worth a shot, if you've access to
one of the newer GSM-based Kindles.
---- -
Roland Dobbins
That I will have to try. Thanks!
===============
If this one doesn't bring tears, we are DEAD!
Click Here <http://www.youtube.com/watch_popup?v=KTb6qdPu8JE>
You may also find this interesting. The letter is at the link:
A Letter to President Obama
A link to Snopes (your favorite folks) -
Did a from nonagenarian World War II veteran write
a letter criticizing President Obama?
snopes.com: Letter to President Obama - Harold
Estes <http://shar.es/0boCA>
Ed
===================
A civil service worker
proposes a corollary
to the Iron Law.
=================
New Global Model for
Climate Change Research Announced
"Scientists can now study climate change in
far more detail with powerful new computer software released by the
National Center for Atmospheric Research (NCAR) in Boulder, CO. The
Community Earth System Model (CESM) will be one of the primary climate
models used for the next assessment by the Intergovernmental Panel on
Climate Change (IPCC)."
http://www.scientificcomputing.com/
news-DA-New-Global-Model-for-Climate-
Change-Research-082010.aspx
They say it takes a lot more things into
account, and that the model itself will be freely available to all
researchers worldwide. And they are trying to make the models match the
actual data.
"Using the CESM, researchers now can simulate
the interaction of marine ecosystems with greenhouse gases; the climatic
influence of ozone, dust, and other atmospheric chemicals; the cycling of
carbon through the atmosphere, oceans, and land surfaces; and the
influence of greenhouse gases on the upper atmosphere. In addition, an
entirely new representation of atmospheric processes in CESM will allow
researchers to pursue a much wider variety of applications, including
studies of air quality and biogeochemical feedback mechanisms."
I will be much interested in whatever comes of this. My expectations
remain low.
And I have posted a lot of mail
over in mail today.
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