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06/26/2001
Stars and Starstuff
We''re fortunate to have in our area of New Jersey a jewel, the
Paper Mill Playhouse. Last month, the production was an
outstanding "Funny Girl", with Leslie Kritzer in the role of
Fanny Brice. I had never heard of Ms. Kritzer but left the theater
feeling that I had seen the next superstar of the theater. This
young lady combined the comedic talent of a Carol Burnett with
a voice like Streisand''s. I had the same feeling when I first saw
and heard an unfamiliar tenor in "Carmen" at the Metropolitan
Opera in New York. I told my wife, "That guy is really good!"
His name was Placido Domingo. Am I a judge of talent or what?
For several days now, I haven''t been able to get the Rogers and
Hammerstein music from "Carousel" out of my head. It was
another spectacular production at the Paper Mill. This time it
was not a rising star that engaged my attention but rather one
who is a setting star - Eddie Bracken. Bracken''s stage and film
career spans some 70 or 80 years. It was Bracken''s voice that
came over the public address system just prior to the curtain
urging the audience to turn off those cell phones, unwrap that
mint or candy now, etc. At 80 to 85 years of age (depending on
where you look on the Web), Bracken turned in his unparalleled
15,000th performance on stage during this run of "Carousel".
His dual roles in the play included that of the Starkeeper. For
those unfamiliar with the play, the Starkeeper sits on a bench
suspended in the sky polishing the stars that hang there. He also
interviews prospective candidates, in this case the recently
deceased Billy Bigelow, for entry into Heaven via the "mother-
of-pearly" back gate. Frankly, I wouldn''t feel secure sitting on
that bench above the stage suspended by a couple of wires but
Bracken looked totally comfortable in the role.
Seeing these stars in their stellar roles prompted me to look for
some material relevant to other kinds of stars for this week''s
column. Ok, I was desperate for some kind of hook to grab your
attention. A couple of brief items in the July 2001 issue of
Discover magazine caught my eye. Both deal with what goes on
out in interstellar space. Over twenty years ago, little round
globules were found in so-called carbonaceous meteorites.
Carbonaceous meteorites are thought to have been formed
billions of years of years ago and reflect the original composition
of the material forming our solar system. The little balls were
about the size of living cells and, though certainly not themselves
alive, gave rise to the speculation that they might have been the
host into which other organic compounds migrated, eventually
forming RNA or DNA. In other words, the speculation is that
these little globules were key in the formation of life on earth.
Recently, at NASA''s Ames Research Center at Moffett Field in
California, a team of researchers led by Louis Allamandola did
some experiments in which they tried to mimic conditions
existing in the gas clouds in space around the time our sun came
into being. They bombarded a mixture of frozen water,
methanol, ammonia and carbon monoxide ices with the kind of
radiation you might expect from hot young stars. A couple
percent of the mixture reacted to form an oily organic material.
When the oily stuff was added to water, the oily stuff formed
multiwalled globules of the size similar to that of living cells.
Some of these globules also converted ultraviolet light into
visible light; that is, they glowed when placed under ultraviolet
illumination. Such cell-like structures could have served to
protect self-replicating molecules doing their thing inside the
membranes of the globules. The conversion of the high-energy
UV light to the lower energy visible light could have provided
the energy to keep the chemistry going. Allamandola concludes
that the experiment suggests that the kinds of molecules required
for life exist throughout the universe.
I remember watching one of the late Carl Sagan''s TV programs
many years ago and listening to him say that we are all made of
the stuff of stars. I don''t recall ever thinking about or knowing
that to be the case before watching that program. I had always
been interested in astronomy but that program sparked a renewed
interest in the subject. Along these lines, there was another brief
article in the same issue of Discover by Kathy Svitil, also the
author of the other article. In the second article, she quotes
astrophysicist Stephan Rosswog of the University of Leicester on
the origin of gold and platinum. We consider gold and platinum
to be pretty special elements and I daresay that many of you have
some kind of gold adornment on your person as you read this.
You should consider that gold is indeed a pretty exotic metal if
Rosswog is correct in his idea of the origin of such noble metals.
A star such as our sun can form a number of different elements in
the process of the nuclear fusion that drives it. The most obvious
is helium, the product of fusing hydrogen nuclei and the reason
we''re all here. Further nuclear reactions in a star can produce
light elements such as carbon and oxygen. However, conditions
aren''t ripe for forming heavy elements such as gold or platinum.
It takes a bit more than a piddly star like our sun to do that.
We''ve talked in earlier columns about neutron stars. These are
formed when stars of a certain size are at the end of their sun-like
fusion career. They may expand and blow off some of their
mass, but gravity takes over what''s left collapses to form a
superdense object that, as the Discover article puts it, can pack
the mass of half a million earths into the size of Manhattan.
These neutron stars are heavy suckers! And they''re not very big.
Because of their size, it''s not all that likely that one will bump
into another in the vastness of interstellar space. However, in a
galaxy like our Milky Way there''s a finite chance that a couple of
neutron stars will come close enough that their gravitational
attraction (remember, they''re superheavy) will lead them into
orbiting around each other. Gradually, they spiral in towards
each other and eventually come together. It may take a hundred
million years!
Things get really hot and heavy when the two stars are only
about 60 miles apart. Rosswog and his colleagues have run
computer simulations of the next fraction of a second before they
actually merge. In the last few milliseconds, the energy released
will be prodigious, outshining anything else in the universe. Most
of the stuff in the two stars will disappear into a black hole. But,
in those last few milliseconds before that happens, a fair amount
spews out in the form of superhot neutrons and nuclei of various
atoms. It is in this superhot mess that the atomic nuclei grab
onto all those neutrons dying to be part of an atom. Voila!
There are your heavy elements like gold and platinum. The less
glamorous element lead is one of the other heavy elements that
are formed. These metal atoms go flying out into space and
some of them become part of the debris or dust surrounding a
star and eventually gets incorporated into a planet such as earth.
How often do these weddings between a couple of neutron stars
take place? In your run of the mill galaxy, there''s one such gala
event about every hundred thousand years. And, according to
the Discover article, that''s enough to have supplied all the
precious metals here on earth. So take off that gold ring or pin
and gaze at it with a little respect. That gold has traveled a very
long and interesting route before it became incorporated into the
little speck of a planet we call home. I imagine its journey from
the depths of the earth up near the surface to be harvested wasn''t
all that dull either!
Allen F. Bortrum
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