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10/26/2005
A Light Potpourri
[Bortrum is on vacation and will return Nov. 9]
By the time this column is posted, I hope that my wife and I are
relaxing comfortably on a cruise ship on the Pacific headed for
the Panama Canal. Not being as experienced as our peripatetic
editor, Brian Trumbore, with shipboard Internet facilities and
computer access, I decided to “prerecord” this column for
posting while I’m out of town. Under the gun of time
constraints, I also decided to make this column a potpourri of
items on the lighter side. As this was written, on October 13, we
needed some light, not having seen the sun for at least 8 days of
record rainfall for our area of New Jersey/New York.
One of my favorite subjects over the years has been the behavior
of certain insects such as the honeybee. Mention the honeybee
and a name that immediately comes to mind is that of Nobel
laureate Karl Von Frisch. You may recall that Von Frisch is the
one who championed the idea that honeybees that find a source
of food return to the hive to tell their fellow workers about their
find. They do this by performing the so-called “waggle dance”.
There have been numerous studies indicating that the waggle
dance conveys considerable information about the source of the
food so that the other bees can go out in force and harvest it.
As with any significant discovery, there are those who question
the validity of the work or its conclusions. In the Autumn 2000
issue of Chemistry, an American Chemical Society publication,
its “Newsblast” column has an item describing research that
should answer the skeptics of the waggle dance. Some skeptics
suggested that the worker bees may just follow odors emitted by
the dancer or simply follow the dancer back to the food source.
Joseph Riley and his co-workers at Rothamsted Research in the
UK have used radar to lay such arguments to rest.
The British workers managed to single out the dancers from the
“spectators” in the hive. After the waggle dance, the spectators
became “recruits” and the researchers nabbed the recruits as they
were leaving the hive. Somehow, they caught the recruits and
attached little radar transponders on these bees. There was a
picture with the article showing a bee with an antenna as long as
the bee sticking up from its neck or head area. I’m not sure
whether this was an actual picture or an artist’s conception but
the bee certainly looked weird with this fixture attached.
After the device was attached, the radar showed that the bees
flew off in the direction of the food source, leaving the dancer
back in the hive. In another experiment, the recruits were taken
to a different location and they took off in the direction that
would have been the right direction had they not been moved.
These rather novel experiments seem to me to be clear evidence
that the waggling dancer does indeed communicate specific
information in the dance. Von Frisch remains at the top of the
heap in my book.
Switching gears, this is playoff season in the baseball world. In
my younger days, I was as rabid a baseball fan as anyone,
cheering on the last place Philadelphia Athletics and then the last
place Pittsburgh Pirates. A former Yankee hater, over the past
decade I’ve grown to like them, possibly due to a need to finally
cheer for a winner. Actually, these days, I only become
interested as playoffs approach, when I finally watch a few
games. I admit that I haven’t figured out the higher mathematics
involved in choosing the “wild card” teams and long for the old
days when there were eight teams in two leagues and only one
playoff, the World Series, played in daylight.
One thing I’ve noticed over the years is the laudable and more
healthful tendency of many players to give up spitting tobacco
juice in favor of chewing bubble gum. The other night, before
the Yanks were eliminated, I saw Derek Jeter blow a particularly
impressive bubble. However, ballplayers blowing bubbles just
doesn’t seem like a very macho thing to do. The problem is that
ballplayers aren’t the only ones chewing gum. According to
another item in the same Chemistry Newsblast column, chewing
gum sales have gone up 27 percent in the past five years.
I suspect this is not the case in Singapore, which banned chewing
gum years ago. The problem, of course, is not the chewing, but
the disposal of the product after usage. Who knows how much
time and money is spent cleaning up spent gum from streets,
sidewalks and theaters or under desks in schools? Packaging
gum as tablets gets rid of the disposal of gum wrappers but
doesn’t address the sticky issue.
There is hope for a solution, however, in the form of a
biodegradable chewing gum. The Wm. Wrigley Jr. Company
got a patent earlier this year on such a gum based on a protein
found in corn. Polyester provides softness in this gum. Some of
us remember the days when polyester suits were all the rage.
Now we’re going to chew the stuff? The Wrigley biodegradable
gum becomes brittle after use and is easier to clean up, a step in
the right direction at least. Workers at the University of Illinois
at Urbana-Champaign are also working on a biodegradable gum
based on a corn protein. Corn farmers should be riding high with
ethanol derived from corn being pushed as a fuel for our cars and
now possibly for chewing gum!
Finally, let’s turn from big globs of sticky gum to the thinnest
crystals, only one atom thick. An item by Stu Borman in the
August 1 issue of Chemical and Engineering News (C&EN)
mentions the work of Andre Geim and co-workers at the
University of Manchester in England. One of the materials they
worked with was graphite. We’ve talked a number of times
about graphite and how it is a layered material. The carbon
atoms in the layers are arranged in hexagons like in a beehive or
perhaps more like a sheet of chicken wire. Graphite is like a
deck of cards in that each layer is held very weakly to the
neighboring layers. This is why the graphite in your pencil slides
off in layers so easily onto your tablet or notepaper.
So, how would you try to make the thinnest possible crystal of
graphite, a layer just one atom thick? According to the C&EN
article, the Brits used the same technique you use when writing
with the pencil – rub the graphite against a surface. To be sure
that they had layers that were only one atom thick they used
various high-powered modern techniques of scanning electron
and atomic force microscopy. The article had pictures of single
atom thick crystals of several materials including graphite and a
compound of niobium and selenium, NbSe2, another layered
compound with which I am quite familiar.
I transferred into the Battery Development Department at Bell
Labs in 1972 to work on NbSe2 as an electrode material for
lithium batteries. In the course of preparing NbSe2, I found
another material, NbSe3, which turned out to have much better
performance in lithium batteries. Over the next 17 years, we
developed the then best rechargeable lithium battery in the world
using NbSe3 in a roller coaster ride that saw us beaten out by the
Japanese and their lithium-ion battery.
But I digress. On the University of Manchester Web site, Geim
and one of his co-workers, Kostya Novoselov, are quoted as
being very enthusiastic about the future for these single atom
thick crystals. They envision ultra-fast transistors, applications
in everything from clothing to computers and who knows what.
Whatever the applications, it will require a lot of work before the
manufacture and handling of such super-thin objects is under
control. I said in the beginning that the topics would be on the
lighter side. You can’t get much lighter than one atom thick!
Allen F. Bortrum
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