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08/29/2000
Close Calls
In only a few more years, in 2008 to be exact, we will celebrate
the 100th and 50th anniversary of two "nuclear" events. The first
is the birth of Edward Teller in Hungary on January 15, 1908.
Teller had a close call when he was a student in Munich. He was
run over by a streetcar but escaped with his life, albeit without
his right foot. Later, he moved to the United States, became an
American citizen and joined the Manhattan Project. As part of
the team of brilliant scientists at Los Alamos headed by J. Robert
Oppenheimer, Teller contributed to the development of the
atomic bomb. Today, we hear a lot about the security of our
nuclear secrets what with missing computers and possible
leaking of classified information. In Teller''s time at Los Alamos,
secrecy was of the utmost importance but at the same time it was
the subject of some humorous episodes.
One of Teller''s colleagues at Los Alamos was Richard Feynman,
later a Nobel Prize winner for his contributions in theoretical
physics. Feynman was not your everyday theoretical physicist
but also an outrageous sort given to such sports as bongo
drumming and safecracking! He particularly enjoyed cracking
safes and picking locks at Los Alamos. In his book "Surely
You''re Joking, Mr. Feynman", he describes a meeting at Los
Alamos during which he explained how easy it was to pick locks
and suggested that his colleagues should pay more attention to
security. Teller said that he kept his papers in his desk drawer
and considered that more secure than storing them in his file
cabinet. Feynman stole out of the meeting, reached under
Teller''s desk and easily pulled out all the papers from Teller''s
drawer before sneaking back into the meeting. After the
meeting, Feynman asked Teller to show him the contents of his
drawer and Teller remarked that he''d be glad to, if Feynman
hadn''t already seen them for himself. Feynman complained that
the very intelligent Teller spotted trouble too quickly and
understood it so fast that a perpetrator didn''t have time to enjoy
his shenanigans. Feynman, incidentally, was probably better
known to the general public for his later role in pointing out the
O-ring problem that led to the Challenger space shuttle disaster.
Whoops, I forgot to mention the nature of the 50th anniversary
that we''ll celebrate in 2008. This, of course, is the dropping of
the atomic bomb on the homestead of the Gregg family of Mars
Bluff, South Carolina on March 11, 1958. Talk about close calls.
A cousin Ella and two of the Gregg sisters were playing in their
playhouse built for them by their father, Walter Gregg. The three
girls, all under the age of 10, got bored and went outside to play
in the yard a couple hundred feet away. It was only some 19
minutes later that a U.S. Force B47E bomber dropped its A-
bomb in the woods near the playhouse. The result was a 50-foot
wide, 35-foot deep crater, a demolished playhouse, an unlivable
house, a totaled car, etc. Fortunately, although all 5 members of
the Gregg family and Cousin Ella were injured, the injuries were
slight. Ella, however, required 31 stitches to repair her wounds.
This obscure incident in our nuclear history was certainly
unknown to me until I read a most interesting article by Clark
Rumrill in the September issue of the American Heritage. Some
have speculated that Edward Teller was the model for Dr.
Strangelove in that classic movie of the same name. Others
thought it was Henry Kissinger but most likely, it was a nuclear
strategist named Herman Kahn. Whatever the case, it seems that,
in the skies over Mars Bluff, we almost had an incident
reminiscent of the final scene in the movie where a fellow is
literally riding the falling bomb on his and its trip to oblivion.
To understand the Mars Bluff incident, we have to delve a bit
into the construction of the atomic bomb and how it was fastened
in the bomb bay of the bomber. First, the atom bomb requires a
high-explosive "trigger". The purpose of this trigger is to push,
quite forcefully, the contents of the nuclear core close enough
together to form the so-called critical mass necessary to initiate
the atomic explosion. In 1958, this explosive trigger was set off
by concussion, as when the bomb hit the ground. Second, in
those days the bomb itself was held in place in the bomb bay by
two mechanisms. One was a simple steel locking pin that was
inserted or removed by hand. When the locking pin was in place
you could not drop your bomb. When the locking pin was not
inserted, you could drop your bomb immediately. For some
reason, the rule was that the pin had to be out on takeoffs and
landings.
The stage was set. The bomber took off from an Air Force base
in Georgia, headed for England on a long training mission. After
takeoff, the copilot turned in his seat and tried repeatedly to work
the lever to reinsert the locking pin. The pin would not go in and
the plane was at 15,000 feet, apparently in formation with three
other planes. This was an unacceptable situation and the
bombardier, Captain Bruce Kulka, was dispatched to the bomb
bay to deal with the problem. This was not a job for the
fainthearted! For one thing, the bomb bay wasn''t pressurized and
the crew had to go on oxygen at 15,000 feet. For Capt. Kulka,
there was the added complication. He couldn''t wear his
parachute because the bomb bay entrance was too small to
accommodate that safety device. Not only that, but Kulka didn''t
know where the locking pin was located. In trying to find the
pin, he decided to pull himself up to look around but his
handhold proved to be the emergency bomb-release gadget!
Well, the bomb dropped in the bay with Kulka straddling the
bomb just like in Dr. Strangelove! The 7,600-pound bomb
paused momentarily, giving Kulka a chance to grab a bag of
some sort before the bomb broke through the bomb bay doors
headed for the Greggs. When the bag also fell away, Kulka
grabbed something else and managed to stay in the plane.
At this point, you may be wondering, "Why wasn''t there an
atomic explosion, with its mushroom cloud?" Well, it seems that
in peacetime the nuclear core was (is, hopefully) stored
elsewhere in the plane and only gets dumped into the bomb when
intended for use in the ultimate worst scenario. The Greggs were
fortunate indeed. The Mars Bluff experience led to a number of
other reassuring changes in the bomb design and procedures. For
example, the explosive trigger was redone to go off, not on
concussion but only when activated by a specific electrical
signal. The regulations were also revised to require that the
locking pin be inserted at all times, takeoffs and landings
included.
The American Heritage article pointed out that the media
coverage of the story of the bombing of South Carolina by our
own military was, by today''s standards, almost a nonevent.
Apparently, within a scant three days, the story had virtually
disappeared from the press. The author of the article speculated
about the coverage such a story would receive today. I suspect it
would get considerably more than three days, although certainly
not as much coverage as the Survivor!
Back to Dr. Teller. I saw him interviewed a couple weeks ago on
the CBS program Sunday Morning. At age 92, Teller is still
active and quite forceful in expressing his views. Teller, of
course, is best known as the "father" of the hydrogen bomb,
arguing that it was necessary for us to develop it to beat the
USSR to the punch. As a result of his views, he was severely
criticized by many, including J. Robert Oppenheimer, who not
only thought it immoral but also thought it impossible to make
such a bomb. Harry Truman''s decision to follow Teller''s advice
and go ahead with the Super, as the hydrogen bomb was known,
was one of the many momentous decisions he faced. David
McCullough''s biography "Truman" includes a fascinating
account of the complex internal and international events playing
out while Truman agonized over whether or not to develop the
H-bomb.
Teller was also influential in persuading Ronald Reagan to
initiate the "Star Wars" missile defense effort. While the
feasibility of such a system remains the subject of heated debate
today, some historians have been moved to credit the USSR''s
conclusion that they could not match our expenditures on Star
Wars as an important factor in the ending of the Cold War.
Teller, in his interview on Sunday Morning, was asked how he
wanted to be remembered and his reply was to the effect that he
wished the controversies would be forgotten. He hoped rather to
be remembered for his contributions to science. Actually, his
name is associated with something far removed from the exotic
world of nuclear explosions and the mushroom cloud. This is
something known as the Brunauer-Emmett-Teller, or BET
isotherm, an equation published in the Journal of the American
Chemical Society in 1938. I won''t burden you with the actual
equation but will discuss its most important application.
Let''s say we have a sample of a powdered material or a bunch of
porous particles. It turns out that the BET equation, despite some
failings, gives a good indication of the amount of gas needed to
cover the surfaces of the particles completely with a single layer
of molecules of the gas in question. What you do is make certain
measurements of the gas pressure and the amount of gas picked
up by the sample under different conditions and feed the data
into the BET equation. Once you know the amount of gas to
form the single layer, called a monolayer, you can calculate the
surface area of the sample. There are many times in science and
technology when you want to know the actual surface area. This
is particularly true if you''re working in the field of catalysis. The
efficiencies of catalysts such as those used to control the
emissions in your automobile depend critically on having a large
surface area.
If you''ve read my column on corn smut, you know of my
fascination with fungi. Would you believe that in searching the
Web, I found that the BET isotherm is being used to study the
fundamentals of drying mushrooms? Mushrooms are a pretty
perishable item and must be processed or eaten within 4 or 5
days after being harvested. Air-drying is commonly used to
preserve mushrooms. When you dry the mushrooms you want to
know how much moisture (water molecules) are on the surface
of the mushrooms. I''m assuming that too much water leads to
bad vibes on the preservation front. Some Turkish workers at
Hacettepe University in Turkey have used the BET approach to
determine that unblanched mushrooms absorb more moisture
than blanched mushrooms. Perhaps Dr. Teller would consider
this contribution to mushroom preservation as a more satisfying
legacy than the mushroom cloud associated with his nuclear
endeavors.
By the way, if you are like me and are uncertain as to the
definition of blanching, I''ve consulted my usual expert. My wife
tells me that blanching consists of a brief immersion in boiling
water.
Allen F. Bortrum
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