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Boomerang Science...



Greetings. I hope everyone is surviving all of this cold weather.
So far I haven't had school for the past three days. One thing I've
learned is that it is a lot easier to teach when there are no students.
(Ha, ha) When I check my messages today, I couldn't believe how many
messages I've received. The topics ranged from the sport of
boomeranging, how they are made, why they work (which I think has
already been covered, but I may touch upon that), and on Gary Broadbent.

The organized sport of boomeranging has several activities and
people from all over the U.S. and around the world come to compete. The
events (to the best of my knowledge) are Accuracy, Aussie Round, Fast
Catch, Endurance, Trick Catch, Doubling, MTA (Maximum Time Aloft). In
all of the events, the boomerang must at least travel 20 meters to even
be counted. Accuracy is perhaps the easiest because you don't have to
catch it. All you do is stand in a bull's eye and throw your
boomerang. The closer you are to the bull's eye, the higher your
points. It's a lot like darts.
Aussie Round is similar to Accuracy, but you have to catch it. You
get points for distance, making the catch, and how close you are to the
bull's eye when you make the catch.
Fast Catch is just as it sounds. You are timed for how long it
takes for you to make 5 catches. Some of the boomerangs are traveling
close to 70 - 100+ mph. The boomerangs will literally scream (ideal for
noticing the doppler effect) as they go flying around. The record
stands at 14.6 seconds which means the person averaged less than 3
seconds to throw, have the rang travel at least 20 meters and back, make
the catch, turn around make the next throw, while noting the direction
and speed of the wind.
Endurance is perhaps the most tiring. It is actually a fast catch
that lasts for 5 minutes. You get points for the number of catches you
make in those 5min. The record is 76, which is the average number of
throws a baseball pitcher makes in an entire game, but this is done in
5min. Bring lots of Ben-Gay!
Trick Catch is making a series of difficult catches ranging from one
handed catches, behind the back, under the leg, and with the feet.
Doubling is the same as Trick Catch, but you throw 2 boomerangs at
once, and must make an assigned trick catch for each one.
MTA is perhaps the favorite of most of the people. Ask yourself how
long do you think you can keep a boomerang in the air with a single
throw and catch it within a 100m circle. For a long time, the average
time ranged between 10-almost 30 seconds. The boomerangs were thin,
very wide, and fairly light. Ted Bailey from Michigan revolutionized
mta by trying to imitate a maple seed. He came up with a boomerang
which looks similar to a hockey stick. The times rocketed to between 30
sec - 2 minutes! John Gorski, from Cleveland, OH, while competing in
Delaware, OH threw his boomerang which stayed in the air for 17 minutes
6 seconds!! He caught it just a few meters from where he originally
threw it. MTAs are a sight to see and sad when you see the wind slowly
take it away from you. I've personally lost some that I lost sight of
it after 8 minutes.
The boomerangs are made from a wide assortment of materials. Some
of the common materials are air-craft grade birch plywood (can have
between 5-12 layers in less than 1/4 inch), G-10 plastic, circuit
boards, hardwood lumber. The materials of the MTA generally consists of
plywood. Gary makes the boomerangs like the one that stayed in the air
for over 17min. It is made of microballoons in an epoxy made with
unidirectional 0.003mm carbon fibers (90/10), bidirectional 3/10 ounce
kevlar. The boomerang weighs less than what a quarter weighs, but is
extremely strong. It actually generates more lift than what it weighs
(at least for a while).
Some additional information of Gary Broadbent is that he holds 4
world records with his boomerangs. He has thrown in all 50 states,
around the Eiffel Tower, Washington Monument, St. Louis Arch (the
world's largest boomerang), around Old Faithful, over the Grand Canyon,
Yosemite Natl. Park, over the White House lawn, in an airplane, and he
has even thrown tomorrow and caught it yesterday (on the International
Date Line). He is a motivational, educational, inspirational
speaker/presenter on the history, science, craft, hobby, sport, and art
of the boomerang. I couldn't believe that boomeranging actually covers
all of this until I got involved. At one moment I'm using my physics to
see if a new idea may work, using an assortment of tools to craft the
boomerang and adding the artistic touch so that it not only looks good
hanging on a wall, but also in flight. He has traveled all over doing
his presentations for SECO (Science Education Council of Ohio, which he
will be there again this year), Natl. American Alliance for Health,
Recreation, and Dance, Polymer Land, Rotary Club, Scout's, Kiwanas,
Churches, Board of Mental Health, Disney, many of the amusement parks,
Case Western, Cleveland U., Purdue U., OSU, Akron U. He has also
appeared on ESPN, Amazing Games, MTV, WGN (Chicago tv station), Energy
Express tv, Paul Gardino cable excercise, Indio Day Festival in Palm
Springs.
The science of the boomerang is quite complex. If you slightly
change one thing, you've set up a series of changes which will affect as
to how the boomerang will perform. A couple of examples is if you take
Gary's Backyarder boomerang, if you push up on the wings and create
dihedral the boomerang will fly high, lay down quickly and hover back
down. If you take the same boomerang and push down on the wings, the
boomerang will fly more horizontal. If you put too much annahedral
(negative dihedral), the boomerang may crash into the ground. Another
example is Gary's Invertable boomerang. It has a rhombic airfoil and
can be thrown with either side of the boomerang facing you. The
boomerang has three swept wings. If you throw it so that the wings are
swept upward, the boomerang climbs high and helicopters down. If you
take the same boomerang but now throw it so that the wings are swept
downward, the boomerang stays low...close to eye level. Can anyone
figure out why? (Hint: Think of it as a spinning top.)
Hopefully all of you can see just how unique and mind boggling they
can be. I personally find them quite relaxing to go out and throw and
catch them for a while. I especially like watching one of mine fly so
close to the ground that it you can see the effects of 'ground effect'
as it glides across the ground, up a hill, back down, and right back to
me while only being just a few inches from the ground the entire
distance.

Dwight
Ashland, OH