Boomerangs

Stapes · 6232. Thu Feb 26, 2004 11:36 am

Important things to note before continuing: "boomerang" is not the word aborigines used for hunting stick; the returning throwing wood probably did not originate in Australia; historians haven't conclusively agreed on how the boomerang developed.

Having said that....

Stapes · 6233. Thu Feb 26, 2004 11:51 am

Ancient peoples all over the world used various hunting sticks, throwing axes and poles, all or any of which could have been "the first boomerang". Rock paintings from the Neolithic Age show what seems to be a throwing wood, which was probably mainly a hunting weapon to hunt hares, birds and other small animals at long range. It was rarely used as a battle weapon. As the planet evolved, the throwing wood developed separately in different places, depending on the stage of development of the peoples, and the types of wood available (which had to be of a certain strength, sufficient elasticity, and a grain which runs uninterruptedly in natural bends).

One German scholar, J.E.J. Lenoch, who seems to be one of the best authorities, wrote a paper on boomerang development in 1949. He differentiates between the "throwing club", where the effect of hitting is mostly concentrated at one end; "throwing stick", which is a straight rod of hard wood which rotates while flying, is sharpened at both ends, and hits top first; and the "throwing wood", which doesn't concentrate on the effect of hitting, is a crooked piece of wood which rotates in the air, and has a variant which returns to the thrower, called a boomerang.

S: How the Throwing Wood and the Boomerang Developed www.rediboom.com/geschich/
S: en.wikipedia.org/wiki/boomerang
S: www.rangs.co.uk

Stapes · 6235. Thu Feb 26, 2004 12:46 pm

Early examples and findings:

the oldest actual returning boomerang was found in the Olazowa Cave in the Polish Carpathians. It is more than 18,000 years old. Researchers tried it out, and it did indeed return. The fact that such a honed example exists, which successfully returns, suggests that there was already a long tradition of using these - the physical properties have to be so exact to make a successful boomerang, that it's pretty unlikely that someone just accidentally made one one day.

Aboriginal boomerangs have been dated at 14,000 years old;

in North Africa, the throwing wood was used from the Neolithic Age (approx 6000 BC) until the recent past;

rock paintings from the Young Paleolithic Age (approx 5000-1800 BC) showing a boomerang have been found in Europe;

advanced civilisations in the Near East from approx 3000BC used throwing woods as royal and godly badges and symbols - they did not seem to be for practical use. It probably developed in Babylon into the scimitar;

various types of throwing woods were developed in Pharaohic Egypt, including noblemen using it to hunt birds, and some ivory versions, probably used for rituals, were found in the grave of Tut-anch-Amun from approx 1340BC. There's also a great picture at historylink101.net/egypt_1/pic_wall_paintings_3.htm of "Hunting scene with boomerang, Tomb of Nakht XVIII Dynasty";

a boomerang was found near Magdeburg in Germany, dated to 800-400 BC;

after the introduction of iron in approx 600 BC, some African throwing woods developed into throwing knives;

a returning throwing stick called a Cateia was used by the Goths to hunt birds from approx 100AD;

at about the same time, throwing woods were used for hunting rabbits and ducks in the Americas.

S: as above

Stapes · 6236. Thu Feb 26, 2004 1:01 pm

A text written in the 7th century by Isodorus Hispalensis, bishop of Seville, called "Origines", describes the history of various bits of wood and throwing clubs:

Stapes · 6237. Thu Feb 26, 2004 1:04 pm

It's generally agreed that it's so difficult to make a successful hunting stick, which you can throw with great accuracy, that the returning boomerang was probably an accidental discovery while trying to hone a hunting stick. A hunting stick is much more delicately balanced and harder to make than a returning stick, and a returning boomerang probably accidentally came about while people were trying to make a stick which would fly straight.

S: www.rangs.co.uk

Stapes · 6238. Thu Feb 26, 2004 1:11 pm

The Encyclopoedia Britannica says that Australian hunters used returning boomerangs to imitate hawks, for driving flocks of game birds into nets strung from trees. This makes sense - surely it's v hard to hit a bird by throwing a stick at it. It sounds more like boomerangs were used in "bird hunting" as a kind of wooden, boomerang-shaped sheepdog. But for birds.

Stapes · 6239. Thu Feb 26, 2004 1:14 pm

www.rangs.co.uk suggests that maybe boomerangs became so associated with Australia because when used as a weapon it is especially effective against upright standing prey, like kangaroos and emus.

Also, Australian aborigines never developed the bow and arrow, which might have surpassed the boomerang. One for Jenny's bows and arrows thread?

Stapes · 6241. Thu Feb 26, 2004 1:38 pm

Origin of the word:

It's impossible that the word "boomerang" was from ''the Aboriginal language", as at the time of European settlement in 1788, there were between 500 and 600 different Aboriginal languages, each with its own terms for tools and weapons.

Also, only about 60% of Aboriginal peoples used both returning and non-returning boomerangs and had words for them, 10% used only non-returning sticks, and 30% used neither.

There is no record of Captain Cook ever having seen a returning boomerang being thrown, or used the term. He did take one back to England, but thought it was a wooden sword, recording in 1770 that the Aborigines were "all arm'd with darts and wooden swords". His botanist, Joseph Banks, and later William Dampier, thought they were scimitars.

The first written record is by Francis Louis Barrallier, a French-born surveyor and engineer and an ensign of the New South Wales Corps. In 1802 he wrote in his journal about a "piece of wood in the form of a half circle" which is thrown "on the ground or in the air, making it revolve on itself, and with such a velocity that one cannot see it returning towards the ground; only the whizzing of it is heard".

Bungaree, an Aboriginal befriended by the First Fleet settlers gave a demonstration of boomerang throwing in Sydney (need to check the date), but colonists had already reported seeing a boomerang in action west of Sydney. It was rumoured that Aborigines could throw a boomerang out, hit a kangaroo, and make it return to the thrower. This is physically impossible, and is actually a failure to distinguish between 2 very different types of throwing sticks.

The first recorded use of the word "bou-mar-rang" was in 1822. The word comes from the language of the Turuwal people of the George's River near Port Jackson. This same people had other words for their hunting sticks, but used "boornarang" to refer to a returning throwing stick. The Turuwal are a sub-group of the Dharug language group, and many of the Aboriginal words we use in English are from this language (waratah, wallaby, dingo, kookaburra, koala and woomera).

If you trace the word "boomerang" to its aboriginal origins, it clearly describes a returning throwing stick, and there are clear words for other kinds of throwing stick. It is only the Europeans who have adopted the word to mean "throwing stick" in general, and have then made up the term "returning boomerang", which doesn't really make sense.

S:The Australian Boomerang Association www.boomerang.org.au

Stapes · 6245. Thu Feb 26, 2004 6:25 pm

Why boomerangs come back:

Boomerangs work according to 3 laws of physics – lift, thrust and drag.

Newton’s 3rd Law of Motion: for every action there is an equal and opposite reaction. When you give something thrust, this deflects the air below it downwards, which in turn deflects the thing itself upwards. This gives 30% of the required lift.

Bernoulli’s Law: an increase in air speed reduces the static pressure. Air produces about 14 pounds of pressure on every object from every direction. If you blow across the top of a piece of paper which is lying flat on a table, the paper will lift up. This is because you’ve moved the air across the top, reducing the air pressure, but the air pressure underneath the piece of paper remains the same, so pushes the paper up. An aeroplane (or boomerang) wing has a flat bottom and a curved top. In order for air to hit the front of the wing, and meet at the same time behind the wing, air is forced to move more quickly over the curved top of the wing than under the flat bottom, because the distance is further over the top. This curvature of the wing produces 70% of the required lift.

Gyroscopic stability keeps the boomerang stable in the air. Something which is spinning on a horizontal axis is vertically stable, like when you sit on a motionless bike you fall off, but as soon as it’s moving, you become more stable.

Gyroscopic precession is what causes the boomerang to fly in a circle or ellipsis. Any attempt to move a spinning object, for example the movement of the lift created by the boomerang’s curved wings, is translated at right angles to the original input. So because the boomerang is spinning vertically and moving forward through the air, eventually this forward vertical movement, which is being acted upon at right angles by gyroscopic precession, will lean towards the horizontal and veer away from moving forwards. By the time it comes back to you, the boomerang is lying horizontally and moving in the opposite direction to how it started.

So:
the throw produces thrust;
the spinning produces gyroscopic stability;
lift and spinning together create gyroscopic precession, which turns the boomerang from vertical to horizontal.

Okay. Non-physicists – does that make sense? Physicists – does that make sense, is it true, and is it too simplified?

Stapes · 6246. Thu Feb 26, 2004 6:31 pm

According to the Australian Boomerang Association, a boomerang is also known as a:
"rang"
"boom"
"boomer"
"returner"
"B"
and
"stick".

Stapes · 6247. Thu Feb 26, 2004 6:43 pm

If you're having problems with your "rang", you can adopt various measures to control the amount of lift or drag, reduce the length of hover, keep the flight lower, alter the distance flown, give more or less spin, and change the shape of flight. See my original post at post 6096

You can drill holes in one or both arms, wrap rubber bands around them, add spoiler flaps, tape coins onto the arms, bend the arms, or even sand them down.

Flash · 6248. Thu Feb 26, 2004 6:52 pm

Oddly enough, when I told my aged mother that we have comedians guesting on the show she said "What, like Charlie Drake, you mean?" - the significance of which to this thread will be entirely lost on young Stapes and anyone else under the age of 45.

Stapes · 6250. Thu Feb 26, 2004 7:34 pm

The arm of the boomerang which you grip before you throw the boomerang is the dingle or dangling arm. This will always be following the leading or upper arm through the air, so the 2 arms will be subject to different aerodynamic forces. The leading arm is making the initial thrust through the air, and the dingle arm is always following in "dirty air", literally in the leading arm's wake. To create the right curvature to provide lift, the inside edge of the leading arm needs to be sharper than the outside edge, and the outside edge of the dingle arm needs to be sharper than the inside edge, as it is the sharper edges which need to be the first to come in contact with air as the boomerang moves forwards.

More lift will always be created by the leading arm, as it moves faster through cleaner air than the beleaguered dingle arm. That also means that the sideways forces of gyroscopic precession are greater on the leading arm, which causes the leading arm to tilt and the direction of flight to change following the direction of tilt.

If your boomer is lying down too early, your dingle arm might be a bit blunt, so to improve its performance, you can sand your dingle arm to give it a sharper outside edge.

S: www.boomerang.org.au
www.rangs.co.uk
How to Dunk a Doughnut - Len Fisher
http://www.coloradoboomerangs.com/index.html

these sources are the same for all my rang posts.

Stapes · 6260. Fri Feb 27, 2004 12:13 pm

Some world records:

Maximum Time Aloft (MTA) - the MTA is a type of boomerang, one of the hardest to create, tune and throw well. It doesn't necessarily have to return to exactly the same spot to qualify as a boomerang, as long is it has a degree of elliptical flight. The MTA record is 17 mins and 6 secs, and the boomerang was caught 70m from where it was thrown. This boomerang hit a thermal, and reached an estimated 200m of height. Apparently, a guy called Bob Reid from Leeds Uni kept a boomerang aloft for 24 hours and 11 secs. He did this by going to the south pole and throwing it through all the time zones. I feel this is cheating rather.

Other records: 80 catches in 5 minutes; 5 catches in 14.6 seconds; a distance record of 238 metres, then returning to the owner. This is held by Manuel Schutz, and was recorded in Switzerland - throwing at altitude obviously helps because of less air density.

S: Doughnut
en.wikipedia.org/wiki/boomerang
www.boomerang.org.au

Stapes · 6261. Fri Feb 27, 2004 12:51 pm

Don't get a boomerang confused with a boomslang, which is an extremely venomous snake, found in sub-saharan Africa.

S: EBR