The maths behind cowboy tricks revealed

  • 7 March 2014
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"Cowboy Craig" Ingram's tricks in super-slow motion. Video courtesy of PT Brun.

Trick-roping was made famous in western movies and it usually takes tons of practice to get it right, but now a scientist says he's worked out a maths formula for creating the perfect lasso.

Dr Pierre-Thomas Brun from Switzerland studied cowboys and their rope stunts to come up with the formula.

Now he says anyone can teach themselves tricks like the famous 'flat loop' by studying his equation.

He showed off his 'cowboy physics' to the American Physical Society.

Performance art

Trick roping came out of cowboys and cowgirls using rope to catch cattle, it then became a performance art form that was made famous in western movies in the 1920s and 1930s.

It also became big competition at Mexican charreades, where traditional horsemen - charros - would take part.

Image copyright Reuters
Image caption A cowboy practices catching cattle with a rope

Texas skip

Some of the more fancy moves include the Merry-Go-Round, the Wedding Ring, and the Texas Skip - which is considered the most difficult.

And while these moves look amazing and incredibly difficult Dr Brun says they are all down to a basic formula.

"Elastic threads are everywhere in our daily lives - from hair and textile yarns to DNA and undersea broadband cables. Even the honey you pour on your toast," said Dr Brun.

"All of these threads twist and coil according to the same equations as the cowboy's lasso."

Studying fancy tricks like "spoke-jumping" and the "Kansas Tornado" could actually help in other areas too - like in the textile industry.

It's all about rules

To begin investigating, Dr Brun created a mathematical equation for the simplest trick - the flat loop.

"The physics boils down to a few simple rules," he explained.

"First, use the maximum amount of rope in your loop - about 70%.

"Then, move your hands with a slow frequency - about two hertz.

"And crucially - with each turn of the rope, roll it between your thumb and forefinger, to avoid accumulating twist."

Do cowboys use the maths?

"Cowboy Craig" Ingram, a champion roper who performs around Colorado says: "Absolutely, there's a lot of science to trick roping: geometry, speed, timing and centrifugal forces,"

"But it's also more than science. It's about artistry. When I perform it's like dancing with a partner - I feel the fluidity of the rope spinning around me and I respond to its movements."

Dr Brun agrees that, beyond the flat loop, the science quickly becomes more complicated.

He added: "When Craig's tricks get more fancy, you have to come up with a more dynamic model."