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Last Updated: Wednesday, 3 August 2005, 10:31 GMT 11:31 UK
Kung Fu? Meet Physics
By Ben Davies
BBC News

What do you get if you put a physicist, a martial arts expert and a pile of wooden planks in one room? Some smaller planks.

We've all seen it. Some bloke with a hand of steel slicing a lump of concrete or block of timber in two. But ever wondered how it's done?

Michelle Cain
The 25-year-old scientist has found new ways of demonstrating physics
Turns out, it's all down to the science of physics...

Michelle Cain - no relation to the roving fighter played by David Carradine in the 1970s series Kung Fu - is a high flying young scientist just embarking on her PhD in atmospheric physics.

Chris Crudelli is a Kung Fu master (and star of BBC Three's Mind, Body and Kickass Moves).

Einstein Year

Somebody at the Institute of Physics, inspired by it being Einstein Year which aims to heighten awareness of the relevance of physics, had the bright idea of putting them together. The mission? To work out just what it takes to chop wood with your bare hands.

Cain, 25, said: "Kung Fu is about force so I had an understanding of it with my physics background."

So what did she think about being asked to take part in the exercise?

"At first I was surprised. It was an unusual idea but an interesting one. The prospect of breaking blocks of wood is not something I have really thought about."

Transferring energy

She explained that you have to put your body weight into the strike as you are bringing your hand down - and that she began by practicing without a board.

That way she was able to achieve a high speed - absolutely crucial to breaking the wood.

Chris Crudelli
Crudelli, before and after
"We did high quality photographs to find out my maximum speed which was 10 metres per second.

"Kung Fu experts get 15 or more. We worked out the kinetic energy generated and the impact of it on the wood. My top was 18 joules but I only needed five - so I knew as long as I went fast enough it would be fine.

"In the end when I did it it was a lot easier than I expected and it didn't hurt."

Crudelli, 32, concedes it doesn't take a physics degree to be a Kung Fu fighter - but it can help you identify areas where you need to increase or even reduce the force you are using.

He says the "two arts" are very different but "Kung Fu is the physics of the body".

New website

"We know about weight distribution, about velocity about pressure," says Crudelli who took up Kung Fu aged eight and as a teenager went to study in China and Malaysia for 10 years.

The process of teaching Cain can been seen on a new website - Kung Fu Science [see internet links] - which has video clips of her learning to break a block of wood without breaking her hand. It is primarily aimed at 11 to 16-year-olds.

But remember, don't try this at home!

Add your comments on this story, using the form below.

Again, another childhood fantasy ruined by the scientist. I would much prefer to belive in the magical side of these accomplishments. Mind you I would like her to test the theory whilst recreating the old shaolin monks favourite of breaking concrete blocks with the head.
Chris H, Connaught,London

Its no longer a thought of mind over matter, but more an understanding of matter with the mind. This gives a whole new outlook for wanna be martial arts goers, including myself. As instead of a person hitting their hand on a block of wood until its red roar, they could look at how to maximise their force and the best way to do this is through utilising their weight and speed.
Matthew Humphreys, Buckley

I have been studying Karate for 4 years now it comes as no surprise that this has to do with energy. The whole idea is that you draw upon your inner strength and force "chi" and use it as a powerful weapon. Humans only ever use a fraction of the power they really have!
Lucy, London

What these people are overlooking is that western science uses 'laws of physics' to determine a probable outcome based on already known equations, which to me seems a bit text-bookish and regurgitative. They aren't taking into account quantum sciences that acknowledge things such as Qi (Chi) energies that exist in every one of us. This Qi energy may be able to be used to perform similar feats with with an amount of effort that would defy our 'laws' of physics.
Kerry Taylor, London

I really don't think it takes a Physics PHD to work this one out!!! - is this science dumbing down??! Elementary GCSE physics will tell you that: Force = Mass x Acceleration. So putting your whole body-weight behind, and continuing to speed through the strike will impart a much higher force onto your target. I think this is just common sense..not Rocket science!!!
Sandeep Paul, London

I've studied both Karate and Jujitsu, and in both of the styles my instructors have explained the physics behind the techniques to get full effectiveness from them. In Jujitsu, where there are a number of throws and locks, a basic knowledge of physics is as handy as knowledge of anatomy and psychology.
Dave Hood, Stevenage

I have practised martial arts for 8 years now, from time to time I use blocks and wood to break for training purposes. For me its not a show of power but more a conditioning exercise of the mind to overcome. But remember, one of the greatest martial artists ever once said, "Boards dont fight back!"
Simon , Darwen, Lancs

Interesting, but something more challanging to explain, such as breaking several bricks piled on top of each other with no gaps between would have been more enlightening.
Dan, London

This doesn't seem to take into account the qualities of the material. Breaking a piece of cheap pine is something my six year old can do, especially if it is well seasoned and cut across the grain, but what about a similar sized plank of mahogany? Breeze blocks, another Kung-Fu favourite, are as crumbly as cheddar cheese, but engineering bricks take considerable force to snap.
Rick Hough, Knutsford, Cheshire

It has been documented that some Kung Fu masters can selectively break bricks in a stack, e.g., the third in a stack of five... how's that done?
David Kirschner, Lebanon, New Jersey, U.S.

An interesting and important study but I'm still waiting for an in-depth study of how kungfu experts acheive some on the power (ie speed of punch not "magic power" type) they do. As an athlete of many years I cannot reproduce that kind of action through either the physical or mental training I have access to - and I'm about 7" taller than most of the guys (and girls) who do this stuff!

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