[nitpick]That’s the relativistic mass-energy conversion formula, and has nothing to do with this discussion. c is the speed (technically velocity, but everyone says speed) of light, which is constant anyway. The formula you’re looking for is for kinetic energy, which is given by mv[sup]2[/sup]/2, where m is the mass and v is the velocity.[/nitpick]
Good post, though.
Not to hijack here, because this is very interesting stuff, but whats the deal with the one inch punch? I assume that Bruce could get his hand moving to a certain speed in he distance of an inch?
2Strew, thanks for the link, I’ll have to reread it a few times, as it made my eyes glaze over if I read more then 2 sections. 
well, i havent seen a clip, but theoretically, couldnt it be possible to continue to deliver the momentum even after contacting the person? Or did lee’s hand literally only move one inch forward, then stop.
If it continued to move forward, perhaps its not all that different from placing a fist ON a persons abdomen, then PUSHING them 6 feet. Visualize that, while that may be hard it seems a lot easier than punching somone 6 feet.
I found this which suggests that to do the one inch punch properly, you only move your hand one inch.
There is nothing special about that one-inch punch. It’s just a hoaz, a slight of hand that tales practice. It’s not like he can accelerate his fist with superhuman abilities.
The Bruce Lee: God or Hoax discussion that generally follows the mention of his name should probably get its own thread, yeah?
World Eater, there is some other stuff on the site that’s less directly related to your question but has more words and fewer numbers, something I find quite helpful myself.
Regarding the difference between speed (meaning simple velocity) and momentum (as defined by velocity times mass): Would you rather be hit by a cotton ball going twenty mph, or a cement truck going ten mph?
[hijack]
Advice from John D. MacDonald’s Travis Magee:
Hit the soft parts with your fist; hit the hard parts with a utensil.
[/hijack]
speed gets you there first. For most boxers a punch is a punch is a punch. Its the amount of punchs that takes your apponents legs away. Once the legs are gone, so is the fighter. Most big punchers are beaten by a great stab artist{ray Robinson, Ali and many others}
hey david, that may be true but isnt it great to really lay into a guy sometimes? i’ve punched qquite a few people in the head ad never broke my hand. i’ve cut quite afew brows and watched noses and eyes swell. hazardous and fullfilling.
i firmly believe bruce could take mike. i also believe that tyson could enter a tough man contest and be beaten pretty quickly by martial arts and grappling…
Strength becomes a factor after impact. More strength leads to a greater ability to keep an arm moving (as well as more resistance to slowing down) after it has hit something which leads to a more powerful follow-through.
What I think is needed here is a physics lesson. While most of the common equations used are used in idealizd situations they answer alot of the questions raised here IMHO.
First, I think you can boil down the question to this. Who generates more Power? Not the esoteric vague “power” used in discussion, but the scientific definition for it.
Power = Work/Time; Power = Force*Velocity
Both are the same.
Work is the amount of force over a distance.
So, in the case of this problem, we assume that Lee can generate 40 Newtons of force in a punch (strength) and Tyson can generate 65 Newtons of force.
Power[sub]Lee[/sub] = 40N * V
Power[sub]Tyson[/sub] = 65N * V
So, in order for Lee to generate as much force as Tyson he’d have to accelerate his hand almost 65% (1.635 times as fast) faster than Tyson.
There are additional concerns here like surface area and momentum, but I think this gets to the meat of the OP.
“There is nothing special about that one-inch punch. It’s just a hoaz, a slight of hand that tales practice. It’s not like he can accelerate his fist with superhuman abilities.”
Fuel - This slight of hand or hoax was developed over 350 years ago by practitioners of the Weng Chun Kuen style of King Fu.
The one inch punch is a technique that has been perfected over centuries and is no slight of hand but rather, a demonstration of how speed and strength can translate into force. Since few people can accomplish this I would consider it to be a superhuman feat and something that is beyond the abilities of ordinary men.
Anyways… lets do some math:
Take two fighters where the smaller fighter’s hitting mass is 2 units and the larger fighter’s hitting mass is 4 units. The larger fighter has a fist velocity of 2 where the smaller fighter has a hand velocity double that or 4. Using ultrafilter’s formula of mv2/2 to determine kinetic energy we get the following result.
Small fighter: m2v4(squared)/2 = 16 energy units
Large fighter: m4v2(squared)/2 = 8 energy units
I am thinking that if the small fighter weighs 120 pounds and the the large fighter weighs two hundred and forty pounds we have fighters similar to Lee and Tyson. If Tyson’s hand speed is equal to Lee’s (v=4) he will hit with twice as much force due to his increased mass.
You wouldn’t want either one hitting you.
Omniscient… note the posting times and the similarity of our posts…
I was going to go into surface area and momentum later.
1" punch - by no means superhuman, but requires practised timing and coordination. In reality, fist probably moves 4-5", but still a short distance.
I have received “1 inch punches” to the gut through a phone book. Based on my experience, they are no hoax (or hoaz!)
There’s a benefit to raw body weight in there, I think, to those who know how to use it. Years ago, I was at a carnival with one of those punching machine things. I weighed around 300, with a decent but not substantial muscle mass, but I was able to outpunch everyone consistently, by a wide margin. It was fun, actually - after a while, a small crowd formed, watching to see if anyone could beat me. I pissed off a few ~30 year olds with their girlfriends who couldn’t beat a 16 (at the time) year old. I was consistently punching over 600 - uh, whatever units they used. - consistently hitting the top “superman” rating. Does anyone know what units those units typically measure in? PSI?
I tried again 2 years later, same carnival, same machine, weighing more like 210 pounds, but with drastically increased muscle mass (from 9+ months of intense training) and wasn’t able to get above 400 or so. So, despite having better muscles, not having the extra weight to ‘throw’ drastically reduced the power I could generate.
I’m sort of thinking of it from the reverse direction, there is a fist moving through the air, and you’re trying to stop it with your face. However, there is more than just a fist, it is connected to an arm, to a shoulder, to a torso, to a hip, all of which are moving in your direction, and all of which need to be stopped.
Bruce Lee weighed about 120lbs soaking wet (big WAG here), so he maybe had 50lbs of stuff moving in your direction at, let’s say, 50mph (averaging speeds between fist and hips) Tyson, on the other hand, weighs 240, so would have 100lbs of stuff moving at 40mph in your direction.
In order to stop the fist, you need to reverse the momentum, and Tyson’s punch has about 60% more momentum to reverse. Tyson punches murderously hard, I recall many moons ago, he got in a fight outside a night club with another top notch heavyweight boxer, it lasted exactly one punch.
Notwithstanding the discussion above on the “one-inch punch”, I found no mention above that follow-through is not necessarily desirable. Read this article from Discover about the physics of karate.
Cooking With Gas - That’s a great article as it provides some figures to use when calculating impact forces… 46fps converts to 31 miles per hour and newtons can be converted into foot pounds which are more understandable by most people.
(hijack) An interesting exercise used to develop focus and speed uses a burning candle… the object of the exercise is to extinguish the candle without touching it.
The punch or strike must come within a few cm of the flame and the strike itself must be performed very quickly. The resulting shockwave will generate enough wind to blow out the candle.
If you can do this then breaking multiple boards or blocks is pretty easy.
(end hijack)
Anyways, the Discovery article states that a well delivered karate chop generated 2800 newtons which is 629 pounds of force. If this force is distributed over 2 square inches (WAG) we have an impact force of about 365 psi. If a one knuckle punch is delivered under the same conditions the force generated will be concentrated into an area that is perhaps half a square inch. The resulting force at the point of impact would be a whopping 1258 psi.
When we apply what we’ve learned here about speed and impact forces we should realize that there are a few people who could probably kill you with a single punch whether they were a well trained martial artist or world class boxer. Death would probably not be instananeous but would be caused by internal hemmorage.
Worldeater - I wouldn’t be worried about the big musclebound guy at the gym killing you with a punch unless he takes up a martial art (including boxing). He’d probably just rip your head off instead.
I wonder how much energy it would require to do that?
The thing I have learned from martial arts about punching is that to generate force you have to rotate around your axis. The "one inch punch” was brought up, and it is a great example of rotational force. The impact is generated by the hips and travels up through the body. The effect is similar to cracking a whip. The hips rotate like the whips handle and the fist strikes like the end of the whip. When you strike like that you are hitting with the force of your whole body and not with the limits of your muscles.