[quote]FightinIrish26 wrote:
Can you explain this a little more thoroughly for those of us who spent science classes smoking cigarettes in the bathroom?[/quote]
Are you talking about the momentum figure?
At the risk of incurring a charge of aggravated dickweedery by quoting myself from this thread.
From page one:
[quote]some retarded monkey on the internet wrote:
WARNING! THE FOLLOWING IS APPROACHING CRITICAL NERD. DO NOT CONTINUE IF YOU WISH TO REMAIN COOL.
To whom it may concern:
I think momentum is the much more germane calculation/nerd factor for striking than kinetic energy. First of all it is a vector so the direction of the force matters. Second, and this is my opinion based on some text book/lab understanding of physics/and mechanisms of wounding combined with redneck/dumb guy normal thought, it better describes what we know happens when we punch or get punched.
Momentum, p, is simply mass, expressed in kg, multiplied by velocity, expressed in meters per second. p = mv expressed in kg-m/s (kilogram meters per second). Kinetic energy undervalues mass and way oversells velocity when we are talking about punches/kicks/strikes. I grant that KE might have more sway when discussing high velocity (lets say 2000 ft/sec plus) rifle bullets because cavitation in tissue is a mechanism of wounding, but with punches momentum tells a better story.
If KE was the appropriate measure, than holding a small weight in my hand, e.g. a roll of quarters, would make me hit lighter than without it. My fist would be traveling slower (lets assume similar punch mechanics so straight vs straight). The velocity difference would be an exponential factor.
This doesn’t seem to work out. The hand load makes you hit harder. Not that it is at all necessary to do physics calculations in order to knock someone onto queer street.
A salient point with both p and KE is that they use velocity not speed. Velocity is directional, so only the amount of ass, mass, you get going in the direction of the strike, velocity, matters.
/NERD
Again good posts guys.
I recommend getting a copy of Jack Dempsey’s book if anyone reading this is interested in the mechanics of punching.
Regards,
Robert A
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And further less nerdy explanation from page 2
[quote]Some jackass who probably likes Star Trek wrote in response to a Sportswriter who just hit some serious deadlift numbers:
Didn’t mean to. Basically kinetic energy could lead one to think that hitting faster, even at a great expense of how much weight/mass/leverage is put into the punch, would equal a harder/stronger blow.
That don’t seem to work out. Sap gloves and hand loads allow harder blows by increasing mass at the expense of speed. If I had a choice of eating your left empty handed, or with you palming a roll of quarters I am taking the former.
I suggested momentum because:
1.) It is a vector (direction matters) so it means that only the body weight you have going into the punch helps. If you are flailing around in a bunch of directions you are increasing the “energy”, but not the effect of the blow. Kinetic Energy is termed a “scaler” and has no direction.
The punchers with great “short power” are usually masters of getting what they can “into” the punch. Meaning getting as much of their body weight going in the direction of the strike. Dempsey called punches where the body and the fist are moving in the same direction as “pure”.
2.) Momentum places a more equal value on velocity, how fast you are moving in the direction of the strike, and mass, how much of your body you are getting “into” the punch (I think this is what you mean by leverage) so it describes what we know. “Pushing” with punches really doesn’t do as much damage regardless because it happens too slowly, but hitting fast with an “arm punch” won’t let me punch my way out of a paper bag either.
Basically get as much as possible, moving as fast as possible, in the direction you want the strike to go. This matches up pretty well with what we all see going on when good punchers punch. It also allows for a quick explanation for common mistakes.
Puncher “A” hits weak because he is too rigid. He thinks he is hitting hard because he is doing a lot of work and his muscles are straining. He is flexing all his muscles and consequently is moving way too slow. If he would loosen up and throws “crisper”, or “faster”, or with “more pop” then he would hit “harder”.
Puncher “B” is plenty loose and fast but still hits like a bitch. He is not getting enough of his body weight into the blows. This is the “slapping” type of puncher. Oh, he’s fast and he can punch in combinations great because he doesn’t need to shift a lot of weight from punch to punch. Maybe his name is Calzaghe? Problem is that you can sort of “walk through” his punches to land on him. If he is not holding a box cutter he is pretty well fucked when anyone grabs a hold of him.
Puncher “C” is definately moving his weight around. He is moving fast. He is putting a lot of “effort” into his strikes. They still are not doing all that well, especially when he gets tired. This is the guy that contracts explosively but is all fucking over. He twists his hips/shoulders way farther than he needs to on straight punches. He tries to drive forward with his hooks. He is wasting energy by moving a bunch of his mass in directions the punch is not going. Stepping foreward with a hook is not the same thing as stepping/“shifting” into the hook. If your knuckles are ripping into my spleen from the side, your body weight should be going as close to that direction as possible. That is the “weight”/“leverage” that goes “into” the punch and breaks my ribs.
I know you have seen these mistakes Irish. Hell, “A”, “B”, and “C” probably have faces for you. Sentoguy teaches, so for him they probably all have too many faces to count.
What I do know is that punching from the stomach - or, one might say, just the hips - is the way I used to do it when I was involved in karate.
It can make for a pretty powerful punch I guess… but in my opinion, never as powerful as actually turning your whole weight into it.
Physics explains this, and it needs to be able to. If we try to use physics to explain something that we know happens, like say you injuring me when you hit me and the math doesn’t add up than we did the math wrong. The broken bones and blackened eyes are all to real.
I have written this before, but if you have good technique you will never fight alone. Issac Newton, Archimedes, and the other giants of physics will be with you ready to pull a train on whomever stands against you.
I went into the whole physics thing not so much for you and Sento, I know that you guys know what you are doing, but in case anyone is lurking and starts trying to match up the great advice you two are doling out with a physics text. Note: I have actually read and heard on real life some instructors saying they hit much harder than boxers because the punch of a boxer is reliant on mass, and that they use speed to create their kinetic energy. Guess how well that shit sits with me?
As for why I wrote this post.
RANT COMING:
I probably go too far into the book shit in my posts because I really don’t want anyone to think they can’t understand it. Physics is about modeling/describing the world. Newtonian physics, the kind we are talking about, is something fighters already understand. I HATE when people convince themselves that something they are already applying is beyond their comprehension. Technical/clinical terms, like all language, are valuable only to convey information/ideas. I realize that some people like to use their education or familiarity with terms to hinder the understanding of others, this is anathema to how I view knowledge. I will go so far as to say that the fact some of those doing this are professors and doctors is fucking unconscionable.
RANT OVER
Regards,
Robert A
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