I know ahead of time I won't get far with you regardless what I say but what on earth has ever passed between us that would lead me to trust you on this one?
It's an expression. You've apparently reached the conclusion that I rarely know what I'm talking about, and that assumption does not serve you well.
I was somewhat surprised a few years ago when I read some articles on the subject of human bodies colliding with the interiors of cars to find that the momentum equation that dominated the calculations.
I'm somewhat surprised at your insistence that car collisions are an appropriate model. In a car collision where the victim hits the interior, the change in momentum he suffers is severe -- he decelerates to zero very rapidly. In a collision of two bodies on the court, the change in momentum of the victim will result in him being pushed back a few feet. They really aren't closely related. You could compose a situation in which the victim hits a third player or a basket support and come closer to something car-like, but the thread implies that we are talking about a generic, one-on-one situation. (The player may collide with the floor in a "car-like" fashion, but his change in vertical momentum will never be very substantial, short of an airborne player falling on him from above.)
You have great faith in your own convictions, and it has been observed that I have the same characteristic. On the other hand, my ultimate pursuit is accuracy, which means that once in a while I am obliged to recognize that I have been mistaken. Your ultimate pursuit, by contrast, is to claim that you are correct, valiantly stepping up the hostility of your language as your foundation of misinformation crumbles beneath your feet. When facts overwhelm your position, you change the subject or drop the matter altogether.
For this reason I don't expect you to get much out of the following articles, but I'll offer them for anyone else who might be interested:
http://www.schwebel.com/RunScript.a...10&NWS=NWS&ap=NewsDetail.asp&p=ASP/~Pg421.asp
This discusses "low-speed" vehicle collisions. Much of it is not terribly relevant (oh -- it could occur to you to check the spelling of that word, since surely you have noticed that we have different "opinions" on the matter), but it does include one point that I thought could be applied to our discussion, at least conceptually:
Although most experts should agree that even in low speed impacts there will be a difference in the acceleration of the torso, and the acceleration of the head, the defense and its experts claim that the change in velocity (or delta v) is so low that, even if the torso goes forward and the head follows, there is no hyperextension or hyperflexion.
(The article, written by injury lawyers, then goes on to concede this point but talk about other ways that injury may be demonstrated.)
Needless to say, Danny Fortson running into another player would qualify as a "low-speed" collision by the standards of automobile crashes, unless the players were running head-first into one another, which again is a specialized scenario outside the scope of this discussion. Although basketball players must fear many other kinds of injury besides whiplash, which is the focus of the artice, low-speed automobile collisions tend not to result in those other kinds of injury in healthy, physically fit adults -- and since you made the decision to invoke car collisions as appropriate to this case, we have to take what it gives us.
http://rabi.phys.virginia.edu/HTW/journal/Article1.1.pdf
This article discusses the physics of a karate blow, which is closer to the basketball situation. It describes momentum-based and energy-based analyses as "equally accurate," but unfortunately stops short of quantifying its discussion in detail. Nonetheless, in the momentum-based analysis, the critical issue is the acceleration of one part of the target with respect to the other. In most respects, the human body is more fluid than a wooden board, so the ability of one section or area of it to experience a severe acceleration with respect to another section or area, given the same change of momentum experienced at a particular source, is less than in the case of the board.
The energy-based discussion focuses on energy transfer and deformation damage. A formula is provided; I won't quote it here, since you suggested that you won't take it seriously, and also it would be hard to represent with lines of text. But it takes the elasticity of the collision into account, with a factor of (1 - e^2). Consistent with what I indicated before, it is the energy absorbed in the collision through inelastic means that is responsible for this deformation damage.
I couldn't find a resource analyzing the collisions of basketball players, so I am forced into an assumption, which that a collision of human beings is likely to hit closer to home, so to speak, than one between a human and an automobile.
momentum is not somehow gathered up in an elastic component and harmlessly carried away, as you seem to be arguing.
No, what I meant was that to the extent that the collision results in an elastic exchange of momentum, the hazard to the player in minimal. The change in momentum, as in the low-speed car crash, isn't enough to do any damage in most cases.