The reason that there is ejecta "almost instantaneously" in your video is exactly because momentum was transferred from the bullet to that ejecta "almost instantaneously." Starting from the very first instant that the bullet begins to lose any velocity, momentum is being transferred to the impacted body, including any pieces that get ejected. Now, if I can just convince you that if the bullet passes through a body, it can't impart any more momentum after it exits, then we're almost there.
> So it is likely that 313 is when the impact occurred.
That's absurd. That's not even possible, much less "likely," because frame 313 shows ejecta several feet away!
If you're going to claim that frame 313 is "when the impact occurred," then you're the one who needs to do some math to show how that ejecta got several feet away "almost instantaneously" while the bullet was still in the head. Until you do, I think I'll continue to be quite sure that the bullet has left the scene by frame 313, thank you.
As for your difficulty in seeing the displacement from 312 to 313 and distrust of my gif, it's pretty easy to find several other versions on the web. Here's a good one:
And as for you request to see more frames, here are 310 through 317:
Note a few things: There was no significant forward motion in frames 310 through 312; frame 313 (which is after the hit!) shows the head displaced forward by a couple of inches; there is only a small backward motion between 313 and 314; and then the head accelerates through the following frames.
There is no way for momentum transfer to be delayed for two frames, and there is no way that momentum transfer from a bullet can cause any more acceleration after it has exited the head. Therefore, the "back and to the left" cannot have been caused by the impact of the bullet.
Beyond any reasonable doubt, the Zapruder film shows JFK being shot from behind. Which just happens to be consistent with all the physical evidence.
Edit history
= new reply since forum marked as read