Electronic Design

Bob's Mailbox

Dear Bob:
Regarding your comments in "What's All This Why Stuff, Anyhow?" (Electronic Design, Sept. 7, p. 115). I doubt if our earliest prehistoric ancestors could throw a rock with the same accuracy and power as a baseball pitcher: (Yeah, but if the TIGER wasn't expecting it, he doesn't get to eat YOU. If the rabbit wasn't expecting it, you get to eat HIM. /rap)

  1. Unlike baseballs, rocks aren't a standard size, shape, and weight.
  2. The "strike zone" wasn't standardized and was probably moving. (When big cats are STALKING, they tend to stop. /rap)
  3. It was quite likely that the "batter" was about to attack them.
  4. There was no umpire with a supply of rocks handy in case they missed the first time. It was a long time before there is any evidence that our ancestors planned ahead and carried their tools with them. (Hard to say. The smart ones probably DID! /rap)
  5. The earliest bipeds were significantly smaller than modern man. (All the more reason to have tools. /rap)

Killing an animal with a rock is problematic at best. Except for intellect, man is not naturally very well equipped to be a predator.

I'm an engineer, not a paleontologist. Even among experts, there tend to be sharp disagreements about the who, when, and where of our ancestors. Our first known bipedal ancestors appeared roughly 4 million years ago. It was certainly a crucial step in the evolution of modern humans. It freed the hands to fashion and use tools and to carry things.

But I believe those gradually came about because they walked upright. The traits didn't evolve simultaneously. The earliest known undisputed tools are about 2 million years old. There were likely primitive tools before then, but they're difficult to identify. A rock used to bash a bone can look pretty much like any other rock. (Maybe, maybe not. /rap)

By the way, I read a story a few years ago about a scientist who studied the patterns of the chips of tools that were several hundred thousand years old. He concluded that the makers were right- or left-handed in about the same ratio as modern man.
GARY WELCH
via e-mail

GOOD POINT!! Thanks.—RAP

Dear Bob:
Agreed, the timing of a pitcher's release is critical, but your analysis is not good. Look at your own arm when you throw. Unless you "throw like a girl," your arm follows a path flatter than a circle. (Not at 90 mph, it don't! /rap)

Furthermore, a pitcher snaps his wrist toward the end of the arm motion, which complicates the ball's trajectory while it is still in his hand. (Yeah, maybe he needs 50 µs instead of 100. /rap) Take a look at the freeze-frame video!
CHRIS MAPLE
via e-mail

That's hard to do at 90 mph!—RAP

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Aren't you glad you paid attention in Science class?! /rap

All for now. / Comments invited!
RAP / Robert A. Pease / Engineer
[email protected]—or:

Mail Stop D2597A
National Semiconductor
P.O. Box 58090
Santa Clara, CA 95052-8090

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