Interesting. So Who may or may not be on first. This changes the entire routine.

What's on second?

Seriously, the first base umpire can still make a valid call, as long as he isn't too far away. The time of arrival can't change within the first base frame.

And visualizing reference frames as baseball bases is not a bad way to go. I know there are a lot of cricket players out there; how about wicket frames?

Some have said "both are right."

I disagree.

Even in the darkest reaches of space, there is a velocity vector that's essentially zero. We know we don't experience that vector, as we're moving around on our planet, our planet is rotating, it's revolving around the sun, the sun is orbiting the Milky Way, and our galaxy is moving through space itself.

Just exactly how do we define the fact that our galaxy is moving through space, if velocity is nothing but relative? Simple - we take the mean of redshifts from all directions, calculate a net effective velocity, then subtract out the vectors for planetary rotation, orbit, and solar system orbit through the galaxy. The result is our galaxy's velocity.

Remove that, and you're at a position of zero velocity. Putting aside the proximity of mass which affects time, you're now experiencing the shortest duration of time compared to all points in the universe. It's true that regardless of the proximity of mass, you're now experiencing the shortest time rate at that particular point in space. If you were in motion, passing that point, your duration of a second would be slightly longer (relativistic effects).

I like to think of this as a "zero-velocity point," and there are an infinite number of such points throughout the universe, such that a chronometer which is stationed at that point experiences time at a rate faster than if the chronometer were transiting that point.

Thus, no, the distance the ball travelled isn't relative to the thrower or the catcher, each with two different but "accurate" answers. The only way this could happen is if you were to say, "relative to the thrower" or "relative to the catcher," neither of which accurately answers the question, "how far did the ball travel?"

The truth of the matter is that the ball travelled a distance relative to it's integrated velocity between being thrown and caught relative to the surrounding zero-velocity points divided by the duration of time as measured at those zero-velocity points along the route (not at the thrower, the catcher, or the ball).

Thus, the distance travelled by the home run hit by Banks was, in reality, quite a few miles...

__________________
I am Mugs, of the Alien clan of Usa, Nordamerica, a Terran, of Sol.

Mine: "Perception isn't reality. It's merely an abstraction thereof, and quite often not a very good one at that."

Heinlein's: "Staying young requires the unceasing cultivation of the ability to unlearn old falsehoods." "Freedom begins when you tell Ms. Grundy to go fly a kite."

No it doesn't. It doesn't travel the entire distance for, while the ball is in flight, Catcher C is closing the distance to Thrower T.

No it hasn't. The original distance the ball had to travel might have been 20m, but that's not how far the ball went. It went some distance less than 20m.

The ball is travelling at 40m/sec.

Less than 1/2 sec. Less than 20 meters... Maybe 15.5m.

...3/4 of the original (at time of throwing) distance to C.

[/quote]while the catcher travels the other 3/4 of the distance toward the ball. [/quote]while C travels the 4.5m towards the ball.

This must be T.

...C has travelled 4.5m. of the original (Time of throwing) 20 meters.

The ball has travelled 15.5m.

T?

...sees the ball travelling 15.5m at 40m/sec....the time of travel is less than 1/2 sec. ...The same as that for C? But the distance travelled (by the ball? By T? By C?) is quite different...?

15.5m. I don't have any difficulty with that, at all.