Re: Clockwise (was: Many things, catching up)

[Mark A Biggar <mab@WDL.LORAL.COM>]

>From: Goran Topic <topic@student.math.hr>
>1) About directions:
>There is only one possible relatively culturally neutral way of
>specifying left/right. I leave it to physicists to explain. As I
>remember, it involves radioactivity and electricity, with magnetic field
>as a go-between. I think. That's what I know that it can be explained.
>From there it shouldn't be too hard to construe a similar argument
>showing cw and ccw. Should it? Bet it would make a killer lujvo.

Small historical note.  Clockwise is the direction that the shadow of a sundial
moves in the northern hemisphere and when clocks were invented they were built
to emulate that.

The physics version of left vs right is based on the preferential emission
of beta particles from an atomic nucleus.  If you look at the spinning
nucleus like it was the earth then more beta particles are emited from
the south pole then the north.  Unfortunately using this to determine
left from right requies the ability to distinguish matter from anti-matter
and so still doesn't help in the classic problem of "How do you describe
left and right to an alien over the radio." below.

>A bit off topic: Even this might fail zo'o: Imagine we make contact with
>an alien race, only by radio. Step by step, they learn our language. We
>try to explain what we look like. OK, we got an oval central part,
>and five major appendices: two for locomotion, two for handling things
>(one of each on each side of body, regarded in direction which is not
>gravity vector, nor direction of usual motion) and one to protect our
>most vulnerable parts on the top (the spot most remote from the ground
>in usual active position): intellect and sensory organs, located forward
>(in direction of motion)... In the chest we have lungs, etc, etc, and
>heart, and it is tilted to the left. What is left? Ugh. Physicists start
>explaining how when you take electrons and direct them in a certain way,
>you get a field of force that declines (is it the right word?) some
>other particles (it's probably about alpha waves, they're the less
>ambiguous of the two that do react to magnetic fields) in a certain way,
>and if you direct the electrons the other way the other particles go the
>other way. So, then, depending on whether you chase the electrons up or
>down, de particles go left or right, or some such, I don't feel like
>doing the actual calculation now. OK, now, they've explained it to the
>aliens, and they say that in our culture it's customary to take the
>new acquaintance's right handling member with your own and shake it
>slightly in a short interval of time, and that that gesture signifies good
>will. Now, they have excellent brains and they got in the first try
>everything we told them. Then, a meeting in open space is arranged: one of
>our astronauts and one of them meet up there, and the alien gives his
>left hand. Do you take it? Read on, the answer is at the end of the
>letter...

No, you don't, else KABOOM!

--
Mark Biggar
mab@wdl.loral.com