SF story ID

Trying to help out on another board with answering a story ID question.

“Does anyone recall the name of a SF first contact story where humans encounter an alien ship, and use the weak force to define left and right. At the very end, as the human and alien space walk out to meet each other, the alien extends its left hand to shake …” and they’re made out of antimatter.

I know that I’ve read that story myself and fairly recently but am drawing a complete black on author and title.

Anybody got any ideas?

I think that’s not a story; I think Martin Gardner used it as an illustration of the idea of parity and parity violation in his “The Ambidextrous Universe”

This is why you need to start by defining “positive charge” using the decay of the long-lived neutral kaon (which very slightly violates CP symmetry).

Or possibly a memory of this poem https://telescoper.wordpress.com/tag/edward-teller/

Here’s an excerpt from Feynman’s “Six Not-So-Easy Pieces” https://books.google.com/books?id=8AIIHo4riSEC&pg=PT62&dq=“antimatter”+“shake+hands”&hl=en&sa=X&ved=0ahUKEwiv7eTE54rXAhWL6iYKHRKfDoMQ6AEIWzAJ#v=onepage&q=“antimatter”%20"shake%20hands"&f=false - it sounds quite close.

As I said in the opening post: It is a story and I did read it recently. I’ve had no exposure to the Feynman.

Sorry about that. I missed the part about you having read the story yourself. The Feynman example is also mentioned in “The Physics of the Impossible” Physics of the Impossible: A Scientific Exploration into the World of ... - Michio Kaku - Google Books ; unfortunately, any number of SF writers might have picked up the idea.

It’s also in Beyond Einstein: The Cosmic Quest For The Theory Of The Universe.

“Chance Encounter” by A. Bertram Chandler Variety SF: A Bertram Chandler's "Chance Encounter" (short story, first contact, free): Even friendly encounter with aliens can be deadly