# A Thought Experiment Involving Weightlessness, Friction, Fluid Dynamics, and a Chess Set

I’ve got a great idea for a picture: Me and an opponent playing chess in zero gravity. It’s not too far outside the realm of possibility: a few thousand bucks and the Zero G Corporation will have be in business.

So during one of my 25-second periods of weightlessness, I whip out the board (assume for this experiment that it’s a \$5 cardboard set that I bought at Wal-Mart) and set up the pieces. The photographer snaps the shot.

What would happen if I oh-so-gently removed the board with the goal of getting another shot, this time with the pieces hovering there in space, sans board? I figure that if I pulled it downward, the movement of the board against the air would create some sort of wind current in the ambient air that would blow the pieces around. If I pulled it out horizontally, would the friction of the board against the bottoms of the pieces pull them with the board and mess up my setup?

Is there a way to achieve the second shot?

“Every action has an equal and opposite reaction.”

If you were super careful you could probably get the photo.

But the tiniest nudge to any of the pieces will make them float away.

In the plane there is air resistance/friction which will help you a bit but not much in this case. I doubt you could manage to do this cleanly without any inadvertent nudge to the pieces no matter how slight.

You are better off using a computer to simulate the effect. Cheaper too.

(Of course doing it on a ZeroG plane would be more fun)

I imagine there are enough minor bumps and air currents inside the plane that in practice the pieces will drift anyway.

There’s no theoretical reason you couldn’t slowly pull the board slightly down so it’s not contacting the pieces, then pull it sideways and away.

For a little more expense, but a lot more time to get the shot, imbed iron slugs in the bottom of the chess pieces, and an electromagnet under the board. That way you can set up the pieces ahead of time and keep them in place, then turn off the magnet once zero-g hits.

I’m not sure how you will even get the first shot. How will you keep the pieces against the board and oriented the right way? The pieces will separate from the board as soon as they’re “placed”.

On a more positive note, you could at least minimize air currents when moving the board by using a rigid screen or mesh rather than a solid board.

nm…

As the OP said, if you tried to pull the board down from underneath the pieces, it would create a vacuum and that would suck the pieces out of position. The same thing would happen, although to a lesser extent, if you tried to pull the board away sideways.

If the pieces are heavy - say, if they’re carved out of marble, or cast out of iron - then air drafts will matter less.