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nadw88
2012-May-30, 12:24 AM
Hi everyone.

I have a kind of thought experiment that I've been considering for a while. Some of my friends have suggested possible answers, but it would be interesting to see what everyone here thinks.

Imagine that humans have made contact with a distant alien civilization. For the sake of this post, imagine that the aliens communicate with us using some kind of faster-than-light technology that we don't understand at all (maybe we found the "trasmitter" buried underground or something). We are able to communicate with them fluently, thanks to translator technology contained within the unit.

We've told them all about our planet and civilization, but the only thing we haven't been able to get across to this species is the concept of "left" and "right" as directions relative to an observer's position and orientation.

Any suggestions for how this could be done?

Additional constraints:

We don't know where they are in our universe, and assume that they are too far away to detect by any means (no use of common reference points).

We can send only audio and strings of numerical data.

Any ideas?

Romanus
2012-May-30, 02:14 AM
I'm not sure a species with no concept of left and right would even be bilateral. Talking to one at all would be a challenge.

nadw88
2012-May-30, 02:33 AM
That's a good point - lets go with clockwise vs counterclockwise instead.

Jens
2012-May-30, 03:14 AM
Assuming they have a technological civilization, and you can't transmit images for some reason, I guess you could do it by something like the right-hand rule.

Ara Pacis
2012-May-30, 04:24 AM
Three rights make a left.

aquitaine
2012-May-30, 04:47 AM
Why not use math somehow? Surely they would understand a basic coordinate system, they would have to in order to develop technology.

John Mendenhall
2012-May-30, 05:54 AM
Old question. IIRC, only one thing works. See Issac Asimov, "The Left Hand of the Electron", probably out of print.

Regards, John M.

WaxRubiks
2012-May-30, 06:22 AM
left and right is just a subjective perspective, which is perpendicular to the other equally subjective up-and-down ,and forwards-and-backwards.

Swift
2012-May-30, 12:12 PM
Hi nadw88, welcome to BAUT.

I moved your thread from Space Exploration to Life In Space, it seems a better fit.

eburacum45
2012-May-30, 06:44 PM
This very question was asked by Martin Gardner in his book The Ambidextrous Universe; he gave the same answer as Isaac Asimov, that it would be possible to communicate the difference between right and left, but only by using some pretty impressive sub-atomic physics.
http://en.wikipedia.org/wiki/The_Ambidextrous_Universe:_Mirror_Asymmetry_and_Ti me-Reversed_Worlds

All other methods don't work; you can't use the right-hand rule without knowing which direction is right in the first place, for instance.

Paul Wally
2012-May-31, 01:01 PM
Maybe parity violation (http://en.wikipedia.org/wiki/Parity_%28physics%29) in weak interactions could be of help. In the Wikipedia article it says:

Only the left-handed components of particles and right-handed components of antiparticles participate in weak interactions in the Standard Model
So assuming that the aliens also discovered the Standard Model or we are able to communicate the experimental setup to them it might just be possible to communicate the concept of left/right. But, what worries me a bit, is that the fact that we call the weak-interactions left-handed may depend on some conventional assignment that we made earlier in our physics.

Jens
2012-Jun-05, 04:57 AM
All other methods don't work; you can't use the right-hand rule without knowing which direction is right in the first place, for instance.

I was thinking that you can. We have established up and down, and forward and backward (because in the OP, it is stated that left and right are the only concepts we haven't communicated). So if we say,

A needle is moving forward through a magnetic field coming from the surface of the planet below. Right is the direction that it will feel a force. Or something like that. I may have it backward or wrong, but that's the general idea. That if something is moving forward through a magnetic field coming from below, that something will happen that will be either right or left.

Grey
2012-Jun-05, 06:15 PM
I was thinking that you can. We have established up and down, and forward and backward (because in the OP, it is stated that left and right are the only concepts we haven't communicated). So if we say,

A needle is moving forward through a magnetic field coming from the surface of the planet below. Right is the direction that it will feel a force. Or something like that. I may have it backward or wrong, but that's the general idea. That if something is moving forward through a magnetic field coming from below, that something will happen that will be either right or left.The tricky part is that the convention for which way a magnetic field points is arbitrary. So you can't unambiguously tell them the field points up without first establishing which convention you're using. And of course, to do that requires you to be able to talk about left and right, since you'll have to talk about which way different types of particles move.

Jeff Root
2012-Jun-05, 06:51 PM
I don't accept the premise that images can't be sent.
If any information can be sent, it can encode an image.
But that doesn't solve the problem of distinguishing
left from right. I think it might solve the problem
suggested by the original post, of aliens who do not
have a concept of left and right at all.

When the problem is to distinguish left from right, you
also need to distinguish matter from antimatter. If the
aliens you are communicating with discovered their
communication device the same way we did, then they
might be made of what we consider antimatter, and so
would the communication device they found.

-- Jeff, in Minneapolis

Ara Pacis
2012-Jun-06, 05:13 AM
I think it was be as simple as "Look left. No, your other left."