I think you are getting a little too hung up on your own specific semantic interpretation of the term ‘the concept of’
Left/ Right is not always intuitive.
Many people get it mixed up. It’s more common in children but I’ve met adults that have trouble.
The ring is on the left side of the dresser.
It’s surprising how many people fumble around.
I had a lot of trouble with L/R in childhood. I finally connected it with my watch. I wore my watch on my left wrist. I eventually didn’t have to think about my watch. Even today I sometimes hesitate before turning or looking in the correct direction.
Then I say, “Wait! Did you mean your right or my right?” (and get slagged while I hesitate).
Probably would do the same even if they weren’t aliens.
It wouldn’t be the first time.
: (
~Max
I interpret the OP: " without referring to specific objects or visual aids?" as meaning without recourse to a common physical object. That implies that the question is one of physical mapping, not the concept.
Heck, in concept all I need to is agree with the alien about the basics of notation in mathematics of 3D coordinate geometry, and say that, by convention we will often label the axies as: left-right, up-down, forward-backward in that order. The concept is easy. Given two vectors, define the cross product. Which way does the result point? Define rotation about that vector. Which way does it go? That is not so easy.
Symmetry in spacetime almost but not quite prevents us from ever being able to sheet home a common convention the directions in physical space. That it requires an experiment on physical objects means the answer to the OP remains “no.” That there is such a broken symmetry is a significant surprise. Of course it may be why we are here to debate the question in the first place.
Are there any known molecules that are asymmetric in structure, but where an opposite chiral form of the molecule is impossible to exist?
(I can’t think of a reason why this constraint could happen)
Nope, you need to get way more subtle than chemistry to see any effect like that.
Good try, but this is where it falls apart. “Lower numbered columns” and “higher numbered columns” is an arbitrary choice. If you saw what they were doing, you might feel they got it backward.
And we don’t need aliens for this. As has already been pointed out, the same miscommunication can happen here, with people from a right-to-left culture (such as Hebrew or Arabic).
I interpreted the OP’s restriction as meaning without reference to a concrete physical object that both groups have access to and not as meaning you can’t look at anything in your isolated area. If I have carbon atoms here, and they have carbon atoms there, we can both look at our carbon atoms as part of the discussion. By “specific object”, I thought OP meant literally a specific object (like a wood screw that gets sent between the two groups).
I had a friend in high school that used this with palms facing in to determine left and right.
I expect the most rigorous answer would come to us through knot theory. Surely the difference between L and D square knots is rigorously defined there. How abstract do we want a knot to be? The string that topologist types use to make knots is a pretty idealized material.
I thought this thread was going to be done after the mention of the cobalt-60 atoms. Before that experiment, we did not have a way of transmitting on a linear communication method which way was left and which way was right, but I thought the whole point of that experiment being a big deal was with the result you actually can transmit the idea. I guess it requires extremely complicated physics to manage to work out, and is still then only statistical so there’s always a finite probability you’ve gotten it reversed, but I had thought that the mention of that experiment would just be the end-all be-all of “yes, in theory you can”.
I saw that post, #12 above, from Senegoid. But it didn’t do much for me, because it merely tells us about a book which asserts that cobalt-60 has some sort of solution to this question, without giving us any clue about how the solution works.
Can someone offer a dumbed-down version of what happens to cobalt-60, and why/how it goes only one way?
The reason why these opposing political stances are named left and right is related to external objects and positions: The terms “left” and “right” appeared during the French Revolution of 1789 when members of the National Assembly divided into supporters of the king to the president’s right and supporters of the revolution to his left. (source)
And of course the political meanings of left and right are irrelevant to the thread.
A few years ago i remember this account of a Psychologist/Sociologist/Anthropologist? who was sent to study a pair of Deaf Twins, who managed to invent their own sign language between each other.
They could adequately describe to each other their respective immediate surroundings, save for one; neither has signs for left or right.
Each struggled to describe objects oriented to the side relative to some other object.
And yet, one cannot draw a general conclusion from a single case. What is the situation with deaf people as a whole? Do they have difficulty understanding the notions of left and right?
I’ve never actually seen an explanation that didn’t have some fatal assumption in it, such as assumptions about angular momentum conventions. These things are usually hand-waved away.
So, put on your shoes, because we’re going on a long walk.
I will assume that the concepts of up/down and front/back have been established already and that other necessary language is shared except when it would beg the question.
Sketch of a procedure:
(1) Place a flat circular disc slightly in front of you and slightly below you. Its axis of symmetry should run up/down.
(2) Begin rotating the disc in either direction around its axis of symmetry. The farthest point on the disc from your view is now moving sideways. Label that direction D1. We’ll eventually determine whether D1 is left or right.
(3) The rotating disc has angular momentum. We must establish a convention that distinguishes the direction of this angular momentum from the case where the disc is spinning the other way. Let’s label the direction of the disc’s angular momentum in the current case as “up”.1
(4) Establish that quantum mechanics is a thing, that angular momentum at the quantum level is quantized, and that particles have intrinsic angular momentum called “spin”.2
(5) Get some cobalt-60. Other isotopes or particles can work, but cobalt-60 has some nice features. It’s half-life is not too long and not too short. Gamma emission can be used to measure the direction and degree of polarization. The nuclear transition from cobalt-60 to nickel-60 changes the nuclear spin by one unit and does not change the nuclear parity.3 All this together means you should next…
(6) Polarize the cobalt-60 such that the nuclear spins are preferentially pointing “up” (i.e., the spins are preferentially in the same direction as the spinning disc from step (3)). Measure the number of “electrons” (in quotes because we haven’t established matter vs. antimatter yet) coming out of the cobalt decays in the “up” hemisphere versus the “down” hemisphere. There should be more electrons in one of those two directions. Let’s call these possible outcomes the ELEC=DOWN (more down) and ELEC=UP (more up) cases.
(7) Now we need to establish whether you are on a matter or antimatter world. Produce a beam of neutral kaons.4 There are both short-lived and long-lived neutral kaons, but after a sufficient distance of travel the short-lived kaons will have largely decayed away, leaving you with a beam of mostly long-lived kaons. Using utmost precision, measure how often those kaons decay to stuff involving “electrons” that have the same electric charge as the “electrons” from your cobalt decays versus how often the decay products involve “electrons” with the opposite charge. One of these cases should be more common by a tiny fraction. If the charge here is more often the same as the cobalt’s “electron”'s charge, call the outcome KAON=SAME; else KAON=DIFF.
(8) If (ELEC=DOWN and KAON=DIFF) or (ELEC=UP and KAON=SAME), D1 is what we call “left”. Otherwise, D1 is what we call “right”.
Easy, right? 
1 For those not familiar: angular momentum is usually indicated with an “axial vector” that points along the axis of rotation. The direction convention used by Earth physicists involves the right-hand rule, but I’ve not assumed that here. We’re calling the disc’s angular momentum direction “up” no matter what any hands might say.
2 Clearly a lot here, but none of it depends on left vs. right, so we can gloss over it and take it as established.
3 “Parity” here has to do with the particle content and orbital angular momentum of the nuclear system. The point here is that this particular transition allows for a clean connection between the outgoing electrons’ directions and the nuclear spin polarization.
4 Left as an exercise for the alien party.
When I’ve laid it out, I’ve started by establishing whether the aliens are matter or antimatter:
Produce a beam of neutral kaons, and let it travel long enough that it’s a pure beam of long-lived kaons. Let them decay, and observe which charged lepton is more often the product of that decay. Define that charge as “positive”.
If, in your ordinary matter, the hadrons in atoms are positive and the leptons are negative, then you are made of what we call “matter”. If your hadrons are negative and your leptons are positive, then you are made of what we call “antimatter”.
How important is this step? In other words, do physicists expect to find a lot of antimatter aliens out there? I remember hearing speculations from deep in the previous century that there could be antimatter galaxies that persist because they have never come in contact with matter galaxies but I thought that idea had not aged well and that we don’t expect to find macroscopic collections of antimatter anymore.
I’ll be tickled pink to learn that I was wrong about that. Even if I am right, I’m tickled pink to have learned the procedure just in case.