Is it possible to explain the concept of, and the difference between, the directions of “Left” and “Right” without referring to specific objects or visual aids?
I was going to suggest using electrons and magnetic fields, but that just changes the problem from “left” and “right” to “up” and “down,” which is basically the same problem.
Some Australian Aboriginal languages use North, South, West, East, depending on body orientation.
Is that what you’re asking? Human bodies are quite symmetrical on the outside, but left human testicle
is usually a bit lower. Or tell a person to run and wait for a side stitch.
My high school physics teacher asked us a similar question.
I want an explanation for the concept itself, and referring non-symmetrical items would definitely be referring to specific objects.
edited to add: and the concept of “Left and Right” is totally different from the concept of N, S, E and W.
Well, all directions have no meaning unless they refer to some other object. Even something as basic as up and down, has to refer to something else; like gravity or the ground and sky.
That being said, left and right are tricky because they can change depending on where you’re looking. So they need two reference points.
If you’re on Earth and understand the concepts of north and south then you can use the sun. But north and south are conventions here on Earth and have no universal meaning (that don’t rely on already understanding left and right).
So, if you’re not on Earth you need something else. The only thing I can think of is that you need an understanding of electromagnetism and gravity, and the concept of near and far or between.
If you have a straight conducting wire with the electricity flowing in the direction of gravity, then the magnetic field generated by that wire will be moving from right to left between you and the wire.
there may be other ways to define left and right but I think they all require increasingly complex concepts.
Since handedness appeared, there has been no need for humans to use an external object to learn left and right.
Little babies learn pretty quickly that they can hold a toy with one hand or two hands, and when they choose to use one hand they can do that with this hand or the other. As a rule, “this hand” will be their first hand of choice whereas “the other hand” will be their second hand of choice, which will generally identify as the right hand and left hand, respectively.
Their parents and teachers will mention position, symmetry, and other concepts when they teach left and right later in life, but the kids will first tend to associate the notions of right and left with their first hand of choice and second hand of choice.
When I was a kid, a special Dennis the Menace comic book came out, in which the Mitchell family went on vacation here in Hawaii.I remember among the hijinks Dennis got up to, he accidentally found himself in a small boat that was being swept out to sea. Henry and Alice were frantic on shore. Some boatman or tour guide or someone was yelling at Dennis to turn the rudder left or to turn it right. Dennis could hear him but had no clue which way was left and which right. Then Alice yelled to him the terms “sandwich side” (because Dennis always held his sandwich in his left hand) and “milk side” (because he always held his glass of milk in his right hand). Or maybe I have the hands reversed, it’s been a long time, but that’s what the OP makes me think of.
Similarly, when our daughter was small, we used to drive around to see the local Christmas lights. I’d drive and we’d use “Daddy’s side” for left and “Mommy’s side” for right so she could look in the right direction.
From first principles, the answer is no. We had a similar thread on this a while ago in the form of trying to determine chirality when communicating with far off aliens. If you can’t directly access a common physical object, you can’t communicate your convention of left versus right to another.
If you agree that you both live in a normal matter world (or you know a-priori the matter versus antimatter nature of the other end) you can define right versus left with reference to physical properties, but the OP is ruling even that out for this question.
Right versus left, or clockwise versus anti-clockwise, is a matter of convention. Everything works fine with either convention. You need to exchange a common reference to know if your convention is the same as the other’s.
CPT symmetry?
Martin Gardner wrote a whole book on this subject, Ambidextrous Universe (Wikipedia page)
https://www.amazon.com/New-Ambidextrous-Universe-Reflections-Superstrings/dp/0486442446
From the Wikipedia page:
Note that, at long last, the solution to the problem does in fact require reference to a common external reference, namely, the beta decay of cobalt-60.
And even the chirality of beta decay still depends (99.8%) on whether you’re dealing with matter or antimatter. You can also establish that, by taking advantage of that 0.2% discrepancy, but it requires some extremely subtle particle physics experiments.
There is at least one culture where the people always know, no matter what, which direction is N, S, E, and W and they talk about everything in those terms. They do not talk about left and right; they talk about north and south, or south and north–depending on which way they are facing.
NSEW is actually connected to left and right. East and west are easy to define: East is where the Sun rises, and west is where the Sun sets. And north and south are easy to define if you already have the concept of left and right: When you’re looking at the rising sun, north is on your left and south is on your right. But how do you define north and south without left and right? Here, it all falls apart. You can say things like “At noon, the Sun is south of the zenith”, but that only works in the northern hemisphere, and then how do you specify which hemisphere you mean?
I think you have to refer to the human body to explain the concept because it hasn’t meaning without us. Up versus down is a concept related to gravity so you can explain it anyplace with a gravity field. Front versus rear or forward versus backward is more limited in that it has to do with movement (and you have to accept the movement with respect to some particular reference frame though we don’t usually think about that when saying something is sitting right in front of us). But left versus right is the remaining dimension centered on our body, and the most subtle one because in general there’s no way of stating it unambiguously without cutting the body open to look for non symmetrical organs, or resorting to dexterity tests with statistics.
The concept of chirality, though, and the idea of things we’re likely to use for example a “right hand rule” to pin down, now that’s a more subtle story.
Or you can ask a six year old girl, who demonstrated it to me very,very,very simply:
1 Stretch out your arms in front of your body, and open your hands so your palms are facing outwards too. (imagine you are pushing a heavy object away from you).
2. Look at your hands, where the first finger and thumb meet.
3. .On one of your hands, the finger and thumb form the capital letter "L ". That’s your left hand.
4. Get it??? Huh??? do you get it??..Huh??? Huh???
.Geez, you adults ask silly questions sometimes… 
What is this “ell” thing you speak of? What does it look like?
Unless they are time reversed.
Without viewing, we wouldn’t even know if yonder aliens are symmetrical, either inside or outside. If we knew, we could say, e.g., “left” is the side your nose is on and “right” is the side your antenna is on.
Their is an additional subtlety as Martin Gardner points out: Suppose, even, that we could transmit photographs of one another, or things in our environments. The “other side” would receive these radio signals and then reconstruct the images. But there is no way to distinguish “left” from “right” even in the electromagnetic radio signals we send back and forth.
In other words, even if we send actual photographs by radio, there is no way to determine if the reconstructed photos are rendered correctly or are mirror images of the correct photos!