# Conveying left/right to alien by description **URL:** \ **Category:** Factual Questions\ **Created:** [February 14, 2016, 3:17pm UTC](https://boards.straightdope.com/t/conveying-left-right-to-alien-by-description/746120 "2016-02-14T15:17:34Z")\ **Posts on this page:** 20\ **Page:** 3
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [February 15, 2016, 1:03pm UTC](https://boards.straightdope.com/t/conveying-left-right-to-alien-by-description/746120/41 "2016-02-15T13:03:36Z")
> [@Trinopus](#): > > But doesn’t that depend on which way up the guy is holding it?.. No. Or yes, but I addressed that. If such a 3-pronged molecule existed (but see my post below), then if you hold it with one uniquely identifiable arm pointing up and another uniquely identifiable arm pointing away, the third arm is uniquely pointing either L or R. Which gives you an unambiguous means to label L and R. If your actual objection is “but which way is ‘up’?” then the answer for anybody on a planet is “up” is outwards in your gravity well and “down” is towards the center of your gravity well. The local gravity vector gives you an unambiguous local up / down. Towards / away is equally unambiguous. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [February 15, 2016, 1:07pm UTC](https://boards.straightdope.com/t/conveying-left-right-to-alien-by-description/746120/42 "2016-02-15T13:07:43Z")
> [@scr4](#): > > No, if a molecule is stable, its mirror image is equally stable. > … > I think this is only true for certain organic molecules. And the only reason one orientation is more likely is because they are synthesized by organisms or molecules that are themselves all one of 2 possible orientations. Thank you. That kills my idea. And yes, I recall that SF short story although I don’t recall the author. I think a corollary to your info would be that the actual L/R weak force asymmetry folks are talking about doesn’t lead to any chemistry-scale consequences. It’s lost in the sauce of lower-level particle physics. ---
**Author:** ![Andy\_L](https://avatars.discourse-cdn.com/v4/letter/a/c67d28/32.png) [@Andy\_L](https://boards.straightdope.com/u/Andy_L)\ **Post date:** [February 15, 2016, 1:18pm UTC](https://boards.straightdope.com/t/conveying-left-right-to-alien-by-description/746120/43 "2016-02-15T13:18:01Z")
> [@scr4](#): > > (I think Asimov had a short story about a man who was thrown up into a higher dimension and came back reversed; he almost died of malnutrition until they figured out how to synthesize mirror images of certain nutrients.) I think you mean Clarke’s “Technical Error” [Technical Error - Wikipedia](https://en.wikipedia.org/wiki/Technical_Error) ---
**Author:** ![jtur88](https://avatars.discourse-cdn.com/v4/letter/j/e9c0ed/32.png) [@jtur88](https://boards.straightdope.com/u/jtur88)\ **Post date:** [February 15, 2016, 1:58pm UTC](https://boards.straightdope.com/t/conveying-left-right-to-alien-by-description/746120/44 "2016-02-15T13:58:15Z")
> [@Francis\_Vaughan](#): > > Give it a go. But remember, left and right are currently not defined. > > As to using this to define north and south poles, you might ask if the technique will even work consistently here on Earth. 800,000 years ago you would have got the opposite answer. Is it possible that a man stepping out of a time machine 800,000 years ago would observe that a majority of animals seemed to be left-handed? Is there a magnetic reason why a most humans and other species exhibit handedness? Since many (or most or all) species are predominantly right- or left-handed, there must be some biological advantage to handedness. In fact, in most species studied, the right-brain-left-brain dichotomy exists, with a strong preference within a species for consistency. Australian marsupials show a strong left-handedness, which suggests that the observation of the apparent movement of the sun might be an evolutionary factor. ---
**Author:** ![naita](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/naita/32/5862_2.png) [@naita](https://boards.straightdope.com/u/naita)\ **Post date:** [February 15, 2016, 2:26pm UTC](https://boards.straightdope.com/t/conveying-left-right-to-alien-by-description/746120/45 "2016-02-15T14:26:40Z")
> [@jtur88](#): > > Is it possible that a man stepping out of a time machine 800,000 years ago would observe that a majority of animals seemed to be left-handed? Is there a magnetic reason why a most humans and other species exhibit handedness? Since many (or most or all) species are predominantly right- or left-handed, there must be some biological advantage to handedness. In fact, in most species studied, the right-brain-left-brain dichotomy exists, with a strong preference within a species for consistency. > > Australian marsupials show a strong left-handedness, which suggests that the observation of the apparent movement of the sun might be an evolutionary factor. Wikipedia only lists humans and ground-dwelling macropode marsupials under handedness. Have you got any sources for the underlying “facts” for this wild speculation? ---
**Author:** ![Anarcho\_Liberalist](https://avatars.discourse-cdn.com/v4/letter/a/df705f/32.png) [@Anarcho\_Liberalist](https://boards.straightdope.com/u/Anarcho_Liberalist)\ **Post date:** [February 15, 2016, 2:34pm UTC](https://boards.straightdope.com/t/conveying-left-right-to-alien-by-description/746120/46 "2016-02-15T14:34:23Z")
> [@jtur88](#): > > (…) Since many (or most or all) species are predominantly right- or left-handed, there must be some biological advantage to handedness. In fact, in most species studied, the right-brain-left-brain dichotomy exists, with a strong preference within a species for consistency. > > Australian marsupials show a strong left-handedness, which suggests that the observation of the apparent movement of the sun might be an evolutionary factor. This is a very interesting point in relation to the OP question! Do you have a cite of some sort? I’m asking because I always thought humans were the one of the few, if not the only, animals with a clear and consistent dexterity and thus the only animals with a clear concept of difference between left and right… ---
**Author:** ![scr4](https://avatars.discourse-cdn.com/v4/letter/s/59ef9b/32.png) [@scr4](https://boards.straightdope.com/u/scr4)\ **Post date:** [February 15, 2016, 2:43pm UTC](https://boards.straightdope.com/t/conveying-left-right-to-alien-by-description/746120/47 "2016-02-15T14:43:47Z")
> [@Blake](#): > > Thus left is the direction that the north pole of a north-facing a compass needle will deflect when current is run under it from a cathode in the south. You’re right that the direction of an electric current is not arbitrary, it can be communicated. (Though this still hinges on the assumption that your aliens are not made of antimatter.) However, **magnetic field** is arbitrary, i.e. labeling the north and south poles of a magnet (or a planet) is arbitrary. [Ampere’s right hand rule](https://en.wikipedia.org/wiki/Right-hand_rule#Amp.C3.A8re.27s_right_hand_screw_rules) may look like it defines the direction, but if you redefine the direction (i.e. swap the definition of magnetic north and south), this just becomes a left-hand rule. This becomes more obvious when you recall that magnetism is not a separate force, but merely the [relativistic effect of moving charge](https://en.wikipedia.org/wiki/Relativistic_electromagnetism). ---
**Author:** ![scr4](https://avatars.discourse-cdn.com/v4/letter/s/59ef9b/32.png) [@scr4](https://boards.straightdope.com/u/scr4)\ **Post date:** [February 15, 2016, 2:49pm UTC](https://boards.straightdope.com/t/conveying-left-right-to-alien-by-description/746120/48 "2016-02-15T14:49:35Z")
> [@Andy\_L](#): > > I think you mean Clarke’s “Technical Error” [Technical Error - Wikipedia](https://en.wikipedia.org/wiki/Technical_Error) That’s it, thank you! ---
**Author:** ![MrDibble](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mrdibble/32/114_2.png) [@MrDibble](https://boards.straightdope.com/u/MrDibble)\ **Post date:** [February 15, 2016, 2:50pm UTC](https://boards.straightdope.com/t/conveying-left-right-to-alien-by-description/746120/49 "2016-02-15T14:50:32Z")
> [@Francis\_Vaughan](#): > > Give it a go. But remember, left and right are currently not defined. Don’t need them to be, but I am assuming “top” and “bottom” are definable in gravitic terms if nothing else. If we’re dealing with antimatter beings or space energy clouds, all bets are off. > [@](#): > > As to using this to define north and south poles, you might ask if the technique will even work consistently here on Earth. 800,000 years ago you would have got the opposite answer. N & S are arbitrary, I i know that. I’m thinking strictly in terms of : 'if you look along the same direction the electrons are flowing, then the lines of flux in the perpendicular plane are going clockwise. We define “left” as the direction the flux is flowing at the bottom, “right” as the direction it’s flowing at the top. I’m assuming a certain degree of technical sophistication here, of course… ---
**Author:** ![scr4](https://avatars.discourse-cdn.com/v4/letter/s/59ef9b/32.png) [@scr4](https://boards.straightdope.com/u/scr4)\ **Post date:** [February 15, 2016, 2:59pm UTC](https://boards.straightdope.com/t/conveying-left-right-to-alien-by-description/746120/50 "2016-02-15T14:59:29Z")
> [@MrDibble](#): > > 'if you look along the same direction the electrons are flowing, then the lines of flux in the perpendicular plane are going clockwise. We define “left” as the direction the flux is flowing at the bottom, “right” as the direction it’s flowing at the top. See my response above. I assume by “flux” you mean the direction of the magnetic field. This is arbitrary. What you are doing here is conveying the definition of the magnetic field direction to someone who already knows what right and left mean. ---
**Author:** ![watchwolf49](https://avatars.discourse-cdn.com/v4/letter/w/e9c0ed/32.png) [@watchwolf49](https://boards.straightdope.com/u/watchwolf49)\ **Post date:** [February 15, 2016, 3:37pm UTC](https://boards.straightdope.com/t/conveying-left-right-to-alien-by-description/746120/51 "2016-02-15T15:37:26Z")
Left is liberal, Right is conservative || ---
**Author:** ![MrDibble](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mrdibble/32/114_2.png) [@MrDibble](https://boards.straightdope.com/u/MrDibble)\ **Post date:** [February 15, 2016, 3:55pm UTC](https://boards.straightdope.com/t/conveying-left-right-to-alien-by-description/746120/52 "2016-02-15T15:55:07Z")
> [@scr4](#): > > See my response above. I assume by “flux” you mean the direction of the magnetic field. This is arbitrary. I thought this was the direction a positive charge would move in if introduced next to the charge-carrying wire? I’m happy to be wrong, though, it’s been decades since i was taught this sort of thing and i’ve never had to use it. ---
**Author:** ![scr4](https://avatars.discourse-cdn.com/v4/letter/s/59ef9b/32.png) [@scr4](https://boards.straightdope.com/u/scr4)\ **Post date:** [February 15, 2016, 4:12pm UTC](https://boards.straightdope.com/t/conveying-left-right-to-alien-by-description/746120/53 "2016-02-15T16:12:10Z")
> [@MrDibble](#): > > I thought this was the direction a positive charge would move in if introduced next to the charge-carrying wire? No, a magnetic field doesn’t do anything to a stationary charged particle. What it does is deflect the path of a _moving_ charged particle, at right angles to the magnetic field and the direction of motion. To figure out which way the path is deflected, you use… the right hand rule. So if you redefined the magnetic field direction, by replacing Ampere’s right-hand rule with the left-hand rule, everything still works. Because you’d use the same left-hand rule to figure out how charged particles behave in a magnetic field. ---
**Author:** ![watchwolf49](https://avatars.discourse-cdn.com/v4/letter/w/e9c0ed/32.png) [@watchwolf49](https://boards.straightdope.com/u/watchwolf49)\ **Post date:** [February 15, 2016, 4:27pm UTC](https://boards.straightdope.com/t/conveying-left-right-to-alien-by-description/746120/54 "2016-02-15T16:27:22Z")
> [@LSLGuy](#): > > Thank you. That kills my idea. And yes, I recall that SF short story although I don’t recall the author. [snip] Roger Zelazny’s short story “Doorways in the Sand” also had a bit about reversing the steriochemistry, the main character absorbed an alien artifact. A fun read, the author started most every chapter with the hero is some preposterous situation and the rest of the chapter was about how he got there. ---
**Author:** ![jtur88](https://avatars.discourse-cdn.com/v4/letter/j/e9c0ed/32.png) [@jtur88](https://boards.straightdope.com/u/jtur88)\ **Post date:** [February 15, 2016, 4:45pm UTC](https://boards.straightdope.com/t/conveying-left-right-to-alien-by-description/746120/55 "2016-02-15T16:45:22Z")
> [@naita](#): > > Wikipedia only lists humans and ground-dwelling macropode marsupials under handedness. Have you got any sources for the underlying “facts” for this wild speculation? - “In contrast to previous views, it has now been shown that cerebral lateralization is a widespread phenomenon in the animal kingdom.”\* > **[Laterality](https://en.wikipedia.org/wiki/Laterality#Laterality_in_other_animals)** > > The term laterality refers to the preference most humans show for one side of their body over the other. Examples include left-handedness/right-handedness and left/right-footedness; it may also refer to the primary use of the left or right hemisphere in the brain. It may also apply to animals or plants. The majority of tests have been conducted on humans, specifically to determine the effects on language. > Most humans are right-handed. Many are also right-sided in general (that is, they prefer to... ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [February 15, 2016, 4:49pm UTC](https://boards.straightdope.com/t/conveying-left-right-to-alien-by-description/746120/56 "2016-02-15T16:49:34Z")
Are there asymmetrical allotropes or molecular forms that could be used to define left and right? I don’t know how to even describe the incomplete memory I have about something involving the legs of insects and some substance found only on one side. That may not resolve the question in the OP but it’s driving me crazy trying to remember what that is and I’m not having any success searching online for it. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [February 15, 2016, 4:54pm UTC](https://boards.straightdope.com/t/conveying-left-right-to-alien-by-description/746120/57 "2016-02-15T16:54:27Z")
> [@TriPolar](#): > > Are there asymmetrical allotropes or molecular forms that could be used to define left and right? … I tried that in post #29 & got shot down in post #33. The problem with asymmetrical biology (or biochemistry) is the aliens don’t necessarily have the same stuff we do. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [February 15, 2016, 5:00pm UTC](https://boards.straightdope.com/t/conveying-left-right-to-alien-by-description/746120/58 "2016-02-15T17:00:30Z")
> [@LSLGuy](#): > > I tried that in post #29 & got shot down in post #33. > > The problem with asymmetrical biology (or biochemistry) is the aliens don’t necessarily have the same stuff we do. Just found out about chirality, I think it didn’t register when I read your post before. I still want to find out about the sinister insect. I think it was a lead in to an explanation of CPT symmetry. ---
**Author:** ![watchwolf49](https://avatars.discourse-cdn.com/v4/letter/w/e9c0ed/32.png) [@watchwolf49](https://boards.straightdope.com/u/watchwolf49)\ **Post date:** [February 15, 2016, 5:02pm UTC](https://boards.straightdope.com/t/conveying-left-right-to-alien-by-description/746120/59 "2016-02-15T17:02:41Z")
If, as the OP suggests, these alien critters already understand the concept of right and left, then it’s just a matter to translate the “words”. Simple enough to tell a German speaker that “right” means “_recht_” ---
**Author:** ![ftg](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ftg/32/2801_2.png) [@ftg](https://boards.straightdope.com/u/ftg)\ **Post date:** [February 15, 2016, 5:32pm UTC](https://boards.straightdope.com/t/conveying-left-right-to-alien-by-description/746120/60 "2016-02-15T17:32:43Z")
Asimov, in one of his science essays (not fiction), conjectured that it is due to the asymmetry of the Weak Force that in turn caused the biological predominance of [homochirality](https://en.wikipedia.org/wiki/Homochirality). Ergo, there might also be a chance that our alien friends biology also has the same forms of handedness (L for amino acids, D for sugars). Note that there has also been some evidence of handedness preferences in meteors. In addition to the Weak Force arguement, another has to with circular polarization. See the above link. Excluding “scientific attributes” in this matter basically makes it a pointless question. It will always come down to some sort of scientific matter. [Previous page](https://boards.straightdope.com/t/conveying-left-right-to-alien-by-description/746120.md?page=2) [Next page](https://boards.straightdope.com/t/conveying-left-right-to-alien-by-description/746120.md?page=4)