What mental abilities did you not know it was possible to lack?

This makes sense. I can’t remember not being able to read a map, but these people have learnt how to navigate by watching the nature around them. A map won’t tell them anything but an aerial photo makes it possible to recognise the landmarks.

That might have been The Ambidextrous Universe by Martin Gardner, a very interesting book well worth reading.

Yes you can: you can define “clockwise” and “counterclockwise” first (based on the light rotation) and then define “left” and “right”. One defines the other, but which does which is not in those stone tablets Moses brought down from Mt Sinai or maybe it was in the fourth tablet, the one he didn’t go back for after breaking the third…

I’ve always taken it for granted, but I’m surprised how many people do not have the power to cloud men’s minds.

You mean he couldn’t multiply by 15% in his head, or that he couldn’t work out multiplying by 15% on paper?

Yeah, thats the story that made me write that post. I was being lazy and didn’t want to get into the details.

I just think its interesting that something so easy to define under certain circumstances is not easy to define at all under others. I think most people’s first reaction to the question is “thats easy”. Then after a few moments of thought its like “hmmm, not so easy”. If it wasn’t for some interesting physics you wouldn’t be able to do it.

It’s the tentacle that makes the “L”. Duh.

I was surprised as hell recently when I wasn’t sure where on a road a certain restaurant was (in other words, if it was before or after the intersecting road we were on, so whether we should turn left or right to get there.) I pulled up a map on my phone at a light and got a glimpse of it before it turned green - it was to the left, which is what I’d suspected. Handed the phone to my fiance just in case we needed the map again.

When we got to the intersection he said “Wait, no, you turn right!” “No you don’t. Obviously. It’s a left.” And it was. So when we pulled into the parking lot I looked at the map where he was trying to show me that it was obviously a right… and I was all, “um, dear, you do realize you’re looking at it upside downish? That we were coming from the top towards the bottom?” And he said “What? Why did it do that?” “Because up is north?” “Oh, why didn’t it reorient to where we were?” “Who the hell wants it to do that?”

He’d never, ever not had a GPS map reorient itself to his position because that for some reason makes sense to him? A map that MOVES? Who the hell wants a map that moves? It weirded me out to even think about wanting it to do that. How on earth do you ever have any sense of the geography of a place if your map moves around?

He is, by the way, awful at directions. Loses his car in the parking lot all the time.

Way back in first grade I had troubles with putting my shoes on the wrong feet. This was because left and right made no sense to me as far as knowing which was which. The shoe trouble happened because we had to change our shoes for recess if we were staying inside and because we wore rubber galoshes over our regular shoes to school in snowy weather. Mom wrote an r and an L in each shoe but that didn’t help since I didn’t know which side was which. People told me my feet would “go out” if I had the shoes on the wrong feet but I couldn’t see that since that effect was so slight on my little feet. Sometime before second grade, I figured out how to tell which foot the shoe went on by the shape of the sole. It took dad showing me with his size 10 1/2 shoes for me to finally see the difference between left and right shoe shapes. There just isn’t much difference in little kid shoes!

Actually, the more I think about it, the more I think “not really”. Try to define “CW” and “CCW” without using any reference to “left” or “right”. You’ll quickly see that you cannot.

You cannot say “ok, CCW is the way the planet turns when looked at from the north pole”. First of all, you have no idea whether their planet turns the same way as Earth does. Also, defining “North” and “South” is pretty tricky as well.

How do you define “light rotation” (CW or CCW) unambiguously without knowing what is left and what is right? Any definition I can think of ultimately rests on knowing what is left and what is right.

Unless you are willing to go ahead anyway and having a 50% chance of the definition ending up completely reversed. You may think that “Fzoox” means “right” in alienese, and that “bdoing” means “left”, but maybe you’ll meet them one day and you find that it’s the other way round. Maybe just changing the dictionaries would be enough, but if there is a lot of scientific work that has been carried out in cooperation using different definitions of “left” and “right”, I imagine there would be problems…

What if the aliens are not bilaterally symmetrical? What if they have radial symmetry like starfish or no symmetry like amoebas?

So I’m a math professor, and through teaching, have come to understand many of the different ways that people understand numbers. I assure you that what you have described, is indeed math. After all, math isn’t the algorithms themselves, but the ability to reason as you have above. It’s the ability to say things like “Once you can figure out 10%, you can figure anything else out.” So, yes, you do need to be good at math.

My contribution: I have a very poor memory for colors. As far as I know, I have normal color vision, and my favorite art is that with the most vivid colors. I also like Rothko rectangles for their subtle play with colors. I also have good geographical, spatial, and textual visualization and memory skills. But I cannot for the life of me remember what color anything is. For example, as I type, I cannot remember the color of my wife’s eyes.

I seem to lack the ability to remember my life. :frowning:

One way to think about memory is to divide it into episodic memory and semantic memory. Episodic memory is memory about things that happen to you. So remembering sitting in a classroom, and it was hot, and the teacher was talking about Columbus–that’s episodic memory. Remembering what the teacher said, on the other hand, is semantic memory.

Learning about this helped me understand why my friends could remember things I couldn’t (“you don’t remember when we went to here or did that?”), but I still got good grades. How is that possible? Lousy episodic memory but good semantic memory. I may not remember where or how I learned something, but I know the information. I know what movies Spielberg directed, but I can’t remember who I saw them with.

This. Twice in the past two weeks, I’ve looked right at someone for an extended moment without realizing they were friends. I was flabbergasted when someone told me they pretty much see the identity in someone’s face immediately.

On the flipside, thinking in pictures is so wired into me that I have a hard time understanding how it might be to not think in pictures. When someone describes something to me, or gives me directions, I pretty much build up a picture in my mind as they describe it, and then use that for reference.

Really? 10% is difficult to figure out? I’m certainly willing to acknowledge it. I probably have the mental blindness towards geography a lot of people on this very board deride. I just don’t see the point - they make lots of maps, after all. But the thing is, I’m not good at math. I have to work at it. Yet this 10% thing is no problem at all for me.

Brynda, might I suggest journaling? When I write things down, it helps me remember them more.

Pretty close to Mrs Gargoyle…she completely lacks the ability to visualize space in her head. Common examples…

Her: “Can we move the bookcase to the corner?”
Me: “No, it’s too tall and will block the window”
Inevitably, I will need to get out the tape measure. We’re not even talking slightly off a few inches in question either, like the bookcase will be 3 feet too tall.

Or “Let’s plant a garden by the front fence”
“You mean where the laurel tree is? We’d have to do something about the fountain and the flagstones.”

It took her a while to understand that I could “see” the images directly in my mind, and wasn’t simply memorizing an infinite number of lists and data about the environment.

There’s other prosopagnosiacs here?

Abilities I did not (originally) know it was possible to lack:

• When someone describes a song as being in a major key, and says to assume it’s in C major and the melody line goes C, C, G, G, A, A, G, you honestly can’t tell that the song can’t possibly be “Free Bird” and also can’t quite be “old MacDonald Had a Farm” but that “Twinkle Twinkle Little Star” could definitely be it.

• When someone says “Hey, does ‘Twinkle Twinkle Little Star’ use the same melody as the ‘ABC’ song, the alphabet song”?, you don’t immediately realize (if you did not already know) that yes indeed it’s the same music.

• That if someone asks you which note is the place where the chord changes, you can’t just tell that it changes on “Little”, on the first A after the C, C, G, G. And that it changes from a major C chord to a major F chord
Abilities I don’t have that many other people seem to:

• They can walk into a building from the sidewalk, make various turns in the corridors, get into an elevator, get off the elevator on a different floor, and when asked point in the direction of the sidewalk they came in from.

• They can meet 10 people at a party that they’ve never seen before in their life and not only can they recognize them as someone they’ve seen before if they see them later the same week, they can identify them by name.

• If told that Column C equals Column A times Column B, and told to eyeball a spreadsheet of some 20,000 rows, they can skim down page after page and stop short on row 9496 to say “this isn’t right; you’ve got 13401 in Column A and 7961 but Column C says 66505, so something’s way off”.

raises hand good god yes.

I worried once that I would not recognize my parents at the airport.

I didn’t say finding 10% is hard. I said being able to make the connection “Once you can figure out 10%, you can figure anything else out” is hard.

Of course 10% is easy to figure out. But we were talking about a 15% tip. What is hard for people is recognizing that
A. I already know how to find 10%
B. Therefore I can easily find 20%
C. Knowing these, I can find 15% by averaging
D. But in part C, I don’t have to be that exact (but did I have to in part B? Why would that be any different?) (which way should I round?)
E. And that A-D not only consists of things I already know (hence I can ignore my god-forsaken Math Phobia), but is also all I need to find 15%.

F. Oh but I have to keep two numbers in my head to figure out the third? Maybe that is a bit much.

You are good at math if you think (as I do) that finding 15% is really just finding 10%, plus a couple other things. That’s the kind of awareness of the connectedness of different numerical concepts that is what math ability actually consists of.

I don’t mean to pick on you, Anaamika, but I think it’s instructive to understand why others don’t understand things.

I’m asuming visual contact, either in person or diagramatic, perhaps because I’m one of those people who get enormously irritated when someone calls CW “right”… “right on top or right at the bottom? :p”

Thank you! You just put in words something that had been bothering me. People tell me “you have such a good memory” when I know I suck at memorization. I have good episodic memory… between you and me, we make one good memory and a lousy one :slight_smile:

Aaaaaah, that’s the problem then :slight_smile: You are assuming visual contact or diagrams. The point of the exercise is to determine what is left and what is right purely via exchanged radio messages, without visual cues of any kind.

Without a visual cue, you have to rely on the basic breaking of parity in beta decay. There is no other physical phenomenon that allows you to distinguish left from right without visual cues.