I’ve been a GIS professional since before it was called GIS. I couldn’t agree more with the above.
I have a cousin (once removed) who could never tell left from right. Everyone always said she was stupid. Then it became known that you can have left-right confusion and still be very intelligent.
My cousin is still very stupid.
In high school physics, we were doing stuff with “the left-hand rule”. I’m left-handed, so it was inconvenient to keep having to pick up the pencil. So I was doing it with my right hand. Teacher sees me, says, “The OTHER left”. I reply, “It’s OK, sir, I’m reversing the sign.” He just shakes his head–he knew I knew what I was doing.
Think of it this way: you could paint the words “PORT” and “STARBOARD” on the sides of a boat in the shipyard, and they’d always be correct no matter where you’re standing or where the ship is pointed.
You can do that with your hands too. Is there some distinction I’m missing?
When I was a lad I wore a watch on my right arm for similar reasons. I think I got the idea from Bob MacAllister or Mr. Rogers.
How did you know which wrist to put the watch on?
Red Right Return.
Exactly the same as you can tattoo “Left” and “Right” on the backs of your hands and they’ll always be correct no matter which way you’re facing, bending or twisting.
Left and port are exactly synonyms. As are right and starboard. The only difference is which frame of reference they apply to.
The real meat here is coordinate system transformation between different frames of reference.
At the scale that matters to people going about their day, the Earth is flat, meridians are all parallel to one another and so North, East, West and South are stable orthogonal directions. Which sets up a single fixed 2D coordinate system = a single frame of reference.
Meanwhile, your body (ignoring for a moment that it’s flexible) has a different immutable coordinate system of head, feet, front, back, left, and right. Which is an equally stable, but different frame of reference from the Earth’s.
The gotcha is that people going about their day need to routinely perform coordinate transforms from body-centric angles and distances to Earth-centric angles and distances. If I’m facing north and point straight out to my left, am I pointing North, East, South or West? What if I’m facing East and point straight out to my right?
Some of us do that effortlessly. Others can barely even comprehend the need to do it, much less how, when, or why.
As between two people there are often coordinate transforms between their body centric coordinates and yours. Sitting at a cocktail table across from your main squeeze with the rack of condiments at your left hand, it’s at their right hand. Some folks can’t see that idea one iota, and others can’t not see it as so obvious as to be unworthy of conscious thought or mention.
Once you introduce ordinary land vehicles and ships you get a third set of coordinates to transform through and between. Quick, on a westbound ship when you’re facing starboard, is the right side of your body facing North, East, South, or West? Trivial for some, incomprehensible for others.
Of course we can add 3D and make it even more fun. Quick, on a westbound airplane when you’re facing starboard, and the plane is flying upside down, is the right side of your body facing North, East, South, or West? Trivial for a smaller subset, hard for most, incomprehensible for even more.
Now bend over so you head’s between your knees and look behind you. In the coordinate system defined by the way your head is oriented and your eyes are pointed, which way is Earth’s up? or North? Or your left? Or your up? Or the airplane’s up? Or the airplane’s starboard?
That’s what’s at the core of all these confusions. People who somehow develop the instinctive idea there is one single rigid set of coordinates and no other. Like the congenitally blind have a hard or impossible time comprehending the idea of color, the coordinate-transform blind have a hard time seeing the need for, much less how to, switch POVs.
If I thought about it, I knew which arm was which; it was during more spontaneous situations I had difficulty - and besides, using my dexterous sinister hand to put the watch on the less-useful arm is more natural than gauchely using my less-dexterous dexter hand to try to put a watch on my good arm.
Apocryphal cute kid story:
Art Linkletter [or similar person]: “Johnny, what do you know about God?”
Johnny: “God is left-handed.”
Art: “Really? Why do you say that?”
Johnny: “Because Jesus sits on the right hand of the Father.”
And then there was the other guy at university, who had learned it reversed because he thought it was funny (and, forgive me, I kind of think he was correct). So when you were sitting in an exam, looking around trying to remember how to answer that question – hang on, which hand should I be using?
The implications of this may not be obvious to everyone, but today I (a non-accountant) had to explain the basics of debits and credits to a Vice President of Finance/Division Controller.
It’s worse than having to explain Germ Theory of disease to a doctor.
The debit and credit joke:
You can label your hands “left” and “right,” and they’d be correct. But you but you couldn’t label one side of the boat “left” and the other side “right” and have it always be correct.
Similarly you can’t label one hand as “port” and the one one “starboard” and have that be correct. Some people don’t seem to get that.
The same is true if you label one wall of your house as west and the other east. That’s fine, but don’t label your hands west and east or walls on your house “left” and “right.”
Apologies if I’m overexplaining.
I’ll be sure to remember that, the new accountant thought, as he re-arranged his office furniture for better feng shui.
Oddly enough, I don’t have a problem with those transformations. When I walk towards the stern, starboard is on my left, but when I head to the bow, starboard is on the right (and equipment with odd numbers is generally starboard, while even numbers are port, and lower numbers are forward of larger numbers)
Yes you can. Port means left, starboard means right. There directions are all relative to a certain orientation of you or a boat.
No - “port” is left when you are facing the front of the boat. When you are facing the back of the boat , “port” is on the right. Port and starboard are relative to the orientation of the boat, right and left are relative to the orientation of your body.
Take this out of the water. Let’s say I’m giving you directions to my house and you have to turn off Elm Street at Main St. I have to know which direction you are traveling on Elm in order to tell you whether to turn right or left at Main , correct? Because right and left are relative to the direction you are traveling. On the other hand, if I tell you to go west on Main, it doesn’t matter which direction you are traveling on Elm. Because west is always west, whether you are going north on Elm or south.
I need a cite for that. I have never heard that left suddenly becomes right when you face the back of a boat. But I haven’t heard of everything, I didn’t realize stray golf shots are named relative to the handedness of your swing. What you say doesn’t make much sense though, it would mean a captain’s orders change meaning depending on which way he is facing.
Perhaps I am misunderstanding the wiki on the subject:
" Port and starboard unambiguously refer to the left and right side of the vessel, not the observer. That is, the port side of the vessel always refers to the same portion of the vessel’s structure, and does not depend on which way the observer is facing."