Answered in the post above
I don’t know what you’re doing but it’s like saying that cars don’t drive on the right. I’m not going to keep repeating things I know you understand but are pretending not to see.
deisil (pronounced deshil) is the Irish word for clockwise. It comes from “deis” meaning “right” and is also related to “deas” meaning “south” and (I speculate) to “dea-”, “deas” meaning “good” or “nice”.
“Holles” is the name of the street where stands our National Maternity Hospital, and by metonymy refers to the hospital itself, whereto my mother parturient went and wherein I was born (and Joyce was not).
I think we can all agree Sinistral Mollusc is a cracking rock band name.
But “righty-tighty” is inaccurate. Turning something in a circle is not turning it to the right. In the case of a screw, when you tighten it, the top is moving right and the bottom is moving left.
That mnemonic only makes sense with the implied term “righty-righty at the top” which no-one ever explained to me, so I was confused by it.
Chronos, I’m with Fubaya - I don’t know what you’re doing. He did say a right twisted rope had to be coiled clockwise, but he has since clarified from what perspective that applies. He has already conceded his original statement was unclear. What more are you looking for? Him to commit seppuku?
That drawing is in conflict with the mollusk image in the Wikipedia page. She describes the curves “clockwise” and “counter-clockwise” by reading the curves from out to in, but if you check the Wikipedia page, they look at the mollusk from the top of the apex down to describe chirality. Actually, they look at the mollusk from the side with the opening facing you and then define a right-handed curl (dextral) by the opening being on the right hand side, which causes the coil inward to curve like your right hand - fingers coil inside palm, point of mollusk coils inside opening. From the top, the coil looks like a 6, where the apex is up and the large section with the aperture is on the bottom. That chirality is clockwise from inside out, which matches the dexter in dextral. That leaves “left-handed” coils as sinistral.
If you use the right hand rule vector form, “righty-tighty” makes sense. The thumb points inward to tighten, and you coil from palm to fingers, i.e. clockwise. Yes, that also makes the right hand rule work for loosening - the thumb would then point outward, thus the right hand would work, but with the thumb away from the screw, which is not typical for screwdriver work.
I wish I’d thought of it before choosing my user name.
And if I use my left hand, which I often do, does it make sense?
There are so many qualifications to this “rule” that it is meaningless.
Ok, folks. The etymology of widdershins over at m-w.com and its definition of sunwise support those alternate words already mentioned. But I am confused as to which goes with clockwise and which goes with counterclockwise. Do we assume we are facing north, so when the sun rises in the east and sets in the west the sun moves counterclockwise through the sky? And thus sunwise is counterclockwise? And widdershins which means contrary to the suns motion is clockwise? Somehow what is written above and in the etymology seem to be concluding the opposite. But I could be seeing a double negative where the writers did not intend it.
It doesn’t matter which direction you’re facing, it matters which hemisphere you’re in. If you’re in the northern hemisphere, where all these terms we’re debating originated, sunwise is clockwise.
Jim, you’re imagining a clockface set on a plane that’s perpendicular to the earth’s surface, so that in the northern hemisphere the sun goes right to left if you’re facing north. But you wouldn’t actually see the sun between about 6am and 6pm. Whereas with ‘sunwise’, the imaginary clockface is the surface of the earth. If you’re looking towards the sun in the northern hemisphere, it is always moving from left to right.
Ok, I’m confused. Suppose I am on one side of a street and I am watching a bike race, and all the wheels are spinning clockwise. If I go to the other side of the street and watch the race it will look like all the wheels are spinning counterclockwise. So clockwise depends on which direction you are looking. Or can you describe how you are interpeting then suns motion so this is moot?
Try this:
If you are in the northern hemisphere and you face towards the Sun you will see it moving from your left towards your right. It’s also rising higher or descending lower as it moves. But what matters for this discussion is only the left to right motion.
Now imagine standing there all day pointing your arm at the Sun as it slowly goes from sunrise to noon to sunset. You’ll end up with your hand sweeping out an arc of about 180 degrees.
Now imagine standing there and sweeping out that same arc with your arm over just a few seconds. That direction of rotation is what the ancients called sunwise. Viewed from above your head looking downwards it’s what we moderns call clockwise. Viewed from your own eyes’ POV you’d probably describe yourself spinning in that arc as turning clockwise.
Now IF you did that exact same experiment while standing in the southern hemisphere, you’d come up with Sun motion from right to left, and we moderns would describe that as counterclockwise.
All the people who mattered for the idea of “sunwise” lived in the northern hemisphere and either never thought of or didn’t care about how things would appear from down south.
Just like the rotation we call clockwise is only truly “clockwise” for clocks that run that way. Other non-standard clocks can and do run the other way. But nobody cares about that when inventing a general term for general use.
I finally get it, but arrived at it by thinking of a sundial. Wikipdeia reveals that sundial shadows go clockwise in the northern hemisphere and counterclockwise in the southern hemisphere. I cannot picture why (yet). But taking that as a given, if I were in a dark room with a flashlight and a sundial and wanted to make the sundial shadow go clockwise, I would walk clockwise around the table (clockwise defined looking down at the table). So as there the flashlight is a stand in for the sun, I can see why one would say sunwise is clockwise.
As to your “why but not yet”.
Think of my example of pointing your arm at the sun that defines clockwise in the northern hemisphere. A sundial shadow is the same thing, just behind you.
As you start out you point first roughly east at sunrise, then south at noon, then roughly west at sunset. Tracing out roughly half of a clockwise circle.
Meanwhile, right behind you your (or your arm’s) shadow starts out at sunrise stretching away from your feet towards the west. At noon it stretches out north behind you and at sunset it’s pointing roughly east. So it made a half of a clockwise circle from west to north to east while the sun made the other half of the same clockwise circle from east to south to west.
Update: I can now see why sundials go in opposite directions in the Northern/Southern hemispheres. If the earth were transparent, and someone in the northern hemisphere were looking through the earth at someone in the southern hemisphere, then the northern observer would say the southern observer was moving counterclockwise, and the southern observer would say the northern observer was moving clockwise. And in the flashlight/sundial example above, instead of walking around the table clockwise, we could stay still and rotate the table counterclockwise.
As I pointed out in the previous thread I linked to earlier, not all sundials are horizontal, esp. in the Middle Ages. Some are vertical. For those the shadow of the gnomon moves counterclockwise in the N. Hemisphere.
Here’s a page with several different types.
And those that have a shadow moving across an arc the direction is clockwise/counterclockwise depending upon which end you’re looking at it from.
Wait, Fubaya, I think I see the source of the confusion. I was picturing the rope being wound onto a rotating spool. Are you instead picturing the already-coiled portions of the rope being fixed against a stationary surface? Because in that case, there is a clear sense of “clockwise” and “counterclockwise” and it does matter, but then the problem is that you said “Coiling is just a spiral and is not helical”, but coiling a rope onto a stationary coil against a surface is in fact helical.
Sorry, I didn’t mean to imply you were holding the screwdriver with the right hand, just that the righthand rule principle applies if you hold out your right hand and orient it to fit the direction (in/out) of the screw.
Jim Peebles, the key is to look at the Sun, then determine which direction it travels. In the Northern Hemisphere, the Sun is to the South of you - by some amount. It may be high in the sky, but it is South. (Equitorial zones may be close enough that you can’t tell - I’m not certain - but this applies to temperate zones.)
As described by LSLGuy, because the Sun moves left to right, the shadow moves behind you right to left. But when you turn around to look at the shadow, it moves left to right, just like the Sun. Yes, this only applies to horizontal sundials. I was unaware of the existence of vertical ones, so thank you, ftg.