What would be the new clockwise?

[chakka35]

This may be an old chestnut; I have certainly thought about it for years:

If analogue clocks and watches, and all memory of them, disappeared, how would one define clockwise?
Unlike north, south, east and west which are absolute, clockwise is relative to the observer. If I rotate my hand in front of me in what is to me a clockwise direction it is anticlockwise to someone looking at me from the front. To a fly on the face of a clock the hands between him and the glass are going anticlockwise, and so on.

One definition is "the direction which the sun appears to take around the sky to an observer in the northern hemisphere looking south". Not exactly snappy. Or "the direction in which a normal screw is tightened". The word"normal" dilutes that one but is necessary to allow for left-handed screws.

Is there a natural object or phenomenon which moves in a circle and which can be viewed only from one direction? Something astronomical comes to mind, since it cn be viewed by us only from the earth. But what?

(Incidentally, have you noticed that , in the opening titles of Have I Got News For You?, the villain who is presumably supposed to be turning the pipeline off is actually turning it on?) chakka35 (Thu 16:54 28/Jan/10)

[vascop]

Chakka
I understand your point and I wasn't trying to annoy you. What I meant was that what you said in reply to my earlier post about the worm is not a valid criticism of my idea about walking around something, because the worm is like the person on the other side of the glass.

[boxtops]

If there weren't any clocks then we'd have to think of something else to call it, anyway...

[vascop]

Chakka
The thing is, I thought you were saying that my definition of walking round something and keeping it on your right was no good because of the worm looking at it the other way round.
I don't see why that's an objection to my idea.

[chakka35]

Because the worm can see the movement as anticlockwise, walking round the pole is no different from the double-sided clock, the fly on the face of the clock, my rotating hand and so on. What we need is something that can't be seen from both directions. We achieve this artificially in the case of the clock by blocking off the rear view.

I have an idea. Years ago a metre was defined as the length of a brass rod kept in controlled conditions in some French academic establishment. That was the only true definition of a metre. (It's done more scientifically nowadays, of course.)

So the Royal Society or some such organisation could broadcast, 24/7, free for all to see and to copy, a video recording of an object rotating in what we now call a clockwise direction. It would bear the legend:

The above rotation defines XXXwise when viewed directly. If viewed in a mirror it defines antiXXXwise.

XXX represents the new name which boxtops rightly says would be needed.

[mibn2cweus]

https://www.youtube.com/watch?v=hDz2Zd9TGaI

https://www.youtube.com/watch?v=aJUd6HC7rbI

[vascop]

In science a right-handed screw is the name given to a screw which moves away from you when you turn it in a clockwise direction. A left-handed screw is the name given to a screw which moves towards you if you turn it in a clockwise direction.
So all anyone in the world needs to do is to have a screw of either type, as long as they know which type it is, and turn it in any direction and observe whether it moves away from them or towards them and then they would know which way was clockwise/anti-clockwise.

[vascop]

What if you put 2 clocks back to back? Then 2 people, one looking at each clock would still disagree about which way is clockwise. We didn't make clocks viewable from one side only for any particular reason! Clockwise is not an absolute concept!

[vascop]

This means that the clock itself does not provide, and never has provided, what you are asking for.

[willowman]

A friend doing DIY used the phrase "righty tighty, lefty loosey" when doing up a screw, and a heated discussion ensued with his wife about which was right and which was left.
He said that turning a screw to the right meant the top of the screw turned right, she argued that the bottom of the screw turned left, so the mnemonic was useless.
But the mnemonic "clockwise tighty, anti-clockwise loosey" doesn't have the same ring about it.
So does a screw or nut being turned clockwise go to the left or the right?

[vascop]

It's not about turning the screw right or left, which, as you say, is a meaningless concept, since the screw does not move to the left or right but just rotates.
It's all about using the right hand or using the left hand to turn the screw.
If you clench your fists and put your hands in front of you, thumbs upwards (it's very hard and almost impossible to do it any other way - try it), and twist your right hand so that your thumb moves away from your body (a natural movement), then you are tightening up the screw (clockwise). If you make a similar movement with your left hand (move the thumb away from your body towards the left), then you are loosening the screw (anticlockwise).
This, it seems to me, must be the origin of the terms right-handed screw and left-handed screw.

[chakka35]

vascop, I know that clockwise is not absolute: I said that way back in my orginal question!

A clock with its back blocked off does show clockwise. As I said before, this is an artificial way of blanking off the other way of looking at the hands, but it works.

The screw idea might work, provided that screw manufacturers quite independently retain the memory of how the thread should be cut.

[vascop]

Another thing about looking at a clock from the back. You would notice that the numbers were back to front and so you would know that the clock movement was anticlockwise. So no confusion arises.

[modeller]

This is a problem in crosswords the clue asks the a word for the way plants twine around a support clockwise or anti clockwise ( dextral or sinistral ). The answer was always opposite to what I had observed however it appears that you look at it from the apex i.e. looking down. The same applies to whorls on snails and fossils you look at the middle point.

[chakka35]

Yes, vascop, but we're wandering off the point. I mooted a world without analogue clocks or any memory of them.