It seems that perhaps they do.
If spinners twist yarn in one direction, clockwise or anticlockwise, we find it is twisted in the same direction if we come at it from the other end. Experienced spinners know that if you spin your yarn clockwise (giving it what we call a Z twist) and then wind it onto a storage bobbin, the new outer end will also show a Z twist, and it can be plied anticlockwise (S twist) without just adding more twist and making corkscrews. Can you see that both ends of the yarn on this storage bobbin twist the same way, like the downstroke of a Z?
WARNING – PHYSICS AHEAD
But don’t panic; we have worked hard to tell the story at a simple level that I can understand. And believe me, my level of physics understanding is very low indeed.
After many years working for a research department, my husband retired – not, as he puts it, from doing physics, just from being paid for it. Now he can spend his time researching anything that interests him, such as the characteristics of matter and energy.
He says that a fundamental particle of matter is a bit like our twisting yarn. It rotates in a constant direction, clockwise or anticlockwise, as it moves through space and time. The movement combined with the rotation can be represented as a twist, or in the language of physics, a helix.
Like spun yarn, a helix is seen to rotate in the same direction, no matter which end it is viewed from. If it’s rotating clockwise the helix is called right-handed (just as you normally start your drive wheel turning to the right) and if it’s rotating anticlockwise it’s called left-handed (the direction we normally ply).
The constant direction of rotation, seen as the helix rotates away from you (no matter which end you’re looking from) is called its intrinsic chirality, or handedness.
But there’s a subtlety that becomes important for cosmology.
Fundamental particles come in different types – protons, electrons and so on – and each type has an opposite number called an antiparticle. A particle and its antiparticle are exactly the same in most ways, but if a particle and its antiparticle meet they destroy each other, usually leaving behind nothing but some electromagnetic radiation.
Physicists generally think of an antiparticle as an equivalent to its particle but moving backwards (from our point of view) in time. And books and articles often say that the antiparticle’s chirality is opposite to that of its equivalent particle.
If you look at a left-handed helix (or some plyed yarn) and imagine you are a particle travelling away from you through time, you will find yourself going around anticlockwise. Try following the path of the blue-green wool –
Now try again from the far end – this time, turn yourself around and come back frontwards and it will be just as it is with the plyed yarn. From either end, you are going anticlockwise.
The authors of those books and articles are not thinking about the motion from the point of view of the antiparticle, which is travelling through time in the opposite direction from them. Their future is its past. They are seeing it coming towards them from their future as though they were walking backwards with it. So what they feel they see is a right-handed helix. But the right-handedness is not intrinsic to the antiparticle.
Trying to explain this clearly, Fred was experimenting with lengths of wire that had been wound around a cylinder. He discovered that if he did two the same, both clockwise for example, they could mesh nicely together. But one clockwise and one anticlockwise could not mesh or work together in any way. This is something I gather will be relevant as he continues developing the topic.
Right now, he just wants to make it clear that equivalent particles of matter and antimatter have the same handedness, whether you see them coming or going. He devised a diagram, with a helix at its heart, and asked me to create it with Photoshop Elements. “Not a chance” I said, “spirals are much too hard. But wait – I think I have just the thing!”
A rummage in my Spinning Wheel First Aid Kit produced a spring, which I had been given for possible use on a scotch brake but which was a little larger than the usual one. It could be stretched as needed.
The spring was right-handed, but he wanted a left-handed, anticlockwise helix, because that is the direction particles rotate in our world. Flipping the picture achieved this (flipping the spring, of course, didn’t) and then the ends were cropped.
After hours of painstaking editing, we finally ended up with the picture below which was exactly what he wanted. Don’t be puzzled by “Z or S” at the far end of the helix – to physicists Z and S mean quite different things from what they do to a spinner.
If you would like to find out more about his work, his blog is here
and this is the post with the spring picture (which is in the second of the PDFs linked at the end)