At 09:40 am 02-05-05 +0000, Grimer wrote: > I was curious as to what would happen if I made a > plait of three strings and drew one of them out. I > used a fairly stiff plastic string, poly-something, > and loosely plaited the three strands. > > The ends of each strand were marked so that I would > know which one to pull and which two to hold. > > I was expecting the two which were left to be coiled > around one another but to my surprise they were > completely separate. > > Jones mentioned the structure of DNA. I wonder if > there is some connection. > > Cheers > > Frank Grimer > > =============================== > et plectentes coronam de spinis > ===============================
To further my investigation into the three dimensional structure of a braid I loosely platted three stiff wires together. The plait was too stiff to draw one of the strands out so I cut a strand into sections with snips so that the short pieces fell away from the braid. Sure enough, two completely separate strands were left. These strands had the structure of a sine wave which rotated along its length. I remember reading once a complaint that the rotational polarization of light tended to be overlooked. I can now understand why. Presumably the speed of the 3 platted sine waves is differentially attenuated in the same way that the speed of blue, yellow and red light is differentially attenuated in refraction. Whilst on the subject of visible radiation it is worth noting that three separate colours are needed to make white light and that we have three sets of cones for the detection of visible light. =============================================================== http://hyperphysics.phy-astr.gsu.edu/hbase/vision/rodcone.html The experimental evidence suggests that among the cones there are three different types of colour reception. Response curves for the three types of cones have been determined. Since the perception of colour depends on the firing of these three types of nerve cells, it follows that visible colour can be mapped in terms of three numbers called tristimulus values. Colour perception has been successfully modeled in terms of tristimulus values and mapped on the CIE chromaticity diagram. =============================================================== A coincidence? I very much doubt it. Cheers Frank Grimer ======================================= dixitque Deus fiat lux et facta est lux =======================================
