well for them, only the"wrong "kind is left! (Left-handed sugar tastes sweet, but gar. So it looks as though the phenomena of life permit a distinction between ight"and"left, "or chemistry permits a distinction, because the two molecules are chemically different. But no, it does not! So far as physical measurements can be made, such as of energy, the rates of chemical reactions, and so on, the two kinds work exactly the same way if we make everything else in a mirror image too One molecule will rotate light to the right, and the other will rotate it to the left in precisely th mount, through the ant of fluid. Thus, so far physics is concerned, these two amino acids are equally satisfactory. So far as we understand things today, the fundamentals of the Schrodinger equation have it that the two molecules should behave in exactly corresponding ways, so that one is to the right as the other is to the left. Nevertheless, in life it is all one way! It is presumed that the reason for this is the following. Let us suppose, for example, that life is somehow at one moment in a certain condition in which all the proteins in some creatures have left-handed amino acids, and all the enzymes are lopsided-every substance in the living creature is lopsided-it is not symmet rical. So when the digestive enzymes try to change the chemicals in the food from one kind to another, one kind of chemical"fits"into the enzyme, but the other kind does not (like Cinderella and the slipper, except that it is a"left foot that we are testing). So far as we know, in principle, we could build a frog, for example in which every molecule is reversed, everything is like the"left-hand"mirror image of a real frog; we have a left-hand frog. This left-hand frog would go on all right for a while, but he would find nothing to eat, because if he swallows a fly,his enzymes are not built to digest it. The fly has the wrong"kind"of amino acids (unless we give him a left-hand fly ). So as far as we know, the chemical and life processes would continue in the same manner if everything were reversed If life is entirely a physical and chemical phenomenon, then we can understand that the proteins are all made in the same corkscrew only from the idea that at the very beginning some living molecules, by accident, got started and a few won omewhere, once, one organic molecule was lopsided in a certain way, and from this particular thing the"right "happened to evolve in our particular geography a particular historical accident was one-sided, and ever since then the lopsidedness has propagated itself. Once having arrived at the state that it is in now, of course it will always continue--all the enzymes digest the right things, manufacture the right things: when the carbon dioxide and the water vapor, and so on, go in the plant leaves, the enzymes that make the sugars make them lopsided because the enzymes are lopsided. If any new kind of virus or living thing were to originate at a later time, it would survive only if it could"eat"the kind of living matter already present. Thus it, too, must be of the same kind There is no conservation of the number of right-handed molecules.Once started, we could keep increasing the number of right-handed molecules. So the presumption is, then, that the phenomena in the case of life do not show a lack of symmetry in physical laws, but do show, on the contrary, the universal nature and the commonness of ultimate origin of all creatures on earth, in the sense de- ibed ab 52-5 Polar and axial vectors where wa we go further. We observe that in physics there are a lot of other places where we have“ right”and“left” hand rules. As a matter of fact, when we learned about vector analysis we learned about the right-hand rules we have to use in order to get the angular momentum, torque, magnetic field, and so on, to come out right The force on a charg moving in a magnetic field, for example, is F= y X In a given situation, in which we know F, v, and B, isn't that equation enough to define right-handedness? As a matter of fact, if we go back and look at where the vectors came from, we know that the "right-hand rule"was merely a convention it was a trick. The original quantities, like the angular momenta and the angular velocities, and things of this kind, were not really vectors at all! They are all 52-6