ON TWO SUNDAY afternoons recently I have seen a few minutes of television in which I was repeatedly told, or very nearly told, in a bullying voice that flying saucers are true, that Atlantis is true, and that Uri Geller can bend keys by the power of his mind. The pictures showed model UFOs, a volcanic eruption somewhere and bent keys.

So much is plausible if you have no use for scientific fact: today planets will guide new love into my life or money into my pocket while UFOs hover above me; today someone's cancer will be cured by apricot pits. The difference between planets or UFOs or apricot pits and the kind of science that these two new books aim to explain is that the new science is more imaginative, more intricately linked to experience, and on the surface much less plausible.

Was it plausible to be told that we and our earth are composed of atoms that are miniature models of the solar system? We were told that 70 years ago and have sort of got used to it. Twenty years ago people used to refer to the electrons, protons, and neutrons that compose an atom as elementary particles. Then as it began to turn out that neither the particles nor the study of them had any reason to be called elementary, the adjective was quietly dropped. There are now perhaps 200 kinds of particles known or surmised, and which, if any of them, are more elementary than the others is one of the more obvious questions that quantum physics is trying to answer.

Twenty years ago people used to talk very little about cosmology, the study of the universe as a whole--its nature, origin, and fate. Einstein and a few others had studied it part-time and there were a few papers and books, but the available scientific data on the universe as a whole were so scanty that no responsible scientist wanted to erect much of an intellectual structure on them. Besides, there was a philosophical question that lay rather near the surface: what would a theory of the universe consist of? General laws with a demonstration of how they can be used to explain the universe? The universe as a particular case of general laws? But there is only one universe--by definition, that's all there is, and so what can it mean to generalize about it? The only possibility was to construct a theory of the cosmos out of the laws learned from other sources--ultimately, from the laboratory. To do this you would have to know, or just assume, that the laws of nature we know so accurately today were valid under the conditions of gigantic heat and pressure and turmoil that accompanied the Big Bang, some 15 billion years ago. And nobody wanted to assume that.

Today we know at least some laws that have not changed appreciably over billions of years, and a remarkable and unexpected linkage is becoming apparent. It is perhaps not surprising that we need to understand particle physics before we can explain the processes by which early chaos developed into the amount and kinds of matter we know now. But the connection goes the other way too. There are some hypotheses of particle theory which can be verified, if at all, only by studies at energies too high for the laboratory. But these energies once existed, during the universe's first millionth of a second, and the new particle theories must be tested by seeing if they can explain what must have happened then.

All this is to explain why Pagels' book on particle physics and Morris's on cosmology are being reviewed together and why, if one is interested, they might very well be read together.

agels is concerned with the order in the universe and its expression in mathematical terms, what he calls the cosmic code. He happily quotes a remark of the 19th-century physicist Heinrich Hertz: "One cannot escape the feeling that these mathematical formulae have an independent existence and an intelligence of their own, that they are wiser than we, wiser even than their discoverers, that we get more out of them than was originally put into them." The origin of much of this mathematical wisdom can be traced to symmetries, and he explains how considerations of symmetry have led people to choose, out of countless possible bad theories, the ones that have a good chance of being right.

To lead us into his subject Pagels gives us several chapters of historical introduction. They are pretty awful. History is not a discipline for Mr. Pagels. Names and dates are wrong; crucial arguments are misrepresented; he talks about an Einstein paper as if he had never read it. He discusses Durer's Melancolia engraving without understanding what it is about. And he does all this in a loud, patronizing voice that reminds me of the man on the tube. If is not enough to use language clearly and simply; it must be hyped with mindless journalistic words like "bombshell." Still, the book improves as it proceeds, and it is a good place to learn the modern ideas if one can stand the noise.

The Morris book is a model of its kind. It is written with unpretentious simplicity and clarity, and organized about the question of the ultimate fate of the universe. Will it continue forever to expand as stars one after another burn out, or will it collapse into the same chaos from which it emerged? The question is in principle easy to answer if one makes the right measurements, but it turns out that our universe is at the balance point, and we cannot say which way it will fall. What this fact means, unless it is a pure coincidence and means nothing, is one of the most interesting questions of modern cosmology, and Morris, with wise caution, touches on only some of the implications. He does, however, describe the cosmos as we know it with its cargo of stars and other forms of matter: gas clouds, quasars, pulsars, and, perhaps, black holes. He points out that we cannot rule out the possibility that our entire universe is a black hole in a larger one. Both these books reach out toward a reader who is interested in knowing where and what we are in the created universe, and what it means to us to know.