A Step Farther Out (31 page)

There is a serious search for extra-terrestrial intelligence, as Frank Drake and his colleagues listen for messages from Out There.

I have been privileged to watch all this. One of the great rewards of my business is attending science conferences, space launches, planetary probe encounters: of
being there
when history is made. It has been a decade of wonder—and thanks to my readers, I was there.

This chapter has been put together from a number of those conferences; it has no theme other than as a potpourri of marvels; but I think it will not be dull.

Did California discover Europe? Will fusion power be used in the Light Water Reactor fission system? Whatever happened to super-heavy elements? Can we build public highways to space?

Every year the Council for the Advancement of Science Writing puts on a week-long series of briefings. The 1976 meeting was different in that the National Association of Science Writers received a generous grant from the Upjohn Company to let them bring in writers who might not otherwise attend, and the NASW for unfathomable reasons thought it would be a Good Idea to have me come down and deliver my thoughts on creative techniques in science writing. Whether my contribution to the program was much use I certainly learned more from my colleagues than I gave them; the bottom line was that for a week I heard briefings from some of the top experts in a number of fields ranging from Dr. Jonas Salk on influenza vaccination to Berkeley's Albert Ghiorso on super-heavy elements; physics, medicine, anthropology, and more. It was all fascinating; I'll see how much of it I can share.

* * *

Until very recently we thought we understood the genesis of man: African origin, long period of evolution from ape to proto-man to Neanderthal Man; then, about 32,000 years ago Cro-Magnon (or Modern) Man appeared in Europe, quickly displacing his Neanderthal cousins. Cro-Magnon man then spread across the globe and simultaneously differentiated into races. Some 11,000 years ago mongoloid (but still modern man) hunters crossed the land bridge from Asia to North America, and 500 years ago came the Europeans and Africans; and here we are.

It may not be that way at all.

Dr. C. Ranier Berger, Professor of Anthropology, Geography, and Geophysics at UCLA, reports recent archeological finds that cast doubt on the Cro-Magnon aspects of this sequence, while Dr. George Todaro, who holds the unlikely (for making anthropological discoveries) position of Chief of the Laboratory of Viral Carcinogenesis, National Cancer Institute, has evidence that mankind evolved first in Asia, not Africa. All rather disturbing, and if any of my readers are looking for a field in which to make really startling contributions, I suggest a career in anthropology. The whole subject is due for a radical and fundamental restructuring. We really don't know very much about Man's prehistory.

First, Dr. Berger and the North American Indians. You can pick up mammoth bones all over Southern California, some of them 50,000 years old and more, and anthropologists have often suspected that a few of these mammoth bones are from beasts that died an unnatural death at the hands of persons unknown; but until recently there was no real evidence of this.

Out on Santa Rosa Island, a privately owned ranch that was once connected to the mainland, one finds both mammoth bones and what can only be hearths. The bones are burnt, and were fairly obviously cooked for someone's dinner. Recent finds make that virtually certain—and radiocarbon dating shows those hearths are more than 40,000 years old. The people associated with them are mongoloid, rather definitely modern man—so, it appears, the earliest evidence of what we call Cro-Magnon Man is now found, of all places, in California, leading naturally to the question, did the New World populate the Old? Alas, though, that's not certain. What we have are some undatable chunks of human bone which seem to be of the same strata and age as the cooked mammoths; stone tools and cooking hearths definitely more than 40,000 years old; but not the two together, yet. It would be nice indeed if we could find the burial grounds, some remains of those Paleolithic hunters who slew wooly mammoths on Santa Rosa Island 40,000 years ago.

All right: modern man was in the New World well before we thought he ought to be. So what? Well, the problem is,
how
did he get here? The Asian land bridge across the Bering Straits opens and closes periodically with the advance and retreat of the glaciers during Ice Ages, and is the only really credible route (unless you credit the Eskimo with a far older culture and water-faring technology than anyone ever has dreamed of); which of those temporary periods brought men from Asia to North America? There have never been any Neanderthal remains found over here. None at all—and at the moment, the oldest remains of Modern Man we know of seem to be associated with California. Very interesting.

Now back to viral cancer and human evolution. No one knows whether viruses cause cancer, are caused by cancer, or prevent cancer; indeed, each of those statements is true under certain circumstances, and actually it's more confusing than that: certain viruses certainly cause cancers, but those same infectious viruses are actually generated,
created,
by healthy animals who are themselves more or less immune to that kind of viral cancer. The theory is that these animals have evolved the cancer-virus-creating mechanism as protection—a kind of self-vaccination process. That evolution takes a long time.

The worst offender is the baboon, some species of which constantly contaminate their environment with cancer virus. Fairly obviously, any animal susceptible to that form of viral cancer has got to evolve protective mechanisms; certainly a species that's immune to baboon viral cancer has a better chance of survival.

Now of the great apes, the gorilla and chimpanzee are the most closely related to Man. This is not in dispute on scientific grounds except as part of a general attack on the whole evolutionary hypothesis mounted mostly by religious authorities. (The Catholic and most Orthodox churches have long ago come to accommodation with evolution, but many Protestant sects continue to oppose the theory, and some of their spokesmen have excellent scientific credentials; I don't care to get into that discussion here.) If though you accept that Man, the gorilla, and the chimpanzee all had a common ancestor, as most evolutionary theorists do, the viral evidence becomes important: because the chimps and gorillas, alone of the Great Apes, have evolved defenses against African baboon viral cancer. Neither Man, nor the gibbons, nor the orangutans have done so.

Baboon virus is infectious to Man, New World monkeys, and Asian apes. Incidentally, the common house cat has also come to terms with baboon virus, but not totally, arguing that the cats reached Africa well before Man, but not as long ago as gorillas and chimpanzees.

Dr. Todaro's conclusion is that somewhere after Man, the Gorilla, and the Chimpanzee differentiated—say 12 million years ago—gorilla and chimpanzee ancestors made their way to Africa and stayed there. Man did not, but must have spent nearly the whole of the Pliocene Era, all that time until perhaps a million years ago, in Asia. The data, he says, "suggest that. . . the older Australopithecines found in Africa, though clearly hominids, were probably, therefore, not in the main lineage to Man, but rather, unsuccessful offshoots whose progeny have not endured to the present." (Beneviste and Todaro, "Evolution of type C viral genes,"
Nature
Vol 261:101, 13 May 1976)

Which brings us back to my earlier statement, that if you're looking for a field that needs some really new contributions, anthropology is ready for a new genius.

So much for anthropology; now for something practical like energy. There were two speakers, Dr. Robert Thresher of Oregon State University who is part of an ERDA project on wind energy, and Dr. Moshe Lubin of the University of Rochester on fusion.

There's either not much, or far too much, on wind: that is, there is no startling new information, only a very great number of studies and experiments designed to inch our way forward to a time when wind might provide as much as 5% of our national electric power; and while 5% is respectable and very much worth working on, it's not going to change the world.

The largest windmill ever built was a 1.25 megawatt machine on Grandpa's Knob in Vermont. It was called the Smith-Putnam machine, it worked in the 40's and it was a failure: it couldn't compete economically with coal, and eventually suffered a catastrophic accident. (Windpower experts study "loss of blade accidents" the same way that nuclear engineers study loss of coolant accidents in fission plants.)

There was once a 200 kilowatt machine working on the city island of Gentzer in Denmark; at present that mill is tethered, but the Danes are thinking of refurbishing it. What's important are the numbers: a modern electric plant generates something like 1000 megawatts; the biggest windmill ever made was 1.25 megawatts; and ERDA's big new experimental windmill, the Mod Zero constructed near Cleveland to study stresses and strains of putting all that much metal up in the sty, is a 100 kilowatt device. It takes a
lot
of windmills to make significant amounts of power, which isn't to say that windmills won't be useful, particularly in remote windy places far from other fuel sources.

Fusion, on the other hand, is generating a bit more excitement. You'll recall from previous columns that fusion has its ups and downs: a few years ago, everyone thought it was the new hope of the future. Last year at the AAAS meeting you could cut the gloom with a knife. The present mood, according to Dr. Lubin (whose work at Rochester is in laser fusion) is one of controlled optimism.

First, nobody has changed their mind: fusion will not produce direct on-line power in significant amounts before the years 2010 to 2020, exactly as I've reported previously.

Second, the national energy plan still calls for about 50% of US baseload electric power to come from nuclear fission by 1990; and thirdly, present uranium reserves cannot sustain nuclear fission power at the rate of consumption for more than forty years.

That's the energy dilemma: we
need
nuclear power. If you think strip mines are bad now, wait until 1995 without nuclear, when there will be enormous freight trains running about the country carrying nothing but coal; coal-slurry pipelines will cross the deserts and rivers and wild places; black-lung compensation payments will be in the tens of billions of dollars a year. The precipitated flyash and other waste products will accumulate in
billions of tons,
and must be disposed of somehow, and even then millions of tons of pollutants will get into the atmosphere even with the best cleanup technology. We need nuclear power, which is to say fission power (the only kind we've got) to get to the end of the century: but the nuclear power fuels can't last very long after that.

Two ways to go. One is to make more nuclear fuel, which is to say breeders. I used to be a big enthusiast for the fast breeder, and I'm still willing to argue the case for them; after all, breeder technology, which we invented, is now in use in England, France, and the Soviet Union although we've yet to build a commercial demonstration plant. However, the breeder has its problems. Plutonium is nasty stuff. The nuclear fuel cycle has vulnerable points in it, times when terrorists might be able to get their hands on weapons-grade plutonium, or at least manage to get something that could be chemically refined into a weapon. Nobody, deep down in his heart, loves plutonium (but nobody really loves blacklung and other coal side effects, though we already put up with them).

What would be really marvelous would be a system that lets us invest in conventional Light Water Reactors (LWR's), a proven technology that we've got on the shelf, and operate them without nuclear fuel reprocessing. It turns out there may be two ways to do this.

One is the "slow breeder": Thorium, a relatively plentiful element, can be bred into U-233, which can then fuel conventional reactors. That's relatively expensive power compared to burning natural uranium, but it has the advantage of being a nearly eternal source of energy. Alas, it also requires a new technology, including mining and refining techniques, and it doesn't do anything with the truly monstrous amounts of uranium we've already mined.

There is enough U-238 around in mine tailings, stockpiles, etc., to last the world at least a thousand years. The value of the U-238 already mined in the US is one trillion dollars—a national treasure indeed if we can use it. U-238 won't fission, though, and has to be bombarded with neutrons to turn it into plutonium—and we've already discussed that. Nobody wants all that plutonium.

But suppose we could make the plutonium safe? Paradoxically, the best way to do that might be to make it more dangerous. That is, nobody in his right mind is going to try to steal spent fuel elements. "Used" fuel rods contain not only long-lived plutonium, but also various fission products, which are short-lived and thus
very
radioactive. You don't want to get close to them, and if you have the technology to work with things like that, you don't need to go steal your fissionables: that is, it takes something like a wealthy government to be able to make useful weapons out of spent fuel rods. The dangerous part of the nuclear fuel cycle comes when the plutonium has been extracted and is lying about by itself; that can be handled with only moderate care.

So now comes the point. Fusion power systems produce neutrons. (For a lot more on this subject, see "Fusion Without Ex-lax") When neutrons interact with U-238, they turn it into plutonium which can be used to power an ordinary LWR Suppose, suppose we took spent fuel elements, left them in the sealed rods, and inserted them into a "recharging" system? Can we do that?

According to Dr. Lubin, we can.

The current status of fusion research is summarized in Figure 27. You can see there are some problems, but we're moving toward getting useful power from fusion devices. However, as will be pointed out in "Fusion Without Ex-Lax," once you have achieved fusion you still do not have a useful power plant. What you've got is a lot of fast neutrons; they still must be caught and their energy extracted. You've still got to build turbines and generators or a big MHD (magneto-hydro-dynamics and don't worry about it) tunnel, or some other very massive and very costly system for taking neutron energy and turning it into electricity. That can be a very large problem, although it hasn't been emphasized much by fusion enthusiasts.