Now the Americans had to hurry up and match the Russians to prove the superiority of capitalism and freedom. They scheduled the takeoff of a satellite in Florida in December 1957, two months after Sputnik’s triumph. Reporters gathered from around the world, and everybody waited through two days of rain and “holds” until at last the moment came. The rocket rose four feet, paused, sank to earth, collapsed, and burned. The little satellite, unwisely christened Vanguard, rolled away, stopped, and chirped. An English newspaper headlined this fiasco as “Kaputnik,” and a paper in Japan described it as a “A Pearl Harbor for American science.” At the United Nations Russian envoys asked if the United States would welcome aid for less developed countries.
The Russians also had their failures, but for decades they would keep the worst one secret. In the fall of 1960 they endured the greatest horror in the history of exploration. Technicians had prepared three rockets to be sent to Mars, but two of them had fizzled after launching. When they tried the third one it would not ignite. The commander ordered his technicians to examine it up close. It suddenly exploded, killing scores and maybe hundreds of his personnel.
In the years that followed Sputnik, space technology advanced in leaps. The United States, having failed the first time, sent aloft a tiny satellite in 1958, and later they recovered a U.S. capsule after it returned to earth. The Russians photographed the far side of the moon, and they orbited two dogs and brought them down alive. The Americans launched a communications satellite to send TV over the Atlantic.
Satellites like this would soon permit twenty-four-hour instant global communications; they drew the continents together. They also made it possible to fully map the earth, learn much more about the earth’s ecology, and discover the alarming changes in its atmosphere. (Even in the early 2000s, the most important exploration done in space so far was that regarding planet earth.)
In 1961 the Russians had their greatest triumph in the race to space: they launched a “cosmonaut” (a Russian astronaut) into orbit. Courageous Yuri Gagarin orbited the earth in an hour and a half, then parachuted to a pasture in central Russia. Three decades later an official would recall that day: “I was in school. All lessons ended. Even today I can recall that tremendous joy…the tears we all had in our eyes — because we were the first, because we were in space…. almost everyone believed that in twenty years we would surpass the U.S. in every way…. We would become Country Number One in the world — and socialism would be utterly victorious”
For America, the Russian triumph was a shock. Two days later President Kennedy held a frenzied meeting with officials. He asked them, “Is there any place where we can catch them?…Can we go around the moon before them? Can we put a man on the moon before them?…Can we leapfrog?…Let’s find somebody, anybody! I don’t care if it’s the janitor over there, if he knows how.” A month and a half later Kennedy addressed Congress asking Americans to bear the costs of sending humans to the moon. He proposed that America “should commit itself to the goal, before this decade is out, of landing a man on the moon and returning him safely to earth. No single space project will be more impressive to mankind, or more important for the long-range exploration of space.”
As Kennedy knew very well, flying humans to the moon didn’t necessarily make sense. Many experts argued then and later that it would be cheaper, safer, and scientifically more fruitful to send robots to the moon or Mars, rather than a man. But Kennedy, a skillful Cold War politician, knew that he must not permit the Russians to be first to put a man on the moon. It didn’t take a rocket scientist to figure that out. With von Braun in charge, Americans prepared to make the journey. They orbited two monkeys, Able and Baker, and a chimpanzee called Ham, and then they sent up astronauts on little flights. Then the U.S. program matched the Russians’ triumph with Gagarin when, in 1962, it put an astronaut, John Glenn, in space. In five hours he circled earth three times and then descended (as was planned) in the ocean east of Florida. Soon after Glenn many other astronauts orbited the earth, and in 1968 Americans made the first manned voyage around the moon. They sent pictures of its rocky surface back to earth, where they were shown on television.
But Kennedy had promised “on the moon,” not around it, and “before this decade is out.” In July of 1969 the United States launched a three-man crew whose destination was the surface of the moon. Four days later Neil Armstrong and Edwin Aldrin landed on it in a “lunar module” while Michael Collins orbited aloft and waited for them. Mission leader Armstrong clambered down a ladder, trod in lunar dust, and spoke his famous line, “That’s one small step for [a] man, one giant leap for mankind.” Aldrin joined him, and a TV camera in the module filmed the two men for the millions watching on the earth. They raised a U.S. flag, gathered soil and rocks, and photographed everything in sight. Before they left for home the earthlings set in place a plaque that reads, “Here men from the planet Earth first set foot upon the Moon July, 1969 A.D. We came in peace for all mankind.”
A science writer (Wilson da Silva) tells us that after the moon landing he, then a little boy, and his grandmother stood outdoors one night gazing at the moon. She’d been born before the Wrights first flew their little plane in 1903. She said, “You know, they didn’t really go to the moon.” He was puzzled so he asked, “You mean, the astronauts?” She nodded. “It was done in a film studio. It had to be. How could someone get to the moon and back?”
For America and Russia both, what next? The moon was mastered, and our neighbor Mars, which might hold “life,” was (then at least) too far away for human flights. So both the rivals chose the same project, and in the 1970s each built a “station” about 250 miles away in space. These stations were short-lived, but in 1986 the Russians built another, and they maintained it for a dozen years. In 1998 a group of nations led by the United States began to build an “international” station as big as the passenger cabin on a jumbo jet. To build these stations astronauts in spacecraft known as “shuttles” left initial pieces of the stations out in space. On later flights they snapped on the additions as one does with Lego parts.
Strangely, no one ever fully clarified the purpose of these stations, though the Russians did use theirs to study how to prevent the breakdown of one’s weightless bones in space. The Americans also studied how to live in space, and carried out a host of small experiments involving weightlessness. Defenders of the stations claimed the stations gave humanity a foothold off the earth, a beachhead in the heavens.
Critics claimed, as they had said before about manned journeys to the moon, that the stations were not worth their cost. (One shuttle flight cost half a billion dollars.) The experiments performed in space didn’t teach us much, and why prepare for flights by astronauts to other planets (if indeed that was a goal) when an interplanetary flight would last too long for humans to endure? (Even getting to our nearest neighbor, Mars, would take the best part of a year.) The money, they maintained, would be better spent, and more would be learned, by sending robots to the planets. (And this was being done, as we’ll see below.) They also pointed to the danger to the astronauts of flying shuttles to the stations.
As if to prove the critics right about the danger, the shuttle Challenger blew up in 1986 a minute after takeoff, killing seven astronauts. In 2003 Columbia fell apart before a landing, also killing seven. As with other space disasters, these two troubled many humans, giving them a sense of having tempted fate (or angered God). Already humans had unleashed the atom’s power, peered inside the molecule that holds our genes, invented ways to store and use a vast amount of information. God had ordered us to “Fill the Earth,” not to leave it. Were we like the Babylonians who tried to build the tower of Babel “with its top in the heavens,” only to have God foil their plan? Or the ancient titan who infuriated mighty Zeus by stealing fire from gods and giving it to humans? Zeus enchained Prometheus and had an eagle feed forever on his liver.
As scientists insisted, America, Russia, Europe, and Japan did send unmanned space machines t
o land on planets, or to fly beside and photograph them, or to otherwise explore our solar system. They visited the smaller planets, Mercury, Venus, and Mars; and those giant balls of gas, Jupiter, Saturn, Uranus, and Neptune. (Far-off Pluto still awaits us.) One craft that did this planet-touring left the solar system during 1983 (as planned), and plunged inside the cosmic ocean. According to one calculation, at its present speed it should soar near a star named Aldebaran in the year 8,001,972. It bears a plaque with drawings of a man and woman and a map of our solar system intended to help a far-off creature who might find the plaque to work out earth’s location.
Astronomers throughout the world are living in their golden age. Using giant telescopes, artificial satellites; and radio, gamma, infrared, ultraviolet, and X-rays they now can peer far out in space. One of their new tools has been the Hubble Space Telescope, which was set in earthly orbit in the 1990s. Because it soars above earth’s atmosphere the Hubble gave much clearer images of things in space than any telescope before it.
However, giant telescopes on earth with better eyesight (aided by computer optics) now complement the Hubble. The telescopes have found titanic happenings in the universe: (in rising order of importance) a comet hitting Jupiter, a tempest raging over Saturn, stars exploding, other stars and planets forming inside hells of gas and dust, galaxies — whole galaxies — devouring one another, and the fireball of the Big Bang when the universe began. Astronomers have arrived at bold new theories, new understandings, about the universe.
What the layman really wants to know about the universe, above all other things, is this: are there other intelligent beings out there, or are we all alone? Since the middle 1990s some astronomers have looked for planets around the nearby stars. (Their purpose was to understand the physics of the forming of planets, not to look for life.) They have found many planetlike objects. Seemingly these findings raise the statistical likelihood that intelligent life exists elsewhere in our galaxy. Other scientists have been trying to eavesdrop on possible interstellar radio communications among conjectured civilizations elsewhere in our galaxy.
If your goal is finding life outside of earth, you must discover planets that are much like ours. They must have liquid water and they can’t be broiling hot, like Mercury and Venus; or mostly gas, like Jupiter, Saturn, Uranus, and Neptune; or sheathed in ice, like Pluto. The planets that astronomers have found so far don’t pass these tests.
EVEN AS WE humans peered around a universe that holds a hundred billion galaxies we also probed in cells that (in the case of humans) measure one 250,000th of an inch across.
This is the story of the finding of our genes, and it begins about 150 years ago when Gregor Mendel bred his peas. Mendel lived while Darwin did and, like Darwin, in his early years he didn’t show much promise. At the age of twenty-one he became a monk in what is now the Czech Republic. When he took an examination for a teaching license in his town of Brno, he failed it, and every time he took the test again he failed. Nevertheless he taught science in a local school, and went to meetings of the local science club.
In 1856 Mendel began to study the inheritance of traits, using the materials he had at hand, which were pea plants in the monastery garden. For about a decade Mendel crossbred plants some 20,000 times. He followed seven of their traits, including height, the color of their flowers, and the shape of their seeds. This is what he learned concerning height. If he crossed tall pea plants with dwarf ones, all of the resulting plants were tall. Strangely, though, if he then crossed his hybrid tall plants with each other, only three-quarters of the resulting plants were tall. The other quarter were dwarfs.
Mendel eventually concluded that inside every plant were unseen “factors” that controlled the seven traits. (In the case of height, factors existed for tallness and dwarfism.) When plants were bred, their factors didn’t blend and disappear in their offspring; they kept their identity. The offspring either did or didn’t manifest the factors they inherited, in accord with simple rules that Mendel figured out. These rules explained, for instance, why three of the offspring of tall hybrid plants were tall and one was dwarfed. Mendel guessed the unseen factors were located in our germ cells.
In 1866 he published a paper called “Experiments with Plant Hybrids” in the journal of the Brno science society. But publication in such a minor journal was tantamount to burial, and almost no one read it. He then was chosen abbot of his monastery and had little time for more research. When he died in 1884 he was practically unknown.
In spite of Mendel’s brilliant work, therefore, our interest in the workings of our cells was probably inspired not by him but by Darwin’s celebrated Origin of Species. Darwin didn’t really know how plants and animals passed on their traits, and when he made a guess he got it wrong. But he excited everyone about evolution and inspired later scientists to learn the facts about heredity.
Unlike Mendel, most of the researchers of the following generations studied heredity on the level of the cell. Thanks to recent improvements in microscopes, they now could dimly see the nuclei of cells, and a German scientist discovered how to stain a nucleus with dyes and make what lay inside more visible. He discovered threadlike shapes and oberved that just before a cell divided these shapes split longitudinally in half.
In 1900 three botanists independently discovered the report that Mendel had published so obscurely a third of a century before. (The fact that three men found it in one year suggests how quickly cell research was moving.) Researchers quickly realized that Mendel’s findings about unseen “factors” (for example, that they didn’t blend) neatly matched what they were learning about those strands that split apart. Scientists soon recognized Mendel as the “father of genetics,” although statisticians found that he had sinned by leaving out the data on some traits that didn’t fit his model.
Between 1900 and the early 1950s scientists discovered, among many other things, that genes (Mendel’s “factors”) provide the recipes for making the proteins that really do the work of cells. They also learned that genes are sited in a polymer or large molecule known as DNA. But how did molecules of DNA store the genes, and how did they pass them on when the cells they were in divided? To learn the answers someone had to figure out the structure of the molecules. But this would be no easy task. A molecule of DNA is so tiny that a million of them side by side would be as wide as a normal sewing thread.
In the early 1950s British scientists used X-rays to study DNA. Their hazy photos showed that the shape of DNA crystals was a helix (or spiral). This information was important. But the X-rays offered no hint of how the compounds that form the molecule of DNA fit against each other, or how they permit the molecule to duplicate itself.
Francis Crick, a youngish Briton, and James Watson, an even younger American, got to know each other at England’s Cambridge University in 1951, and started to research the structure of DNA. Instead of using test tubes in a lab, they placed and endlessly replaced bits of wire and cardboard, beads, and metal plates. They were trying to build a model of the molecule that matched what was known already about its chemistry and what the X-ray crystallographers were learning about it. Watson’s splendid memoir of their research (The Double Helix) suggests that even though the two were quite obsessed with DNA, they tinkered with the model in the intervals between their fencing lessons, tennis, movies, skiing in the Alps, and chats with pretty women.
Bit by bit they figured out the structure. They concluded that a molecule of DNA is shaped like a double helix, or a twisted ladder. It consists of two connected strings, each of which in humans is two yards long and made up of four types of tiny compounds. Scientists would later learn that hundreds, even millions, of these compounds — just a tiny bit of the strings — form a single gene.
What a DNA molecule does when its cell divides is as clever as a zipper. Before the cell divides, the two DNA strands must duplicate themselves. So the two strings separate, and then each string collects the needed elements and makes a new partner string just like t
he string it lost. Then one double string goes to one of the new daughter cells, and the other string goes to the other. The two DNA molecules (in two cells) are like the original in all respects.
This solution was (said Watson) “too pretty not to be true,” and on the morning of February 28, 1953, Crick and Watson decided that they had it right. (The writer is typing these words on the morning of February 28, 2003.) When they went to lunch at a favorite pub Crick announced to everyone that they “had found the secret of life.”
How much we, the human race, had learned about ourselves in just a hundred years! During a little fraction of our total time on earth so far, Darwin and a host of others had discovered how we and other species had evolved. Mendel and others had learned that genes inside our cells control our traits. Now Crick and Watson (building on the work of others) had described the molecule that holds the blueprint for maintaining life. (And others soon would learn much more about our genes.)
Scientists now began to work on medical applications of this knowledge. They found that many diseases result at least in part from missing or defective genes, and they began to search for ways to treat them. Starting in 1991 doctors injected “vectors,” usually prepared viruses, into a patient’s cells. The vectors spliced “good” genes exactly where they should be in the patient’s DNA, and the good genes would, the doctors hoped, direct his cells to make the enzyme that was needed. This was promising, but by the early 2000s gene therapy still hadn’t had one clear success.
The Human Story Page 47
