by Marc Kaufman
“The more we learn of the universe, the more we learn how great the fine-tuning really is,” he told me. “Since science cannot tell me that any of the various explanations for that reality is true or false, then a plausible hypothesis is that of a Creator. It’s not provable, but nothing else is, either.”
His long-ago collaborator, Stephen Hawking, sees the same fine-tuning and comes to a very different conclusion, one that did not sit well with some of the more religiously minded. In his 2010 book, The Grand Design, written with California Institute of Technology physicist Leonard Mlodinow, Hawking describes the universe (or universes) as ultimately understandable by science—a view shared by quite a few in the field.
“Our universe seems to be one of many, each with different laws. That multiverse idea is not a notion invented to account for the miracle of fine tuning. It is a consequence predicted by many theories in modern cosmology,” he writes. “As recent advances in cosmology suggest, the laws of gravity and quantum theory allow universes to appear spontaneously from nothing. Spontaneous creation is the reason there is something rather than nothing, why the universe exists, why we exist. It is not necessary to invoke God to light the blue touch paper and set the universe going.”
A strong statement for sure, but notice how many qualifiers are written into even Hawking’s explanation. The issue is far from settled and few scientific challenges are as great as those posed by the fine-tuning of the universe. But few hold greater potential for explaining how and perhaps why we are here, and why other life-forms in the universe might be out there, too.
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Just as astrobiology is inevitably drawn into the worlds of cosmological fine-tuning and multiverses, so too is it being pulled into an equally fantastical world here on Earth—that of a possible shadow biosphere that supports life with a different origin and different characteristics than our own. Science has never found any alternate life-forms, proponents say, not because they don’t exist, but because scientists have never looked for them.
That has begun to change. Nothing is for certain in their work, but a handful of researchers have made some intriguing discoveries that suggest a shadow biosphere just might be present. What began as a theory is now the subject of NASA-funded work at hypersalty, hyperalkaline Mono Lake in California, about one hundred miles north of Death Valley. A terminal lake that receives water from the nearby mountains, it has no outlets and so only loses water through evaporation (until the city of Los Angeles began siphoning off water in 1941). Mono Lake is known for the “tufa” columns of limestone that stand in its midst and give it a distinctly spooky quality, as well as a very unusual chemistry caused by its lack of outlet streams. That means elements and compounds that pass through other lakes and get dispersed into big rivers and later oceans stay put in Mono Lake and concentrate to abnormally high levels. Arsenic from the nearby Sierra Nevada flows into Mono Lake and stays—creating a toxic stew with arsenic levels seven hundred times higher than what the Environmental Protection Agency considers safe. Despite being a virulent poison for most living things, arsenic has emerged as the key element in shadow biosphere research. In fact, if the research holds up to the critiques it has attracted, it will represent the beginning of a new era of biology—one where the already fuzzy concept of life as we know it will get much fuzzier.
The main force behind the arsenic biosphere research is a thirty-three-year-old biochemistry whiz named Felisa Wolfe-Simon. She broke onto the NASA scientific scene in 2008 when she attended an exclusive Gordon Conference meeting on “The Origins of Life” and raised the possibility of life-forms on Earth with chemical makeups that are entirely incompatible with all other life that we know. At the time, she recalls with something between pride and dismay, her mane of dark hair was dyed bright pink, and she sported a number of piercings. That probably didn’t help her establish early credibility.
But over the next four years, she attracted the attention of a number of top scientists, ranging from biologists to cosmologists. She worked with geochemist Ariel Anbar at Arizona State University and he introduced her to Paul Davies, the unconventional physicist/astrobiologist (and prolific writer), who already had a strong interest in the “shadow biosphere.”
Davies has promoted the shadow biosphere idea for some time, as had University of Colorado philosopher and astrobiologist Carol Cleland, who actually coined the word. His argument is part scientific, part practical. Why spend billions on flying to distant planets in the hope of finding evidence of current or former life different from ours when it may well exist right under (or in) our own noses? Many origin-of-life scientists assume that life didn’t begin just once on Earth, but rather a number of times in similar but nonetheless distinct forms. The organisms that weren’t based on carbon, nitrogen, and phosphorus perhaps couldn’t compete as well and died out, or maybe remnant populations live undiscovered because nobody has ever looked for them. But now they’re looking.
Davies and Wolfe-Simon submitted a proposal on an arsenic-based shadow biosphere to the John Templeton Foundation in 2007, but the request was turned down. A prime reason why was that one of the reviewers, a senior arsenic specialist at the U.S. Geological Survey in California named Ron Oremland, didn’t believe there was sufficient reason to think the research would be successful. But Oremland was nonetheless intrigued. He had spent much of his career, after all, studying the interactions between arsenic compounds and surrounding biology, and he felt a little guilty that he had panned the proposal. He ran into Wolfe-Simon several more times in the next few years and then opened his USGS lab to her so she could focus on Mono Lake as the location for a possible shadow biosphere.
But that required outside funding, which ultimately came in the form of a fellowship from NASA’s Astrobiology Institute. She headed to California, started collecting mud from the lake, and began the tedious process of sifting and concentrating samples containing already high levels of arsenic. She then began to examine the microorganisms that made their living in the toxic environment, and found something unusual. All known living things on Earth contain the elements carbon, hydrogen, nitrogen, sulfur, oxygen, and phosphorus, which forms the backbone of all genetic material and, in the form of the molecule adenosine triphosphate, is essential for energy storage and transfers in cells. Yet it appeared that some of the microbes from Mono Lake could survive with little or no phosphorus in them, while having very high levels of arsenic.
Arsenic is chemically very similar to phosphorus, a downstairs neighbor in the table of elements, and its toxicity is in large part a function of the fact that other molecules initially mistake it for phosphorus and then are destroyed when the difference is revealed. But the microscopic Mono Lake organisms—from the domains of bacteria and archaea—not only withstood the arsenic but seemed to be possibly using it as a substitute for phosphorus, which, along with carbon, oxygen, hydrogen, and nitrogen, are the key and essential elements of life on Earth. Through months of lab work, Wolfe-Simon and Oremland grew Mono Lake samples with higher and higher levels of arsenic until they reached a point where arsenic had replaced a significant percentage of the phosphorus and arsenic levels were some forty thousand times the EPA safe level. Yet some microbes survived when fed glucose and vitamins, as evidenced by how the water slowly became cloudy with biological activity.
The samples were then sent to several of the nation’s best labs with the most sophisticated equipment for molecular-level testing, and the results were startling: The arsenic, they found, was incorporated into the genetic material (the DNA and RNA) of the cells as well as essential proteins and the cell membranes.
Word of the potentially ground-breaking discovery was first announced in an embargoed release from the journal Science, which was followed by the NASA public announcement of an upcoming press conference to discuss a finding that could have implications for extraterrestrial life. The news shot through the blogosphere, with detailed predictions of life on Jupiter’s moon Titan, or a new day in extra
terrestrial research. Both Science and NASA remained silent for four days until the press conference, which by then was anticipated to be news on the scale of the 1995 Mars meteorite announcement or greater.
The press conference focused on the findings in the Science paper—that microbes from Mono Lake could be grown with lots of arsenic but virtually no phosphorus, and that sophisticated technology had been used to find that the arsenic was contained within the DNA and other essential genetic and life-supporting molecules of the microbe. While the result was remarkable, the larger take-home message was even more so. “We have cracked open the door to what is possible for life elsewhere in the universe,” Wolfe-Simon said. Ed Weiler, NASA’s associate administrator for the Science Mission Directorate, was not at the press conference but did add this in a formal release: “The definition of life has just expanded…. As we pursue our efforts to seek signs of life in the solar system, we have to think more broadly, more diversely, and consider life as we do not know it.”
The results were presented with the proper caveats—that they had to be confirmed and expanded upon—and respected chemist and astrobiologist Steve Benner was also onstage to make a strong case for the near impossibility of the substitution of arsenic for phosphorus in DNA. Arsenic breaks down quickly in water, he said, while phosphorus does not. So how could arsenic bonds hold up in an aqueous environment?
To say the scientific blogosphere was skeptical would be an extreme understatement. Some bloggers immediately attacked the research as incomplete or incompetent, and others concluded the results were simply impossible. Many dinged NASA for “hyping” the discovery, and the peer reviewers at Science were dismissed as compromised. Some of the critiques and challenges were sincere and based on science, but many were personal and nasty. The Mono Lake researchers had predicted a heated response, but they were taken aback by the venom. Perhaps they shouldn’t have been. History tells us that developments related to astrobiology and the search for extraterrestrial life bring out intense emotions. And NASA did put out a release the day of the press conference, saying that agency-funded “astrobiology research has changed the fundamental knowledge about what comprises all known life on Earth.” What was an historic and proud moment for NASA and the researchers was a red flag to many others.
For the first week, editors at Science and the researchers were silent except to say they would address challenges and critiques through the traditional peer review process. But after two weeks, the blogosphere was sufficiently livid that all felt the need to respond—to address some specific charges and to make clear that the microbes would be made available to anyone who wanted to test them in their own labs. In other words, they acknowledged the criticism but held their ground. Their research had been peer reviewed on several levels and so had already been challenged and challenged again. Nonetheless, Wolfe-Simon’s colleague at the U.S. Geological Survey, Ronald Oremland, joined a panel set up at an American Geophysical Union annual meeting specifically to discuss the controversy, as opposed to the science. An old-school scientist, who said he was trained to discuss his work in journals and at conferences rather than on the web, said he had not responded online because, “You can wind up in a Jerry Springer situation before you know it, with people throwing chairs.” But if the controversial research holds up and further investigation supports the finding that the arsenic really is woven into the microbes’ genetic material, then we’ll be in uncharted waters. Microbes with arsenic instead of phosphorus in their DNA backbones would not just represent another interesting discovery. The work of Wolfe-Simon and her team would open a new window into life—an alien life, if you will, right here on Earth.
9 FAR-FLUNG INTELLIGENT WORLDS
The countdown was set to begin at Shin-ya Narusawa’s mission control room at the Nishi-Harima Astronomical Observatory in southern Japan. Nobody was going out into space; no spacecraft were being sent into orbit. But it was a noteworthy night because another nation was joining the improbable yet increasingly sophisticated search for extraterrestrial intelligence elsewhere in the galaxy.
Jumping up to suddenly rigid attention, Narusawa called out “T minus ten.” The assembled reporters and camera crews jumped up too and surged toward him.
Narusawa, the chief researcher of the observatory in the hills northwest of Osaka, had eyes red with fatigue, but his smile radiated triumph. For more than two years he had been preparing and organizing for this moment and now it was about to begin: Japan’s first coordinated, all-country observation of a single star system that might, just might, be home to intelligent beings sending signals out into space. Narusawa said he wasn’t 100 percent sure of this, but it might be the first large-scale, simultaneous SETI observation of its kind in the world.
“T minus eight minutes,” he called out. The star system that the thirty radio and optical telescopes were focused on was one recommended two decades earlier by none other than Carl Sagan and Harvard University’s Paul Horowitz, then and now a leading proponent of the search for extraterrestrial intelligence, or SETI. As a young man, Narusawa was enamored and inspired by Sagan and his work—he read the book Cosmos at least five times—and now he was about to launch his own major SETI observation based on guidance from the masters. Their “Megachannel Extra-Terrestrial Assay,” or META, spectrum analyzer had a capacity of 8.4 million channels and the ability to use Doppler shift to distinguish between terrestrial and possible extraterrestrial samples. The project, begun in 1985, was led by Horowitz with the help of the nonprofit Planetary Society and with financial support from movie director Steven Spielberg.
Getting to countdown had not been easy. The day before, Narusawa had explained with evident emotion that the observation would be named “Sazanka,” after a light purple shrub flower that comes out in the fall, the rainy season around the observatory in Sayo. He chose Sazanka because, in Japan, the plant represents the ideal of “never giving up”—a designation earned by the way that the flower survives the cold, even after snowfalls. The choice also carried a small, inside joke: The rainy season is the high time for sazanka, when it flourishes, but is a low time for the observatory because the clouds make it much more difficult to get a good night’s observation. Several banners with images of the sazanka were hung around the control room, and one perfect flower was placed in a small glass vase near Narusawa’s chair. All around him was the message: “Never give up.” Given both the difficulty he had experienced devising and planning the effort, to say nothing of the needle-in-a-haystack chance that he would succeed where no other SETI observation had for fifty years, the sazanka seemed an apt symbol of encouragement.
“T minus six minutes,” he proclaimed. Narusawa had begun his optical SETI observations in 2005, after reading that Horowitz himself had begun a program using an optical telescope for SETI purposes, rather than the traditional radio telescopes used since the beginning of the SETI effort in 1960. The Nishi-Harima telescope that Narusawa controls is the largest optical telescope in Japan, and he was looking for an exciting and unique additional use for it after it came on line six years earlier. Optical SETI looks for nanosecond flares or lasers coming from a distant star system, just as the far more widespread radio SETI listens for radio messages or bursts that intelligent creatures might be sending. Optical SETI had long been seen in the field as useless because neither it nor laser technology was sufficiently refined. But now it is.
Narusawa, briefly seated, jumped up again and declared: “T minus four.” Playing in his mind at that moment was one of those long-ago, formative moments of his life. He was watching live on television an early Apollo moon walk; or, rather, a series of goofy Apollo moon jumps since the astronaut’s movements looked to him exactly like a kangaroo hopping. He was beyond delighted—he was inspired and decided then and there to study astronomy and learn about the universe. If his memory is correct, the forty-four-year-old Narusawa was then four or five.
“T minus two,” he called. Nishi-Harima is on a mountaintop, or perhaps more a
ccurately a hilltop, outside the town of Sayo and quite far from the major cities of Japan. So the fact that six television stations and several newspapers had sent reporters out to record the event showed a not insignificant interest. As in the United States, curiosity (and skepticism) about advanced extraterrestrial life is always present, if not terribly sophisticated. It’s more the stuff of science fiction, comics, and horror films than of real science in the public mind. But Narusawa is one of many trying to change that. He believes that searching for intelligent extraterrestrial life is science at its best, science “serving humanity” in the way it should but often does not. In addition to the high-mindedness, he also knows searching for ET can be popular, can engage the public if done with the right pizzazz. Narusawa has some of the showman in him, and he’s not shy about it. He would like to be Japan’s Carl Sagan.
“T minus one.” Over the whole length of Japan, some thirty observatories, university telescopes, and amateur sky watchers were set to turn on their machines, having set them to the precise coordinates Narusawa had ordered: a star system in the constellation Cassiopeia, just where Horowitz and Sagan had proposed years before, and where a Japanese radio astronomy colleague, Mitsumi Fujishita of Tokai University, had detected an unusual and unexplained blip in his monitoring four years before.