Book review: “Dark Matter and the Dinosaurs” by Lisa Randall

On the one hand, we have the elusive dark matter particles, dispersed throughout the universe across billions of light-years; on the other, we have the sorely missed dinosaurs, who lived in our own proverbial backyard but were driven extinct by a mysterious impactor 66 million years ago. What if these fascinating yet disparate phenomena, separated by so much space and time, were somehow related?


That, in essence, is the premise of Lisa Randall’s book, “Dark Matter and the Dinosaurs.” Maybe the “vanilla” cold dark matter model we have isn’t the only possible explanation of observations of the expanding universe and the cosmic web of millions of surveyed galaxies, she argues. It’s more fun to consider other more exotic models, even if they turn out to be wrong.

Dark matter particles don’t interact with each other the way our familiar atoms do. In fact, they hardly interact at all. They mostly just move apart with the growing universe and then clump together as they feel the effects of gravity over time. As a result, we end up with nearly spherical dark matter clumps throughout the universe, and we and the rest of the Milky Way are living inside one of those clumps. But if some dark matter interacts like normal matter, it could form a dense and thin disk—even thinner than the disk of our own galaxy. (Picture a compact disk hidden inside a bagel. Here’s a good composite image of our galaxy, on edge, which would be the bagel.)

If that’s the case, then as our solar system moves up and down through the disk, we’ll experience an extra little gravitational nudge each time we go through. This could periodically dislodge comets traveling in tenuous orbits in the Oort cloud in the distant realms of our solar system, flinging one comet away forever and sending another in an unfortunate Earthbound direction, where the consequences of its destructive impact in the Yucatan kills off the dinosaurs some 66 million years ago, thus finally linking dinosaurs to dark matter.

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Inside Science: Dark Matter Particles, Cosmic Lenses, and Super-Earths

Here’s a few new stories I reported on and wrote for Inside Science News Service over the past couple weeks:


Physicists Look Beyond WIMPs For Dark Matter

Physicists are on the hunt for elusive dark matter, the hypothesized but as yet unidentified stuff that makes up a large majority of the matter in the universe. They had long favored “weakly interacting massive particles,” known as WIMPs, as the most likely dark matter candidate, but after an exhaustive search, some scientists are moving on to more exotic particles.

Most estimates suggest that there’s 5-6 times as much dark matter as there are things that we can see, such as galaxies, stars, and planets. Yet physicists know very little about what the mysterious dark matter particles actually are, as they cannot be directly observed and barely interact with normal matter.

New research leaves dwindling room for WIMPs, motivating a search for other particles that could fit the bill.

“The WIMPs are getting harsh experimental scrutiny, and may get ruled out,” said Kathryn Zurek, a physicist at Lawrence Berkeley National Laboratory in California. [Note: She later clarified that WIMPs may become more “strongly constrained” rather than “ruled out.”]

Physicists have used the Large Hadron Collider's ATLAS experiment to probe for potential dark matter particles. (Credit: CERN)

Physicists have used the Large Hadron Collider’s ATLAS experiment to probe for potential dark matter particles. (Credit: CERN)

Zurek and others presented ongoing work on dark matter alternatives to WIMPs in April at an American Physical Society meeting in Salt Lake City. “We should broaden the searchlight, and the natural place is to go lighter,” Zurek said.

She and her colleagues are looking into less massive particles that interact more weakly with ordinary matter. These include an array of particles with exotic names like “axion,” “sterile neutrino,” and “Higgsino,” a theoretical super-partner of the famous Higgs boson.

Axions are hypothetically abundant particles originally proposed in the 1970s to solve a problem with nuclear physics. In the presence of a powerful magnetic field, these minuscule particles, which are lighter than electrons, are predicted to turn into detectable photons. In spite of years of searching, however, they have yet to be found. But the Axion Dark Matter eXperiment, currently being upgraded, should definitely determine whether the particle exists, said Leslie Rosenberg of the University of Washington in Seattle.

Kevork Abazajian, a cosmologist at the University of California, Irvine, sees a new trend in the field over the past decade. “The new generation of early-career physicists is more open to dark matter other than WIMPs,” he said.

He argued that physicists should consider sterile neutrinos, which interact even more weakly than their neutrino counterparts. As they decay, the particles—which are tinier than electrons—could produce detectable X-ray radiation such as that observed in clusters of galaxies. But scientists struggle to distinguish between X-rays that could be emitted by sterile neutrinos versus traditional astrophysical events. Research along these lines suffered a setback when Japan’s powerful X-ray satellite Hitomi broke into pieces last month. But it may have accumulated limited science data before it was lost…

[For more, check out the entire story in Inside Science, published on 28 April 2016. Thanks to Chris Gorski and Sara Rennekamp for editing assistance.]

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Exciting and Controversial Science: Gravitational Waves and a New Ninth Planet?

We’ve had some fantastic astronomical news this month. Last week, we encountered evidence of a “new ninth planet” lurking in the outer reaches of our solar system—170 years after the discovery of Neptune. And earlier in January, we heard a cacophony of whispers about minute gravitational waves being detected for the first time ever. Either one, if true, would be amazing to both astrophysicists and space lovers and would be the biggest discovery of 2016. We should be excited about them, but we should be careful about getting our hopes up so soon.

A New Planet, Far, Far Away?

A couple fellow science writers and I went hiking at Castle Rock State Park in the middle of the Santa Cruz Mountains yesterday, and along the trail, we encountered a variety of people. On our way down, we happened to overhear a conversation: “What’s your favorite planet?” followed by a reply, “Did you hear about the new planet scientists discovered?” Isn’t that great? I’m glad that the story got so much media attention and made it to the front pages of newspapers. It intrigued people, and they’re talking about it.

By studying the strangely aligned orbits of Kuiper Belt Objects far beyond Pluto’s realm, astronomers may have inferred evidence of a planet up to 10 times bigger than Earth. It would be much, much farther than Pluto, making it hard to spot. And from that distance, our sun would look almost like any other star. But if it exists, a new world (dubbed “Planet X”) joining our solar system’s family, even such an estranged cousin, would be exciting indeed.

Eric Hand (Science magazine) points out that the Subaru Telescope could search for Planet X. (Data) JPL; Batygin and Brown/Caltech; (Diagram) A. Cuadra/Science

Eric Hand (Science magazine) points out that the Subaru Telescope could search for Planet X. (Data) JPL; Batygin and Brown/Caltech; (Diagram) A. Cuadra/Science

Nevertheless, we should be concerned that the results are still very uncertain. The authors of the paper in Astronomical Journal, Konstantin Batygin and Mike Brown (both at Caltech), argue that there’s only a 0.007% chance, about one in 15,000, that the clustering of the distant objects’ orbits could be a coincidence. But it’s possible that the behavior of the orbits could have other possibly more likely explanations, such as other unseen Kuiper Belt Objects with orbits aligned in the opposite way. (Other astronomers, like Scott Sheppard and Greg Laughlin, estimate the chance of a planet really being out there at 60-70%. I wouldn’t bank on those odds.)

For that reason, we should remain skeptical for now. Some reporters and editors were a bit more careful than others. For example, while some headlines used appropriately hedging words like “suggest” and “may,” papers like the Denver Post and Washington Post had “The New No. 9” or “Welcome to Planet Nine.” This is already an exciting story to tell though, and we don’t need to exaggerate to get readers’ attention. If the planet turns out not to exist, people who read overblown headlines like those will be frustrated and confused.

Finally, we should all recall that Mike Brown was the main force behind Pluto’s demotion by the International Astronomical Union ten years ago. Since he calls himself the “Pluto Killer” (and wrote a book, “How I Killed Pluto and Why It Had It Coming”), it would be ironic if he helped discover a new ninth planet, replacing Pluto. But he and the Caltech news office seem to have hyped up his paper’s findings more than they deserved, given all the uncertainties involved.

Gravitational Waves Discovered?

While procrastinating and flipping through Twitter earlier this month, I came across some juicy gossip. I heard what sounded like the tantalizing detection of gravitational waves—an unprecedented achievement. These tiny ripples in space-time, predicted by Albert Einstein and thought to be produced by collisions of black holes or neutron stars, had been too small to measure before. Gravity is the weakest of forces, after all.

But it turns out that Lawrence Krauss, a well-known cosmologist and provocateur at Arizona State University, had caused the hullabaloo with some ill-advised tweets. He once again drew the media’s limelight to himself by spreading rumors that scientists in the Laser Interferometer Gravitational-Wave Observatory (LIGO) collaboration had detected gravitational waves for the first time. In the process, he put those scientists in a tough spot, as I’m sure they faced pressure to make sensitive statements about their ongoing research.

The LIGO Laboratory operates two detector sites, one near Hanford in eastern Washington (pictured here) and another near Livingston, Louisiana. (Credit: Caltech/MIT/LIGO Lab)

The LIGO Laboratory operates two detector sites, one near Hanford in eastern Washington (pictured here) and another near Livingston, Louisiana. (Credit: Caltech/MIT/LIGO Lab)

The LIGO team is still working on their analysis using a pair of detectors in Louisiana and Washington state, and they haven’t yet produced conclusive results. From what I can tell, they may have evidence but the situation is far from clear. There is nothing wrong with waiting a while until you’ve thoroughly investigated all the relevant issues and sources of error before announcing a momentous discovery. The alternative is to prematurely declare it, only to face the embarrassing possibility of retracting it later (which sort of happened to BICEP2 scientists with their supposed discovery of primordial gravitational waves).

Gravitational waves will have to remain elusive for now. And if and when LIGO physicists do have convincing evidence of gravitational waves, they need not share any of the glory or credit with Krauss.

Fortunately, in spite of this excitement, science writers and editors kept their cool and soberly pointed to Krauss’s rumors before digging into the fascinating and painstaking work LIGO scientists are doing. Here’s some excellent coverage by Clara Moskowitz in Scientific American and by Lisa Grossman in New Scientist.

[26 Jan. update: I decided to tone down my criticism of Mike Brown, but not of Lawrence Krauss.]

Philanthropists are Enabling and Influencing the Future of Astronomy

[This is a longer version of an op-ed I published in the San Jose Mercury News with the title “Tech moguls increasingly deciding what scientific research will be funded.” Thanks to Ed Clendaniel for help editing it.]

Billionaires and their foundations are both enabling and shaping scientific endeavors in the 21st century, raising questions that we as a society need to consider more seriously.

I have spoken to many astronomers, who consistently clamor for more reliable funding for scientific research and education. With broad public support, these scientists passionately explore the origins of life, the Milky Way, and the universe, and they naturally want to continue their research.

But what does it mean when private interests fund a growing fraction of scientific work? Can we be sure that limited resources are being directed toward the most important science?

Research & Development as a Fraction of Discretionary Spending, 1962-2014. (Source: Budget of the U.S. Government FY 2015; American Association for the Advancement of Science.)

Research & Development as a Fraction of Discretionary Spending, 1962-2014. (Source: Budget of the U.S. Government FY 2015; American Association for the Advancement of Science.)

After the Apollo program, federal funding for science and for astronomy in particular has never been a top priority, declining as a fraction of GDP. Since the Great Recession, science has received an increasingly narrow piece of the pie. Acrimonious budget debates perennially worry scientists that the mission or research program they’ve devoted their careers to might be cut.

Trends in Federal Research & Development. (Source: National Science Foundation, AAAS.)

Trends in Federal Research & Development. (Source: National Science Foundation, AAAS.)

Perhaps as a result, philanthropic funding for scientific research has bloomed, increasing sharply relative to the federal government, according to the National Science Foundation. For example, the Palo Alto-based Gordon and Betty Moore Foundation, built on the success of Intel, agreed to provide $200 million for the Thirty Meter Telescope in Hawaii, intended to study distant stars and galaxies. This summer, Yuri Milner and the Breakthrough Prize Foundation dedicated $100 million to research at the University of California, Berkeley and elsewhere to expand the search for extraterrestrial intelligence.

“Because the federal role is more and more constrained, there is a real opportunity for private philanthropy to have a lot of influence on the way in which scientific research goes forward,” Robert Kirshner, head of the Moore Foundation’s science program, told me.

These laudable initiatives put personal wealth to good use. They enable important scientific research and technology development, and some scientists benefit from the philanthropists’ largesse. But they also transfer leadership from the scientific community and public interest to the hands of a few wealthy businesspeople and Silicon Valley tech moguls.

While philanthropists support leading scientists and valuable scientific research, they and their advisors decide what is “valuable.” If they desire, they could fund their favorite scientists or the elite university they attended. They have no obligation to appeal to the scientific community or to public interests.

Philanthropists sometimes go for attention-getting projects that gets their name or logo on a major telescope (like Keck or Sloan) or a research institute (like Kavli), which also happen to enable important science for many years.

For better and perhaps also for worse, private funding of science is here to stay. Although fears of billionaires controlling science might be overblown, we should ensure that we support a democratic and transparent national system, with scientists’ and the public’s priorities guiding decisions about which projects to pursue.

Public funding involves thorough review systems involving the community, and projects develop upon a strong base with considerable oversight and transparency. This takes time, but it’s worthwhile.

Government agencies and universities support “basic” science research, allowing scientists to focus on science for its own sake and to explore long-term projects. Private interests often ignore basic research, typically spending 80 cents of every research and development dollar on the latter. In response to this shortcoming, the Science Philanthropy Alliance formed recently near Stanford University to advise foundations about how to invest directly in fundamental scientific research.

“If you’re going to have an impact in the long run, then you should be supporting basic research, which is often where some of the biggest breakthroughs come from,” said Marc Kastner, its president, referring to the Internet and the human genome.

These well-intentioned efforts offer no guarantee, however. We should urge policy-makers to reliably fund science and consider it as sacrosanct as healthcare and social security, regardless of budget limits. At the same time, we should clearly delineate the role philanthropy and private industry will play.

Finding Earth 2.0

In honor of Carl Sagan’s birthday, I figured I’d write a few thoughts I had about a fascinatingly unique conference I attended in the Bay Area last week. It was called “Finding Earth 2.0,” and it was organized by 100 Year Starship, a group partially funded by NASA and the Defense Advanced Research Projects Agency (DARPA) to plan for interstellar travel within the next century.

A potential spacecraft called Icarus Pathfinder would be powered by electric propulsion engines called VASIMR, taking it out to 1,000 times the distance between the Earth and Sun. (Credit: NBC News)

A potential spacecraft called Icarus Pathfinder would be powered by electric propulsion engines called VASIMR, taking it out to 1,000 times the distance between the Earth and Sun. (Credit: NBC News)

Like you might imagine such an organization, the conference speakers and attendees appeared rather eclectic, including astronomers and planetary physicists and science journalists—whom I’m usually hanging out with—as well as aerospace engineers, science fiction writers, business people, teachers, space enthusiasts, and many others. But everyone displayed an active interest in exploring the distant universe and imagining what our future might be like.

Dr. Mae Jemison, the first woman of color in space, heads the 100 Year Starship, and she gave a plenary talk. She pointed to many motivations people have for finding another Earth, including conundrums and challenges our planet and species face, such as limited resources, overpopulation, and our own behavior—perhaps a reference to climate change or nuclear weapons. I think we have many other compelling reasons for interstellar space exploration, but I’ve written about that here before.

I also saw many interesting perspectives and presentations about hunting for planets beyond the solar system, called exoplanets, including habitable ones or even inhabited ones. Dr. Jill Tarter, SETI (Search for Extraterrestrial Intelligence) Institute co-founder and inspiration for Sagan’s protagonist in Contact (Dr. Arroway), gave a provocative presentation on attempts to detect “technosignatures” from distant planets. (She clarified that possessing technology doesn’t imply an intelligent civilization; however, technologies serve as a proxy for intelligence.) Advanced species on these planets could be giving off radio and optical signals that could reach the Earth, but we’d have to listen really really hard to hear them. But if they had a Dyson sphere or an “alien superstructure,” that would be easier.

Other astronomers and astrobiologists talked about their work on related subjects. Margaret Turnbull, also of the SETI Institute, spoke about the “massive harvest” of planets reaped by NASA’s Kepler probe, which confirmed more than 1,000 planets in our Milky Way neighborhood and which showed that about 1 in 5 stars has a planet in the “habitable zone.” Stephen Kane (San Francisco State University) made a convincing case that we should view the habitable zone boundaries as uncertain, and that many planets in the zone would actually be not very hospitable to life. Natalie Batalha (NASA Ames) argued that we should be open-minded about planets in other systems. In one of a few relationship-like quotes, she said, “In our search for a [Earth-like] soul-mate, we may be a bit myopic.” But she was talking about the fact that we have no planets between Earth and Neptune sizes here, while according to Kepler observations, such planets seem rather common throughout the galaxy. She and others also made the point that we need detailed imaging or spectra of planetary systems to learn more about their habitability.

Niki Parenteau (SETI) talked about her efforts to study exoplanets and spot signs of life, which would likely be microorganisms and would have to cover the world to be detectable. “There’s no one smoking gun for biosignatures,” she said. “We need multiple lines of evidence.” She looks for things like biogenic gases and certain planetary surface features. But for her, water is the #1 requirement…and then Morgan Cable, a nerdy joke-telling astrochemist from Jet Propulsion Laboratory, considered a range of other liquids life might be able to develop in, including ammonia, carbon dioxide, petroleum, and liquid hydrocarbons. She ended with her main argument: “NASA shouldn’t just be looking for places with liquid water.”

Artist's illustration of NASA's NEA Scout CubeSat, which is scheduled to launch aboard the maiden flight of the agency’s Space Launch System rocket in 2018. (Credit: NASA)

Artist’s illustration of NASA’s NEA Scout CubeSat, which is scheduled to launch aboard the maiden flight of the agency’s Space Launch System rocket in 2018. (Credit: NASA)

A bunch of people gave presentations about propulsion systems, trying to push the boundaries of space travel. I thought the most interesting one was by Les Johnson, Deputy Manager for NASA’s Advanced Concepts Office at Marshall Space Flight Center. In back-to-back talks, he described current efforts to design and construct giant solar and electric sails. The sails involve ultra-thin reflective materials that are unfurled in space and use solar energy to propel a spacecraft to the distant reaches of the solar system and beyond. In an important step toward that goal, Johnson and NASA engineers are currently building a solar sail for the Near-Earth Asteroid Scout mission to transport a CubeSat “nanosatellite” to study asteroids past Mars in two years. He and his colleagues are also currently testing electric sails for fast solar wind-powered spacecraft, which—if as powerful as hoped—could even send a probe to another star.

Finally, I saw a few strange talks at the conference, and I wasn’t sure what to make of them. For example, one person spoke about the new field of “astrosociology.” He avoided giving any specifics though, even though he had been discussing “deviant” behavior, and admitted after the talk that he had envisioned studying multi-year trips transporting tens of thousands of colonists beyond the solar system. Maybe for the 200 Year Starship! Unfortunately, the speaker had not considered small missions, such as handfuls of astronauts traveling to Mars or private ventures conducting asteroid mining. I’d imagine that such small groups of people stuck together for long periods could benefit from sociological study.

What happens if you fall into a black hole?

Q: What happens if you fall into a black hole?
– Jane Doe, Calif.

Ramin Skibba, a science communicator and astrophysicist at UC Santa Cruz, illuminates:

When a dying star much bigger than our sun burns the last of its fuel, it finally collapses under its own weight, explodes, and leaves behind a black hole. If you fell into the black hole, even in a sturdy spacecraft, powerful tides from its gravity would rip you into a ribbon of atoms.

Artist's drawing of the black hole Cygnus X-1, pulling matter from the blue star beside it. (Credits: NASA/CXC/M.Weiss)

Artist’s drawing of the black hole Cygnus X-1, pulling matter from the blue star beside it. (Credits: NASA/CXC/M.Weiss)

According to Albert Einstein’s relativity theory, the laws of physics break down near extremely massive objects. Black holes have such densely compressed mass that they warp the very fabric of space around them. If you got too close, it would inevitably suck you in. Along the way, you would perceive distorted colors and shapes as if through carnival mirrors. Your clocks would run differently, too; black holes bend not only space, but time itself.

Suppose you fell in feet first. Your legs would feel a much stronger gravitational force than your head. In a fraction of a second, this tide would stretch you and tear you apart like taffy. The resulting shrapnel and debris would spiral into the hole, vanishing forever.

Astronomers see evidence of this at the centers of galaxies, where the largest black holes grow. It happens to entire stars that venture too close, then get shredded in blazes of energy.

[Thanks to Rob Irion for editing help with this piece, which is written to resemble the short Q&A-style articles previously published in Scientific American.]

Book Review: Five Billion Years of Solitude

As long as humans have roamed the Earth, they have looked up to the skies, speculating and pondering about the celestial wonders populating the distant cosmos. From the early astronomers and natural philosophers until today’s (including me), people have observed and studied the billions of twinkling dots, all the while wondering whether there are other worlds out there and whether they might host lifeforms like us.


In his first book, “Five Billion Years of Solitude: The Search for Life Among the Stars,” Lee Billings explores these and related questions. He chronicles the story of space exploration, planet-hunting and the growing field of astrobiology, while meeting fascinating characters and discussing their research, telescopes, discoveries and challenges. He offers clear and compelling explanations, such as of planetary physics and habitability, and he takes important asides into debates on space exploration budgets and the fate of our own planet, including the ongoing climate change crisis.

Billings is a talented science journalist. Like his work for Scientific American and other publications, the book is excellently written and researched. It won the 2014 American Institute of Physics science communication award in the book category, announced at the American Astronomical Society meeting in January.

Over the course of the book, Billings tracks down and speaks with important figures in planetary astronomy. He begins with Frank Drake, who along with nine other scientists in 1961 attempt to quantify the abundance of life-supporting planets in the galaxy in a calculation now known as the Drake Equation. He also meets with other astrophysicists, including University of California, Santa Cruz professor Greg Laughlin, Space Telescope Science Institute director Matt Mountain and MIT professor Sara Seager.

Since the time-scale or life-time of civilizations plays a role in the Drake Equation, his investigations lead to an examination of our own history and the longevity of humanity on Earth. Billings discusses the planet’s changing climate and other looming threats, for which our society appears unprepared. His reporting takes him to southern California too, where he quotes from my former colleague, UC San Diego physicist Tom Murphy, who considered the question of growing global energy consumption.

Other important questions come up as well. How far away are planets beyond our solar system and how long would it take to get there? What kind of atmospheric, geological and climatic conditions must a habitable planet have? How do astronomers detect planets, when they are so small, so faint and so close to their brightly glowing suns? What are our prospects for finding more Earth-like planets?

And what will happen to the Earth and humankind—if we’re still around—over the next few billion years, as our sun brightens, expands and transforms into a red giant star? As Billings starkly puts it in his interview for The Atlantic, “We may have—we may be—the only chance available for life on Earth to somehow escape a final, ultimate planetary and stellar death.”

Artist's conception of NASA's Kepler spacecraft. (Image credit: NASA/Ames/JPL-Caltech)

Artist’s conception of NASA’s Kepler spacecraft. (Image credit: NASA/Ames/JPL-Caltech)

With the Kepler telescope, we have the good fortune to be living at a time when actually Earth-like worlds, not just super-Earths and gas dwarfs, can be identified. Astronomers have already used the telescope to find a few potential Earth cousins, which have the right size and the right “Goldilocks” distance from their stars, and many many more candidates are on the horizon. Under certain conditions, follow-up observations can measure the planets’ atmospheres and climates to further assess their habitability.

It’s an exciting time! With even more advanced planet-finding telescopes coming up, such as the Hubble successors, the James Webb Space Telescope and High-Definition Space Telescope, we can look forward to more detailed images and observations of exoplanets in the near future. Maybe Earth has twins and maybe we are not alone.

I have a few criticisms of Five Billion Years, but they’re very minor ones. I liked the analysis of federal budget debates at multiple points in the book, but Billings could have written a little more about why as a society we should prioritize space exploration and astronomical research. If, say, a member of the House Science Committee (or more likely, their staffer) were to read this, it would be helpful to spell that out. Early in the book, he provides an engaging historical survey of astronomy, but he neglected Eastern contributions, such as from Persians, Arabs and Chinese. A few chapters meandered quite a bit too, but I enjoyed his writing style.

In any case, this is a beautifully written and thoroughly researched book, and I recommend it. Billings puts the search for extraterrestrial life in a broader context and pushes us to think about our place in the vast universe. The story continues.

[P.S. I’m extremely busy these days with the UC Santa Cruz science communication program and writing internships, so I may write posts here less often. But I will link to pieces I’ve written elsewhere, which have the benefit of rigorous editing, so if you like my blog, you’ll like them even more.]

My Surprising and Exciting Journey from Scientist to Science Writer

I’ve been drawn to science since I was a kid. I had many excellent and creative teachers along the way, including one who taught us students to be more observant and to think critically and another who smashed bowling balls into desks and who ran into a wall (while wearing pads and a helmet, of course) to demonstrate momentum conservation. I grew up in Colorado, and I enjoyed gaping at the Milky Way and the beautiful night sky while in the Rockies, even if I couldn’t name many constellations. Carl Sagan’s Cosmos program and the Star Trek TV shows also inspired me to explore astrophysics later in life.

Milky Way over Great Sand Dunes National Park, Colorado. (Photo by Carl Fredrickson)

Milky Way over Great Sand Dunes National Park, Colorado. (Photo by Carl Fredrickson)

But my head isn’t always in the stars. I have many other interests too, including sociology, political science and philosophy of science, and I’ve always enjoyed literature and poetry too. I’m not just interested in doing science and analyzing datasets and phenomena; that, by itself, is not enough. I also desire to use science and critical thinking to help people and connect with them. Since science plays such an important role in human society, I’d like to communicate scientists’ research and debates and the scientific process as well as I can. While the behavior of neutrinos, ice sheets and red pandas might sound interesting, for example, we always have to ask, why are they important? What do scientists claim to have learned about them and how did they learn it? What are the broader implications and context for the research?

Ever the lifetime student, a couple years ago I thought I might become an absent-minded, nerdy, activist professor, maybe widening my scope beyond astronomy and physics into interdisciplinary research and public outreach. But then I realized that I wanted to do more. I examined many interconnections between science and policy—often posting about them on this blog—and I investigated ways I could utilize and develop my science writing skills. I earned fellowship opportunities in both science writing and science policy, and I considered going on both directions. As the head of our astrophysics and space sciences department told me while I mulled over the options, “Those aren’t actually that different. They both involve communicating science to people who might not understand it well.”

In the end, after fifteen years working as a Ph.D. student, teaching and research assistant, postdoctoral researcher, research scientist and lecturer, I decided that I would make the shift and become a science writer! It’s a big step, and I felt a bit nervous about it. Now that I’ve made the decision, I am happy and excited to be trying something new, and I look forward to improving my skills and working on it full-time.

For those of you considering working in science writing or science policy, or for those of you just interested in learning more, I am happy to help. In any case, here are a few suggestions and pieces of advice, which will be particularly relevant for you if you’re coming from a science background as I did.

First, I recommend becoming involved in public outreach and education programs. You may even decide to organize your own events. Just connect to people in whatever ways work well for you, such as speaking in local school classrooms, making demonstrations for students at your university, mentoring prospective students, interacting with members of the public at museums and planetaria, talking to people at cafes and pubs (such as Two Scientists Walk into a Bar, Astronomy on Tap, and other programs), etc.

Second, become more involved in and volunteer for the relevant professional scientific societies, such as the American Astronomical Society, American Physical Society, American Geophysical Union, etc. Be more than just a card-carrying member. All of these societies, and especially the American Association for the Advancement of Science (AAAS), have many useful resources, scholarships and internships at your disposal.

Third, it is crucially important to talk to a variety of people who work in science writing or science policy (or whatever you might be interested in), get involved and try it yourself. Make sure that you don’t merely like the concept of it but that you actually enjoy and excel at doing it. You will need to make the time to do this. You may find new people in your own college, university or community working in these professions who have much to teach you. Try a variety of media and styles too, possibly including social media, blogs, podcasts, news articles, feature stories, videos, etc. If you’re curious about what I’ve done over the past year or so, look here.

Fourth, check out professional science writing organizations. In particular, I recommend looking up the National Association of Science Writers, the Society of Environmental Journalists and the Association of Healthcare Journalists. Furthermore, you might find useful local organizations too. (We have the San Diego Press Club here, for example). Science writing workshops, such as those in Santa Fe, New Mexico and in Banff, Alberta, could be beneficial for you and could introduce you to others like yourself who are also just starting to venture into the profession. Finally, if you are interested, the AAAS has mass media and science policy fellowships, and the University of California, Santa Cruz, MIT, NYU, and other universities have graduate programs you may consider, though these involve an investment of time and money.

Before diving in, consider the job prospects. Although we have our ideals, we also want to work for a livable salary with sufficient job security. Staff writers, editors, freelancers and public information officers (PIOs) all have pros and cons to their jobs, and it’s important to understand them well.

I’ll make it official: I decided to head to the UC Santa Cruz science communication program, and I’m looking forward to it! In a few days I will be on my way north to Santa Cruz. I plan to try my hand working with a local newspaper, magazine, and an online news outlet, and this fall I will be working with PIOs at Stanford Engineering. Stay tuned for my new articles!

Coming from a science background, I have many challenging things to learn, but I think I’m up to it. I’m trying to learn to write more creatively and evocatively, while identifying compelling characters. I’m learning to assess which scientific discoveries and developments make for the most intriguing stories. Moreover, scientists and science writers have different ways of thinking, and bridging the gap between them involves more steps than you might think it does. Perhaps most importantly, after thinking of myself as a scientist for so many years, it’s hard to craft a new identity. It turns out that while I am an astronomer and a physicist, I am many other things too. I’m continuing to explore the universe, just in a myriad different ways than before. I’m boldly going where I haven’t gone before, and the sky’s the limit!

Why do we engage in space exploration?

A review of diverse perspectives on space exploration and extraterrestrial life reveal fundamentally human hopes, fears and flaws

Since the dawn of civilization thousands of years ago, humans have looked to the skies. Archaeologists have found evidence of people from China, India, and Persia to Europe and Mesoamerica observing and contemplating the many stars and planets that fascinated them. We humans have also wondered about—and often hoped for—the existence of other intelligent life out there. Considering the large number of planets in the Milky Way and in billions of other galaxies, perhaps we are not alone, and maybe even while you are reading this, extraterrestrials could be looking in our direction through their telescopes or sending us interstellar telegrams. But if our galaxy teems with aliens, following Italian physicist Enrico Fermi’s persistent question, we must ask, “Where are they?”

Artist's depiction of a travel poster for a "Tatooine-like" planet orbiting two suns, recently discovered by NASA's Kepler spacecraft. (Courtesy: NASA)

Artist’s depiction of a travel poster for a “Tatooine-like” planet orbiting two suns, recently discovered by NASA’s Kepler spacecraft. (Courtesy: NASA)

Two recent pieces in the New Yorker and New York Times, as well as numerous books over the past couple years, motivate me to consider this and related questions too. Astronomers and astrophysicists around the world, including scientists working with NASA, the European Space Agency (ESA), the Japanese Space Agency (JAXA) and many others, have many varieties of telescopes and observatories on Earth and in space, just because we want to investigate and learn about our galactic neighborhood and beyond. We also attempt to communicate, like sending a message in a bottle, with the Golden Records aboard the Voyager spacecrafts, and we listen for alien attempts to contact us. In our lifetime, we have dreams of sending humans to Mars and to more distant planets. Why do we do this? We do it for many reasons, but especially because humans are explorers: we’re driven to see what’s out there and to “boldly go where no one has gone before.” As Carl Sagan put it in Cosmos, “Exploration is in our nature. We began as wanderers, and we are wanderers still.”

Views of human space exploration

Elizabeth Kolbert reviews three recently published and forthcoming books by Chris Impey, an astronomer at the University of Arizona (where I used to work three years ago), Stephen Petranek, a journalist at Discover, and Erik Conway, a historian of science at Jet Propulsion Laboratory. (She did not mention an award-winning book by Lee Billings, Five Billion Years of Solitude, which I will review in a later post.) She fault finds with the overoptimistic and possibly naïve “boosterism” of Impey and Petranek. “The notion that we could…hurl [humans]…into space, and that this would, to use Petranek’s formulation, constitute ‘our best hope,’ is either fantastically far-fetched or deeply depressing.” She asks, “Why is it that the same people who believe we can live off-Earth tend to believe we can’t live on it?”

Kolbert’s assessment has some merit. Astrophiles and space enthusiasts, of which I am one, sometimes seem to neglect Earth (and Earthlings) in all its wonder, marvels, complexity, brutality and messiness. But is the primary reason for exploring the universe that we can’t take care of ourselves on Earth? Mars should not be viewed as a backup plan but rather as one of many important steps toward better understanding our little corner of the galaxy. Furthermore, we should be clear that sending humans to Mars and more distant worlds is an incredibly complicated and dangerous prospect, with no guarantee of success. Even if the long distances could be traversed—at its closest, Mars comes by at least a staggering 50 million miles (80 million km) away, and then the nearest star, Alpha Centauri, is about 25 trillion miles from us—future human outposts would face many obstacles. The popular novel by Andy Weir, The Martian, demonstrates only some of the extraordinary challenges of living beyond our home planet.

Overview of components of NASA's Journey to Mars program, which seeks to send humans to the red planet in the 2030s. (Credit: NASA)

Overview of components of NASA’s Journey to Mars program, which seeks to send humans to the red planet in the 2030s. (Credit: NASA)

Though Kolbert criticizes Conway’s dry writing style, she clearly sympathizes with his views. “If people ever do get to the red planet—an event that Conway…considers ‘unlikely’ in his lifetime—they’ll immediately wreck the place just by showing up…If people start rejiggering the atmosphere and thawing the [planet’s soil], so much the worse.” This line of criticism refers to flaws of geoengineering and of the human species itself. Many times in history, humans ventured out acting like explorers, and then became colonists and then colonialists, exploiting every region’s environment and inhabitants.

Note that Kolbert is a journalist with considerable experience writing about climate, ecology and biology, while astrophysics and space sciences require a stretch of her expertise. In her excellent Pulitzer Prize-winning book, The Sixth Extinction, Kolbert argues provocatively that humans could be viewed as invasive species transforming the planet faster than other species can adapt, thereby constituting a danger to them. “As soon as humans started using [language], they pushed beyond the limits of [the] world.” I agree that humans must radically improve their relationship with nature and Earth itself, but this does not preclude space travel; on the contrary, the goal of exploring other worlds should be one aspect of our longer-term and larger-scale perspective of humanity’s place in the universe.

Views of extraterrestrial intelligence

Dennis Overbye, a science writer specializing in physics and astronomy, covers similar ground, but focuses more on the search for extraterrestrial intelligence (SETI). He mentions the Drake Equation, named after the American astronomer Frank Drake, which quantifies our understanding of the likelihood of intelligent life on other planets with whom we might communicate. Both Drake and Sagan “stressed that a key unknown element in their equations was the average lifetime of technological civilizations.” If advanced species don’t survive very long, then the possibility of contact between overlapping civilizations becomes highly improbable. It would be unfortunate if similarly advanced civilizations, like Earthlings and Klingons, could never meet.

Overbye introduces the controversial University of Oxford philosopher, Nick Bostrom, who is rooting for us to fail in our search for ETs! “It would be good news if we find Mars to be sterile. Dead rocks and lifeless sands would lift my spirit.”

Bostrom bases his argument on a concept he refers to as the Great Filter. Considering the likelihood of advanced civilizations, many conditions and criteria must be satisfied and steps must be taken before a planet in the “habitable zone” has a chance of harboring intelligent life. The planet probably must have the right kind of atmosphere and a significant amount of liquid water and some kind of possibly carbon-based building blocks of life, and after that, the alien species’ evolutionary developments could go in any direction, not necessarily in a direction that facilitates intelligence. In addition, asteroids, pandemics, or volcanic eruptions could wipe out this alien life before it got anywhere. In other words, myriad perils and difficulties filter out the planets, such that only a few might have species that survive and reach a level of social and technological advancement comparable to those of humans.

On the other hand, if we do find life on other planets and if intelligent extraterrestrial life is relatively ubiquitous, our lack of contact with them could mean that advanced civilizations have a short lifetime. Perhaps the Great Filter is ahead of us, “since there is no reason to think that we will be any luckier than other species.” Maybe nuclear war, climate change, or killer robots might wipe us out before we have the chance to explore the galaxy.

I am not convinced by Bostrom’s pessimism. Even if the Great Filter is ahead of us, implying that humans face more existential threats in the future than have been overcome in the past, this doesn’t mean that we are doomed. Humanity does have major problems with acknowledging large-scale impacts and long-term outlooks, but I hope we could learn to change before it is too late.

A more positive outlook

We have learned a lot about planets, stars, galaxies, black holes and the distant universe from our tiny vantage point. But we would be immodest and mistaken to brazenly presume that we’ve already figured out the rest of the universe. We really don’t know how many other “intelligent” species might be out there, and if so, how far they are, what level of evolution they’re at (if evolution is a linear process), or whether or how they might communicate with us. We should continue to discuss and examine these questions though.

While traveling to other planets will take a long time, in the meantime astronomers continue to make exciting discoveries of possibly “Earth-like” planets, such as Kepler-452b, an older bigger cousin to our world. It seems likely that the Earth has a very big family, with many cousins in the Milky Way alone.

So why do we engage in space exploration and why do we seek out extraterrestrial life? This question seems to transform into questions about who we are and how we view our role in the universe. I believe that humans are fundamentally explorers, not only in a scientific sense, and we have boundless curiosity and wonder about our planet and the universe we live in. Humans also explore the depths of the oceans and dense rainforests and they scour remote regions in arid deserts and frigid glaciers (while they still remain), just to see what they’re like and to look for and observe different lifeforms.

More importantly, even after tens of thousands of years of human existence, we are still exploring who we are, not just with scientific work by psychologists and sociologists but also with novelists, poets and philosophers. We still have much to learn. To quote from Q, a capricious yet occasionally wise Star Trek character, “That is the exploration that awaits you: not mapping stars and studying nebulae, but charting the unknown possibilities of existence!”

As Galaxies’ Light Gradually Fades, the Universe is Slowly Dying!

The Universe, long past retirement at an age of 13.8 billion years, appears to be gradually “dying.” New observations strongly indicate that galaxies, vast collections of billions of stars such as our Milky Way and neighbors Andromeda and Triangulum, generate much less energy than they used to across the wavelength spectrum, a clear trend revealing the fading cosmos.

This composite picture shows how a typical galaxy appears at different wavelengths in the GAMA survey. The energy produced by galaxies today is about half what it was two billion years ago, and this fading occurs across all wavelengths. (Credit: ICRAR/GAMA and ESO.)

This composite picture shows how a typical galaxy appears at different wavelengths in the GAMA survey. The energy produced by galaxies today is about half what it was two billion years ago, and this fading occurs across all wavelengths. (Credit: ICRAR/GAMA and ESO.)

Scientists with the Galaxy and Mass Assembly (GAMA) survey, led by Simon Driver of the International Centre for Radio Astronomy Research in Australia, extensively and thoroughly examined more than 200,000 galaxies. Driver and his colleagues presented the results of their analysis at the general assembly of the International Astronomical Union (IAU) in Honolulu, Hawaii, which came to a close last weekend. Their announcement coincided with their data release and the submission of their paper to the journal, Monthly Notices of the Royal Astronomical Society. The paper has not yet been peer-reviewed or published, but the authors’ main conclusions are unlikely to change.

“While most of the energy sloshing around in the Universe arose in the aftermath of the Big Bang, additional energy is constantly being generated by stars as they fuse elements like hydrogen and helium together,” Driver said. “This new energy is either absorbed by dust as it travels through the host galaxy, or escapes into intergalactic space and travels until it hits something, such as another star, a planet, or, very occasionally, a telescope mirror.”

Stars of all ages throughout this multitude of galaxies convert matter into energy (remember E=mc2?) in the form of radiation ranging from ultraviolet to optical to infrared wavelengths, and astronomers have long known that the total energy production of the universe has dropped by more than a factor of 1.5 since its peak about 2.25 billion years ago. But GAMA scientists, utilizing the Anglo-Australian Telescope at Siding Spring Observatory in eastern Australia, were the first to document the declining energy output so comprehensively over 21 wavebands.

Check out this fly-through of the volume mapped out by the GAMA survey, which is expected to be approximately representative of the rest of the “nearby” universe, with the galaxies’ images enlarged (video courtesy of ICRAR/GAMA/Will Parr, Mark Swinbank and Peder Norberg (Durham University) and Luke Davies (ICRAR)):

The GAMA astronomers’ results point toward the universe’s continued “gentle slide into old age,” as Driver put it, but there is no need to panic! The time-scales involve billions of years, and we humans have only been around for about 100,000th of the universe’s lifespan so far. (That’s like the incredibly short lifetime of mayflies relative to ours.) We should be careful to note that the scientists’ conclusions come from a statistical assessment of numerous and diverse galaxies, similar to the way pollsters or census takers evaluate a population by studying a large number of its members. Individual galaxies and their stars may be young or old, but the general population continues to age with no indication of deviations from the demographic trend, much like the gradual aging of people in Japan.

Filled with galaxies and much more dark matter and much much more empty space, the universe rapidly expands and pulls objects away from each other, countering gravitational forces. Old stars within galaxies provide the fuel for new stars to form, but eventually it becomes harder and harder to scrape enough fuel together to make those new stars and galaxies, and on average the aging universe becomes fainter and fainter. It’s as if potential parents become increasingly unlikely to meet with random encounters and many ultimately die alone.

The universe will eventually pass away, but long after our sun has exploded in its red giant phase and destroyed the Earth and long after the Milky Way and Andromeda collide. I think the universe—and humans—has many more good years left though.