Consciousness: Pushing the boundaries of science and pseudoscience

I attended a conference in La Jolla last week with the ambitious title, “The Science of Consciousness”. As it brought together neuroscientists, psychologists, biologists, physicists (like Roger Penrose), mathematicians, linguists (like Noam Chomsky), and many others, I looked forward to a variety of perspectives, including those outside the mainstream, but I got more than I bargained for. It turns out that it also included people more involved in various kinds of spirituality, wellness, meditation, and…interesting artistic interpretations.

(Image by Robert Fludd, 1619, Wikimedia Commons.)

Instead of shedding light on something as perplexing and seemingly impenetrable as consciousness, which people have been trying to understand for millennia, these other approaches threaten to undermine the whole enterprise. I worry that some of the conference could be better characterized as “The Pseudoscience of Consciousness.” And the distinction between science and pseudoscience never seemed more blurred.

But what do I know. Science hasn’t really given us that much of an understanding of the murky concept. What is consciousness and do only humans have it? What about babies and the elderly and people with debilitating mental illnesses? Exactly what parts of the brain are involved (just the frontal cortex? microtubules in neurons everywhere?) and how did it appear in evolution?

Science is only getting us so far, and consciousness is a fundamental conundrum of the human condition, so why not consider other avenues toward probing it? But some people aren’t doing that argument any favors. There’s people like Deepak Chopra (who was at the conference) who add the word “quantum” to their speculative if not fanciful ideas to try to make them profound or something. That’s B.S. (And anyway, the interpretation of the quantum behavior of particles and waves remains disputed and poorly understood since their discovery some 90 years ago, so that’s not the best reference to make!)

I’m glad people continue to speculate and investigate different facets of consciousness, such as how we’re conscious about our perceptions of language and conversation, music, making and retrieving memories, etc. Some scientists are also studying the kinds of neuronal activity that are dampened by anesthetics and enhanced by psychoactive drugs, which sounds weird, but it might illuminate, just a bit, what’s going on in our parts of our complex brains.

I’m also glad that people aren’t limiting this endeavor science. After all, poets, philosophers, musicians can make insights no one else has thought of before, and we need to listen to them. But when there’s the risk of pseudoscience being passed off as science and gaining legitimacy at the expense of it, then we have a problem.

Maybe this sort of thing is inevitable when you’re pushing the frontiers of something unknown while answers remain illusive. For example, think of interstellar space exploration, which also naturally captivates the imagination of a wide range of people. At times the consciousness conference reminds me of parts of the “Finding Earth 2.0” conference organized by 100-Year Starship that I went to back in 2015. While some impressive people like Jill Tarter and Mae Jameson focused on space travel technology and the search for extraterrestrial intelligence (SETI), other people worked on things like “astrosociology.” I was expecting people to talk about what it might be like for a handful of people to be stuck in an enclosed spaceship for years or a slightly larger planetary colony for decades. Those are important and tractable questions—and scientists at NASA and elsewhere are studying them right now. But instead a handful of people spoke about giant ships at least a century in the future, like it was Battlestar Galactica or the starship Enterprise or something. Yes, let’s think about what things might be like in the 23rd century, but all that’s premature unless we figure out how to get there first.

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.

New Science at the American Astronomical Society Meeting

I’d just like to summarize some of the exciting new scientific results presented at the American Astronomical Society meeting in Seattle last month. I think it will be interesting to those of you science lovers who’re wondering what all the hubbub was about and for you astronomers who weren’t able to make it.

This is my third and final post in a series about the AAS meeting. The first two dealt with science policy, and diversity and sustainability. As I mentioned in a previous post, I enjoyed attending as both a scientist and science writer, and I was happy to personally meet the journalists writing excellent stories about the meeting (some of which I’ve linked to below).

I’ll start with some special sessions and other sessions focused on interesting science that included results I hadn’t seen before, and then I’ll end with some interesting plenary talks given by great speakers. It was a busy meeting and many of the sessions ran in parallel, so it’s inevitable that I missed some things and that this summary is incomplete. (Plus, I’m usually drawn to the sessions about galaxies, dark matter, and cosmology, and I often miss the other ones.) If you know of interesting announcements or talks that I missed here, you’re welcome to comment on them below.

Sloan Digital Sky Survey (SDSS)

After 15 years of great science, it was exciting to see the SDSS have its final public data release—until SDSS-IV data eventually come out, that is. At the press conference, Michael Wood-Vasey gave an overview, Constance Rockosi spoke about the data release, Daniel Eisenstein spoke about the Baryon Oscillation Spectroscopic Survey (BOSS), Jian Ge spoke about the Multi-object APO Radial Velocity Exoplanet Large-area Survey (MARVELS), and Steven Majewski spoke about the APO Galactic Evolution Experiment (APOGEE). According to Rockosi, more than 6,000 papers have been published using publicly released SDSS data. The SDSS has observed tens of thousands of stars, hundreds of thousands of quasars, and millions of galaxies.

In addition, members of the BOSS collaboration presented (nearly) final results at a session dedicated to the survey. If you’re interested, check out this article I wrote about it for Universe Today. (Thanks to Nancy Atkinson for editing assistance.)

Distribution of galaxies in a slice of the BOSS survey. (Courtesy: SDSS-III)

Distribution of galaxies in a slice of the BOSS survey. (Courtesy: SDSS-III)

3D-HST

Researchers presented newly published results and interesting work-in-progress about the evolution of distant galaxies using spectroscopic data from the 3D-HST survey, which is led by Pieter van Dokkum (Yale Univ.) and Ivelina Momcheva (Carnegie Observatories), combined with imaging data from the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS), taking advantage of instruments aboard the Hubble Space Telescope. The figure below shows the spectral features of tens of thousands of galaxies, which indicate star formation activity, active galactic nuclei activity, and stellar age. If you’re interested, I wrote an article about some of these results for Sky & Telescope. (Thanks to Monica Young for editing assistance.)

Spectral features of high-redshift galaxies. (Courtesy: Gabriel Brammer, 3D-HST)

Spectral features of high-redshift galaxies. (Courtesy: Gabriel Brammer, 3D-HST)

Andromeda Galaxy

In a session dedicated to Andromeda—known as M31 by astronomers—as well as in other related sessions, research scientists and Ph.D. students presented studies about the stars, globular clusters, molecular clouds, dust, structure, dynamics, surface brightness profile, and stellar halo of the galaxy. The continued interest in our fascinating neighbor is understandable; Andromeda’s only 2.5 million light-years away from our galaxy! Like our Milky Way, Andromeda is a spiral galaxy, and it’s the most massive galaxy in the Local Group.

Many of these AAS results came from the Panchromatic Hubble Andromeda Treasury (PHAT) Survey, which is led by Julianne Dalcanton (Univ. of Washington), who presented highlights in a press conference as well. Dalcanton and her colleagues released this PHAT panoramic image of the galaxy below, and it received well-deserved press attention, including in NBC and Sky & Telescope.

Map of Andromeda galaxy. (Courtesy: HST, PHAT)

Map of Andromeda galaxy. (Courtesy: HST, PHAT)

Exoplanets

Many people were understandably excited about extra-solar planets, or exoplanets, detected by scientists with NASA’s Kepler space telescope. Every day of the meeting included talks and posters about the masses, abundances, dynamics, compositions and other properties of exoplanets as well as those of stars and supernova remnants examined with Kepler. In addition, astronomers’ announcement that they now have more than 1,000 confirmed exoplanets with Kepler and follow-up observations garnered considerable media attention (including these articles in Nature, BBC, and New York Times). They have at least 3,000 more planet candidates, and they will surely identify many more as Kepler continues its mission through 2016.

Of course, astronomers seek to find as many as possible Earth-like planets in or near the habitable regions orbiting Sun-like stars (often referred to as the “Goldilocks” zone). When these are successfully identified, the next step is to characterize their properties and try to assess the likelihood of life forming on them. Astronomers have found at least eight Earth-size planets in the habitable zone, including two of the newly announced ones, Kepler-438b and Kepler-442b. They also released these cool old-school travel posters. If you have a space ship that can travel 500 light-years a reasonable time, you should check out 186f on your next vacation!

Kepler's alien planet travel posters. (Courtesy: NASA)

Kepler’s alien planet travel posters. (Courtesy: NASA)

“Pillars of Creation”

On the 25th anniversary of the launch of the Hubble Space Telescope, astronomers released new images of the iconic star-forming region in the Eagle Nebula in the Serpens Cauda constellation, known as the “pillars of creation.” Journalists at Slate, CBS, and elsewhere shared these amazing images. At first I thought not much science was done with them, but by combining observations at visible and infrared wavelengths, astronomers can investigate what’s happening with the cold gas clouds and dust grains and assess how rapidly new stars are forming and where. For more, you can also see Hubble’s press release, which coincided with the press conference on the first day of the meeting.

Image of "pillars of creation." (Courtesy: NASA and ESA)

Image of “pillars of creation.” (Courtesy: NASA and ESA)

Other Results

I saw many other interesting talks and posters at the meeting, but I don’t have the time/space to get into them here. On galaxies and the large-scale structure of the universe (which I’m interested in), I saw talks involving modeling and measurements with the Galaxy And Mass Assembly (GAMA) survey, the Six-degree Field Galaxy Survey (6dF), and I presented research using the PRIsm MUlti-object Survey (PRIMUS). But the SDSS dominated the field.

In addition, Joss Bland-Hawthorn, Sarah Martell, and Dan Zucker presented some impressive early science results from the GALactic Archaeology with HERMES (GALAH) survey of the Milky Way, which uses an instrument with the Anglo-Australian Telescope. (GALAH is named after an Australian bird.) Astronomers combine GALAH observations with astrometry from Gaia and over the survey’s duration will produce detailed data for 1 million stars in our galaxy! In particular, they utilize a technique called “chemical tagging” to study the abundances of at least 15 chemical elements for each star, allowing for studies of stellar dynamics and merger events from infalling “satellite” galaxies. I look forward to seeing more results as they continue to take data and analyze them; their first public data release is planned for 2016.

PLENARY SESSIONS

I’ll briefly describe a couple of the plenary talks below, but I missed a few others that sounded like they could be interesting, including “The Discovery of High Energy Astrophysical Neutrinos” (Kara Hoffman); “Gaia – ESA’s Galactic Census Mission” (Gerry Gilmore); and “The Interactions of Exoplanets with their Parent Stars” (Katja Poppenhaeger).

Also, Paul Weissman (JPL/Caltech) gave an overview of the Rosetta mission and the comet C-G/67P, and Al Wootten (NRAO) gave an overview of many recent science papers using the Atacama Large Millimeter Array (ALMA). Rosetta and its lander Philae has run a few experiments already, and scientists with the mission have found that the bulk density of the nucleus is less than half the density of water ice and that its D/H ratio is different than the abundance ratio of the Earth’s oceans. More recently, Rosetta detected a crack in the “neck” of the comet, and they’ve abandoned an idea for a close flyby search for the lost lander, which might wake up in a few months when it receives more solar power. And if you’re interested in ALMA science, such as involving the gas kinematics of protostars and protoplanetary disks and the gas and dust clouds of distant galaxies, watch for proceedings from their recent Tokyo meeting, which are due to be published next month.

Cosmology Results from Planck

Martin White (UC Berkeley) gave an excellent talk about cosmological results from the Planck telescope, which he described as having the “weight of a heavy hippo and the height of a small giraffe.” Based on analyses of the power spectrum of the cosmic microwave background (CMB) radiation, so far it seems that the standard model of cold dark matter plus a cosmological constant (ΛCDM) is still a very good fit. Scientists in the collaboration are obtaining tighter constraints than before, and the universe still appears very flat (no curvature). They are planning a second data release this year, including more simulations to assess systematic uncertainties and more precise gravitational lensing measurements. White ended by saying, “I can explain to you what really well, but I can’t tell you why at all.”

White also hinted at, but didn’t reveal anything about, the joint analysis by Planck and BICEP2 astrophysicists. That analysis was completed recently, and now it seems that the detected polarization signal might be at best a mixture of primordial gravitational waves produced by inflation and of Milky Way dust, and they’ve obtained only an upper limit on the tensor-to-scalar ratio. Check out my recent article in Universe Today about this controversy.

Courtesy: ESA

Courtesy: ESA

Inflation and Parallel Universes

Max Tegmark (MIT) has talked and written about both inflation and the multiverse for many years, such as in a 2003 cover article and a recent blog post for Scientific American and in his book, “Our Mathematical Universe.” From the way he presented the talk, it was clear that he has discussed and debated these issues many times before.

Tegmark began by explaining models of inflation. According to inflation, the universe expanded for a brief period at an exponential rate 10-36 seconds after the Big Bang, and the theory could explain why the universe appears to have no overall curvature, why it approximately appears the same in all directions, and why it has structures of galaxies in it. In one entertaining slide, he even compared the expansion rate of a universe to that of a fetus and baby, but then he said, “if the baby kept expanding at that rate, you’d have a very unhappy mommy.”

Expansion rates of a baby (human) and a baby universe

Expansion rates of a baby (human) and a baby universe

He subtitled his talk, “Science or Science Fiction?”, and that question certainly came up. Tegmark argued that inflation seems to imply at least some levels of a multiverse (see his slide below), which makes many astrophysicists (including me) nervous and skeptical, partly because parallel universes aren’t exactly testable predictions. But he made the point that some general relativity predictions, such as about what happens in the center of a black hole, aren’t testable yet we accept that theory today. He discussed “modus ponens” arguments: once we accept “if p then q,” then if p is asserted, we must accept q, whether we like it or not. In other words, if inflation generally predicts parallel universes and if we accept inflationary theory, then we must accept its implications about parallel universes. This is an important issue, and it’s another reason why BICEP2 and Planck scientists are trying to resolve the controversy about polarization in the CMB.

Predictions of different levels of the multiverse.

Predictions of different levels of the multiverse.

The Dark and Light Side of Galaxy Formation

Finally, in another interesting talk, Piero Madau (UC Santa Cruz), who was recently awarded the Heineman Prize for Astrophysics, spoke about galaxy formation and dark matter. In particular, he spoke about difficulties and problems astrophysicists have encountered while attempting to model and simulate galaxies forming while assuming a cold dark matter (CDM) universe. For example, he described: the cusp-core controversy about the inner profiles of dark matter clumps and galaxy groups; the problem of angular momentum, which is conserved by dark matter but not gas and stars; the missing satellites problem, in which more simulated dark matter subclumps (“subhaloes”) than observed satellite galaxies are found; and the “too-big-to-fail” problem, such that simulated subhaloes are much more dense than the galaxies we see around the Milky Way. These problems motivated astrophysicists to rethink assumptions about how galaxies form and to consider warm or self-interacting dark matter.

Madau ended by saying that evidence that the universe conforms to expectations of the CDM model is “compelling but not definitive,” and warm dark matter remains a possibility. Considering all of the exciting work being done in this field, this could be “the DM decade”…but then he said people have been talking of a DM decade for the past thirty years.

Conference on Nearby Galaxies in Memory of Charles Engelbracht

I just returned from a small conference on “Observations of Dust in Nearby Galaxies” at the University of Arizona in Tucson. It honored Chad Engelbracht, an influential astronomer in the field who rather suddenly passed away in January, before his 44th birthday.

chad.fb

It was great to be back in Tucson! This was my first visit since I moved away in 2012. I worked as a postdoc at the University of Arizona—an internationally renowned center of theoretical, observational, and instrumental astronomy—for three years, and I spent much of that time working with Chad on research projects with the Key Insights on Nearby Galaxies: a Far-Infrared Survey with Herschel (KINGFISH) and Herschel Inventory of The Agents of Galaxy Evolution (HERITAGE) surveys. Chad has written numerous publications on extragalactic infrared astronomy, especially on the distributions of dust, stars, and gas within galaxies in the “local universe.” He was also the MIPS Instrument Scientist for the Spitzer telescope, which enabled a lot of excellent research by others.

As you may know, I’m trained in theoretical astrophysics, and my expertise is in the large-scale structure of the universe, dark matter, galaxy formation, and cosmology, and when I’ve used data, they’ve usually been in optical wavelengths. Needless to say, I had a steep learning curve to navigate in order to work on my infrared research, and Chad helped me up it. Chad was my friend and colleague, and I really enjoyed working with him. He was patient with me, had a great sense of humor, gave me insightful suggestions and feedback, and helped me produce interesting results. (The two main papers we wrote together are here and here.) If I continue with my academic career, he would be one of my role models.

Chad also liked beer, so we definitely got along well. While I worked at Steward Observatory, he and I and others in the “infrared wing” frequently went to 1702 for pizza and beer for lunch. The night before the conference, many of his old friends and I went back to 1702 for a few pints. Chad also liked to play the computer game Quake, where he was known as “Chuckles the clown.” During her opening remarks at the conference, Joannah Hinz said, “Since no one is admitting to have played Quake, it seems that Chad must have been playing it by himself!” Well, I’ll admit that Chad didn’t have to twist my arm much to convince me to play it when I was at Arizona, and when I’d gotten a new computer, his first task was to make sure that Quake ran on it well. The game made for a good afternoon break and a funny way to interact with people. (If you’re wondering, I played as The Tick.)

Many of Chad’s colleagues and collaborators attended and spoke at the conference, including Rob Kennicutt, Margaret Meixner, Bruce Draine, Maud Galametz, and Dennis Zaritsky. I was moved by all of the personal and astronomical tributes to Chad throughout the conference. It’s clear that he influenced, inspired, and was respected by many people. His legacy lives on.

Chad is survived by his parents and siblings, his wife Sue Dubuque, their three children (Max, Sydney, and Henry), and his numerous friends. He is missed.

Astrophysicists Gather in Aspen to Study the Galaxy-Dark Matter Connection

I just returned from a summer workshop at the Aspen Center for Physics, and I enjoyed it quite a bit! The official title of our workshop is “The Galaxy-Halo Connection Across Cosmic Time.” It was organized by Risa Wechsler (Stanford) and Frank van den Bosch (Yale) and others who unfortunately weren’t able to attend (Andreas Berlind, Jeremy Tinker, and Andrew Zentner). The workshop itself was very well attended by researchers and faculty from a geographically diverse range of institutions, but since it was relatively late in the summer, a few people couldn’t come because of teaching duties.

photo 1

Since I grew up in Colorado, I have to add that Aspen is fine and I understand why it’s popular, but there are many beautiful mountain towns in the Colorado Rockies. Visitors and businesses should spread the love to other places too, like Glenwood Springs, Durango, Leadville, Estes Park, etc… In any case, when we had time off, it was fun to go hiking and biking in the area. For example, I took the following photo after hiking to the top of Electric Peak (elev. 13635 ft., 4155 m), and lower down I’ve included photos of Lost Man Lake (near the continental divide) and the iconic Maroon Bells.

photo 11

The Aspen Center for Physics (ACP) is a great place for working and collaborating with colleagues. As they say on their website, “Set in a friendly, small town of inspiring landscapes, the Center is conducive to deep thinking with few distractions, rules or demands.” As usual, we had a very flexible schedule that allowed for plenty of conversations and discussions outdoors or in our temporary offices. Weather permitting, we had lunch and some meetings outside, and we had many social events too, including lemonade and cookies on Mondays and weekly barbecues. It’s also family-friendly, and many physicists brought their spouses and kids to Aspen too. I’ve attended one ACP summer workshop on a similar theme (“Modeling Galaxy Clustering”) in June 2007, and it too was both fun and productive. Note that the ACP workshop is very different than the Madrid workshop I attended earlier this summer, which had specific goals we were working toward (and I’ll give an update about it later).

This year’s Aspen workshop connected important research on the large-scale structure of the universe, the physics of dark matter halo assembly, the formation and evolution of galaxies, and cosmology. We had informal discussions about the masses and boundaries of dark matter haloes in simulations, ways to quantify the abundances and statistics of galaxies we observe with telescopes and surveys, and how to construct improved models that accurately associate particular classes of galaxies with particular regions of the “cosmic web”—see this Bolshoi simulation image, for example, and the following slice from a galaxy catalog of the Sloan Digital Sky Survey:

rcolor_main_all_z0

While some of these issues have plagued us for years and remain unresolved, there are some subtle issues that have cropped up more recently. We (including me) have successfully modeled the spatial distribution of galaxies in the “local” universe, but now we are trying to distinguish between seemingly inconsistent but similarly successful models. For example, we know that the distribution of dark matter haloes in numerical simulations depends on the mass of the haloes—bigger and more massive systems tend to form in denser environments—as well as on their assembly history (such as their formation time), but these correlations can be quantified in different ways and it’s not clear whether there is a preferred way to associate galaxies with haloes as a function of these properties. For the galaxies themselves, we want to understand why some of them have particular brightnesses, colors, masses, gas contents, star formation rates, and structures and whether they can be explained with particular kinds of dark matter halo models.

IMG_1862

The main purpose of these workshops is to facilitate collaborations and inspire new ideas about (astro)physical issues, and it looks like we accomplished that. The previous workshop I attended helped me to finish a paper on analyzing the observed spatial distribution of red and blue galaxies with dark matter halo models (arXiv:0805.0310), and I’m sure that my current projects are already benefiting from this summer’s workshop. We seem to be gradually learning more about the relations between galaxy formation and dark matter, and my colleagues and I will have new questions to ask the next time we return to the Rockies.

Finally, here are those Maroon Bells you’ve been waiting for:

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Comparing Models of Dark Matter and Galaxy Formation

I just got back from the “nIFTy” Cosmology workshop, which took place at the IFT (Instituto de Física Teórica) of the Universidad Autonoma de Madrid. It was organized primarily by Alexander Knebe, Frazer Pearce, Gustavo Yepes, and Francisco Prada. As usual, it was a very international workshop, which could’ve been interesting in the context of the World Cup, except that most of the participants’ teams had already been eliminated before the workshop began! In spite of Spain’s early exit, the stadium of Real Madrid (which I visited on a day of sightseeing) was nonetheless a popular tourist spot. I also visited the Prado museum, which had an interesting painting by Rubens involving the Milky Way.

IMG_1760

This was one of a series of workshops and comparison projects, and I was involved in some of the previous ones as well. For example, following a conference in 2009, some colleagues and I compared measures of galaxy environment—which are supposed to quantify to what extent galaxy properties are affected by whether they’re in clustered or less dense regions—using a galaxy catalog produced by my model. (The overview paper is here.) I also participated in a project comparing the clustering properties of dark matter substructures identified with different methods (here is the paper). Then last year, colleagues and I participated in a workshop in Nottingham, in which we modeled galaxy cluster catalogs that were then analyzed by different methods for estimating masses, richnesses and membership in these clusters. (See this paper for details.)

This time, we had an ambitious three week workshop in which each week’s program is sort of related to the other weeks. During the first week, we compared codes of different hydrodynamical simulations, including the code used by the popular Illustris simulation, while focusing on simulated galaxy clusters. In week #2, we compared a variety of models of galaxy formation as well as models of the spatial distributions and dynamics of dark matter haloes. Then in week #3, we’re continuing the work from that Nottingham workshop I mentioned above. (All of these topics are also related to those of the conference in Xi’an that I attended a couple months ago, and a couple other attendees were here as well.)

The motivation of these workshops and comparison workshops is to compare popular models, simulations, and observational methods in order to better understand our points of agreement and disagreement and to investigate our systematic uncertainties and assumptions that are often ignored or not taken sufficiently seriously. (This is also relevant to my posts on scientific consensus and so-called paradigm shifts.)

Last week, I would say that we had surprisingly strong disagreement and interesting debates about dark matter halo masses, which are the primary drivers of environmental effects on galaxies; about the treatment of tidally stripped substructures and ‘orphan’ satellite galaxies in models; and various assumptions about ‘merger trees’ (see also this previous workshop.) These debates highlight the importance of such comparisons: they’re very useful for the scientific community and for science in general. I’ve found that the scatter among different models and methods often turns out to be far larger than assumed, with important implications. For example, before we can learn about how a galaxy’s environment affects its evolution, we need to figure out how to properly characterize its environment, but it turns out that this is difficult to do precisely. Before we can learn about the physical mechanisms involved in galaxy formation, we need to better understand how accurate our models’ assumptions might be, especially assumptions about how galaxy formation processes are associated with evolving dark matter haloes. Considering the many systematic uncertainties involved, it seems that these models can’t be used reliably for “precision cosmology” either.

Climate Change Resilience and Governance: Preparing for the Effects of Global Warming

I just came back from Washington, DC, where I attended an AAAS meeting on Climate Change Resilience and Governance, which included speakers from local governments and federal government agencies, nongovernmental organizations (NGOs), industry, and academic researchers. The meeting’s program is here. I’ll summarize the presentations and debates that I found interesting, but if there are others you’d like to hear more about, let me know. By the way, I should do this more often when I write about conferences, but the hashtag participants used is #RGR14.

First I’ll tell you what we mean by resilience and governance, then I’ll mention a couple important new developments that people talked about throughout the conference, and then I’ll tell you about some of the major issues and themes we discussed. If you don’t want to read all the details below, the major issues included these: the framing of climate change with different people; water issues, including droughts and floods; responding and recovering from disasters; and economic issues.

Before I continue, I’d also like to point out that, thanks to the efforts of the organizers, the program was very diverse, with speakers and participants with a variety of backgrounds and coming from a variety of places. In addition, women constituted nearly two thirds of the speakers, and more than 10% of the speakers were people of color. There were even back-to-back sessions of all-women speakers. (This is much better than the physics and astrophysics conferences I usually attend; see this post for more on diversity issues in science.)

key terms and definitions

If you’re interested in my previous posts about climate change issues, including an introduction to the concept and implications of climate change, look here. I and others usually focus on climate change mitigation, since we’re working to avoid the worst of climate change and reduce its many potentially harmful effects. Nonetheless, we know that the climate is changing and our planet is warming. Even with radical and politically unlikely changes to our fossil fuel-based economic system, we still have to contend with the greenhouse gases we’ve already emitted, which will warm the planet by an average of at least 1.5 or 2 C this century, according to the recent report by the Intergovernmental Panel on Climate Change (IPCC). Therefore, we need to adapt to the expected consequences. Let’s be clear though: we need to work on both mitigation and adaptation simultaneously (a point explicitly made by Susan Ruffo, of the White House’s Council on Environmental Quality).

“Resilience” is similar to “adaptation,” though it sometimes refers to efforts to restore things back to normal after a weather-event or climate-related disaster, but as some speakers pointed out, in the future we may be adapting to a new normal. “Governance” refers to actions being taken by local, national, and international governments, and it’s of course related to politics and policy. At the meeting last week, it was Laura Petes (an advisor at OSTP) who defined these terms (and see this executive order for official government definitions).

the context

The US Global Change Research Program released its third National Climate Assessment (NCA) in May. The NCA was a major five-year undertaking by hundreds of climate scientists and is both comprehensive and detailed. It’s US focused, unlike the international IPCC reports, though both make for sober reading. It includes studies of the looming climate change effects across the US (such as effects on water resources, agriculture, transportation, urban systems, rural communities, etc.) and within particular regions of the country. (The report also received considerable media attention, such as Phil Plait’s article on Slate.) The NCA’s interactive website is very useful, well organized, and worth checking out. The last of its key findings is the following:

Planning for adaptation (to address and prepare for impacts) and mitigation (to reduce future climate change, for example by cutting emissions) is becoming more widespread, but current implementation efforts are insufficient to avoid increasingly negative social, environmental, and economic consequences.

NCA3_overview_p14

The report includes an entire chapter dedicated to adaptation, which describes examples of actions being taken by federal agencies, states, cities, NGOs, and the private sector, and outlines the next steps, including the identification of critical adaption threshold or “breakpoints” beyond which social or ecological systems are unable to adapt to climate change.

In addition, a week ago the Environmental Protection Agenca (EPA) announced new power plant carbon standards. According to Ken Kimmell of the Union of Concerned Scientists (UCS), this is a potential game changer. As you can see in the following graph, power plants, especially coal-fired ones, dominate our carbon emissions, and these standards could reduce those emissions by half by 2030 (to less than a million metric tons of CO2). The EPA and its administrator, Gina McCarthy, should be applauded for taking this important first step. The new standards must be combined with major efforts to ramp up renewable energy technologies and improved energy efficiency, and they will require strong leadership from the states. As argued by Vivian Thomson (professor at U. of Virginia) at the meeting, California, New York, and Washington are among the “active states” on climate change, and most of the rest of the country can do much much more.

SectorEmissions1990To2012_GHGInventoryReport2014
Power-plant-carbon-dioxide-emissions-chart

framing

A number of speakers argued that we should be careful about how we frame these issues when interacting with different communities and different sectors of the public. For example, some people react different when they hear “global warming” versus “climate change.” Some people can be turned off by hearing either of these, but they will be receptive when they hear about energy efficiency and ways to reduce their family’s gas and electricity bills. In addition, terms like “sustainability,” “smart growth,” and “resilience” may be too vague, but “risk reduction” in a specific context can be clearer, for example.

water

I’ve written before on water policy issues in the southwest , where we’re always talking about drought, but in the east, people are worried about floods and stormwater. Water issues are perhaps the most important of those facing us, and it’s no surprise that the NCA devoted two chapters to water resources and interactions between water, energy, and land use. I should note that climate change affects the food supply as well, through agriculture, fish catch, rising food prices, and so forth.

NCA3_water_Fig11

Many speakers spoke about water issues. Susan Leal (who co-authored a book, Running Out of Water) pointed out that most people take water and wastewater for granted, but maybe the shouldn’t. We should expect water rate payments to increase in the future. Pilar Thomas, who works with the Department of Energy, spoke about the water-energy nexus and the vulnerability of energy systems. She also spoke about water law and water rights, since disputes between states, tribal communities, and the private sector about water will surely increase in the future. I asked a question about preparing for future droughts, and these speakers argued that we can gain much from reduced water usage in agriculture and the food industry; water recycling in urban areas; and maybe we should try again to have “Meatless Mondays,” since producing a pound of animal protein requires, on average, about 100 times more water than producing a pound of vegetable protein (and beef is the worst).

environmental justice

I was happy and impressed that many speakers, especially Jalonne White-Newsome (WE ACT for Environmental Justice), Michael Dorsey (member of EPA’s National Advisory Committee), and Barbara Allen (professor at Virginia Tech) discussed important issues of environmental justice, injustice, and inequality. In my opinion, we don’t talk about these issues enough, and we certainly aren’t adequately addressing them. If you’re interested in learning more about environmental justice (EJ), see my recent post about the issues involved.

Currently EJ communities are not engaged in the process, argues Dr. White-Newsome, and the failure to mobilize the majority of Americans to want action on climate change is partly due to the fact that not everyone is part of the conversation. Many black, Latino, and Native American communities, as well as working class white communities, live closer to power plants, land fills, oil drilling platforms, polluting industries, etc., and are in more vulnerable areas, such as those that will be affected by rising sea levels, droughts, fires, hurricanes, and so on. Dr. Dorsey talked about the injustice of extreme weather events, such as Hurricanes Katrina and Sandy, which should not be seen as “acts of God.” (He also had a way with words; at one point he referred to “persistent corporate sociopathy.”) Dr. Allen argued that we need endogenous ideas for transforming a community, such as when a community is rebuilding following a weather event, but if green technologies and buildings seem like too external to people, then they won’t “take” and will be less popular and successful.

disasters

A couple speakers, such as Sabrina McCormick (professor at George Washington U.) and Dr. Allen, talked about the benefits and perils of “disaster thinking.” It can be dangerous to think of climate change as a series of disasters; we might benefit from seeing the opportunities for improvement, such as by appealing to people’s self-interest. (For example, because of successful incentives, Germans now associate climate change and renewable energy with ways to make money.) Nonetheless, we can expect more weather events, flooding, and temperature extremes in the future. In fact, and this was new to me, heatwaves kill more people than all other weather events combined! Young children and people over 65, especially those on the top floors of poorly cooled buildings in dense urban areas, are among the most vulnerable. Simple solutions like white-painted roofs can save many lives.

“it’s the economy, stupid”

Finally, a few people, especially David Orr (author of seven books and professor at Oberlin), Kate Sheppard (reporter at Huffington Post), and Gar Alperovitz (writer and professor at U. of Maryland), talked about economic issues and policies. Dr. Orr discussed the relation between carbon emissions, climate change adaptation, and economic systems and unequal wealth distributions. He warned that, if the current political culture doesn’t change, “when times get rough, humans get nasty”—fairness goes out the window. Katrina is just an example of what’s to come. What will governments have to do when sea levels rise to get people out of harm’s way? It will help if we begin to think more like a community. We’re all in this together, but as it is now, the 7% richest people are responsible for half of carbon emissions, while the costs of climate change are being outsourced to the third world and future generations. Dr. Orr also asked a couple provocative questions: Is our capitalist system resilient and sustainable? Is democracy sustainable? (He asked this in the context of a point that Exxon-Mobil could legally burn all of their reserve fossil fuels and single handedly take us all past the tipping point.) While specific questions about responding to the next big storm are important, we should also be asking these big questions about systemic challenges, since climate change is likely the biggest crisis of our time.

From Dark Matter to Galaxies

Since I just got back from the From Dark Matter to Galaxies conference in Xi’an, China, I figured I’d tell you about it. I took this photo in front of our conference venue:
photo 2

Xi’an is an important historical place, since it was one of the ancient capitals of the country (not just the Shaanxi province) and dates back to the 11th century BCE, during the Zhou dynasty. Xi’an is also the home of the terra cotta warriors, horses, and chariots, which (along with a mausoleum) were constructed during the reign of the first emperor, Qin Shi Huang. The terra cotta warriers were first discovered in 1974 by local farmers when they were digging a well, and they are still being painstakingly excavated today.

IMG_1731

Back to the conference. This was the 10th Sino-German Workshop in Galaxy Formation and Cosmology, organized by the Chinese Academy of Sciences and the Max Planck Gesellschaft and especially by my friends and colleagues Kang Xi and Andrea Macciò. This one was a very international conference, with people coming from Japan, Korea, Iran, Mexico, US, UK, Italy, Austria, Australia, and other places.

Now scientific conferences aren’t really political exactly, unlike other things I’ve written about on this blog, though this conference did include debates about the nature of dark matter particles and perspectives on dark energy (which is relevant to this post). I should be clear that dark matter is much better understood and determined by observations though, such as by measurements of galaxy rotation curves, masses of galaxy clusters, gravitational lensing, anisotropies in the cosmic microwave background radiation, etc. (On a historical note, one conference speaker mentioned that the CMB was first discovered fifty years ago, on 20 May 1964, by Penzias and Wilson, who later won the Nobel Prize.) In contrast, the constraints on dark energy (and therefore our understanding of it) are currently rather limited.

the main points

I’ll start with the main points and results people presented at the conference. First, I thought there were some interesting and controversial talks about proposed dark matter (DM) particles and alternate dark energy cosmologies. (The currently favored view or standard “paradigm” is ΛCDM, or cold dark matter with a cosmological constant.) People are considering various cold dark matter particles (WIMPS, axions), warm dark matter (sterile neutrino), and self-interacting dark matter. (Warm dark matter refers to particles with a longer free-streaming length than CDM, which results in the same large-scale structure but in different small-scale behavior such as cored density profiles of dark matter haloes.) The jury is still out, as they say, about which kind of particle makes up the bulk of the dark matter in the universe. There were interesting talks on these subjects by Fabio Fontanot, Veronica Lora, Liang Gao, and others.

Second, people showed impressive results on simulations and observations of our Milky Way (MW) galaxy the “Local Group”, which includes the dwarf galaxy satellites of the MW and the Andromeda (M31) galaxy’s system. Astrophysicists are studying the abundance, mass, alignment of satellite galaxies as well as the structure and stellar populations of the MW. Some of these analyses can even be used to tell us something about dark matter and cosmology, because once we know the MW dark matter halo’s mass, we can predict the number and masses of the satellites based on a CDM or WDM. (Current constraints put the MW halo’s mass at about one to two trillion solar masses.) There were some interesting debates between Carlos Frenk, Aldo Rodriguez-Puebla, and others about this.

The third subject many people discussed involves models, and observations of the large-scale structure of the universe and the formation and evolution of galaxies. There are many statistical methods to probe large-scale structure (LSS), but there is still a relatively wide range of model predictions and observational measurements at high redshift, allowing for different interpretations of galaxy evolution. In addition, simulations are making progress in producing realistic disk and elliptical galaxies, though different types of simulations disagree about the detailed physical processes (such as the treatment of star formation and stellar winds) that are implemented in them.

There were many interesting talks, including reviews by Rashid Sunyaev (famous for the Sunyaev-Zel’dovich effect), Houjun Mo, Joachim Wambsganss, Eva Grebel, Volker Springel, Darren Croton, and others. Mo spoke about impressive work on reconstructing the density field of the local universe, Springel spoke about the Illustris simulation, and Wambsganss gave a nice historical review of studies of gravitational lensing. I won’t give more details about the talks here unless people express interest in learning more about them.

my own work

In my unbiased opinion, one of the best talks was my own, which was titled “Testing Galaxy Formation with Clustering Statistics and ΛCDM Halo Models at 0<z<1.” (My slides are available here, if you’re interested.) I spoke about work-in-progress as well as results in this paper and this one. The former included a model of the observed LSS of galaxies, and you can see a slice from the modeled catalog in this figure:
figure

I also talked about galaxy clustering statistics, which are among the best methods for analyzing LSS and for bridging between the observational surveys of galaxies and numerical simulations of dark matter particles, whose behavior can be predicted based on knowledge of cosmology and gravity. I’m currently applying a particular set of models to measurements of galaxy clustering out to redshift z=1 and beyond, which includes about the last eight billion years of cosmic time. I hope that these new results (which aren’t published yet) will tell us more about how galaxies evolve within the “cosmic web” and about how galaxy growth is related to the assembly of dark matter haloes.

The Physics of Sustainable Energy

I attended a conference this weekend called “The Physics of Sustainable Energy” at the University of California, Berkeley. It was organized by people affiliated with the American Physical Society, Energy Resources Group, and a couple other organizations. Most of the speakers and attendees (including me) seemed to be Californians. I had some interesting conversations with people and attended some great talks by experts in their fields, and here I’ll just give you a few highlights.

First though, I want to make two general comments. I did notice that only ~20% of the speakers were women, which is worse than astrophysics conferences, and it’s too bad the organizers weren’t able to make the conference more diverse. (There were a few people of color speaking though.) Secondly, I think it’s excellent that people (and not just in California) are actively involved working on solutions and innovations, but I think we should be careful about an technophilic or technocratic emphasis. This was a conference for physicists and engineers though, and energy policy and communication with the media and policy-makers, for example, were mostly beyond the scope of it. I was struck by the apparently close ties with industry some speakers had (such as Amory Lovins and Jonathan Koomey); to some extent that’s necessary, but I was a little concerned about potential conflicts of interest.

…On to the conference. Ken Caldeira spoke about the global carbon balance. When accounting for CO2 emission per capita from fossil fuel use and cement production: the US is worst (50kg CO2/person/day), followed by Russia, China and the EU. California emits half as much as the rest of this country, but 2/3 of the difference is due to a fortunate climate (it doesn’t get very cold); according to an audience member (Art Rosenfeld?), “we’re mostly blessed with good luck as well as some brains.” Daniel Kammen (one of the organizers) then talked about developing a framework for energy access for all. According to the International Panel on Climate Change (IPCC AR4 in 2007): “warming will most strongly and quickly impact the global poor.” Kammen described the concept of “energy poverty”: 1.4 billion people lack access to electricity today, and that will still be the case for a similar number in 2030, with more having unreliable/intermittent access. There appears to be a strong correlation between electricity access and human development index.

VAWTs

It seems that many people are working on interesting research & development on renewable energy sources. Jennifer Dionne spoke about the “upconversion” of solar cells, which includes thermodynamic, electronic, and photonic design considerations. The upconversion process improves cell efficiency by at least 1.5× (see Atre & Dionne 2011), and it often works well at optical near-infrared wavelengths. (She pointed out that of energy from the sun, 5% is in the UV, 43% in optical, and 52% in infrared. And if you’re interested in what those proportions are like for different types of galaxies, check out my recent paper.) Then Chris Somerville spoke about the status and prospects of biofuels, the production of which is currently dominated by the US and Brazil. The combustion of biomass has challenges for providing low-carbon energy: depends on tilling of soil, land conversion, fertilizer, transportation, and processing. I’m concerned about deforestation and effects on ecosystems as well as the effects on food/crop prices (remember the food riots in 2007-2008 and the rising cost of corn/maize?). In my opinion, Somerville didn’t sufficiently address this, though he did argue in favor of miscanthus and other biomass rather than the use of corn. John Dabiri spoke about the advantages of vertical-axis wind turbines (called VAWTs, see the figure above), in addition to the ubiquitous horizontal-axis variety. VAWTs have a smaller structure size and cost, simpler installation logistics, and are safer for birds and bats as well. Currently only four countries get >10% of their electricity from wind (Spain, Portugal, Ireland, Denmark, followed by Germany with 9%), but this can be easily improved.

LLNL_Flow-Chart_2012

This flow diagram is pretty nice, and it describes current energy use in the US (presented by Valerie Thomas). And Daniel Kammen, in a paper on the relation between energy use, population density, and suburbanization, shows the spatial distribution of carbon footprints (where the units are tCO2e, or total carbon dioxide equivalent per household).

JonesKammen2014_Fig1

Tilman Santarius give a nice talk about energy efficiency rebound effects, which is closely related to my previous post, where you can find more information. He discussed the interactions between energy efficiency, labor productivity, human behavior, and economic growth, and he distinguished between rebounds due to an income effect vs a substitution effect. In any case, average direct rebound effects appear to be around 20-30% (Greening et al. 2000; Sorell 2007), in addition to a 5-10% of indirect rebound. In other words, around 1/3 of income savings due to energy efficiency is lost because of an increase in energy demand. He also talked about the psychology of rebounds, including moral licensing (such as Prius drivers who drive more) and moral leakage (people feel less responsible). It will be a difficult task to try to separate energy demand from economic growth.

There were many other interesting talks, but I’ll end with the issue of climate adaptation and geoengineering. Ann Kinzig described how the combined risk of a phenomenon is the sum Σ p (event) × impact (event). Mitigation seeks to reduce the probability p while adaptation seeks to reduce the impact. Climate change will have impacts on food, water, ecosystems, and weather events, and decision-makers in urban areas can try to prepare for these (see this website). Kinzig also spoke about historical case studies of failed adaptations by people in the Hohokam (Arizona), Mesa Verde (Colorado), and Mimbres (New Mexico) regions, and the dependence on societal hierarchy and conformity. Alan Robock spoke about the risks and benefits of “geoengineering”, which involves gigantic projects in the future to address climate change, such as space-based reflectors, stratospheric aerosols, and cloud brightening (seeding clouds), and basically involve using the Earth as a science experiment with a huge cost of failure. In particular, he studies the many problems of injecting sulfate aerosols into the stratosphere to cool the planet. (Some people have supported this idea because of the supposedly benign effects of volcanic eruptions in the past.) He discussed the potential benefits of stratospheric geoengineering but compiled a list of 17 risks, including drought in Africa and Asia, continued ocean acidification, ozone depletion, no more blue skies, military use of technology, ruining terrestial optical astronomy, moral issues, and unexpected consequences. For more on Robock’s research and for other useful references, go here.

Robock_figure

Reporting from the American Association for the Advancement of Science (AAAS) meeting

I’d like to tell you about the AAAS meeting I’m attending. (Look here for the program.) It’s in Chicago, which is definitely much colder than southern California! I know it might sounds strange, but it’s nice to experience a real winter again.

There were some astrophysics sessions (such as on galaxy evolution in the early universe and dark matter particles) but that wasn’t my focus here. I took some brief notes, and this is based on them…

There were a few sessions about science communication, outreach, and media. These are very important things: for example, according to Rabiah Mayas, the best indicator of whether people participate in science or become scientists as adults is the extent to which they engaged in science-related activities outside of school as kids. One person discussed the importance of fact-checking for producing high-quality and robust science writing, but it takes time; one should note that peer-review in scientific research is supposed to perform a similar purpose, though it can be time-consuming as well. In any case, many people agreed that scientists and journalists need to interact better and more frequently. (As a side note, I heard two high-profile science journalists mispronounce “arXiv”, which is pronounced exactly like “archive”.) In addition, it’s worth noting that smaller regional newspapers often don’t have dedicated science desks, though this could provide opportunities for young writers to contribute. There was also an excellent talk by Danielle Lee about “Raising STEM Awareness Among Under-Served and Under-Represented Audiences,” who talked about ways to take advantage of social media.

There were interesting presentations about scientists’ role in policy-making, but I’ll get back to that later. Someone made an important point that scientists should be extremely clear about when they are just trying to provide information versus when they are presenting (or advocating) policy options. I should be clearer about that myself.

I also saw interesting talks by people about public opinion surveys in the U.S. and internationally of knowledge and opinions of science and technology. According to these polls, although some Americans are worried about global warming/climate change, people are more worried about toxic waste, water and air pollution. According to Lydia Saad (of Gallup), 58% of Americans worry a “great deal” or “fair amount” about global warming, 57% think human activities are the main cause, 56% think it’s possible to take action to slow its effects, while only 34% think it will affect them or their way of life. In addition, she and Cary Funk (of Pew) found huge partisan gaps between self-identified Democrats, Independents, and Republicans. As one person pointed out, climate change is not just a science issue but has become a political one. Americans in polls had pretty high opinions of scientists, engineers, and medical doctors, but people had the best views of those in the military. There is a wide range of knowledge of science, especially when it comes to issues such as evolution. (Note that fewer Republicans believe in evolution by natural processes, due to a drop in those who are not evangelicals, who already had a low fraction.) Also note that the numbers depend on how poll questions are asked: for example, ~40% agree to, “The universe began with a huge explosion”, and when you add “according to astronomers”, then the proportion jumps up to 60%. (If you’re curious, this image basically describes astronomers’ current view of the Big Bang.)

bigbang

There was an interesting session dedicated to climate change science, which included scientists that contributed to the IPCC’s recent 5th Assessment Report (which we talked about in an earlier blog). Note the language they’re required to use to quantify their un/certainty: “virtually certain” means 99% certain, and then there’s “very likely” (90%), “likely” (67%), and “more likely than not” (>50%). Michael Wehner discussed applications of “extreme value statistics” (which are sometimes used analyze extremely luminous galaxies or large structures in astronomy: see this and this) on extreme temperatures. Extremely cold days will be less cold, while extremely hot days will be more common and hotter. For particular extreme weather events, one can’t say whether they’re due to climate change, but one can ask “How has the risk of this event changed because of climate change?” or “How did climate change affect the magnitude of this event?” It seems very likely that the there will be heavier heavy rainy days, longer dry seasons, and more consecutive dry days between precipitation events. There will be more droughts in the west (west of the Rockies) and southeast, and more floods in the midwest and northeast.

The plenary speaker today was Steven Chu, former Secretary of Energy until last year, who gave an excellent talk. He compared convincing people about climate change to earlier campaigns to convince people about the dangers of tobacco use and its connection to lung cancer; both issues have had industry-promoted disinformation as well. On rising temperatures with climate change, he channeled Yogi Berra when he said, “If we don’t change direction, we’ll end up where we’re heading.” He talked a little about the role of natural gas (see also these NYT and Science blogs), and he discussed carbon capture, utilization, and sequestration (CCUS). Finally, he talked about how one might determine an appropriate price of carbon. He advocated a revenue-neutral tax, starting at $10/ton and over ~12 years raising it to $50/ton, and then giving the money raised from this directly back to the public. He also talked about wind turbines, which are now more reliable, efficient, and bigger, and he predicted a 20-30% decline in price in the next 10-15 years. The cost of solar photovoltaic (PV) modules is also dropping, but installation costs and licensing fees (“soft costs”) should be reduced. I definitely had the impression that, now that Chu is no longer Energy Secretary, he could be more frank than before about his views on contentious issues.