Second Week of Class, Wherein I Get Distracted by a Picture of the Earth

Earthrise from the Lunar Reconnaissance Orbiter

I can't help it. I get to the end of another lecture, one I've done dozens of times over the years, and it dawns on me what an extraordinary time we live in. We were talking today about the origin of our planet, and the evidence that has accumulated regarding the formation of planets in general. I presented a PowerPoint that ended with the picture above. I dismissed the class, but left the picture on the screen as I gathered up my things. This picture amazes me, in much the same way as the earth rise picture from the Apollo Mission in 1968. From the perspective of teaching for more than thirty years, I stand in awe at the wonders revealed by our exploration of the cosmos.

When I started teaching, the origin of Earth and Solar System was reasonably well-understood, but direct visual evidence was somewhat lacking. Quantitative measurements and laboratory simulations shed a great deal of light on the process of planetary formation, but visual evidence provides an emotional charge to understanding. Emotion is not a prerequisite to learning, but it can inspire the desire to learn.

When I started teaching all those years ago, I had slides, images that were shone by a piece of technology called a "slide projector". They mostly described the origin of the Solar System with a series of paintings, depicting what we thought the process would have looked like. I didn't scan them all, but one of them looked like this:

Credit: William K. Hartmann, Planetary Science Institute, Tucson, Arizona

As the years passed, our ability to look farther into the Universe improved, and striking images appeared in the media. One by one, the paintings disappeared from my presentations, to be replaced by actual scenes of planetary formation taking place outside our own Solar System. The first was a fuzzy image of dust clouds around Beta Pictoris, a star about 65 light years away from Earth. It was the first time such clouds were imaged.

Then, in the early 1990s the Hubble Space Telescope transformed our view of the Universe. Spectacular images arrived, including those of the Orion Nebula, showing numerous planetary disks in the stellar nursery. More paintings disappeared from my class presentations.

Hubble image of planetary disks (proplyds)

Most recently, in 2014, it was the stunning image of a newly forming star with gaps in the dust cloud, showing where new planets were clearing space in the planetary disk. We aren't quite to the point of seeing the individual planets or their features, so the last painting in my presentation will probably remain, but who knows? The new James Webb space telescope is set to launch in 2018. It will represent 30 years of technological improvements over the Hubble Telescope, and it will be bigger. Who knows what wonders we will see next?

ALMA image of the young star HL Tau and its protoplanetary disk.  Credit: ALMA (NRAO/ESO/NAOJ); C. Brogan, B. Saxton (NRAO/AUI/NSF)

But we always come back in my lectures to the home planet, our Earth. It's our home and will be for the conceivable future. Images of the pale blue dot in space illustrate both our isolation, but also our hope. Knowing it's all we have, one can hope that our students and our society will chose to care for, rather than exploit our fragile planet. The most distant picture of our planet was photographed by the Voyager Spacecraft in 1990 after it left the Solar System for an unknown future in interstellar space. The Earth was a single pixel at that distance.

If you've never heard or read Carl Sagan's comments about the Pale Blue Dot, here they are. I certainly could never have said it better:

We succeeded in taking that picture, and, if you look at it, you see a dot. That's here. That's home. That's us. On it, everyone you ever heard of, every human being who ever lived, lived out their lives. The aggregate of all our joys and sufferings, thousands of confident religions, ideologies and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilizations, every king and peasant, every young couple in love, every hopeful child, every mother and father, every inventor and explorer, every teacher of morals, every corrupt politician, every superstar, every supreme leader, every saint and sinner in the history of our species, lived there – on a mote of dust, suspended in a sunbeam.

The Earth is a very small stage in a vast cosmic arena. Think of the rivers of blood spilled by all those generals and emperors so that in glory and in triumph they could become the momentary masters of a fraction of a dot. Think of the endless cruelties visited by the inhabitants of one corner of the dot on scarcely distinguishable inhabitants of some other corner of the dot. How frequent their misunderstandings, how eager they are to kill one another, how fervent their hatreds. Our posturings, our imagined self-importance, the delusion that we have some privileged position in the universe, are challenged by this point of pale light.

[...] To my mind, there is perhaps no better demonstration of the folly of human conceits than this distant image of our tiny world. To me, it underscores our responsibility to deal more kindly and compassionately with one another and to preserve and cherish that pale blue dot, the only home we've ever known.

Meanwhile, in the Skies Tonight...

Lunar eclipses are always interesting, and they can be shared by most of a planet, unlike solar eclipses that follow a narrow strip of land across the globe. I was a little frustrated tonight because high cloudiness affected the view of the unfolding eclipse, but I did what I could.

I was reminded of one of the greatest teaching moments I've ever had, among them having an earthquake take place while teaching about earthquakes. During one of those moments, I was watching the students intently taking a test on quakes when the room shook. Barely anyone even looked up and I told them to look at the swaying monitors on the ceiling and then told them they all failed for not getting under their desks. The ultimate surprise quiz.

But the truly best night was an earth science class a decade or so ago. I was introducing the course and commenting on the shape of the Earth and the students answered in various versions of round, circular, or spherical. I argued that we were on the back of the turtle. They laughed, but I then asked any of them to prove it wasn't.

Dead silence....

Someone said we have pictures from space. I responded that we had pictures of the Death Star and the Enterprise too.

More silence...

So I was able to take the whole class outdoors and point at the ongoing lunar eclipse and ask them what shape the Earth was casting across the surface of the Moon. None of them said turtle. They were impressed (for once!).

In any case, here are my somewhat clouded shots of tonight's eclipse. Other skywatchers

in areas with clear skies will no doubt have finer shots, but what can I say? It was certainly more fun than the taxes I was working on...

It's way too late to catch the other side, so here is totality, and I'm calling it a night...

Don't Let Them Fall Through the Cracks! An Accretionary Wedge...

The Wedge is back! This month's new Accretionary Wedge, hosted at Geology Happens, is asking what we geologists are up to:

"Not everything I am studying ends up in a published paper, well actually nothing I study ends up in a published paper. Sometimes my HS students hear about my adventures and sometimes I write a blog post, but mostly it is just for me.

This AW is to share your latest discovery with all of us. Please let us in on your thoughts about your current work. What you are finding, what you are looking for. Any problems? Anything working out well?"

This seems a great opportunity to find out what kinds of things one can do as a geologist, and I hope lots of bloggers and readers out there are responding. As my readers must probably know by now, I teach geology at a community college. I've talked many times about the joy and motivations of being a teacher of geology (here, here, here, and very recently, here), but I don't think I've said much about the day-to-day grind.

As a professor at a community college, I wear a number of hats. Unlike many four-year universities, we are oriented more towards teaching rather than research. The school loves to tout our research if we pursue it, but it is not expected of us. Consequently, the teaching load is larger than it would be at other schools (15 hours a week of instruction time is considered full-time, plus required office hours). A teaching overload is not unusual. I teach classes in physical and historical geology, geology of California, and a distance-learning course called "Introduction to Geology". Laboratory sections are taught as part of the first two classes. Because geology is such a field-oriented science, I teach several field courses each semester, with an extended five-day trip to the Cascades, Death Valley, or the eastern Sierra Nevada, plus a number of day trips to Yosemite, the Coast Ranges, or the Sierra Nevada Mother Lode. The summer usually includes a two week exploration of the American southwest, or Pacific Northwest. If you have read my blog for any period of time, you know that taking students into the field is my favorite part of teaching.

I spend lots of time grading lab reports and tests, which I don't particularly enjoy, but responding to the student's work is one of the most important things I do; in a classroom people can hide in the back and not participate verbally, but their written work and my response is an important direct line of communication.

My job includes other responsibilities. As part of a philosophy of shared governance, we are generally expected to serve on committees, such as Academic Senate, Curriculum, Petitions, Scholarship, and so on. We participate in department and division meetings. All professors, full-time and part-time, are periodically evaluated, which includes peer review, so we spend time sitting in on other prof's courses, and providing advice and guidance. We are also involved in the hiring processes of both professors and administrators.

Finally, although it is not always spelled out in our career announcements, we are ambassadors for our school. We visit elementary school classrooms to talk to children about our work, we give presentations on geologic topics to the community (I talked about the Haiti earthquake a few months ago), and we provide expertise to local governments. I get visits all the time from people who wish an explanation of the strange rock specimens that they have discovered.

Community colleges fill many roles. We provide a bridge for high school graduates who are unsure of what path they want to follow into the future (some data suggests that our students may change majors six times or more) and we are also a cheaper alternative to high tuition universities (our transfers often do very well). We have many reentry students as well, people who need a new career after being laid off or divorced, or need to develop new skills for a changing workplace. And some students, well, they have a life-long love of learning. We are trying to make sure no one with an educational need is falling through the cracks (I had to justify the title somehow...).

So that's what I do, if you have ever wondered (no doubt all of three or four of you), but if it sounds like something you might like to do as a career, you will need to earn at least a master's degree in geology or related science. Most geology departments at California's 112 community colleges are fairly small, so full-time openings are relatively uncommon, especially in difficult budgetary times (like right now, for instance). On the other hand, the average age of us professors is, well, not so young, and many retirements can be expected in the next decade or so.

It is not very often that a newly minted college graduate scores a full-time position as a professor. Many people teach part-time at several schools for a time, or like me, work in a related capacity for a few years (I know some of my old colleagues at Santa Barbara City College occasionally look in on the blog: thanks from the bottom of my heart for the wonderful opportunity you provided me back in the 1980's!).

Teaching at a community college is a great career choice. I'll never be financially wealthy, but I have had a rich life. I have never regretted it for a moment.

"...(they) must teach them how to get history from the ground"

"After customary greetings and handshaking, White gets down on his hands and knees with a few fossil hunters to show the tribesmen how the researchers crawl on the ground, shoulder to shoulder, to look for fossils...White explains that these stones and bones reveal the ancient history of humankind. The Alisera smile wanly, apparently amused that anyone would want to grovel on the ground for a living. They grant permission to search for fossils - for now. But they add one caveat. Someday, they say, the researchers must teach them how to get history from the ground."*

This short passage, from an article this month in Smithsonian magazine, brought to mind much of what I find so wonderful about being a teacher in the earth sciences. And a bit of frustration that I occasionally feel as well.

Human beings are curious creatures, and the earth sciences are a treasure trove of fascinating phenomena. Children are endlessly intrigued by dinosaurs, volcanoes, earthquakes, crystals and rocks. Though they try to hide it under a veneer of jaded indifference, my "grown-up" students will suddenly act like excited kids when unleashed on a slope that may reveal a fossil trilobite, a shark tooth or a gemstone. To enter the world of geology is to enter a realm of time and space where pretty much everything that could have happened did happen at some point in the past: massive volcanic eruptions, asteroid impacts, exploding stars, mass extinctions, evolution of strange and wonderful creatures of all shapes and sizes. The clues to these events lie in the grains of sand and silt, in the shapes left behind in the rock of the creatures that swam, walked or crept in numerous environments, in the trace elements found in the rocks. There are even atomic clocks in the rock that allow us to put a date to these events. I love being a teacher, I love being a story-teller. It is what makes "groveling on the ground for a living" a wonderful career. Reading of the natural curiosity of the Alisera people made me smile in recognition of the same impulses that led me into the earth sciences.

Because I realize this curiosity exists, I am patient with the visitors from the community who come to my office, explaining why the chunk of rock they found in their yard is not a dinosaur egg, or an asteroid fragment. They have come to learn something, after all. My enthusiasm dims a bit sometimes when they say "well, where can I go to find out the truth about my rock?" (it happens...), or they ask if I want to buy it anyway. But sometimes something really neat happens. A woman last year brought in what she thought was a piece of petrified wood, only to find she had a one foot section of a mammoth tusk!

But how to explain the willful and downright irrational ignorance I encounter on a too-regular basis? Well, I can't. Sometimes it is relatively harmless, but in other instances it dangerously misguided.

In the relatively harmless category we have a long discussion from Eric's Dynamic Earth about a hilariously over the top video made by an expanding earth supporter. What started as a bit of hilarity among geologists turned into a long debate with true believers, who turned out to be ignorant of some of the most basic tenets of geology. But they believe the earth is expanding, by golly, and we geologists are involved in a conspiracy of silence, preventing the truth from emerging (or expanding, as it were). For a while it was amusing to respond to the questions, but it was soon clear that the people asking the questions had no real interest in learning anything new, and especially not from people who actually understand the processes involved.

And then there are the discussions that pop up once in awhile about evolution and global climate change. The former gets into religious issues, and the latter into conservative politics. I don't want to go into details just now, but I've had a frustrating week in both areas. In short, it saddens and angers me how easily people will believe there is some kind of scientific conspiracy designed to control minds and research dollars. It makes no logical sense, but that doesn't matter. It does make sense that energy companies who stand to lose money would pay immense amounts of money to manufacture doubt. In any case, people have been told specifically what to believe by preachers with no science education, and senators or talk radio hosts with no science education. But the Jim Inhofes and Rush Limbaughs of the world do have their agendas, and the majority of us will not benefit if they are successful. Neither will our grandchildren and great-grandchildren. And how they kill a sense of wonder and understanding!

The sciences like biology, geology, and astronomy have led humanity into some of the greatest adventures of our history. We've explored the limits of outer space, and the innermost workings of the cell. We explored the vast expanse of time, the development of life, and the forces that have moved continents thousands of miles. I don't know the solution to dealing with global warming deniers or creation scientists (although I have some suggestions here). It's not easy, but it must be done.

Below, a treasure of the past, and one of the more exciting moments in one of my student's life!


* Ann Gibbons, 2010, The Human Family's Earliest Ancestors, Smithsonian, volume 40, number 12.

Some Things Never Change...and Some Do

Digging through the old archives of two decades of teaching, I found the other "field note" from my very first field trip. I was leading students along a stretch of the San Andreas fault where it passes through Cajon Pass in southern California. Along the way we passed the Indian Hill fault, the Cucamonga fault, the San Jacinto fault, and finally the San Andreas. Looking at the 25 year-old comic, I was reminded once again that many people in our fair state don't really know the dynamics of the land they live on.

A common discussion in my class:

The professor: "All earthquakes in California happen on the San Andreas fault. True or false?"

The class: "Uh, (suspicious pause) false?"

The professor: "Very good! Name another fault in California."

The class: ....(crickets chirping)....

Teachers of earth science have a daunting task: educating a public that is ignorant of the very real geologic hazards that surround them, in a time when a typical google search list is topped by Britney Spears and Obama's choice of dog.

One thing has certainly changed in two decades: television has made a difference. Cable channels like Discovery and National Geographic have in fact tapped into the very real curiousity people have about the world and geologic hazards that exist there. My students seem better informed about earthquakes and volcanoes and other topics than they used to be. It's a good thing, but there is a problem. But they also know more about sharks from "Shark Week" than they know about ocean ecosystems and the threat of over-fishing and ocean pollution. In other words, they know the flashy stuff, but their understanding of the underlying principles is still lacking. A television show cannot communicate that kind of deeper understanding. That's part of what we must do as teachers: adding the protein and vitamins to the empty calories of mass media presentations.

Want to learn more about teaching earth sciences? Check out the National Association of Geoscience Teachers (also here, and here) or the National Earth Science Teachers Association.

Why I Teach - The Long Journey of the Australian Marsupials

If anyone wonders why I teach at a community college, and why I don't dabble much in research, it would be because I have a scientific version of attention-deficit disorder: as soon as I start concentrating on one subject, something interesting pops up somewhere else, and I explore it for a few weeks, and then get distracted by something else. My students love it; there is almost always some weird tidbit of information that will pop up in classroom discussions. And hopefully it is a disorder that works well with running an interesting geoblog.

I was reminded of this when I saw this article in National Geographic News (Ancient Lion With "Bolt Cutter" Jaws: Best Killer Ever?) about the Australian marsupial version of a lion(Thylacoleo carnifex). Apparently, the creature had one of the strongest bites of any carnivore, and those cuddly kangaroos once had a most fearsome predator in their midst. In fact, they had more than just one.

Generally, when students are presented with the biographical evidence for plate tectonics and continental drift, it involves a discussion of mammal-like reptiles, and the distribution of the glossopteris flora across the southern hemisphere. This makes sense, given the role they played in Alfred Wegener's fight to have continental drift accepted as a plausible scientific hypothesis.

On the other hand, the story of the marsupials is a fascinating tale of journeys across vast continents, incredible adventures in successful adaptation, and horrific tragedies of extinction in unlikely places and times, as well as the on-going extinction event that is seeing the probable disappearance of koalas, tasmanian devils, and others. After a discussion of which continent has been isolated the longest, most students guess Australia, on the basis that the continent hosts the most unique mammal ecosystem, the marsupials. I am then able to point out that the ecosystem was once much richer. For nearly every animal filling an environmental niche in the more familiar climes of Europe and North America, there was an equivalent creature in Australia. For the antelope and deer, there are kangaroos and wallabies. For mice and rats, there are opossums and marsupial mice. For cats there are quolls. A stretch, perhaps, but for pigs, there are wombats. For foxes, we find the Tasmanian Devil. Less than a century ago there were Tasmanian wolves (hunted to extinction by 1930). In the paleontological record, we find a 3-ton marsupial buffalo or cow equivalent (diprotodon), and the subject of the linked article, the Marsupial lion, Thylacoleo carnifex. There was even a carnivorous species of kangaroo (Ekaltadema ima)!

The next obvious assumption is that marsupials originated in Australia. Why not? It makes sense that the most complex ecosystem of marsupials on earth must have arisen on the continent where they are found today. But they did not originate there, and were in fact relative late-comers to Australia.

The oldest marsupials known are reported from China, from Mesozoic time. My students immediately assume these marsupials got to Australia via the Indonesian Islands, which brings up the Wallace Line, which is a clear demarcation between many kinds of animals that exist on either side. The concept dates from the 1800's, and is in fact the work of Alfred Wallace, of evolutionary theory fame. The reason is tectonic. The continents are currently moving closer, and have been much further apart, making island-hopping essentially impossible.

Instead, the fossil records chronicles the successive arrival of later marsupials in North America, South America, Antarctica, and finally Australia. The distribution of these creatures makes no sense if the continents are stationary: they couldn't and wouldn't swim such distances. Instead, the journey of the marsupials is a fascinating line of evidence that supports the one-time existence of Pangea, Laurasia and Gondwana. And the story doesn't end there...

South America once supported a thriving marsupial ecosystem, including a marvelous example of convergent evolution in the existence of a sabertooth marsupial cat. It survived until around 4 million years ago, when the isthmus of Panama linked north and south America, allowing predators, especially the big cats, to move south, and treat South America like a giant buffet. The marsupials were decimated for the most part. On the other hand, the marsupial rat (the Virginia opossum) thrived in competition with North American placental species, and expanded its range into the United States.

It is a privilege and a joy to be a teacher. I've been thinking about this month's geoblogosphere carnival (subject, "what things make us go hmmm?"; see http://lablemminglounge.blogspot.com/2008/01/accretionary-wedge-5-and-6.html). I may end up with wondering what it is we do to destroy a student's sense of wonder about all things scientific. More to come....