The opinions expressed here are well-reasoned and insightful -- needless to say they are not the opinions of my employers

20 December 2007

Pale Blue Dot

Phil Plait reminded me that Carl Sagan died 11 years ago today. I'm too old for this to be true, but Cosmos was what inspired me to a career in science. Better late than never.

In February 1990 the Voyager 1 spacecraft, by then 12.5 years and four billion miles from home, spun around to take a “family portrait” of our Solar System from about 32 degrees above the ecliptic. The image above is of Earth, a few pixels of blue against the blackness of space. The light streak is a ray from the sun, just off the image to the right.

Look again at that dot. That's here. That's home. That's us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives. The aggregate of our joy and suffering, thousands of confident religions, ideologies, and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilization, every king and peasant, every young couple in love, every mother and father, hopeful child, 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 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 this pixel on the scarcely distinguishable inhabitants of some other corner, 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. Our planet is a lonely speck in the great enveloping cosmic dark. In our obscurity, in all this vastness, there is no hint that help will come from elsewhere to save us from ourselves.

The Earth is the only world known so far to harbor life. There is nowhere else, at least in the near future, to which our species could migrate. Visit, yes. Settle, not yet. Like it or not, for the moment the Earth is where we make our stand.

It has been said that astronomy is a humbling and character building experience. 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 with one another, and to preserve and cherish the pale blue dot, the only home we've ever known.

-- Carl Sagan in a commencement address, May 11 1996

16 December 2007

The Reason for the Season

It's been a week since Phil Plait posted this link on his Bad Astronomy blog. It made me very angry, that I didn't think of it first. Nonetheless, it will from this year forward be my Christmas card...

Merry Christmas, y'all!

15 December 2007

Where On (Google) Earth? #80

Well I managed to win my first northern hemisphere WOGE challenge, though it looks like Ron may have had a better claim had he signed on a few minutes later, after Joe re-posted the image.

It only seems fair to stay with the recent trend and not invoke the Schott Rule this time.

However to add to the challenge this time I won't remind you to look at the north arrow.

13 December 2007

Accretionary Wedge #4: My Pet Rock

For show-and-tell today I brought this fulgurite specimen, which I unfortunately did not collect myself.

In 1998 I took a group of intro geology students on a trip to Capitol Reef National Park in southern Utah, and while we watched a storm play out over the Henry Mountains I gave an impromptu lecture on convective thunderstorms and lightning.

Lightning is the sudden release of huge static charges that develop in convective storms due to rapid vertical movement of air. No one really understands the details of the transfer of charge (the primary carrier of charge appears to be small fragments of ice crystals), but typically the cloud becomes a 5-10 km high capacitor with negative charge concentrated near the base. When the stress becomes too high the cloud discharges very rapidly. Globally there are roughly 5000-10000 lightning discharges per minute, mostly in the tropics, of which roughly one third strike the ground (the rest occur between clouds or within the cloud).

A cloud-to-ground strike transfers billions of joules of energy, most of which dissipates in the atmosphere (heating the air to tens of thousands of degrees and creating visible as well as infrared light that ranges down into the radio spectrum). In the end only a tiny amount of the original energy is delivered at the point of impact, but anyone who has observed or experienced the results will testify that it is sufficient.

Since the cloud is looking for the easiest path to the ground, it is most likely to strike objects above the local base level, as trees, houses, and people (especially those holding lightning rods golf clubs) are much better conductors than relatively dry air.

The subject of fulgurites, or fossil lightning, came up and I explained that quartz has a melting point of about 1600 degrees C, a temperature easily achieved in the near surface, though in very wet soils the charge can be dissipated pretty rapidly. The best examples therefore result when lightning strikes the ground directly in an area where the soil is dry and is thus not a good conductor.

Quartz sand works particularly well as it conducts heat as poorly as it conducts electricity. This prevents charge from dissipating rapidly, so the bolt can travel through the ground for several meters, fusing sediment to glass and vaporizing all of the volatile components. Some of the best examples of fulgurites are discovered in dune fields, where dry unconsolidated sands subsequently are eroded by winds, exposing the fused structure. Unfortunately fulgurites are quite fragile and tend to crumble when excavated.

One of the students on that trip was visiting relatives in Temecula later that year when she saw lightning strike the ground a few hundred feet from her back door. She got her husband to help her dig up the yard after the storm had passed, and she brought us a shopping bag full of this broken chunks of this fossilized lightning. The largest piece here is about 25 cm long and 8 cm in diameter and was found less than 40 cm beneath the surface.

The soil was very sandy in this location, and was fused to glass at temperatures exceeding 2000 degrees C. You can see what a poor conductor of heat this material is, as it transitions from glass to barely altered sand in less than a centimeter. There is a general relationship between current and diameter indicating that this sample was created by a fairly powerful lightning strike.

The moisture and organics flashed to vapor, leaving lots of vesicles. The explosive expansion of the volatiles can create hollow tubes down the center of the structure, pushing the molten (or melting) sand outward. There is a common misconception about these hollow tubes that they represent a zone where temps were high enough to vaporize quartz, but this is not true.

The second piece is from about a meter beneath the larger sample and is barely more than a glass tube. You can see the charge branching off from this piece in several directions simultaneously.

I've found that, in addition to being great samples to pass around when I’m talking about thunderstorms in class, fulgurites are great ringers to slip into an igneous rocks practical exam.

23 November 2007

Meme of Four

I haven't quite finished all of the grading I brought home this weekend, and I'm about to leave for the movies (yes, I'm spending money on Buy Nothing Day, but only on a movie ticket for What Would Jesus Buy? ...and a bag of popcorn), but this post by Brian has been bouncing around in my head for a couple of days; so when Zoltan bit I had to also...

4 jobs you’ve had:

  1. busboy
  2. did laundry for sports clubs (high school, college and professional)
  3. battery factory
  4. clerk at US Postal Service

4 movies you could watch over & over:

  1. Beyond Rangoon (it’s not great, but it gets to me every time)
  2. Bullets Over Broadway
  3. Casablanca
  4. Life of Brian

4 places you’ve lived:

  1. Long Beach
  2. Berkeley
  3. Santa Cruz
  4. Laguna Beach (all within walking distance to the beach; never though about it much, but I apparently don't like to be surrounded by continent)

4 TV shows you love to watch:

  1. The Wire
  2. Family Guy
  3. Arrested Development (only the good die young)
  4. The Daily Show (though I confess to watching Kitchen Nightmares, also)

4 places you’ve been on vacation:

  1. Switzerland
  2. Ireland
  3. British Columbia
  4. Guana Cay, Bahamas

4 authors you love to read:

  1. Edward Abbey
  2. John McPhee
  3. Douglas Adams
  4. Dava Sobel

4 websites you visit daily:

  1. Astronomy Picture of the Day
  2. Google Reader
  3. New York Times
  4. USGS Earthquakes page

4 of your favorite foods:

  1. Neapolitan Pizza (I try not to be too much of a purist, but if you haven’t had the genuine article, you’ve never taste pizza)
  2. Kung Pao Chicken
  3. Tortilla Soup
  4. Chili

4 places you’d rather be:

  1. Thousand Island Lake, Eastern Sierra
  2. San Francisco (two more weeks!)
  3. Rafting the Grand Canyon
  4. Laguna Beach (sometimes you have to appreciate where you are)

4 lucky people to tag:

  1. Kim
  2. Riverbend
  3. Thermochronic
  4. Jon Carroll

29 October 2007

be careful what you put into that head, for you will never get it out!

I caught the second half of a session on teaching climate change to underclassmen and secondary students. The issue is a complex one, as are all scientific topics, but the politicization brings it up by an order of magnitude. As it does, I guess, with any topic.

I have strong opinions on issues of civil liberties, economics, the environment and science in general. I like to consider myself pretty well informed on most topics, but on science and the environment I’m kind of paid to be an “expert” (at least from the point-of-view of the layman). In class I make every attempt to direct the conversation toward process: how the systems work, what we know about driving and mitigating forcings, how we determine what happened in the past and to what degree of certainty.

If a student asks me what my opinion is on the death penalty my standard response is “buy me a beer after the final exam and I’ll tell you.”

One of the two greatest insults a student can throw at me is that I’m only presenting my opinion (the other is that my ability to understand logarithms is some genetic quirk, that doing math is “easy for you.”). Where I work is pretty politically conservative, though not nearly so much as people think.

I haven’t run into too many students who challenge me on climate science, because those who get all of their science information from Fox News and Rush Limbaugh, are a bit intimidated by an actual science class – I think they’re afraid that if I dismantle their misconceptions they won’t have anything upon which to hang their opinions.

I get mostly ambiguous questions (Hasn’t all of that evolution stuff been proven wrong? I heard that we never landed on the moon). And every semester, without fail, at least one student who wants to “SAVE” me – because, you know, someone who teaches that the Earth is older than 6010 year, and that humans have not been around for very long, and that the chemical and physical systems that govern its operation are incredibly complex but, nonetheless, largely understandable by our measly brains must be a non-believer. And a non-believer in 21st century America clearly has never been exposed to Jesus.

So what these few students get out of my class is that I’m the ignorant one.

But you know what? A majority of them can, at the end of the semester, explain why the Earth experiences seasons that are inverted in the other hemisphere, and why the temperature of the troposphere gets cooler with altitude.

So I’ve got that going for me, which is nice…

28 October 2007

I could see it happening to one of the many Red Sox fans at the airport, but...

Well, I wanted to blame the lost bag on Denver’s state-of-the-art computerized baggage handling system, which made the national news, what, 10 year ago because they still couldn’t get the bags out on time. As it turns out though, it all comes down, as always, to human error aided by bureaucracy. Someone didn’t pull my suitcase off the plane, so it continued on to Baltimore, where it sat for 5 hours before someone scanned it into the system, and now it sits waiting for a flight tomorrow, so it will (hopefully) arrive at my hotel sometime late in the afternoon. I think United owes me back some of the $5 billion we bailed them out with after 9/11.

Of course I’ve never lost a bag before, so this was largely probability catching up with me. As I often say at such times, no one is bombing my house and family so shaking my fist at the heavens is pretty inane and self-centered. So I can just blog about it…

Anyway, it cost me about an hour, which was just enough that I entirely missed a special panel on new things happening with Google Earth (thanks Andrew, for filling us in).

23 October 2007

Have some fire, Scarecrow!

We just returned from a weekend trip to Death Valley. Beautiful fall weather and we avoided ruining several sets of shocks on the road to Racetrack Playa. I'll write about the trip soon, but on the way home Sunday night we passed through the origins of several southern California wildfires. The Santa Ana winds have been as wild as I ever remember them, with 100 mph gusts in places. Between Cajon Pass and Corona we passes 3 or 4 big rigs that had been blown over. Passing through the Santa Ana mountains we came across the Santiago fire in its infancy: This one began near Silverado Canyon, where I had a field trip planned two weeks from now. Five minutes earlier and we'd have been driving through as it was crossing the road. As it happened we came upon a closed road and had to make our way south along the coast. So far, 20 or so homes have burned in Modjeska Canyon, and several of my students have been evacuated. They closed the school down on Monday afternoon; driving to school the winds and gray sky made me think of a volcanic eruption.

By the afternoon both yesterday and today the sky overhead was relatively clear though the smell of smoke remained. To the south the fires in the San Diego area are producing a thick, dark brown smoke that hangs on the horizon. The smoke to the north (most from the Santiago fire) is thinner and the sky reminds me a lot of the pre-clean-air-act sky from when I was a kid, though this doesn't make my eyes burn as much.

The image below is a sunset image taken this afternoon at Aliso Creek in southern Laguna Beach. I missed the cherry-red sun by a few minutes, but the smoke here is from several of the LA fires in addition to the Santiago fire. Below is an image taken on Monday by NASA, showing the smoke from various fires being blown out to sea. The chaparral covering the local hills and mountains is uniquely well adapted to life with fire as the climate is not conducive to the kind of bugs that promote the decay of dead vegetation. The leaves contain oils and resins that allow them to hold moisture. Many of these plants are more flammable than Christmas trees or eucalyptus. Unfortunately, the 21st century humans who live adjacent to the chaparral have not adapted to the fires as well...UPDATE (8:40 AM): A couple of new fires on Camp Pendleton to the south have closed I-5 between LA and San Diego, and some parts of the Marine base are being evacuated. The smoke is much heavier over campus than it was on Monday when the campus was closed, but the Santa Ana winds are largely gone.

Also, I corrected some spelling erorrs...

15 October 2007

Death without disequilibrium

We are all doomed.

We live in a 5 km thick layer of vapor at the surface of a 12,750 km sphere that, so far as we know, is the only oxidizing environment in the universe.

We can die from too much water or from too little water or from too much oxygen or too little oxygen.

At sea level or river level you are vulnerable to floods, at altitude you are vulnerable to gravity.

There’s aridity in Arizona, tornadoes in Texas, flooding in Florida, hurricanes in Hawaii, nor’easters in the north east, winter storms in Wisconsin, volcanoes in Vancouver, and in California the crust is moving simultaneously in more directions than the Governor.

But what are the alternatives? Our atmosphere and hydrosphere are, molecule by molecule, atom by atom, leaking off into space, and an Earth with no earthquakes and volcanoes (i.e., a cold, tectonically dead Earth) would no longer replace those gases (see Mars, Moon, Mercury, basically all of the M-worlds). Life needs an active world, one with outgassing volcanoes.

Storm activity not only brings water to the middle of continents, it is part of the processes that bring some thermal equilibrium to the planet. Greenhouse heating turns the atmosphere over, moving water vapor from the oceans to the continents, heat from the tropics to the poles, and prevents those pesky 250 degree day-night temperature variations. For planets with life, look for clouds and rain and storms and high winds. Just ask the Venusians.

Life is, and thrives on, disequilibrium, whether it is chemical, thermal, or gravitational. All of the universal plots to kill us involve, in one way or another, a reduction in disequilibrium and an increase in entropy.

Equilibrium is calm, quiet and deadly.

06 October 2007

Where On (Google) Earth? #59

Looking at Zoltan's meandering channels took me back to my first class in geomorphology, and I've had images of area:slope ratios, shear stress, the law of the wall, and ::shudder:: Reynolds numbers (OK, the equations, not the images) running through my head for the last few days.

While scanning around, looking for potential sites that might present enough of a challenge for the brilliant members of this community I came across this NW-SE drainage. The beauty of the image, the sharp angles of the hills and the broad curves of the channels, just blows me away (notice that there's even a lovely little stream capture at the center of the image).

I had a natural history teacher once tell me that the more I understood the details of the natural world the less I would notice its beauty. I knew he was full of shit at the time and every time I go into the field I'm reminded again how incredibly wrong he was. And other geologists I meet seem to have the same sense of the numinous when looking at landscapes.

So without further ado I present you with WOGE #59:

All the usual boilerplate, including the Schott Rule, are hereby invoked. Winners will have their names carved in the digital plaque and have the honor of hosting #60. Post time is 10:45 PDT.


Update (10/9): These rocks were deposited in a large inland sea and contain both ammonites and inoceramus...

14 September 2007

Where On (Google) Earth? #48

Welcome to all of the competitors! I've explained things to my students, and I imagine everyone knows the drill by now. The Schott Rule is in effect.

Post time is 1745 on the leftist coast.

Cheers everyone...

03 September 2007

M = 4.7, WNW of Lake Elsinore

My brother, his buddy Eric and I were reading the NYT yesterday morning and drinking our Sunday coffee yesterday morning (RIP Alfred Peet) when there was a small creaking sound. It passed right by me but the cat popped her head up and Eric asked "What was that?"

After a few seconds, the familiar rocking began, lasting ~10 seconds. "Earthquake" I replied. We discussed how big and how far away while I waited for my laptop to wake up and find the network. I guessed 3.5 and Yorba Linda, because most of the half-dozen small earthquakes we've seen the past 10 years seem to have originated in that general area.We marveled at how well the USGS Earthquakes page works these days, as the event description was posted within 2 minutes, and it showed up on the map within 4 minutes along with Lat/Long, and the moment-tensor solution. I know that within the last year it's taken as long as 10 minutes to see data posted ("10 minutes! But I want it now!"). Click on the image below to access the USGS information page on this earthquake:The image below is a map of the major faults in Southern California available on the page of the Southern California Earthquake Center. Click on it, then on the purple shaded region, then on the purple blue fault line in the lower right of the image to get a description of the fault that produced this earthquake.

13 August 2007

The Muslim view of the Grand Canyon

In Salon (the article is free to read, non-members need to sit through an advert) today, Steve Paulson interviews Turkish physicist Taner Edis, the author of "An Illusion of Harmony: Science and Religion in Islam" on the state of science in the Muslim world. What is interesting is not that the religious culture that gave modern science (among other things) algebra and the number zero has become a scientific backwater but how much the Muslim world's fundamentalists have in common with the Christianity's fundamentalists on scientific issues:

SP: Is the critique of Darwinism basically the same as what you'd find from American creationists?

TE: Much of the rhetoric is similar. There are only so many ways you can argue against evolution, only so many ways you can say the fossil record doesn't tell you what the biologists say. But there are also differences. For example, in American creationist circles, one of the stronger options is "Young Earth creationism." People who read the Book of Genesis literally believe in a creation that happened 10,000 years ago, literally done in six days. But the Quran is much vaguer about the time frame of divine action. Therefore, they are not as committed to fitting earth history into thousands of years. So Muslim creationists are almost invariably "Old Earth creationists." They tend to think of Noah's flood as a local event -- not such a big thing -- unlike the American creationists who think of the flood as the major geological event in earth history. So there are lots of differences that adapt creationism to the Islamic context.

Reading this made me flash back on one of my last trips to the Grand Canyon, when I was explaining the geologic history of the canyon to a non-scientist friend. A guy walked up to me, out of the blue, to tell me that the story I was telling was completely wrong, because the Bible tells us that the Canyon and all of the rocks were formed in the Great Flood. That guy is backed by the western world's most visible religious fundamentalists, so mainstream that even Al Gore famously waffled on Darwin during the 2000 campaign.

Yet for all the disagreements I might have with a Muslim fundamentalist about science (or about many other things) he wouldn't have had any serious problems with the standard scientific explanation for the formation of the Grand Canyon (at least until I got to the part about what fossil evidence tells us about evolution in the Paleozoic).

09 August 2007

The Internets is the Commons

Al Gore did not personally invent the internet (nor did he ever claim to have), but it was created largely through the work of publically-funded entities, primarily universities and the military.

Like the radio, TV, and wireless spectrum private enterprise now wants to plant its flag into this public square and claim ownership.

From the official website of the band Pearl Jam:
When asked about the missing performance, AT&T informed Lollapalooza that portions of the show were in fact missing from the webcast, and that their content monitor had made a mistake in cutting them.

During the performance of "Daughter" the following lyrics were sung to the tune of Pink Floyd's "Another Brick in the Wall" but were cut from the webcast:

- "George Bush, leave this world alone." (the second time it was sung); and

- "George Bush find yourself another home."

This, of course, troubles us as artists but also as citizens concerned with the issue of censorship and the increasingly consolidated control of the media.

AT&T's actions strike at the heart of the public's concerns over the power that corporations have when it comes to determining what the public sees and hears through communications media.

Complaints about the stifling of voices in the corporate media are commonly met with sweeping references to the expansion of our choices since the advent of cable (though the vast majority of cable channels are owned by the same media giants); satellite radio (though there are only two satellite companies, soon to be only one); and the democratic (some say anarchic) nature of the internet.

Major broadcast companies have made it clear the last few years that they feel that they have the right to reject paid television advertisements based on the most specious of reasons: CBS refused to sell time to MoveOn.org and PETA by saying “The network simply does not accept any advocacy advertising of any kind,” as if there were such a thing as non-advocacy advertising.

Well, say goodbye to the democratic internet. The FCC has essentially handed the internet over to a few giant phone and cable companies, allowing them the right to control traffic and charge a premium for fast service. The lobbying arms of these corporations are keeping legislation to prevent this bottled up in congress. Learn about Net Neutrality at savetheinternet.com and let your congressman, your senators, and the FCC know that you think that this is important.

08 August 2007

Students: ready for fall 2007?

I will have the course syllabi posted on the notes web site by the beginning of next week.

The books are all in the bookstore and available:

Geol 01 -- Earth: Portrait of a Planet by Marshak (2nd)
Geol 20 -- Earth Science by Tarbuck/Lutgens (11th)
Geol 04 -- Natural Disasters by Abbott (6th)
Astr 20 -- Horizons by Seeds (10th)
Hum 10B -- Earth in the Balance by Gore and Beyond Oil by Deffeyes

If you are in one of the lab courses, there are no lab books to purchase. All labs will be posted on the notes site.

You are free to try to save yourself some money by looking for these books on the internets. Sometimes you can get a pretty good deal. If you end up with an older edition, keep in mind that the chapters may not correlate with the syllabus, so it's up to you to figure out what you should be reading.

07 August 2007

Paying for the commons

I enrolled in community college right out of high school, because no self-respecting 4-year school would've taken me. It was the mid-70's, Vietnam was over, FM radio was still kind of subversive, and horrible fashion decisions were ubiquitous.

Through fits and starts, I worked my way through the higher education system successfully and now I find myself trying to help young people who are not so different than I was 30 years ago. There is of course one big difference -- these kids are charged through the nose for a system that was essentially free when I was a student. Until the mid 1980's California community colleges were free for students to attend. The Cal State University system cost a few hundred dollars per semester back then, and fees at the University of California were about twice as much.

Nothing in life is free of course: these low fees were heavily subsidized by the state. The higher education system in California was a gift of the previous generation to the next generation.

Until my generation came along. We boomers gladly accepted all of the stuff payed for by our parents: education, the state water system, highways, bridges, parks, the commons -- and when we became responsible adults we decided that we should only have to pay for that which benefits us directly.

In the last decade Hollywood began to market our parents to us . Our fathers were The Greatest Generation because they answered the call and fought the War, we are told. Books were written, movies and mini-series were produced, monuments were lobbied for and built.

My father passed away before all of the celebrations of his service began. He would have been embarrassed by most of the nostalgia.

We do owe a lot to his generation, because they did a lot for us. They, and the generations before them, built and paid for the world we all live in. They built the railroads and the highways. They built bridges and dams. They built canals and waterways to bring clean water to farms and cities and suburbs, and sewers and treatment plants to clean up the water afterward. They built the primary, secondary and higher education systems that would make sure their progeny had a future at least marginally better than theirs.

How can we pay them back? We can't pay them back, we can only pay forward. We can reclaim the commons, and pay collectively for the infrastructure that our progeny will inherit. Replacing and repairing old bridges and dams and water mains is more boring than building publically-financed sports stadiums, just like paying the electric bill is more boring than buying a new iPhone. But it's necessary.

If we make sure that a good, inexpensive higher education is available for everyone, then it will be available for our own kids, and tomorrow's graduates won't begin have to choose their career based on what will help them pay off their crushing debt. And schools won't need to sell Coke or Pepsi or McDonald's products to fund programs.

And I thus begin my blogging career with a polemic.

Contact Me

You can send me email at jrepka@saddleback.edu