Monday, April 26, 2010

Will the world end on December 21, 2012?

No. We’re not going to line up with some death ray from the center of the galaxy or collide with some mysterious planetary object just because some cycle on the Mayan calendar supposedly comes to an end on that date (despite what you’ll come across when you enter “Maya 2012” into Google).

If you’d like to hear about what the ancient Mayans really accomplished astronomically, and why people are always so anxious to predict the end of the world, come see Dr. Anthony Aveni on Friday, April 30 at 7:00 pm in the Student Lounge at SUNY Ulster County Community College as he gives a talk on his newest book – The End of Time: The Maya Mystery of 2012. The talk is free and open to the general public.

Dr. Aveni has been teaching at Colgate University for over 40 years and is the Russell B. Colgate Professor of Astronomy and Anthropology, serving a dual appointment in both the Departments of Physics and Astronomy and Sociology and Anthropology. He was featured in Rolling Stone magazine's 1991 list of the ten best university professors in the country (how cool is that!) and was also voted 1982 National Professor of the Year by the Council for the Advancement and Support of Education, Washington D.C.

Aveni helped develop the field of archaeoastronomy and now is considered one of the founders of Mesoamerican archaeoastronomy, in particular for his research in the astronomical history of the Maya Indians of ancient Mexico. He is the author of over twenty books on the subject.

I'll be introducing him and it should be a great talk!

Saturday, April 24, 2010

Solar Dynamics Observatory

Launched on February 11 of this year, and only recently returning images, NASA's Solar Dynamics Observatory (SDO) has started returning some spectucular images of the Sun.  The Sun has an 11 year cycle of magnetic activity which is reflected in the sunspot cycle.  We're now moving into a sunspot maxima over the next few years and it will be the most intensely-studied one yet - we're going to learn a lot more about how the Sun works.

A multispectral image of the Sun - it's not just a featureless orange ball.

Friday, April 23, 2010

This made me laugh

Thursday, April 22, 2010

Happy Earth Day

Way back in 1990, the late great astronomer and science popularizer Carl Sagan convinced NASA that it would be worthwhile to have Voyager 1 try and snap a shot of Earth as it was 4 billion miles away and leaving our planetary neighborhood for the far reaches of our solar system.

Below is that famous image of the Earth as a "pale blue dot."

Carl Sagan wrote a book by that name in 1994.  Below is an excerpt.

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.

In the entire universe, the only place we know for sure has life is our little rock orbiting the Sun.  It's a humbling thought.

Eyjafjallajökull from space

Really nice satellite image from April 17 (REUTERS/NERC Satellite Receiving Station, Dundee University, Scotland).  Click to embiggen.

Saturday, April 17, 2010


Interesting eruption in Iceland that's been all over the news.

Iceland, of course, is located astride the mid-Atlantic Ridge in the North Atlantic Ocean - the boundary between the North American and Eurasian tectonic plates where seafloor spreading is occuring.  Why is there a volcanic island here while other areas of the Mid-Atlantic Ridge are far under the surface of the ocean?  It appears that there's a mantle plume under Iceland - a column of hot material coming up from the core-mantle boundary (there's one under the Big Island of Hawaii too, in the middle of the Pacific Plate).

Iceland was born of innumerable volcanic eruptions and lava flows since it started forming less than 150 million years ago after the opening of the Atlantic Ocean when the ancient supercontinent of Pangaea split apart.  Today there are over 100 volcanoes located throughout the island.

The volcano, a tongue-twisting Eyjafjallajökull, is located under a glacier (a common occurrence for icelandic volcanoes).  Lots of glaciers in the interior of Iceland given it's location close to the Arctic Circle although the climate along the coast is moderated by the warm Gulf Stream/North Atlantic Drift currents.

Subglacial volcanoes pose special hazards because as the erupt under a glacial ice sheet hundreds of feet thick, the 1,200 degree Celsius lava easily melts the ice resulting in flash floods bursting out from underneath the glaciers.  Geologists describe these events by the Icelandic word jökulhlaup (pronounced "YOKE-uhl-howp" and meaning "glacier burst").  Here are pictures of the waters currently coming from under Eyjafjallajökull glacier.

Eyjafjallajökull  has actually been erupting since March 20, where I've been following it at the Eruptions blog.  This is the first time it's erupted since 1821-1823.  It didn't really come to the attention of the media, however, until the ash cloud started causing problems.

The ash plume from this volcano has reached the stratosphere and is being blown over Europe.  Ash is very bad for jet engines - it's like shoveling sand into it.  Airplane engines have been shut down mid-flight after flying through ash (not good over the North Atlantic Ocean).  The cost of this to the airline industry is estimated at $200 million/day plus and it can go yet for several weeks to months!

Click here for a really neat animation of the volcanic ash plume moving from Iceland to mainland Europe.

Here are a couple more cool pictures:

By the way, Eyjafjallajökull (a newscasters nightmare) is pronounced "AY-yah-fyaht-lah-yook-kutl" where, in Icelandic, "j" turns into a "y" sound and "ll" turns into a "tl" sound.  It means "island-mountain glacier."

Wednesday, April 14, 2010

A Mathematician's Lament

A Mathematician's Lament: How School Cheats Us Out of Our Most Fascinating and Imaginative Art Form (Bellevue Literary Press, 2009) is a a book by Dr. Paul Lockhart, a mathematician who taught at Brown and U.C. Santa Cruz and then decided to devote himself to teaching math to K-12 students at a private school in Brooklyn.  What he's lamenting is the present state of mathematics education.

The argument is radical.  Lockhart advocates doing away with the formal step-by-step progressive method of teaching kids mathematics.  Starting kids with arithmetic, then moving up through algebra, geometry, trigonometry, and eventually getting to calculus (ideally).  He says most people don't really need math (at least beyond an elementary checkbook balancing or calculating square feet of carpeting level) and instead we should just teach kids to play around and "discover" math. 

Lockhart gives a number of examples of things I assume he does with his students where they're asked to discover proofs for simple concepts in geometry or number theory.  The students are given a statement or a figure (e.g. a triangle drawn inside a box) and then asked a question about it (e.g. how much of the area of the box does the triangle take up) and then the students just play around to see if they can figure it out.

The claim is that the students will then discover how math works, see the beauty of it, and basically fall in love with it as the author has.  Hopefully I'm not misrepresenting Lockhart's claims since I'm about to criticize them a bit.

Here's my perspective as the department chair of the science and math department at a community college and a homeschooling parent of two children.

Lockhart is working with a special group of children at St. Anne's in Brooklyn.  I checked out their website and it's an exclusive school that admits really bright kids.  While they may work in St. Anne's under the tutelage of an innovative Ph.D. mathematician, I wonder how well these ideas would work in a typically inner city public school with a typical elementary school math teacher.

Also, while Lockhart claims most adults don't need or use formal algebra, geometry, or trigonometry; some people do go on to major in science or math in college.  I can't imagine that those who go through Lockhart's suggested program would be prepared to enter college and go into a typical Calculus I class.

While it's admirable to want to pass on the beauty of mathematics to kids, I think it needs to be done in conjuction with a more formal progression through mathematical concepts.  At least that's the bet I made with my kids who, even though homeschooled, use a formal math curriculum (Saxon).  We also try to play around a bit so they see how useful and interesting math really is!

One thing I do see at our community college is that public school math education fails miserably.  All incoming students at our institituion take a placement exam in math and English.  Many students place into remedial math courses (even those students who just graduated with a NYS high school diploma a few months earlier).  Non-science and math students have to take a course called College Algebra to graduate - when I look at the topics covered it reminds me of what I had in 9th grade algebra some 30+ years ago.  Many of our high school graduates instead place in Pre-Algebra, a 6th grade-level course covering topics like fractions and decimals.

I just don't think Lockhart's ideas are the answer for the failure of the public school system in math education.  I don't think I'll discuss my ideas either, since they'll offend most people!  Maybe some other time.

Monday, April 5, 2010

Good Friday Hike

On April 2, Good Friday, I took the day off and went for a hike with the family at Lake Minnewaska State Park.  The weather was sunny, in the 70s, with a light breeze and couldn't have been better.

Fortunately, there weren't many people up at the lake when we arrived in the morning (normally I avoid the place on the weekends or holidays since it's a mob scene).

I have to say that Lake Minnewaska really is a treasure - one of the most beautiful places in the area where I live.  Deep blue water surrounded by white rocky cliffs and green pines - on a sunny day, it's incredible and pictures can't do it any justice (clicking on pictures will embiggen them).

We started on the Millbrook Mountain Carriageway, an easy walk with some mild ups and downs, and followed that to Patterson's Pellet - a spectacular glacial erratic.  No one placed this rock here, it was picked up in a glacier during the last ice age when thousands of feet of glacial ice filled the Hudson Valley, and then dropped precariously on the edge of a cliff over the Palmaghatt Ravine when the glacier melted a bit over 10,000 years ago.

There is a lot of evidence of glaciation in the park.  Most flat bedrock surfaces of the Shawangunk Conglomerate (a rock composed of quartz pebbles cemented by quartz sands) have glacial striations (scratches) and chatter marks (crescent-shaped gouges chipped out by rocks carried in the base of the glacier).  Here's a picture of some striations (parallel the knife) and chatter marks (showing bottom to top movement).

After passing Paterson's Pellet, we came to the Gertrude's Nose Trail.  A footpath quickly climbed through the woods to a high point and then steeply descended into the Palmaghatt Ravine (to everyone's groans).  A pretty Hemlock forest and swamp were found at the bottom and then the trail started climbing some tilted slabs of polished and fractured bedrock (with some surprisingly deep crevices).

This is one of the most scenic hiking trails anywhere in the Shawangunks with expansive views to the south and, when reaching Gertrude's Nose proper, to the east over the entire Hudson Valley.  I noticed that some of the fractures were not simple fractures but were instead strike-slip (horizontal movement) faults.  Here's a view into a fracture showing fault striations (formed by ancient fault movement) on the walls of the fault.

There were also a lot more glacial erratics along the trail.

Here's my son Lucas (and Simon the dog) leaning against one.

After eating lunch atop the cliffs at Gertrude's Nose, we continued along the trail which followed the cliffs overlooking the Hudson Valley.  The trail once again descended into a ravine (more groans) with unsightly power lines and then steeply climbed back up to the tops of the cliffs.  A nice walk along more flat slabs brought us to the top of Millbrook Mountain which has the highest cliffs in the Shawangunks.  These are the cliffs you see from places like Wallkill and Gardiner in the Wallkill Valley.

Another rest was needed on the cliffs of Millbrook Mountain.  Here's my daughter Emily relaxing in bare feet (poor girl had a blister by the end of the day).

Another picture of my wife Jennifer.

From Millbrook we plodded back on the Millbrook Mountain Carriageway, dragging ourselves to the car after the 8.5 mile hike (Gertrude's Nose Trail, with its two ravines is what did us in).  First major hike of the year.  If you like hiking, I highly recommend this one.

Sunday, April 4, 2010

Still alive

Haven't posted for a while.  I was sick a couple of weeks ago, then fell behind at work, then the beautiful spring weather happened.  I will post again soon - lots of ideas, not much ambition.