Tuesday, December 31, 2013

Treed

"Get that dog out of here and I'll come down."

Saturday, December 28, 2013

Goldfinch Gallivantings

We have three kinds of birds that visit our feeder: (1) year-round residents who come most every day for a snack, (2) year-round residents who periodically come and go, and (3) migrants who we see either temporarily residing here through the summer or winter, or just passing through in the spring or fall.

American goldfinches fall into the middle category above: we may see them visit the feeder at all times of the year, but only for few days. A flock of them will hang around for a while and then disappear for a few weeks—to return again. (At least I believe I'm seeing the return of the same group, although it's possible that I'm seeing a new flock of finches each time.)

I call the goldfinch a "periodic" resident, because it doesn't leave for Central America for the winter or head north to Canada for the summer. We'll see them at all times of the year, but, as I wrote above, it has the interesting habit of hanging around the feeder for a few weeks, and then disappearing for a month or so. Goldfinches engage in what ornithologists call "irregular seasonal movements," which finds them roaming in groups—their current territory being determined by the availability of the food supply they find there.

Okay, so they are resident roamers. That fits my experience, as I see them come and go from time to time. But why leave for a spell, apparently seeking new sources of food, when I put seed out all year long? The other regulars at the feeder dine on the continuously-offered sunflower seeds—supplementing them with bugs; a good source of protein. Do the goldfinches get tired of sunflower seeds and wish to change their diet occasionally? I could buy special finch food (they love thistles), that might entice them to hang around, but that option gets kind of pricey for my wallet.

Ornithologists have a difficult time tracking the roaming habits of any type of songbird—especially the little guys like goldfinches. Most any radio tracking device is too heavy for them to carry around, so their roaming habits are not yet well understood. (Although this is another ornithological barrier about to be cracked, as new, ultralight transmitters have been developed and are being deployed.) Thus, I have no idea where our finches go when they depart, how far they roam, or even if the group we see is the same one. When I see a flock appear at the feeder, I wonder if it is old friends returning or new visitors coming in for a temporary feed. Maybe I'll figure this out before long.

It's another one of those mysteries you constantly encounter, when you come to observe closely the natural world's goings on. If you don't take the time to watch, you rarely notice these intriguing details, and you're unlikely to become interested enough to ask the questions that occur to you, once you do begin to pay attention. When I observe closely, I find that many questions begin forming a long queue in my head. I love it! It's what adds endless interest to my life, way out here in the woods.

Wednesday, December 25, 2013

Christmas Snow

This great photo taken by my friend Shell. (Click to enlarge.)

Sunday, December 22, 2013

MOOC Manna—Part 2

I have listed some of the positive aspects of MOOCs that I enjoy. But they can't be the greatest thing since "sliced bread," so what are some of their downsides? Since they are a current, well-received phenomenon—if not exceedingly popular right now—do they as yet have a downside that has had a chance to show up? Well, yes, a few detractors have offered a few criticisms, or have asked a few pointed questions.

Are the MOOC courses being over hyped? Is the quality as high as advertised or expected? Will there be a letdown on the part of students who are led to expect too much from a course? What about access to the lecturer: there is little chance to have access to the professor, when thousands of students are taking the course. Some courses offer credit: How do you grade appropriately or avoid students cheating on tests? Of students who sign up, typically only 10% finish a course. With this dropout rate, what's really been accomplished by offering that course?

I recognize that some of these concerns are valid, but have either discarded them as not relevant for me or worked through them for my needs. But I have my own misgivings about MOOCs—mostly in the arena of money. Right now they are free and of high quality, but how long before greedy profit motives muck things up? At the moment, MOOCs are almost too good to be true, and I fear that commercial interests will spoil the treat or dilute the teachings. TV once (back in the 1950s) promised to be a medium of merit, but has degraded into shallow and trivial entertainment. Will the money grubbers eventually demand their pound of flesh from MOOCs?

Another concern I have about the future of MOOC manna: right now, MOOCs are being taught by highly-qualified professors, who I think may be offering these courses for several motivations (none of them money): (1) reaching a worldwide student audience, (2) exploring a new venue, and (3) teaching students who really want to be there. (Too many of today's university professors lecture to an audience of minimally-interested students.) How long will the teachers' enthusiasm last and how long will the high quality continue?

Who knows where the MOOCs will go? No one. In the meantime, I aim to take full advantage of their remarkable manna.


Wednesday, December 18, 2013

MOOC Manna—Part 1

We online beings currently have been offered access to a wonderful educational opportunity—something dubbed MOOCs—Massive Online Open Courses. They come in the form of instructional videos—as if you are sitting in a college lecture hall, listening to a qualified professor giving you a lesson on an academic subject, but in the comfort of your own living room. (With maybe even a beer in your hand!)

MOOCs have erupted into the online world as the latest form of what's been designated as "distance education." Numerous leading universities around the world are participating in this process, offering their most experienced teachers the opportunity to present their courses to thousands of curious people worldwide. These online courses are provided free of charge to anyone who is interested. What a bargain!

MOOCs give us a unique opportunity to broaden our minds in an extremely wide variety of subjects—virtually all of which are exceptional learning experiences, given the fact that the most reputable universities are participating. Most of the courses do not require prior knowledge or prerequisite college courses to participate. Most are introductory enough or general enough that virtually anyone can sign on and learn.

Distance education has existed for over 100 years. The internet has provided the perfect medium for their emergence in this new medium. In the late 19th century, postal correspondence courses were the first distance education process that arose, followed by radio courses in the 1920s, followed by TV courses in the 1980s. So now we have the latest manifestation of distance education in the form of MOOCs.

This new phenomenon of what could be also designated as the Chautauqua process (an outdoor adult mass educational experience that originated on Chautauqua Lake in New York State in the late 19th century) is now available to anyone with online access, from their own home. Many universities (MIT, Harvard, Stanford, Princeton, etc.) have encouraged their professors to offer their courses. Coursera is a major MOOC offerer—providing over 300 online courses. EdX is another main offerer. Some courses enroll hundreds of thousands of students worldwide. So the term “massive” is certainly relevant.

I have signed on to four MOOC courses in the last year. Two of them I have followed and completed, for a dozen weeks or more each—watching lectures, taking quizzes, and participating in online forums and discussions with other students. The other two I dropped after a week or so—upon realizing that I either did not have the appropriate prerequisites after all, or the subject matter did not appeal to me, or the lecturer's style was problematic for me. Unlike my college classes all those many years ago, I can easily drop a MOOC course without the stigma of feeling inadequate or suffering the loss of tuition.

I love the ability to be able to watch lectures from home at my leisure. I can take notes, repeat a lecture, join a forum, or further pursue the subject on my own, via references that are given. My science education did not provide me with an extensive background in the humanities, literature, or other liberal arts—so MOOCs give me a wonderful opportunity to pick up on those subjects I missed in my formal education.

More on MOOC manna next time...

Saturday, December 14, 2013

Tuesday, December 10, 2013

Seeing Double—Part 2

NASA’s Kepler mission has recently scored another success in its planet-finding work. (Kepler is a special telescope that orbits the sun as our Earth does, while keeping itself constantly pointed at a small, single patch of sky containing nearly 150,000 stars in a nearby part of our Milky Way galaxy.) This telescope has recently discovered several so-called “circumbinary” planets—worlds that orbit double stars. (Kepler has already found about a thousand planets orbiting single stars.) So now Kepler has also proven that planets orbiting double stars can and do exist. In fact, astronomers now estimate (from Kepler’s findings) that there may be “tens of millions” of circumbinary planets in our galaxy… in addition to the estimated billions of planets around single stars.

Yet it’s a whole other issue whether these circumbinary planets have any chance of harboring life. Our precious Earth orbits a single star in a nearly circular orbit—keeping the amount of solar heat falling upon us relatively constant. (We get seasonal temperature differences only because planet Earth’s axis tilts about 24° to its orbital plane, which points us towards the sun in summer and away from it in winter.) A planet that orbits two stars could experience wide and wild temperature swings, which would prevent life from either forming or surviving.

The Star Wars movie had a fascinating scene, in which the fictional planet Tatooine experienced a double sunset. Of course, the views of suns on real circumbinary planets could be bizarre and quite different from Tatooine. For example, it could be a case of one of two suns always shining down, bathing the planet in nearly constant daylight; or the lengths of days could vary wildly, as the double stars dance around each other; or the planet’s seasons could be random; etc.

Now we know that circumbinary planets do exist—thanks to Kepler. It’s one more fascinating piece of knowledge brought to us by our space programs. What’s next in this extra-terrestrial planet hunt? Astronomers are hoping to find an Earth-sized planet (around a solitary star) with an atmosphere like ours. If so, that would be a strong hint of the possibility of life “out there.” There’s no telling what the next discovery will be, but stay tuned—we are bound to learn more captivating details about our fantastic universe soon.

Our Single Star


Friday, December 6, 2013

Seeing Double—Part 1

I have posted several blogs here about stars; describing meditations that come to me, as I soak in the tub under dark winter skies, while becoming absorbed in the heavens. It is now late fall. The trees above my tub have dropped their leaves and the sky turns inky dark by 8 PM. This provides me with wonderful stargazing opportunities. Bring the winter on! I love my summer evenings in the tub, since I can watch the ever-morphing clouds and the graceful, leafy trees sway in the balmy breezes above me; but there’s something very special about cold weather’s dark, starry skies.

I lie back, floating in the hot water, and fix my gaze on one patch of sky, slowly becoming absorbed into its star field. Some stars are bright, some dim; some are farther away than others; some gather in clusters and nebula. The patterns (especially the constellation-like figures) mesmerize me. I become aware that I’m peering into a three-dimensional star field that has depth, rather than just viewing points of light which all seem to emanate from the same distant celestial sphere.

I sometimes ponder the fact that about half the stars I see are really binary systems: two stars that dance closely around each other, rather than standing as solitary suns like ours. I rarely can resolve the pair by naked eye, but astronomy’s large telescopes can do that, to show us that many of them are truly double stars. In fact, many of them are actually multiple star systems, where one or two additional small, almost invisible, minor stars add to the complex dance.

A recent issue of Scientific American magazine has an article on binary stars and their planets, titled “Worlds With Two Suns,” by two cosmologists. Until recently, some astronomers tended to doubt that binary stars could even have planets orbiting them—let alone that they would have a chance of harboring life on their worlds. This is because a planet attached to a double star system could randomly be jerked around by the competing pull of the two stars. Such planets would not settle into stable orbits, or, worse yet, could even get sucked into one of the suns, or flung off into deep space by the opposing tug of the double stars. The complex gravitational field a planet would be forced to negotiate would cause its orbit to be too chaotic—most certainly too disordered for life ever to be able to take hold.

More on double suns next time...

Wednesday, December 4, 2013

Sunday, December 1, 2013

Primordial Beach Ball

A trillionth of a trillionth of a trillionth of a second after the Big Bang that initiated our universe, all of the cosmos was about the size of a beach ball. (That fraction of a second is something like 10-36 second after Time Zero, for those who grasp scientific notation.) What happened before that unimagineably tiny fragment in time, physicists are baffled about; but after that point in time, they have a pretty good handle on the universe’s subsequent expansion and behavior. The so-called “standard model” of cosmology does a fine job of describing that succeeding behavior.

It’s virtually impossible for us normal folks to wrap our heads around how all of the universe’s hundreds of billions of galaxies—each of which contains hundreds of billions of stars—could once have been squeezed into something like a beach ball. If nothing else, this fact is a testimony as to how empty matter really is: every atom is almost wholly empty space containing an infinitesimal amount of matter, in the form of ephemeral protons and electrons. So once upon a time (10-36 second after the Big Bang, that is) all those countless atoms found themselves confined to the primordial Beach Ball.

At that moment, the inside of the beach ball was, in fact, more like a mush of elementary particles, than a sea of individual atoms. It was so opaque and dense that light could not escape, which is why astrophysicists are not sure what happened up to that point, since whatever transpired, did so in utter darkness. The subsequent expansion of the beach ball sort of happened after the divine command, “Let there be light,” was uttered.

The nature of the universe at this early moment is the subject of intensive ongoing research. Many PhD theses get spawned by these studies. It may soon be known how the primordial Beach Ball became inflated from an earlier baseball—or maybe even a golf ball, or...