Dance of Galaxies

Whenever I watch a science documentary, I think of Carl Sagan and the book version of Cosmos and the seemingly limitless ocean of inspiration that was presented to me in those pages, to draw from in times both good and bad. Cosmos has such a ridiculously sacred place in my heart that I’ve been very guarded and skeptical about the follow-up series that is currently being shown on many channels. However,  watching episode 3 tonight, an irrepressible jolt of happiness returned once more to poke through my melancholy fog, when Neil deGrasse Tyson described the collision of galaxies. I sense in the concluding quote, the lyrical hand of Ann Druyan:

[…] one last prophecy: Using nothing more than Newton’s Laws of Gravitation, we astronomers can confidently predict that 7 billion years from now, our home galaxy, the Milky Way, will merge with our neighboring galaxy, Andromeda. Because the distances between the stars are so great compared to their sizes, few, if any, stars in either galaxy will actually collide. Any life on the worlds of that far-off future should be safe, but they will be treated to an amazing billion-year-long light show, a dance of a half-trillion stars, to music first heard on one little world by a man who had but one true friend.”

[When Knowledge Conquered Fear (Episode 3)]

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Condors of the Grand Canyon

[While we are still on the birding theme, this is an old post that I wrote (but never published) almost exactly 4 years ago. It is about the experience of seeing a live condor for the first time. The bird in the photograph – Condor #3 – was spotted not far from Lee’s Ferry Lodge at Vermillion Cliffs in Arizona. On purpose, the posting below has not been revised, so all numbers and ages pertain to 2008.]

One of the many attractions of the Grand Canyon is the California Condor. Indeed, having no conception of the grandeur of the canyon, the only question I had asked friends returning from the canyon was, “Did you see any condors?” – a question answered, with one rare exception in the quizzical negative. On my visit to the Canyon on Memorial Day Weekend, I saw at least 7 distinct condors and it was a wish fulfilled.

On the brink of extinction in the early 1980s, the last few remaining condors were captured for a rehabilitation program that is slowly but surely increasing their numbers. Condors are being bred in captivity at three centers in Arizona, California and Idaho. The goal is to have three separate populations of 150 birds each, two of these populations being wild, and the third being held in captivity to account for emergencies. At this time of writing, there are 63 wild condors in the Grand Canyon, and they can be seen gliding on the thermals at the South Rim near Tusayan, AZ.

A ranger at the South Rim showed us how to distinguish between a condor and a turkey vulture, and between a condor and a common raven. Confusing the latter pair is not as ridiculous as it sounds, because the Canyon plays havoc with one’s sense of scale. On the backdrop of huge boulders and multicolored cliff faces thousands of feet deep, the nine-and-a-half foot wingspan of the condor is dwarfed significantly, and if one’s estimate of distance is unsound, a raven close by might be confused with a condor far away.

At Vermilion Cliffs, a place one gets to by following the North rim eastward on route 89A toward Glen Canyon, an inn-keeper told us that condors are routinely seen from the Navajo Bridge, a steel arch bridge built across Marble Canyon at the point where the Colorado valley widens again into Glen Canyon. Sure enough, around 10 am on May 25, there were three condors near the bridge (1) #53, a four-year old condor who still hasn’t lost all the hair on his head and neck, (2)#3 who is eight years old and seems fully mature, (3) one condor whose head and numberplate I could not see.

It is a fascinating bird – its ugliness on the ground compensated when one beholds it in the air – graceful, strong, unhurried. In the gliding position, the condor’s wings are positioned in a much shallower V than that of the turkey vulture, a characteristic I found useful when I couldn’t see the underside of the birds’ wings. This happens many times in the canyon, for instance, when one is hiking near the cliff while the birds are gliding peacefully in the canyon below. It was surprising to know that the feet of a condor are webbed, and not very useful for tearing meat; that job is performed exclusively using their beaks. It is thus a bird that needs very large quantities of carrion to feed while being unable to hunt on its own. This seems to have been the cause of their small numbers – as human civilization progressed over the Americas, land was reclaimed for agriculture, housing, and industry with the result that condor habitat and the probability of finding carrion must have dwindled, almost sending the birds into extinction. In addition, lead poisoning from consumption of meat riddled with bullets has also been held responsible for the death of many wild condors. For more detailed information, visit the Condor Re-introduction Program website.

Name: California Condor

Latin Name: Gymnogyps californianus

Number of distinct birds sighted: 7

Places: Marble Canyon (3 birds), South Rim Bright Angle Lodge (3 birds), South Kaibab Trail (1 bird)

Dates: May 25-26, 2008

Will they know we were once here?

All that night long, the boy slept and the man waked, gazing forward steadily into the dark. There were no stars. – Ursula K. Le Guin, The Farthest Shore.

In San Francisco on Labor Day Weekend, the folks at the California Academy of Sciences screened a special live show called “Tour of the Universe”. Here, a narrator took the audience from Earth into Outer Space, beyond our solar system, beyond the limits of our galaxy and galactic cluster, to the edge of the observable universe. As eager observers of many a starry night, P and I watched the digital projections with interest. When we filed out of Morrison planetarium, P, whose curiosity is not easily contained, wondered aloud what the narrator had meant by the concept of the Earth’s Radiosphere and why any intelligent life outside the Radiosphere has no chance of knowing about us.

Between the two of us, the explanation that we developed at the time was as follows: the Radiosphere is an imaginary sphere whose center is the same as the center of the earth, and whose radius equals the distance traveled by the first radio signals emitted by human beings in the 1930s. If you remember the opening sequence of the movie Contact, the camera is taking to the far reaches of outer space, where we here radio signals documenting several historical events of the last century, becoming older as the camera zooms further out from the Earth. In order for another intelligent civilization in the Universe to know about our existence, they must necessarily have to intercept the transmissions that human beings have inadvertently sent out into space – all manner of radio signals, soaring arias, documentaries, bad reality TV programs, tragedies and comedies, nuclear explosions, the 11 minutes of athletic activity embedded inside three hours of advertising static that constitutes a game of American football. This necessarily means that the listening civilization has to be within the imaginary Radiosphere. Or, in other words, if there is intelligent life on an exoplanet that lies outside the Earth’s Radiosphere, then it would be impossible for them to know of our existence.

P’s question was that, since the Radiosphere will grow outwards at the rate of 1 light year per year in all directions, would an intelligent civilization currently outside the Radiosphere eventually hear about us? And not thinking carefully enough, I said, “Yes, eventually”. However, as is often the case, her questions are harder and deeper than they initially seem; I was wrong. Since we live in an expanding universe, the correct answer is “Not necessarily”. This has bizarre implications, if we allow our minds to wander a little. First, let us see why the Radiosphere cannot grow fast enough for its surface to reach any given exoplanet: To be specific, let this exoplanet belong to a star in a different galaxy from ours, one that is far far away as in Star Wars lore. Given that we live in an expanding universe – as opposed to a stationary or a contracting universe – every galaxy is moving away from every galaxy owing to the expansion of space time. Furthermore, if the physicists are right, then the farther two bodies are, the faster they are receding from each other. Thus, our chosen exoplanet is moving away from us faster and faster. Much to my surprise, physics does not put the usual constraints on the speed of this expansion, i.e., the expansion of spacetime can take place faster than the speed of light! I don’t know why exactly this is true, and I must find this out from an advanced physics textbook or from a physicist. The Radiosphere is, of course, growing at the speed of light. Now, if our exoplanet was far enough to being with, and was moving away fast enough, then it is possible that the expanding Radiosphere may never grow fast enough to swallow it.

Unless I am mistaken, the implications of this thought experiment – academic though they may be – are both somber and fascinating: Assuming that some intelligent species does not kill itself off in a nuclear holocaust, survives the interplanetary billiards of meteor and comet collisions, weathers volcanic eruptions and similar catastrophes, evolves, migrates to other distant worlds to escape the inevitable expansion and death of their parent star, they will eventually be alone in a practically limitless sea of empty space. Owing to the expansion of space time, every other star and every other planet has receded far away out of reach, so far away that even light cannot catch up, and therefore any communication with any outside world is impossible. The odds of any earthbound species surviving many billion or more years into the future are exceedingly slim, but if it does, what a strange life awaits it? For, other than the parent star system which gives it life during the day, and a possible dim moon or two, the night sky will be utterly dark – No visible stars, no constellations, no galaxies, no nebulae. Without these keepers of cultural lore, these signposts for voyagers, these pointers in a coordinate system, what would a species’ culture be like? Their stories? Their myths? Their gods? Their science? Their place in the universe? Where will they put their heroes and villains, if not in imagined patterns in the skies?

[I wonder though, won’t a universe in that incredible state of dissipation, where everything is so far away from everything else, be utterly, mind-numbingly cold; too cold to support any kind of life as we know it? But let us set that interruption out of our minds for a few more moments of irrational speculation :-)]. Now, what if there was no evolutionary continuity between our time and the time of this hypothetical species that we have dreamed up? What if they evolve long after every currently thriving species and currently thriving archival technology has long been extinguished? How could they ever know that there once was a time when billions of celestial pinpoints made awesome patterns in the sky? Could their Einsteins and Newtons ever know that they were once part of a galactic conglomeration of stars, planets and interstellar gas and dust? Could their Sagans and their Asimovs figure that, many eons before them, star-stuff had come to life and contemplated the cosmos? In the absence of celestial signposts, will they again return to thinking, as the pre-Copernicans did, that their planetary home is the center of the universe?!

Addenda:

More information on the Radiosphere from the Hayden Planetarium.