Like many people, I’ve gotten in the habit of using Instapaper and its wonderful iPad/iPhone app to read a lot of my news. Unfortunately, the amount of material that I want to read in a day far outweighs the amount I can reasonably find time to read in said day. The articles have been piling up for months now—I’m creeping up on the 500 article limit on my queue in the iPad app. This means I end up reading a lot of old news.
For example, just now, I was reading this article in the New York Times from November of last year, written by one of my favorite science journalists, Dennis Overbye. In it, he previews the year 2011 in planetary science and cosmology. Overbye singles out what is one of the most anticipated results in the astronomical field in many years—next month’s announcement of the latest findings of NASA’s powerful Kepler satellite, which has been searching for the last year and a half for exoplanets the size of earth—and goes on to succinctly summarize the upcoming activity of many other astrophysical projects, including the search for dark matter at the Large Hadron Collider.
One of the reasons I like him as a journalist is that he writes in a breezy style that avoids the tersely anonymous factoid-regurgitation of a wire report without succumbing to the excessive rhetorical flourishes about the beauty and wonder of the cosmos that Carl Sagan could pull off, but few others can. His descriptions of complex scientific concepts are vivid, often anthropomorphized, and economical. He’s also capable of dropping an achingly beautiful fragment of prose onto the pages of the Times‘ Science and Technology section, as he does here:
Meanwhile, the Hubble Space Telescope, rejuvenated by on-orbit surgery a year and a half ago, will keep scrutinizing the heavens with its matchless clarity, sifting eternity pixel by pixel.
“…sifting eternity pixel by pixel.” When I read that phrase, I nearly choked on my food and said out loud in admiration, “Are you kidding me?!” I can only hope sometime in my life to write a sentence about a lifeless piece of metal and mirrors that’s half as lovely as that one. But it’s not just pretty for its sibilance and dactyl meter; its aesthetic beauty belies a technical knowledge of the workings of Hubble.
When Hubble looks at stars and galaxies, the pictures it sends back aren’t quick snapshots. Because starlight is so dim, it will leave its shutter open and expose its digital sensor for up to nearly an hour at a time for a single exposure. (In my research, I’ve been working with images that have exposure times of approximately 40 minutes.) Later, astronomers may stack multiple exposures of the same area of sky, generating a final image that can be the result of over a week of exposure. The most famous examples of these are the spectacular images known as the Hubble Deep Fields and their follow-up, the Hubble Ultra Deep Field.
If we were able to watch such an image form in real-time as Hubble’s telescope and cameras were gathering light, we would see at first only a blizzard of random noise, punctuated by the points of light of the nearest stars. But if we continued to watch for minutes, hours, and days, the noise would eventually subside and we would begin to see ghosts of galaxies and other structures slowly solidifying out of the shadows. At first, we would be seeing galaxies close enough that we could distinguish their spiral arms, or make out the outlines of their fuzzy, elliptical halos. But as Hubble sat with its eye wide-open, we would begin to see deeper and deeper into its field of vision, receding deeper and deeper into the dusts of time. We would eventually begin to see galaxies so far away that they would appear to be stars—mere pinpoints of light. And they would be so ancient that the starlight carrying their image would have journeyed across the universe for 13 billion years before coming to an end on Hubble’s sensor, converted into a tiny pulse of voltage that becomes a bit on magnetized tape that becomes knowledge in the hands and minds of the astronomers who look at it.
In this context, could the phrase “sifting eternity” be any more apt or evocative? When I read it, what immediately came to mind was an image of photons of starlight as a shower of sand, sifting softly through the sensor’s metal grid of pixels—and these lines:
To see a world in a grain of sand, And a heaven in a wild flower, Hold infinity in the palm of your hand, And eternity in an hour.