Let there be light

Today astronomers know with certainty that the universe is neither eternal nor unchanging.

menorah 88  (photo credit: )
menorah 88
(photo credit: )
The flames of the Hanukka candles recall that historic, holy miracle when light illuminated the darkness of the moment. I'm not talking about the miracle of the Maccabees, although our candles certainly do recall those events. I mean the miracle of the creation. The light of "Let there be light!" that first cosmic illumination on Day One - carries the same underlying religious message as our menora candles do during days one through eight, the miracle of light. It also highlights something else: the insights of modern science. From the time of the Maccabees until the 1930s virtually all theologians and scientists adopted the Greek view of creation: the universe is eternal and unchanging. Greek ideas of perfection dictated that it had to be so. But in 1929, Edwin Hubble discovered that galaxies are moving away from us, and Einstein's theory of relativity explained those motions as cosmic expansion. The universe was created in the remote past in a big bang, a blaze of light from an infinitesimal speck, and has expanded and evolved into today's cosmos. Today astronomers know with certainty that the universe is neither eternal nor unchanging. A few Jewish philosophers, most eloquently Maimonides (Rambam) in the 12th century, had rejected the Greek view. He argued that everything except God has been brought into existence out of nonexistence. Four centuries after Rambam, the Kabbalists of Safed, building on their long mystical tradition, explicated the first word of the Bible - b'reishit - in the beginning. They wove an intricate account of how the universe was created with light from an infinitesimal speck, and described its expansion and evolution with light into today's universe. They called the speck the reishit, hence the first word of Torah literally means "with the reishit." ASTRONOMERS NOW understand that light in the embryonic cosmos was scattered by hot plasma like headlights in a fog. About 380,000 years after Creation, once things had cooled and atoms could assemble, light traveled freely. That same light is seen today as the cosmic microwave background radiation. It dates from a time about eight billion years before the birth of the Sun. Discovered in 1965, that light has become, like the motions of galaxies, a key scientific diagnostic of what happened way back then. The 2006 Nobel Prize in Physics went several months ago to two astronomers who measured this radiation. Last March, other scientists announced their latest results from analyzing this cosmic light, among them the age of the universe: 13.73 billion years, plus or minus about 1%. The Hanukka lights are not only a reminders of events past, they are a moral guide to the future. They teach the lesson that people have the ability to effect change. We can reject idolatries. We can, by our deeds, shine light into the darkness of a cruel, selfish world. We can make life better. What is less appreciated is that the cosmic lights of creation have taught a similar message. The universe is not eternal and unchanging; it is evolving, and therefore we can make a difference to its progress. The Kabbalists explain that imperfections were embedded in the fabric of the newly born universe. Humanity's task, they say, is tikkun olam, healing or repairing these breaches in the world through righteous deeds. By our engagement in tikkun, we invoke the spirit of the light of that creation. MODERN SCIENCE recognizes that light, from the Creation or from our Hanukka menoras, is much more than just the visible glow of electromagnetic radiation we see with our eyes. The electromagnetic radiation we currently measure with our instruments spans nearly 80 octaves from the longest radio wavelengths to the shortest X-ray wavelengths. The visible portion is merely one octave. If light were music, then the music of the visible that we can perceive comes from the 12 keys in one octave of a piano whose remaining octaves and keys stretch the length of a football field. Physics also understands that there are three other forces in the universe besides electromagnetism: gravity, and two nuclear forces, each with its own kind of light. All four kinds of light were born in the creative declaration, "Let there be light"; all four participate in our evolving, expanding universe. There is more, much more, to the lights of Hanukka than meets the eye. Science's precise, self-consistent methodology likewise prompts a holiday reflection. Its intellectual openness and quantitative inquiry have been wonderfully productive, and are worthy of emulation by us all. Astronomy has uncovered deep new puzzles: the existence of dark matter, for example, and an outward acceleration of the distant cosmos. But both the answers and questions increase our confidence in the methods of science. The new questions also compel humility: we do not know it all. "Not by conflict, and not by power, but by My spirit..." This is the ethical message that the rabbis see in the Hanukka season. May the lights of our candles and our deeds, like the miraculous light of creation, illuminate the darkness. The writer is an active member of the Boston Jewish community. He is a senior astrophysicist at the Harvard-Smithsonian Center for Astrophysics, and was the chairman of the astronomy department at the Smithsonian's National Air and Space Museum in Washington, D.C. His new book is Let There Be Light: Modern Cosmology and Kabbala, a New Conversation between Science and Religion.