The Hidden Reality_ Parallel Universes and the Deep Laws of the Cosmos - Brian Greene [25]
The two groups agreed to publish their papers simultaneously in the prestigious Astrophysical Journal. The Princeton group discussed their theory of the background radiation’s cosmological origin, while the Bell Labs team reported, in the most conservative of language and with no mention of cosmology, the detection of uniform microwave radiation permeating space. Neither paper mentioned the earlier work of Gamow, Alpher, and Herman. For their discovery, Penzias and Wilson were awarded the 1978 Nobel Prize in physics.
Gamow, Alpher, and Herman were deeply dismayed, and in the years that followed struggled mightily to have their work recognized. Only gradually and belatedly has the physics community saluted their primary role in this monumental discovery.
The Uncanny Uniformity of Ancient Photons
During the decades since it was first observed, the cosmic microwave background radiation has become a crucial tool in cosmological investigations. The reason is clear. In a great many fields, researchers would give their eyeteeth to have an unfettered, direct glimpse of the past. Instead, they generally have to piece together a view of remote conditions on the basis of evidence from remnants—weathered fossils, decaying parchments, or mummified remains. Cosmology is the one field in which we can actually witness history. The pinpoints of starlight we can see with the naked eye are streams of photons that have been traveling toward us for a few years or a few thousand. The light from more distant objects, captured by powerful telescopes, has been traveling toward us far longer, sometimes for billions of years. When you look at such ancient light, you are seeing—literally—ancient times. Those primeval comings and goings transpired far away, but the apparent large-scale uniformity of the universe argues strongly that what was happening there was also, on average, happening here. In looking up, we are looking back.
The cosmic microwave photons allow us to make the most of this opportunity. No matter how technology may improve, the microwave photons are the oldest we can hope to see, because their elder brethren were trapped by the foggy conditions that prevailed during earlier epochs. When we examine the cosmic microwave background photons, we are glimpsing how things were nearly 14 billion years ago.
Calculations show that today there are about 400 million of these cosmic microwave photons racing through every cubic meter of space. Although our eyes can’t see them, an old-fashioned television set can. About 1 percent of the snow on a television that’s been disconnected from the cable signal and tuned to a station that’s ceased broadcasting is due to reception of the big bang’s photons. It’s a curious thought. The very same airwaves that carry reruns of All in the Family and The Honeymooners are infused with some of the universe’s oldest fossils, photons communicating a drama that played out when the cosmos was but a few hundred thousand years old.
The big bang model’s correct prediction that space would be filled with microwave background radiation was a triumph. During a mere three hundred years of scientific thought and technological progress, our species went from peering through rudimentary telescopes and dropping balls from leaning towers to grasping physical processes at work just after the universe was born. Nevertheless, further investigation of the data raised a pointed challenge. Ever more refined measurements of the radiation’s temperature, made not with television sets but with some of the most precise astronomical equipment ever built, showed that the radiation is thoroughly—uncannily—uniform across space. Regardless of where you point your detector, the temperature of the radiation is 2.725 degrees above absolute zero. The puzzle is to explain how such fantastic uniformity came to be.
Given the ideas presented in Chapter 2 (and my comment four paragraphs ago),