Serendipity means you’re looking for one thing, but find something else. Throughout the history of science there are numerous examples of just such fortuitous occurrences. One of the best illustrations of how scientific serendipity can change the world occurred back in 1964, when the first cries of our baby Universe were luckily heard–by chance! It was in that year that Dr. Arno Penzias and Dr. Robert W. Wilson at the Murray Hill facility of Bell Telephone Laboratories in New Jersey noticed a mysterious and inexplicable “noise” coming from their new radio antenna. They later found that what they were, in fact, picking up with their radio dish was the first solid proof that the Universe was born in the Big Bang. Penzias and Wilson were noticing the first whispers of the Cosmic Microwave Background (CMB) radiation, stretched out to exceedingly long electromagnetic wavelengths due to the expansion of the Universe. As it turns out, anyone can bear witness to the relics of our Universe’s birth. If you tune your television set between channels, some of the “snow” that appears on your screen is actually “noise” caused by the CMB radiation.
The CMB radiation is a faint glowing light that fills the entire Cosmos, falling on our little blue planet from all directions with almost unvarying intensity. It is the heat left over from the beginning of our Universe almost 14 billion years ago; the afterglow of the Big Bang. This ancient light whispers to us some very wonderful secrets about an extremely remote epoch that existed long before there were any observers around to witness it first-hand. The CMB is the most ancient light that we can see–it has been traveling to us from the greatest distance that we can observe in Space and Time. This light began its long journey almost 14 billion years ago, and this was billions of years before our planet, our Solar System, or even our ancient Galaxy, the Milky Way, existed. It tells of a vanished, extremely remote time when all that existed was a writhing storm of fire-bedazzling radiation and a raging sea of elementary particles–hardly the relatively quiet and frigid dark place that we know now. The familiar objects that we observe in our Universe at present–the glittering incandescent stars, enchanting planets and moons, and even the majestic galaxies –eventually congealed from these newborn particles, and the Universe expanded and dramatically cooled off.
This precious, glowing relic of our Universe’s infancy is a little gift, of sorts, to observers on Earth today. This is because it carries the fossil imprint of those ancient particles–a pattern of exquisitely tiny intensity variations from which scientists can figure out the attributes of the Cosmos.
When the CMB began its long journey billions of years ago, it shone as brightly as the surface of a star, and it was just as hot. However, the expansion of the Universe stretched Space a thousand-fold since then, causing the wavelength of that ancient light to be stretched, as well–to the microwave portion of the electromagnetic spectrum. The temperature today of that once searing-hot light is a truly frigid 2.73 degrees above absolute zero!
The late Dr. Carl Sagan of Cornell University wrote in his book Cosmos (1993): “As space stretched, the matter and energy in the universe expanded with it, and rapidly cooled. The radiation of the cosmic fireball, which… filled the universe, moved through the spectrum–from gamma-rays to X-rays to ultraviolet light; through the rainbow colors of the visible spectrum; into the infrared and radio regions. The remnants of the fireball, the cosmic background radiation, emanating from all parts of the sky can be detected by radio telescopes today. In the early universe, space was brilliantly illuminated. As time passed, the fabric of space continued to expand, the radiation cooled and, in ordinary visible light, for the first time space became dark, as it is today.”