In a field just below the crest of Crawford Hill, almost within sight of the skyscrapers of New York City, lies a group of shacks and sheds. Next to them is the Holmdel Horn Antenna, a radio telescope that looks a bit like the shovel of a giant steam excavator: an aluminum box measuring 6 square meters at the mouth and tapering to a 20-centimeter opening, through which radio waves are channeled to the “cabin,” a wooden cabin on stilts. From a distance, the place could be mistaken for an old mining camp.
What he once extracted was the sky. While listening with the antenna in May 1964, Two young radio astronomers, Arno Penzias and Robert Wilson, captured an eerie and persistent hum. For a long time they thought it was caused by pigeon droppings that had accumulated in the horn. Instead, finally They discovered that they were listening to the last gasp of the Big Bang, which gave rise to the universe 13.8 billion years ago and which is now detectable only as a faint, omnipresent hiss of microwave radiation.
Until then, scientists had debated whether the universe even had a beginning; maybe it was timeless. That was resolved. The discovery also brought the beginning of time to the laboratory, where it could be dissected. Encoded in that microwave hiss are vestiges of events that occurred when the cosmos was less than a billionth of a second old and brimming with energies far beyond the capacity of modern particle colliders.
The cosmic microwave background offered a new window into the nature of reality, a window that astronomers have been peering through ever since. In 1978, Penzias and Wilson received the Nobel Prize in Physics for their discovery, and in 1988, the antenna was designated a US National Historic Landmark.
The Holmdel Horn was built in 1959 by Bell Laboratories for an experiment, Project Echo, whose goal was to send messages from one place on Earth to another by bouncing microwaves off giant aluminized balloons. When the project was completed, Bell gave the antenna to Penzias, who had left Nazi Germany before the Holocaust, and Wilson, a radio genius from Houston, Texas.
They wanted to measure the brightness of galaxies. But on May 20, 1964, there was an unsettling surprise—a persistent hiss wherever they pointed the telescope.
The intrusive noise corresponded to a temperature of about 3.5 degrees kelvin, barely, but clearly above the absolute zero expected of space. It was present regardless of which direction they pointed the antenna. No matter how hard they tried, they couldn’t get rid of the extra heat. Two pigeons that had made a nest in the antenna were scared away and their excrement was cleaned. But the noise persisted, eluding explanation for almost a year.
“We were desperate,” Wilson said.
A few miles away, Robert Dicke, a physicist at Princeton University, and his students had begun studying the conditions under which the universe may have begun. They concluded that any such Big Bang must have been hot enough to sustain thermonuclear reactions, at millions of degrees, to synthesize heavy elements from primordial hydrogen.
They realized that this energy should continue to exist. But as the universe expanded, the early fireball would have cooled to a few kelvins above absolute zero—which, they calculated, would put cosmic radiation in the microwave region of the electromagnetic spectrum.
The Bell Labs and Princeton teams got together and wrote a pair of papers, published consecutively in the Astrophysical Journal. The Bell Labs group described the radio noise, and the Princeton group proposed that it could be leftover heat from the Big Bang — “probably each side thinking, Well, what we’ve done is right, but the other side may not be.” Wilson said. “I think both Arno and I wanted to leave open the idea that there was some other source of this noise,” he added. “But of course, that didn’t work.”
In the novel “Requiem for a Nun,” William Faulkner wrote, “The past is never dead. “It hasn’t even happened.” The sounds of creation still resonate, if you have ears to hear them.
By: DENNIS OVERBYE
The New York Times
BBC-NEWS-SRC: http://www.nytsyn.com/subscribed/stories/6890409, IMPORTING DATE: 2023-09-12 20:30:09
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