In what appears to be a pivotal step in the quest to understand the origin of the universe, scientists announced yesterday that they’d observed a signature of long-sought ripples in space known as gravitational waves, generated less than a trillionth of a second after the big bang. These primordial ripples showed up indirectly as a pattern in a background of microwave radiation that pervades space. The observations come from a detector called BICEP2 located at the South Pole.
Though a press release distributed last Wednesday didn’t specify the nature of the discovery, it was intriguing enough that many reporters were able to get lots of reporting ready for stories that coincided with the official announcement Monday morning. The Guardian ran a story Friday, which seemed fair enough since the news wasn’t under embargo.
Most ledes focused on the way the observations confirmed a theory called inflation, which posits a period of hyper-expansion in the first sliver of a second after the start of the universe. That focus created a classic conundrum for those attempting to write for the general public, since most readers are only familiar with inflation as an economic phenomenon. How to introduce the news?
Some started with a first sentence of pure textbook background. Here’s Malcolm Ritter with his AP story:
NEW YORK — The universe was born almost 14 billion years ago, exploding into existence in an event called the Big Bang. Now researchers say they've spotted evidence that a split-second later, the expansion of the cosmos began with a powerful jump-start.
Here’s the Carolyn Y. Johnson for the Boston Globe, with a more direct news lede, including the local angle:
A team led by a Harvard astronomer announced Monday that it had detected a pattern in the distant cosmos that reveals what happened in the first known moments after the Big Bang 13 billion years ago: a hyper-expansion of our universe known as inflation.
Here’s Alan Boyle for NBCnews.com, putting inflation right there in the first sentence but with context that offered some help:
New findings show that the universe underwent a burst of inflation that was seemingly faster than the speed of light in the first instant of its existence, throwing off a storm of exotic gravitational waves in the process.
At the New York Times, Dennis Overbye included the boldest, most attention-grabbing statement I'd seen:
Radio astronomers reported that they had seen the beginning of the Big Bang ….
Oddly, this is the second sentence in paragraph five. The top of the story is all history. If, allowing for poetic license, it’s a reasonable interpretation to say that radio astronomers have seen the beginning of the Big Bang (not the TV show), then that sentence seems like it should kick things off.
Here’s the actual first sentence in the story:
CAMBRIDGE, Mass. — One night late in 1979, an itinerant young physicist named Alan Guth, with a new son and a year’s appointment at Stanford, stayed up late with his notebook and equations, venturing far beyond the world of known physics.
It was surprising to see such a drawn-out feature lede when there’s been so much buzz about the news. But at least by the time he gets to the news about inflation, readers have been given an introduction. And overall, the Times story was more gripping and clearer than others I’d read. The language is all non-technical and yet the story is rich with information and context. There are aspects of the news that others didn’t get, including the implications of inflation:
Confirming inflation would mean that the universe we see, extending 14 billion light-years in space with its hundreds of billions of galaxies, is only an infinitesimal patch in a larger cosmos whose extent, architecture and fate are unknowable. Moreover, beyond our own universe there might be an endless number of other universes bubbling into frothy eternity, like a pot of pasta water boiling over.
And some understanding of why gravitational waves are so exciting for physics:
According to inflation theory, the waves are the hypothetical quantum particles, known as gravitons, that carry gravity, magnified by the expansion of the universe to extragalactic size.
“You can see how the sky is being distorted by gravitational waves,” said Andrei Linde, a prominent inflation theorist at Stanford. “We are using our universe as a big microscope. The sky is a photographic plate.”
We can't yet discount the possibility that the finding won't be replicated, but competing scientists working on similar projects should be able to find out reasonably soon whether the result stands up. And I learned from this story by Clara Moskowitz in Scientific American that there’s already some hint of confirmation from the Keck Array:
In fact, the researchers were so startled to see such a blaring signal in the data that they held off on publishing it for more than a year, looking for all possible alternative explanations for the pattern they found. Finally, when BICEP2’s successor, the Keck Array, came online and began showing the same result, the scientists felt confident. “That played a major role in convincing us this is something real,” Kuo says.
There’s also a nice breakdown in Nature, called All You Need to Know about Gravitational Waves, but if you read Overbye’s story, you’ll already have much of this information.
Even after reading all these stories, I still wanted to know more about how the findings might help cosmologists tackle the remaining mysteries about the origin of the universe. Several scientists quoted in these stories touched on it, noting that the detection of gravitational waves will not just back up the idea of inflation but answer specific questions about how it happened and when.
Looming questions remain about why and how the big bang happened, what might have triggered inflation, and once inflation started, why it stopped. It would be interesting to know how this finding might or might not answer those questions that nag at the curiosity of scientists and lay people alike.
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