|Big bang science: From left, Clem Pryke, Jamie Bock, Chao-Lin Kuo and John Kovac give a press conference at Cambridge, Massachusetts, on their discovery (top); their tool, background-imaging cosmic extragalactic polarization telescope at the South Pole|
NEW HAVEN: There was excitement in the air at noon March 17 as a television crew and other media waited for the scientists to appear. The team of cosmologists using the sensitive telescope and array of sensors known as BICEP2, based at the South Pole, announced the discovery of evidence for cosmic inflation confirming the Big Bang theory of the creation of the universe. The press conference, live streamed, crashed under the pressure of exceptionally high traffic from all over the world.
News of the discovery of tiny ripples in space – gravity waves – created at the moment of the Big Bang, as postulated by the currently accepted theoretical model – went viral on Facebook, Twitter and science discussion boards. But within a few weeks the focus of attention changed as scientific scrutiny by other cosmologists raised questions about the claims in the dramatic announcement.
The story of a Big Bang announcement that fizzled offers a cautionary tale about scientific research in an era of intense global competition and instant fame. In another era, the process would have unfolded over months, if not years, of painstaking peer review and confirmation from several independent teams. Now, announcing a “discovery” takes minutes to reach scientists all over the world. In just a few minutes more, curious and publicity-hungry researchers and amateurs consume and analyze the material before releasing their own pronouncements, either agreeing with or dismissing the claims. In this globally connected age, the opinions of non-experts can get as much air time as those of experts.
Science is often perceived as an orderly, objective process to uncover fundamental truths about nature.
The BICEP2 announcement caused a sensation, involving recovery of an extremely hard-to-detect signal that would corroborate the idea of cosmic inflation – the lightning exponential expansion of our universe almost instantly, within a tiny fraction of a second, after the Big Bang. The scientific team reported the discovery of a wiggly polarization pattern that inflation would imprint as ripples in space. They claimed a robust detection of the polarization signal on the basis of accumulated data that the experiment had been collecting since 2010. The theory of cosmic expansion, originally proposed by Georges Lemaître in 1931, offers the best explanation for observational data of our universe, starting with Edwin Hubble in 1929 to the present. If proved, the first detection of these gravity waves emanating from the early universe would add support to the critical cosmic episode of rapid inflation.
Analysis of the BICEP2 data requires inputs from other experimental efforts, and a key one is how dust in our galaxy might modify or obscure the ripples. Dust generates a sieve through which the ripples need to pass, and the question is what modulation of these tiny ripples could be an artifact of this filtering process. The properties of the dust-sieve need to be precisely calibrated to measure and correct for its effect on the signal. To evaluate the effect of this local dust, data from the Planck satellite, launched in 2010, are needed. The scientists in the Planck collaboration, working round the clock to process the information beamed from the satellite, have yet to release their own data. That data will settle disputes over the BICEP2 findings. Rather than wait, the BICEP2 collaboration used an estimate of the dust’s contribution and proceeded to calculate the significance of their finding. Deeming it robust, the team decided to go public and share the exciting result that answers one of the cutting-edge questions in cosmology corroborating the Big Bang model.
Today every step of the process of reaching intellectual consensus within the scientific community happens in full public view.
Closer scrutiny of the BICEP2 results by other cosmologists quickly cast doubt on the robustness of their claims. In his blog, French physicist Adam Falkowski argued that the team underestimated the effects of dust within the Milky Way galaxy by relying solely on properties inferred from only one frequency channel. Proper characterization of the dust-sieve requires measurements at multiple frequency channels, which will be available soon from the Planck team and other independent experiments currently underway. Controversy brewed on whether the BICEP2 team used other required inputs accurately, in particular with regard to the dust issue.
Science is often presented and perceived as an orderly and objective process to uncover fundamental truths about nature. This view ignores the human factor or how motivations other than purely scientific curiosity drive the process of finding the scientific truth. New data are interpreted and evaluated for concordance with existing theories. Regardless of whether the data support or contradict theoretical claims, close scrutiny of the data quality and the interpretation within the scientific community ensues. If the data fail to support theoretical claims, then the theory is vigorously questioned. How this transpires in practice was laid bare after the reported discovery of gravitational waves.
As the news hit the world, other scientists not on the team busily worked at trying to understand the methods and the results. A decade ago disagreements among competing scientific teams happened behind closed doors at specially convened workshops of experts. Today every step of the process of reaching intellectual consensus within the scientific community happens in full public view. Some high-profile topics capture the public imagination – and people around the world stop to watch and listen.
Holding scientific debates in full public view affects the popular understanding of how science works. It is inevitable in our globally connected age that high-profile discoveries and challenges of validity will attract popular attention, particularly if scientists themselves court the press. Some scientists are uncomfortable about what they view as washing of dirty linen in public.
The BICEP2 event opened the curtains on the process of science, offering a ringside view to the public as witnesses and participants.
Yet it is not only useful, but also critical for the public to view the process. Instances like the BICEP2 announcement open the curtains on the process of science, offering a ringside view to the lay public as both witnesses and participants to the ensuing debates. The public, empowered by an instantaneous global media, can witness in real time how progress is made via a complicated and collaborative process of building consensus.
Before the end of this year, the Planck collaboration and other independent experiments are expected to present their own findings about these ripples in the early universe. It is imperative that the scientific establishment in cosmology remains diligent and informs the public about how this dispute is resolved.
The importance of understanding this complex process goes well beyond the question of whether inflation occurred or not. It reveals how science operates and thereby provides the toolkit required to make sense of other scientific endeavors that do have a more immediate impact such as efficacy of drugs or the impact of climate change.
Collaborative scientific research – with laboratories, equipment, travel and personnel – is costly. Budgets are tight. It has now become incumbent on scientists to explain the process, the evidence and the arguments by which scientific progress is made. In a highly connected world, scientists must be continually engaged with the public. Demystifying the scientific process, justifying the huge investments, requires sharing every step to radically change the old sanitized narrative of science as a cold, objective means of deriving fixed truths about our universe.