An Infant Universe, Born Before We Knew

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Correction Appended





In a statement issued by the European Space Agency, Jean-Jacques Dordain, its director general, said, "The extraordinary quality of Planck's portrait of the infant universe allows us to peel back its layers to the very foundations, revealing that our blueprint of the cosmos is far from complete."

Within the standard cosmological framework, however, the new satellite data underscored the existence of puzzling anomalies that may yet lead theorists back to the drawing board. The universe appears to be slightly lumpier, with bigger and more hot and cold spots in the northern half of the sky as seen from Earth than towards the south, for example, and there is a large, unexplained cool spot in the northern hemisphere.

Those anomalies had shown up on previous maps by NASA's Wilkinson Microwave Anisotropy Probe, or WMAP, satellite, but some had argued that they were because of a bad analysis or contamination from the Milky Way.

Now cosmologists will have to take them more seriously, said Max Tegmark, an expert on the early universe at the Massachusetts Institute of Technology who was not part of the Planck team and who termed the new results "very exciting." It could be, he said, that "the universe is trying to tell us something."

George Efstathiou of Cambridge University, one of the leaders of the Planck project, said in the European Space Agency news release: "Our ultimate goal would be to construct a new model that predicts the anomalies and links them together. But these are early days; so far, we don't know whether this is possible and what type of new physics might be needed. And that's exciting."




the patterns within them date from less then a trillionth of a second after the Big Bang, when the universe is said to have undergone a violent burst of expansion known as inflation that set cosmic history on the course it has followed every since. Those patterns are Planck's prize.


Marc Kamionkowski, an astrophysicist at Johns Hopkins University who commented on the work at a news teleconference sponsored by NASA, called Planck "cosmology's human genome project," saying, "It shows the seeds from which the current universe grew."

David N. Spergel, a Princeton University cosmologist, described the new results "beautiful," adding that "the standard cosmological model looks even stronger today than yesterday. The universe remains simple and strange."

The biggest surprise here, astronomers said, is that the universe is expanding slightly more slowly than previous measurements had indicated. The Hubble constant, which characterizes the expansion rate, is 67 kilometers per second per megaparsec -- in the units astronomers use -- according to Planck. Recent ground-based measurements combined with the WMAP data gave a value of 69, offering enough of a discrepancy to make cosmologists rerun their computer simulations of cosmic history.

The fact that astronomers once would go to war with one another over a factor of two in measurements of this parameter shows how cosmology has progressed over the past 20 years. Pressed for a possible explanation for the discrepancy, Martin White, a Planck team member from the University of California, Berkeley, said it represents a mismatch between measurements made at the beginning of time and those made more recently, and that it could mean that dark energy, which is speeding up the expansion of the universe, is more complicated than cosmologists thought. He termed the possibility "pretty radical," adding, "That would be pretty exciting."


Submicroscopic quantum fluctuations in this force field are what would produce the hot spots in the cosmic microwaves, which in turn would grow into galaxies. According to Planck's measurements, those fluctuations so far fit the predictions of the simplest model of inflation, invented by Andrei Linde of Stanford, to a tee.

Dr. Tegmark of M.I.T. said, "We're homing in on the simplest model."


Dr. Tegmark and others said that another clue to the nature of inflation could come from the anomalies in the microwave data -- the lopsided bumpiness, for example -- that tend to happen on the largest scales in the universe. By the logic of quantum cosmology, they were the first patterns to be laid down on the emerging cosmos -- that is to say, when inflation was just starting.


"It may be," he said, "we're coming in early to the cosmic brawl."

Correction: March 21, 2013, Thursday



This article originally appeared in The New York Times.


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