Cosmology

Caltech physicist Sean M. Carroll has been wrestling with the mystery of time. Most physical laws work equally well going backward or forward, yet time flows only in one direction. Writing in this month's Scientific American, Carroll suggests that entropy, the tendency of physical systems to become more disordered over time, plays a crucial role. Carroll sat down recently at Caltech to explain his theory. What's the problem with time?

Round may be the preferred shape of baseballs, bubbles and Cocoa Puffs. The universe, however, may favor the ellipsoid. Italian scientists using data gathered by NASA's WMAP probe say evidence points to the universe having a shape somewhat akin to an egg, rather than the expected round kernel of puffed cereal. This, say the authors of a paper published this week in the scientific journal Physical Review Letters, would explain some curious anomalies over the heavens' expanse.

Wendy Freedman, director of the Carnegie Observatories in Pasadena, and two colleagues were named this month as recipients of the $500,000 Gruber Prize, one of the world's top awards in the field of cosmology. Freedman, along with Robert Kennicutt and Jeremy Mould, were honored for their nearly decade-long effort to find a more precise value for the Hubble constant, one of the key values in cosmology, a measure of how fast the universe is expanding and thus how old it is. The Freedman team's work helped scientists to arrive at the currently accepted age of the universe: 13.7 billion years.

Black holes, those fearsome galactic traps from which not even light can escape, may not be quite so terminally destructive after all, according to physicist Stephen Hawking. The author of "A Brief History of Time" now believes some "information" sucked into black holes escapes over time, contradicting some of his most famous work on the phenomenon. Hawking will present his findings at a scientific conference in Ireland next week, New Scientist magazine said.

Scientists using a robotic NASA probe have determined with precision the age of the universe -- 13.7 billion years -- and figured out when stars began to shine. Astronomers have been closing in on these numbers for decades, but a spacecraft now about a million miles from Earth has been able to look back to nearly the dawn of time to find the answers, NASA researchers said Tuesday.

A combination elf, oracle and rock star, Cambridge University physicist Stephen Hawking makes waves in physics that other people ride. So scientists listened when Hawking proposed in a technical talk Thursday at Caltech that the universe sprang from nothing into something in the shape of a wrinkly pea, and that the universe can be both open and closed, depending on how you look at it.

Ever since people first stood up amid the tall grasses and looked about the world in wonder, religion, mythology and science all have struggled to explain how the world came to be. But when it comes to creation stories, few can hold a candle to the tale cooked up by modern cosmologists. Dialing back the cosmic clock about 15 billion years, they depict a time before time, a place before space existed.

As cosmologists struggle to get a handle on the universe, their biggest adversary is time. Probing the whys and wherefores of the universe turns on getting information from sources that are millions (or even billions) of light-years away. That means they are also millions (or billions) of years back in time. Deciphering starlight is like reading a letter from a friend who writes that he's sitting at a window looking at the crocuses in bloom.