Cooing at the universe's baby pictures
Astronomers who study the childhood of our universe are amazed at their discoveries. Contrary to earlier theories, "the universe did grow up fast," says Piero Rosati. It turned on its lights and established its general structure in less than a billion years. That covers only a small fraction of the universe's 13.7-billion-year existence.
The report from the European Southern Observatory in Garching, Germany, where Dr. Rosati works, calls this a "highly surprising" discovery. It further explains that, "Indeed, until recently, it would even have been deemed impossible."
Now, thanks to the reach of orbiting telescopes, astronomers are listening to the universe's birth cries, tracing its first steps, and even grabbing snapshots of its adolescent activity.
The latest development is the probable detection of light from the very first stars. They lit up when the universe was only 100 million years old. They burned hot and fast, emitting strong ultraviolet light. As the universe - including space itself - has expanded, the wavelength of that light has stretched so it now appears as long-wave infrared radiation. It's hard to detect. But if you know what to look for, and own a powerful enough infrared telescope, you can find it.
Previous studies of a general cosmic infrared radiation that permeates the cosmos found hints of the first starlight. Two weeks ago in the journal Nature, Alexander Kashlinsky and a science team at the NASA Goddard Space Flight Center in Greenbelt, Md., described how they have refined the search. NASA's Spitzer infrared orbiting observatory has the observing power needed. It can't image the actual stars. Its view is more like looking though a frosted glass window and seeing light and dark patches of objects in the scene beyond.
But Spitzer's view is good enough for John Mather, co-author of the Nature paper, to say that "this infrared glow with giant blobs ... could be the glow from the very first stars."
Commenting on this in Nature, Richard Ellis with the California Institute of Technology in Pasadena notes: "The genuine excitement in this work lies in the practicality of detecting the stellar radiation from hitherto uncharted distances corresponding to a time when the universe was barely 100 million years old."
Dr. Ellis and colleagues at the Space Telescope Science Institute in Baltimore, stimulated similar excitement in September. They had found a massive mature galaxy that existed when the universe was only 800 million years old. It shows that at least one galaxy - and probably more - had fully matured by the time the universe was only 6 percent of its present age.
Last spring, Mark Whittle, of the University of Virginia in Charlottesville, delighted an audience at an American Astronomical Society meeting in Denver with sounds of the baby universe. The substance of space was dense enough back then to support sound. Dr. Whittle found the trace of the sound in the cosmic microwave radiation left over from the Big Bang. He transposed those very low tones up to the range of human hearing and played their music.
The attempt to understand how our universe grew up is, itself, in its infancy. But such discoveries suggest it can no longer be considered an impossible quest.