Big-Bang Work Brings Big Prize
|Who are NASA's Space Science Explorers?
The scientist studying black holes in distant galaxies. And the engineer designing robotic instruments for probing hard-to-reach planets. But also the teacher explaining the mysteries of the cosmos. And the elementary schooler wondering if life exists anywhere besides Earth. All of these people are Space Science Explorers -- they are all connected by their quest to explore and understand our solar system and universe. This series will introduce you to NASA Space Science Explorers, young and old, with a variety of backgrounds and interests.
Somewhere around 13.7 billion years ago, a massive explosion threw matter around in all directions, and the universe was born. At least, that is what most scientists agree happened. Although this big-bang theory is accepted widely, it is difficult to prove with 100 percent certainty.
In the early 1990s when John Mather, an astrophysicist at NASA's Goddard Space Flight Center, and his colleague George Smoot, a scientist at the Lawrence Berkeley National Laboratory, presented the best, most overwhelming proof to date for the big-bang theory, it was a triumphant moment for space science.
Image to right: John Mather receives the Nobel Prize for Physics. Copyright: The Nobel Foundation 2006. Credit: Hans Mehlin
More than a decade-and-a-half later, Mather and Smoot are being rewarded for their work -- they recently received one of the greatest honors in science, the 2006 Nobel Prize for Physics. Mather is the first NASA scientist to win a Nobel Prize. Sixteen years may seem like a long time to wait for such recognition, but Mather has learned throughout his career that hard work, combined with patience, is often rewarded.
Mather first proposed a satellite mission to test the big-bang theory in 1974, when he was 28 years old and just a few months out of graduate school. Eight years later, in 1982, his group got the go-ahead for building the Cosmic Background Explorer satellite, or COBE. But four years after that came a setback -- the 1986 loss of the Space Shuttle Challenger.
Not only was the Challenger accident a personal tragedy felt by the entire nation, but it had a serious impact on the launch plans for COBE. The satellite was expressly designed to fit aboard the space shuttle, in anticipation of being included on a future flight. When the shuttle fleet was grounded after the Challenger accident, that plan became uncertain.
Image to left: In this COBE image of the cosmic microwave background radiation, the pink and blue colors show tiny fluctuations in the temperature of the radiation. Credit: NASA
Engineers on the team found a way to reduce the satellite's weight and reconfigure it so that they could send it up on a Delta 2 rocket. The COBE satellite finally went into space in November 1989. This was the team's only chance for launch, and Mather recalls that his sense of accomplishment was overshadowed by fear. He remembers thinking, "There's our life's work standing on top of hundreds of thousands of pounds of explosive material."
The mission was not only successful -- it led to indisputable results that reinforced the big-bang theory.
Back in 1929, Edwin Hubble showed that the universe is expanding when he discovered that distant galaxies were traveling away from Earth at tremendous speeds. Scientists suggested the big-bang theory as a way to explain why galaxies would be moving away.
The theory also predicted that the universe is filled with leftover radiation from the original explosion. A little more than 40 years ago, two scientists accidentally discovered this radiation, which cannot be seen with human eyes. Their discovery of what is known as the cosmic microwave background radiation -- because it emits waves of energy in the microwave portion of the electromagnetic spectrum -- was the first strong evidence for the big bang and earned the scientists the Nobel Prize in 1978.
Mather and Smoot and the COBE science team wanted more solid proof. Working with engineers at Goddard Space Flight Center, the team conceived and built the COBE mission, which would measure the cosmic microwave background radiation in two different ways.
"One was to measure the color very precisely, which is to say how bright is this radiation at each different wavelength," Mather said. "The other was to see if it was equally bright in all directions, as it should be if it comes from the big bang, because that would surround us completely."
The match between the data from COBE and the theoretical big-bang predictions was very precise, which is rare in scientific research. Even the project leaders were not expecting such an unusually close match, said Mather, who adds that unexpected surprises like this are part of what makes scientific research exciting.
"Being a scientist is one of the most exciting things that I could imagine doing," he said. "And if you love solving puzzles, if you love finding out things that are unknown, it's just the thing [to do]."
Prachi Patel, Institute for Global Environmental Strategies