It was an interesting day my freshman year at Oberlin. I was taking Intro Mechanics
and for the first time, I would get to go to a talk given by an interesting mind in the world of physics at large. The weather was a bit rainy, but being in Ohio in the fall, this was no great surprise. The days were still pleasant, but a bit damp. It seems odd but it's been nearly five years since then 2003.
That morning brought an interesting bit of news. The journal Nature published an article by one Jeff Weeks which proposed a good deal of mathematical evidence for the thesis that the universe was curved in on itself. Specifically, that it was curved back on 12 sides at once. The universe that morning became a d12, though at this point I had yet to get into gaming so it really meant little to me. The fact that the universe's geometry resembled a dodecahedron was just as unfathomable to me as any other explanation. This explanation roused a great deal of hub-bub. News articles were written. My Dad sent me a link by email.
That evening, the Physics Department was hosting a talk by David Spergel of Princeton, an animated professorial type (read: bearded) and one of the lead researchers of the Wilkinson Microwave Anisotropy Probe data. For those that don't know, the WMAP, as it is called, provides us with a set of data about the structure of the very early universe. It shows us, with high accuracy, which parts of the early universe were hotter and which were colder. Wilkinson was one of the scientists who pioneered the study of the early universe. He and his colleagues at Princeton were working on Cosmic Microwave Background in the 1960s when Penzias and Wilson at Bell Labs managed to scoop them by measuring it first. These earliest measurements showed that the entire universe was suffused with a ubiquitous field of microwave radiation that made empty space a few Kelvin above absolute zero. In the 90s, the COBE satellite was sent to measure things again, but within a narrower band, to see if there were anisotropies in the CMB, which it found. And the WMAP was sent to measure those tiny differences within an accuracy of ~20 microKelvin.
What the WMAP found was just being released in 2003 after 5 years of data collection. In February, NASA made the first press releases about the WMAP data collection coming to a close. It was October when the first trickle of analysis began to seep from that mountain of data. It was the previous day, October 8th, when Spergel and his team put the first paper of analysis on arXiv. That Thursday evening, a pair of talks were given by Spergel in the room where Intro Physics Lectures were taught. He held up a copy of Nature, dodecahedron speckled with stars on the cover, and gave a response to the curved universe.
He explained how the topology of the universe can be constrained by the data they had collected and that the world is flat. The tests done on the data were very brute force methods, looking for mirror images using large amounts of computer time. The tests showed that either the universe was flat or it was much, much larger than we think. In a pair of hour-long lectures, I had the basics of Big Bang cosmology explained to me by one of the people who was up to his elbows in it every day. One of the thoughts I had as I left the auditorium was that I had just met a man destined to win a Nobel Prize for his work.
Thinking back on this experience, I realize that seeing this talk may have been a major impetus for my entrance into the field of Astrophysics. It was an inspiring look into how science changes the world around us. The very shape of the universe was made as malleable as moist clay for one fall afternoon in 2003. That morning, people woke up to the possibility that the universe was shaped like the damage done by a Great Axe, and that evening, for me and the physics community at my school, it was smashed flat once again by the most complete and precise data we have of the Big Bang, it's long dying embers simmering the universe lightly in 2.7 Kelvin radiation. Astrophysics is like Engineering, it takes everything we know and uses it all at once and the things we can learn continue to astound us.
After five years of analysis, study and probably a dozen Ph.D.s granted, the teams working on this project and data have announced that the age of the universe is 13.73 ± .12 billion years old, <1% error. In science this is what is generally referred to as fact. If anything the WMAP is one of the triumphs of science in the contemporary world, one which will shape my field for the next century.