“It’s a vivid picture that the universe was once a seething hot cauldron of plasma, and we’re seeing the fading embers of that now, 13 billion years later,” said assistant professor of physics Don Smith of the phenomenon called cosmic microwave background radiation (CMB).Smith spoke on CMB at Guilford’s observatory open house last November and has taught classes on the subject. As Smith suggests, CMB is theorized to be light emitted during the earliest stages of the big bang.
“If you can look at the whole sky and take out the stars in the way and the hot gas and the galaxies and everything else in the way,” said Smith, “what you have left is a dim glow that’s all over the sky. It’s everywhere.”
This dim glow is CMB, and it is one of the main tracks of evidence for support of the big-bang theory.
Since it takes a certain amount of time for light from an object to reach an observer, when astronomers view light from space, they see light from the past. Thus, the farther away in space one looks, the farther back in time.
By looking past all the objects Smith described, astronomers found light that had traveled billions of years potentially emitted from that “hot cauldron of plasma,” which was the universe before big-bang expansion.
On July 31, 2008, the European Space Agency plans to launch its Planck satellite into space in order to study CMB. Two major satellites, COBE and WMAP, have previously studied CMB, but Planck is intended to record much more detailed data with better accuracy.
Planck will measure tiny variations in the temperature of CMB. The main theory behind these fluctuations is that they resulted from unevenly spaced clumps of matter in the mass that was the universe before the big bang. By studying these variations, cosmologists may be better able to understand the geometry of that pre-big bang universe.
“When we look back to the past, we can see everything between the past and now, and that allows us to project to the future,” Professor George Smoot said to BBC News. “I want to know how the universe came into being, how it developed and what its future might be.”
Smoot, along with John Mather, won the 2006 Nobel Prize in Physics for their research of CMB.
Cosmologists hope the data provided by Planck will provide not only glimpses of past and future, but also a more thorough understanding of the present. Planck’s mission may lead to an understanding of the nature of what scientists call dark matter and dark energy.
These two names are really placeholders for a giant question mark in the scientific world. Scientists observed that there must be more “stuff” in the universe than we can see and identify, so they called this “stuff” dark matter and dark energy.
Dark matter and dark energy constitute 96 percent of the mass of the universe. Only 4 percent of the universe appears on the periodic table.
“It’s kind of creepy that we live in a universe where we can’t explain what 96 percent of it is,” said Elise Weaver, junior physics major and observatory assistant.
The results of cosmological research of CMB will not only affect scientists.
“New information about creation always affects our perception of our own importance because it always affects our perception of science and religion,” said senior theatre major Aaron Goldfarb. “It’s always going to be bouncing around in our heads in terms of what the creation of our planet is, what the creation of everything outside of our planet is and how that might relate to our own creation.”
“If the data constrain us to accept that we live in a universe that is 13 billion years old and huge,” said Smith, “and we’re on a tiny speck of a planet whirling around the sun in the backwaters of a galaxy that’s out in the middle of nowhere, either that has no bearing on how you live your life or it’s crucial to how you live your life, and either way you have to come to terms with it.