A University physics professor will lecture on unseen forces and forms of matter that are part of the universe today at 7 p.m. in 100 Willamette. Jim Brau’s talk is titled “Realizing Einstein’s Dream: Exploring Our Mysterious Universe.”
“The talk is about the mysteries of our universe and our understanding of the universe and our prospects for improving that understanding,” Brau said.
Brau said one mystery is dark matter. While it is not visible to telescopes, radio emissions or the naked eye, it outweighs normal matter by a five to one ratio. Physicists are convinced that dark matter exists because if no matter existed beyond what is observable, the universe would spin itself apart.
Brau said this fact suggests a type of particle, called a supersymmetric particle, that mirrors the actions of particles that compose visible matter.
As an example, Brau described the physicist Paul Dirac, who, while composing a theory of electrons, postulated the concept of anti-particles in 1930. The anti-particle for an electron is a positron, which is similar to an electron in mass and other properties but has a positive charge. This is different from protons, which are also positively charged, because protons are much bigger than electrons and do not annihilate electrons on contact. Four years after Dirac’s paper, anti-particles were discovered in cosmic rays.
“He had to invent a whole new set of particles and they turned out to be real,” Brau said, speculating that the current idea of supersymmetric particles may someday be proved in a similar fashion.
“Physics suggests that this should be true,
astronomy sees the effects, and we’re trying to bring the two together,” Brau said.
Another mystery is dark energy. Brau said the universe has been expanding for 14 billion years after the Big Bang arose out of a very small concentration of matter and energy. Brau said that according to the laws of gravity, the universe should be coming back together, so it is hypothesized that a force of dark energy is pushing the universe outward.
“It turns out we can calculate it,” Brau said.
Dark energy is three times larger than dark matter. This makes the composition of the universe about 25 percent dark matter, almost three-quarters dark energy, and about 5 percent regular matter and energy, Brau said.
“The universe is overwhelmingly built out of stuff we haven’t yet
figured out what it is,” Brau said.
Brau’s lecture is part of the University’s celebration of World Year of Physics 2005, which previously included a lecture by California Institute of Technology physics professor Kip Thorne. World Year of Physics 2005, a United Nations-endorsed event, commemorates the 100th anniversary of Albert Einstein’s “Miracle Year,” during which he published papers on the theory of relativity, quantum theory and the theory of Brownian motion, according to the World Year of Physics 2005 Web site.
Brau said Einstein’s theory of gravity, general relativity, shows that the presence of matter and energy distorts the fabric of space, resulting in the motion of planets around the sun, and this applies to more recent findings involving the distortion of dark matter.

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