I am a graduate student at the University of Notre Dame, where I will graduate with my PhD (advisor is Dr. Grant Mathews) in May 2005. My dissertation work is on galactic chemical evolution, with a particular emphasis on the first stars and their role in cosmology. A more detailed description can be found in my Research section. My wife, Kathleen, is also a graduate student at Notre Dame, where she studies quantitative psychology.

Einstein's Miraculous Year

     This year marks the 100th anniversary of Einstein's PhD and publication of four acclaimed papers. It has been called "Einstein's Miraculous Year" for his earth shattering papers. Any of those papers alone would have made Albert Einstein a famous physicist, however, he came out with four paradigm changing papers! In a few short months, Einstein was able to coalesce hundreds of years of uncertainty on the biggest question in physics. Is light and the forces of nature propagated through particles or waves?

     Albert Einstein is best known as the founder of Relativity. Einstein came out with two papers in 1905 on special relativity. It was not the first relativistic theory, though. Before Einstein, Maxwell was able account for classical electromagnetism with a theory that violated the cornerstone of classical physics, Galilean invariance (ie all physical laws are the same regardless of the velocity of the measurement frame). Maxwell thought that the reason that electromagnetism followed Lorentz invariance and not Galilean invariance was from the properties of the medium in which light propagates (since all waves propagate in some medium). Not only did Maxwell link the electric field with the magnetic field, but he showed that the propagation of that field was roughly the same as the speed of light. Thus, the electromagnetic field can be thought of a disturbance in the aether associated with light. Michelson & Morley sought to measure the preferred direction (ie absolute frame of reference) for this light propagating medium. They found no effect, thus placing a wrench in the understanding of physics. Right before Einstein came up with relativity, Lorentz came up with an account of electromagnetism that was consistent with the Michelson and Morley experiment, the Lorentz transformation. In order to save the concept of the aether, it was proposed that the reason for the null result was due to the contraction of length in the direction of the aether's flow and a difference in the time rate in two different locations. Einstein used the recently developed Lorentz transformation and the fact that electromagnetism was Lorentz invariant to develop special relativity. If the speed of light is a fixed constant in all inertial (constant velocity) frames of reference, and the laws of physics are the same for all observers, then there can be no effect of an aether as was observed. His second paper on relativity for the year 1905 was the famous E=mc² conversion of rest mass and energy. This theory eventually would grow into general relativity and the sciences of nuclear energy. The idea of no classical medium for the propagation of light and electromagnetic fields would seem to go against the wave nature of light and the forces. But on the other side of the spectrum, Einstein showed that mass, which can be associated with particles, can be associated with energy, which is considered a wave.

     Einstein never won the prestigious Nobel Prize for relativity. He actually won it for another work from 1905 on the explanation of the photoelectric effect. He expanded the work of Planck on the discretized nature of light in the form of light quanta to solve the phenomenon of the light induced emission of electrons from a metal. Unlike the standard wave formalism, the ejection of electrons from a metal did not depend on the intensity (energy) of the light, only on its frequency. It did not matter how intense the light was on a metal, if it did not have the minimum frequency then it would not knock off the electrons in a metal. This phenomenon is what happens in a microwave when you put some metal in it, the microwaves (independent of intensity) knock off the electrons in the metal and produce a spark. Einstein confirmed that Maxwell assertion that light and electromagnetic fields were the same phenomenon, that energy was quantized into packets, and that there is a wave-particle duality associated with light. This paper sparked the birth of the most successful and paradigm altering theory of the 20th century, quantum mechanics.

     Finally, Einstein published a paper in 1905 on random motion (Brownian motion) of microscopic particles due to its macroscopic properties like temperature and pressure. Before Einsteins work, the idea of an atom was met with much skepticism even though it was a mathematically useful way to look at properties of gases. Einstein illustrated that if atoms existed as they were in the kinetic theory of gases, then the ensuing random collisions would induce the macroscopic (and measurable) effects like pressure, temperature, diffusion, and the observed Brownian motion of small particles. Elastic impacts of random strength and direction on a particle would induce a very large distribution of states that will determine the observed macroscopic states. Statistical mechanics, kinetic theory of gases, and the reality of atoms were very much up in the air until Einstein provide the link along with testable predictions. The controversy was so intense that genius of Boltzmann, one of the founders statistical mechanics, was not recognized by the established scientific community. His despair at not being taken seriously eventually led to him taking his own life. Fortunately, the scientific community would not treat Einstein in the same fashion as they did for Boltzmann.