Saturday, May 12, 2007

How Did It Begin?

I do not seriously believe there is such a thing as serendipity. I tend to beleive it is a consequence of the unending pursuit for the quest for the truth of the nature. The process of finding it doesn't stop in our conscious memory. Subconscious mind takes over and continuously seeks for the answer even while we are in sleep. When it finds all the clues relevant to the subject question and links between them, voila you have the answer. Nothing happens without reason.

While studying physics at the Rackham graduate school of the University of Michigan, Ann Arbor, I was interested in the quark confinement problem. I devised some phenomenological quark potential using the result from the renormalisation group equation and also by introducing the simple transformation between the scaling factor and the length element. The result was interesting. One of the interesting consequence of the finding was that the ratio of the mass of an electron from QED and the mass of a quark from QCD turned out to be 1830, which happens to be about the ratio between the mass of an electron and a proton. The ratio could be obtained because the infinities in the form of 1/(n-4) ,where n denotes dimension, factors out from both QED and QCD within the dimensional regularisation scheme in quantum field theory. Dr. Veltman's lecture on dimensional regularisation was brilliant, inspiring and filled with energy. The measured coupling strengths predicted the mass ratio of the two most stable elementary particles. I thought it was a very exciting discovery. It may have proven that the infinite quantities (eg, mass of the elementary particles) quantum field theories provide to us are not exactly infinities and also the universe may not be exactly in the four dimensional space.

In the course of the liberal thoughts and day dreaming about the nature at the beautiful campus in Ann Arbor, I always felt that there was something missing about our knowledge on gravity that it is not complete or there is something missing in our understanding without having any idea on what it may be. I remember taking a look at the text book on gravitation at the library to see if there is anything beyond Newtonian gravity. However gravity was not my main subject of interest at this time. I was interested in the theoretical high energy physics. The most puzzling experience in this episode was when I looked up the page describing the linearized form of general relativity. There was something next to Newtonian gravity and that was the dipole gravitational moment. And it was dismissed by a reason that I thought was too much of tongue in cheek argument. The fact that one has to move the origin of the coordinate system to the center of mass of the object to remove the term seems too convenient or/and unnatural(can't find the right word for it) because one can always set up the origin of the coordinate system at the center of mass of the object and forget about the coordinate alignment problem. I thought it was an unnecessary and non physical activity and it may hide some more serious physics involved. But there was no way I could have guessed at the time that it could have something to do with the anomalous center of mass shift from a rotating hemisphere. In 1995, the puzzle was solved after 13 years since I was wondering about the gravitational dipole moment. It happened when I asked the following two questions in my mind. What is so special about rotating hemisphere? And then how about the center of mass? Answers to these two questions answered the 13 years old questions in my mind. The gravitational dipole moment. It looks like there is no way we can avoid this solution. As it turned out later, the jets and the dark matter problem are the two different sides of the same coin due to the dipole gravity effect from the fast rotating black hole.

What is so peculiar about the jets from the black hole accretion discs it is that the normal gravito magnetism can not work simply by observing the fact that the jets are coming out of both sides of the axis not from only one side. So it must be completely different from the simple "gravito magnetism" in analogy to electricity and magnetism. Rotating mass may create gravito magnetism but not in such a simple way as one would expect a charged sphere would create a magnet by its rotation.

And then there was a popular issue of the jets from the black hole accretion disc at the time. I didn't believe jets could be explained by plasma and the surrounding strong magnetic field, when the event horizon was defined as the line that can not be crossed even by light. It was to me a monumental self contradiction. I couldn't believe how people could be bought into it. I remember thinking to myself that if there was any force that can make jets possible, it must be some kind of gravity but not electromagnetism.

I met Dr. Donald Hinson at the UT lab after I came back to Austin and asked him if he could plot the potential diagrams and the result was the beautiful quadrupole gravity potentials and the saddle diagram. Since the first result didn't come out in such a way that it was consistent with Lens-Thirring force, I told him to fix it to match with Lens-Thirring's. It was plotted using the reversed sign from the original mathematical form of the potential.

Still, anyone could tell there are jets on both sides of the poles of the rotating ultra compact stellar objects just by reading the potential diagram. The result was published in the journal Physica Scripta in 1999 . As anyone may have guessed, it was not easy to make it published as it was a humongous heresy in the gravitational physics community at the time and as it may still be now. It should have gotten a space in Physical Review Letters.

The identity of the dipole gravitational moment has been hidden from the plane view for the last 90 years since the birth of special relativity. In a way, this problem should(could) have come out to question the compatibility between Newtonian mechanics and special relativity in a much earlier time. It could have been a serious subject of debate. If it did, the gravitational dipole moment would have been discovered much earlier. There may be people who tend to think that gravitational dipole moment would have been such an easy thing to discover. But for the last 90 years, out of the total population of the earth lived in that period of time with so many talented geniuses in the physical and scientific field of the world, I thought to myself, from time to time, why it had to be on my table. I was not talking until late compared to other kids and it concerned my parents. And my questions bothered adults in the family that they always had to hush me down from asking too many bothersome questions when I was a little boy. My sister knows how I was called in the family which I'm not going to reveal to protect my dignity. My sentences don't finish right when I'm writing. My thought process has wild disconnected jumps from one subject to another with totally different issues as anyone may have guessed in this blog. I'm not a good writer and never felt I could write anything more than a few sentences or paragraphs without totally confusing the reader on what I'm really trying to say. It's all there but it takes a long while to get it all together. I always wondered how anyone could write a book with thousands of pages without repeating the same story or content over and over again. I truly admire them all who do. If there is anything that I may have done to deserve it is that I never stopped asking questions and asked the right question at the right moment. The answer is not always immediately obvious but our brain is such a marvelous thing that it works hard day and night to provide the answer to the one who seeks it.

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