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Quantum Mechanics
"... I think I can safely say that nobody understands Quantum Mechanics"
Richard P. Feynman Around the turn of the century, the German physicist Max Planck postulated that a black body emitted light in discrete packets of energy. A few years later in 1905, Einstein invented the concept of light quanta by which he explained the photoelectric effect (and for which he received the 1921 Nobel Prize). The next twenty years were filled with revolutionary ideas. Niels Bohr postulated that electrons orbiting atoms could do so only in a discrete set of orbits, and Louis de Broglie proposed the idea that not only did light, previously thought to be a wave, have particle properties, but all particles had wave properties. The cumulation of all this was the theory of Quantum Mechanics, developed in the mid twenties by Erwin Schroedinger, Werner Heisenberg and Paul Dirac. Quantum Mechanics describes all of the microscopic world of atoms, electrons ..... (this definitely needs to be worked out more! A nice parting quote attributed to Niels Bohr: If anyone says he can think about quantum problems without getting giddy, that only shows that he has not understood the first thing about them
Last modified: May 31, 1994
All things are made of atoms-little particles that that move around in perpetual motion, attracting each other when they are a little distance apart, but repelling upon being squeezed into one another. The Universe in a Glass of Wine audio A poet once said, "The whole universe is in a glass of wine." We will probably never know in what sense he said that, for poets do not write to be understood. But it is true that if we look in glass of wine closely enough we see the entire universe.
There are the things of physics: the twisting liquid which evaporates depending on the wind and weather, the reflections in the glass, and our imagination adds the atoms. The glass is a distillation of the earth's rocks, and in its composition we see the secrets of the universe's age, and the evolution of the stars. What strange array of chemicals are in the wine? How did they come to be? There are the ferments, the enzymes, the substrates, and the products. There in wine is found the great generalization: all life is fermentation. Nobody can discover the chemistry of wine without discovering the cause of much disease. How vivid is the claret, pressing its existence into the consciousness that watches it!
If in our small minds, for some convenience, divide this glass of wine, this universe, into parts - physics, biology, geology, astronomy, psychology, and so on - remember that nature does not know it! So let us put it all back together, not forgetting ultimately what it is for. Let us give one more final pleasure: drink it and forget it all! The Feynman Lectures on Physics In the early 60's Feynman (at the time faculty member at Caltech) was asked to teach Caltech's undergraduate 2 year introductory course in physics. He agreed to teach the course only once. The lectures he gave during these 2 years were audio recorded and the blackboards where photographed. A couple of years later, these lectures came out in written form as The Feynman Lectures on Physics, and are considered one of the most important achievements of the 20th century: the encapsulation of the entire field of physics, by its greatest living practitioner.
He taught physics like none had before him; in the normal physics course they usually went through all the historical developments until in the final weeks they reach the chapter on atoms and molecules, the very essence of our world. However in Feynman's very first lecture in the fall of 1961, over 200 students were gathered to listen to him announcing the words you can find at the beginning of this page. In his second lecture he summed up "Physics before 1920's" in less than half an hour and went on to quantum physics, the new stuff that students came excited to hear. Here is an audio sample on his concluding remarks on the near symmetry in nature - one of Feynman's finest moments: symmetry.mp3 (2min - 700KB)
And this is his explanation of the existence of our world: why atoms do not fall apart! atoms.mp3 (2min - 700KB)
Apart from these official lectures, for more than 20 years he taught unofficially a course called Physics X; once every week people gathered somewhere on campus under the sun of LA and they could ask Feynman any physics question they wanted. The students were meeting the previous days in order to come up with questions that could possibly frustrate him, although it is said that none ever managed to do that.
The Mysterious 137 If you have ever read Cargo Cult Science by Richard Feynman, you know that he believed that there were still many things that experts, or in this case, physicists, did not know. One of these 'unknowns' that he pointed out often to all of his colleagues was the mysterious number 137.This number is the value of the fine-structure constant (the actual value is one over one-hundred and thirty seven), which is defined as the charge of the electron (q) squared over the product of Planck's constant (h) times the speed of light (c). This number actually represents the probability that an electron will absorb a photon. However, this number has more significance in the fact that it relates three very important domains of physics: electromagnetism in the form of the charge of the electron, relativity in the form of the speed of light, and quantum mechanics in the form of Planck's constant. Since the early 1900's, physicists have thought that this number might be at the heart of a GUT, or Grand Unified Theory, which could relate the theories of electromagnetism, quantum mechanics, and most especially gravity. However, physicists have yet to find any link between the number 137 and any other physical law in the universe. It was expected that such an important equation would generate an important number, like one or pi, but this was not the case. In fact, about the only thing that the number relates to at all is the room in which the great physicist Wolfgang Pauli died: room 137. So whenever you think that science has finally discovered everything it possibly can, remember Richard Feynman and the number 137. Dr. Bill Riemers writes: classical physics tells us that electrons captured by element #137 (as yet undiscovered and unnamed) of the periodic table will move at the speed of light. The idea is quite simple, if you don't use math to explain it. 137 is the odds that an electron will absorb a single photon. Protons and electrons are bound by interactions with photons. So when you get 137 protons, you get 137 photons, and you get a 100% chance of absorption. An electron in the ground state will orbit at the speed of light. This is the electromagnetic equivalent of a black hole. For gravitational black hole, general relativity comes to the rescue to prevent planets from orbiting at the speed of light and beyond. For an electromagnetic black hole, general relativity comes to the rescue and saves element 137 from having electrons moving faster than the speed of light. However, even with general relativity, element 139 would still have electrons moving faster than light. According to Einstein, this is an impossibility. Thus proving that we still don't understand 137. One hundred [and] thirty-seven is the 33rd prime number; the next is 139, with which it comprises a twin prime, and thus 137 is a Chen prime. 137 is an Einstein prime with no imaginary part and a real part of the form 3n − 1. It is also the fourth Stern prime. 137 is a strong prime in the sense that it is more than the arithmetic mean of its two neighboring primes. Using two radii to divide a circle according to the golden ratio yields sectors of approximately 137° (the golden angle) and 222°. 137 is a strictly non-palindromic number and a primeval number.
In physics The numerical value of the fine structure constant α, a dimensionless physical constant, is approximately 1/137. The physicist Arthur Eddington at one time thought α to be exactly 1/137, but careful measurements have shown this not to be the case: its value is currently estimated at 1/137.035 999 76(50). This leads to predictions on the nature of electron orbital. See untriseptium.
In other fields 137 is also: The importance of the number 137 is that it is related to the so-called 'fine-structure constant' of quantum electrodynamics. This derived quantity is given by combining several fundamental constants of nature:
where e is the charge on the electron, c is the speed of light, h-bar is Planck's constant and the epsilon represents the permittivity of free space. Despite the fact that each of these constants have their own dimensions, the fine-structure constant is completely dimensionless!
The importance of the constant is that it measures the strength of the electromagnetic interaction. It is precisely because the constant is so small (i.e. 1/137 as opposed to 1/3 or 5 or 100...) that quantum electrodynamics (QED) works so amazingly well as a quantum theory of electromagnetism. It means that when we go to calculate simple processes, such as two electrons scattering off one another through the exchange of photons, we only need to consider the simple case of one photon exchange -- every additional photon you consider is less important by a factor of 1/137. This is why theorists have been so successful at making incredibly accurate predictions using QED. By contrast, the equivalent 'fine-structure' constant for he theory of strong interactions (quantum chromodynamics or QCD) is just about 1 at laboratory energy scales. This makes calculating things in QCD much, much more involved.
It is worth noting that the fine-structure 'constant' isn't really a constant. The effective electric charge of the electron actually varies slightly with energy so the constant changes a bit depending on the energy scale at which you perform your experiment. For example, 1/137 is its value when you do an experiment at very low energies (like Millikan's oil drop experiment) but for experiments at large particle-accelerator energies its value grows to 1/128.
Answered by: Brent Nelson, M.A. Physics, Ph.D. Student, UC Berkeley Psalm 137 1 By the rivers of Babylon we sat and wept
when we remembered Zion. 2 There on the poplars
we hung our harps, 3 for there our captors asked us for songs,
our tormentors demanded songs of joy;
they said, "Sing us one of the songs of Zion!" 4 How can we sing the songs of the LORD
while in a foreign land? 5 If I forget you, O Jerusalem,
may my right hand forget its skill . 6 May my tongue cling to the roof of my mouth
if I do not remember you,
if I do not consider Jerusalem
my highest joy. 7 Remember, O LORD, what the Edomites did
on the day Jerusalem fell.
"Tear it down," they cried,
"tear it down to its foundations!" 8 O Daughter of Babylon, doomed to destruction,
happy is he who repays you
for what you have done to us- 9 he who seizes your infants
and dashes them against the rocks. Finding the Higgs particle has become the greatest goal in physics. It will help scientists figure out why the universe is made of something instead of nothing, why there are atoms, people, planets, stars and galaxies. Ronald Kotulak, Chicago Tribune | 
