MadSci Network: Physics |
I’m not sure where to begin because I don’t know how much you already know about quantum mechanics, so I’ll take the safe way out and start at the beginning. Quantum mechanics started at the beginning of the 1900s when physicists noticed matter had certain properties that classical physics (also known as Newtonian Physics) couldn’t explain – or at least couldn’t explain properly. Basically, classical physics says that for any object, all energy levels are possible. That is, an object can have any arbitrary amount of energy. But when physicists started to experiment with atomic spectra, they noticed that the spectra were not continuous as classical physics predicted but rather the spectra seemed to be discontinuous, and only certain wavelengths were possible. Max Plank (using blackbody radiation) was one of the first to notice this and propose an explanation. According to Plank, energy could only exist in small packets, which he called quanta (hence the name quantum mechanics). Further experiments showed that matter had wavelike properties. On the macroscopic scale, we cannot notice these properties, but on the microscopic scale, such as the scale of an atom, properties like wavelength and frequency are quite noticeable. So now that we know matter has wavelike character, we have to find a way to incorporate that into our theory of the atom. In the 1920s an Austrian Physicist named Erwin Scrodinger came up with the “Schrodinger Equation” and something he called the “wavefunction.” According to these ideas, one cannot know exactly where a particle is, but we can speak of its location in terms of probability by using its wavefunction. Like Newton’s Laws of Motion, the Schrodinger Equation cannot be derived, but if one studies it closely, the equation can be used to derive other known and accepted relations such as the de Broglie equation, which relates an object’s momentum to it’s wavelength. Some other physicists who have contributed to quantum mechanics include Albert Einstein, Max Born, and Heisenberg (I’m not sure what his first name is). Heisenberg probably demonstrated one of the most interesting ideas put forth by quantum mechanics. According to the Heisenberg Uncertainty Principle, one cannot know an object’s momentum and location with arbitrary precision. That is, if you know exactly how fast something is moving (you can use velocity to find momentum) then you cannot know exactly where that object is. As for what to study while in college: You can either study physics or chemistry as an undergraduate. In both majors you will get a taste of quantum mechanics. Chemists usually deal with lower energy measurements and calculations since they are only interested in the relatively low energies involved in chemical reactions and to excite electrons in. Physicists are usually involved in the high-energy end of the spectrum when it comes to studying quantum mechanics. If you major in chemistry you will probably get a small taste of quantum mechanics during your freshman year. More advanced quantum mechanics is usually taught in junior or senior level physical chemistry course. I’m not sure how it works out in if you were to major in physics; I’m sure depending on school it will vary. I’m not sure what the leading schools are for studies in quantum mechanics. What’s really important is to go to a school that you like. Also remember that as an undergraduate you’ll study a wide variety of topics in your field, not just quantum mechanics. As a graduate student, you will usually focus attention on one topic (such as quantum mechanics). If you want to teach yourself some quantum mechanics basics any introductory text will probably do the trick. Quantum mechanics also involves quite a bit of calculus, so a good math background will help quite a bit. In fact, in order to understand a lot of quantum mechanical proofs and concepts, you will need to know how to differentiate and integrate equations as well as some basic formulas (some important formulas include Euler’s Formula and de Moivre’s Formula). Hope this helps! Good luck with reaching your goal!
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