Pengenalan pada mekanik kuantum

Mekanik kuantum adalah sekumpulan prinsip saintifik yang menjelaskan kelakuan jirim dan interaksinya pada skala atom dan subatom.

Menjelang kurun kedua puluh yang lalu, ia menjadi jelas bahawa fizik klasik tidak dapat menjelaskan beberapa fenomena. Memahami batasan fizik klasik ini membawa kepada suatu revolusi dalam fizik: perkembangan mekanik kuantum dalam dekad-dekad awal kurun ke-20. Banyak perkara seperti alam semesta pada skala yang paling besar tidak patuh kemas dengan fizik klasik (kerana kerelatifan am), mekanik kuantum bermakna perkara yang serupa pada skala terkecil alam semesta. Prinsip mekanik kuantum agak sukar untuk difahami oleh minda manusia, oleh kerana manusia sudah terbiasa menaakul tentang dunia pada skala di mana fizik klasik ialah suatu penghampiran baik. Mekanik kuantum berlawanan dengan intuisi, dalam kata Richard Feynman, ia berurusan dengan "Nature as She is—absurd".

Banyak bahagian-bahagian asas alam semesta, seperti foton (unit diskret cahaya) mempunyai sesetengah sifat yang menyerupai zarah tetapi sifat lain yang menyerupai gelombang. Penyinar foton seperti lampu neon mempunyai spektrum pancaran, tetapi spektrum ini terputus-putus, cuma frekuensi tertentu yang wujud. Tenaga foton membentuk suatu urutan yang terputus-putus dan berkod warna. Hukum mekanik kuantum meramalkan tenaga, warna, dan keamatan spektrum sinaran elektromagnet. Tetapi hukum yang sama memutuskan bahawa lebih seseorang mengenal pasti satu ukuran (seperti kedudukan zarah), lebih sukar untuk menentukan suatu ukuran lain (seperti momentum). Dalam kata lain, mengukur kedudukan dahulu dan kemudian momentum tidak akan memberikan hasil yang sama dengan mengukur momentum dahulu dan diikuti kedudukan. Malah lebih kurang menyenangkan, pasangan zarah boleh memiliki kekusutan kuantum, bermakna menentukan suatu sifat satu zarah akan menentukan sifat yang sama atau lain pada zarah lagi satu, tanpa mengira berapa jauh kedua zarah itu terpisah.

Catatan

Rujukan
 Bernstein, Jeremy, 2005, "Max Born and the quantum theory," Am. J. Phys. 73(11).
 Beller, Mara, 2001. Quantum Dialogue: The Making of a Revolution. University of Chicago Press.
 
 Louis de Broglie, 1953. The Revolution in Physics. Noonday Press.
 Albert Einstein, 1934. Essays in Science. Philosophical Library.
 Herbert Feigl and May Brodbeck, 1953. Readings in the Philosophy of Science, Appleton-Century-Crofts.

 Fowler, Michael, 1999. The Bohr Atom. Lecture series, University of Virginia.
 Werner Heisenberg, 1958. Physics and Philosophy. Harper and Brothers.
 Lakshmibala, S., 2004, "Heisenberg, Matrix Mechanics and the Uncertainty Principle," Resonance, Journal of Science Education 9(8).
 Richard L. Liboff, 1992. Introductory Quantum Mechanics, 2nd ed.
 Lindsay, Robert Bruce and Henry Margenau, 1936. Foundations of Physics. Dover.
 McEvoy, J.P., and Zarate, Oscar.  Introducing Quantum Theory, ISBN 1874166374 
 Nave, Carl Rod, 2005. Hyperphysics-Quantum Physics, Department of Physics and Astronomy, Georgia State University, CD.
 Peat, F. David, 2002. From Certainty to Uncertainty: The Story of Science and Ideas in the Twenty-First Century. Joseph Henry Press.
 Hans Reichenbach, 1944. Philosophic Foundations of Quantum Mechanics. University of California Press.
 Paul Arthur Schilpp, 1949. Albert Einstein: Philosopher-Scientist. Tudor Publishing Company.
 Scientific American Reader, 1953.
 Sears, Francis Weston, 1949. Optics. Addison-Wesley.
; cited in: 
 
 Van Vleck, J. H.,1928, "The Correspondence Principle in the Statistical Interpretation of Quantum Mechanics," Proc. Nat. Acad. Sci. 14: 179.

 Wieman, Carl, and Perkins, Katherine, 2005, "Transforming Physics Education," Physics Today.
 Westmoreland, M. D., and Schumacher, B., 1998, "Quantum Entanglement and the Nonexistence of Superluminal Signals."
 Bronner, P., Strunz, A. et al. (2009). "Demonstrating quantum random with single photons." European Journal of Physics 30(5): 1189-1200

Bacaan lanjut
The following titles, all by working physicists, attempt to communicate quantum theory to lay people, using a minimum of technical apparatus.

 Richard Feynman, 1985. QED: The Strange Theory of Light and Matter, Princeton University Press.  ISBN 0-691-08388-6
 Ghirardi, GianCarlo, 2004. Sneaking a Look at God's Cards, Gerald Malsbary, trans. Princeton Univ. Press. The most technical of the works cited here. Passages using algebra, trigonometry, and bra-ket notation can be passed over on a first reading.
N. David Mermin, 1990, “Spooky actions at a distance: mysteries of the QT” in his Boojums all the way through. Cambridge Univ. Press: 110-176. The author is a rare physicist who tries to communicate to philosophers and humanists.
Roland Omnes (1999) Understanding Quantum Mechanics. Princeton Univ. Press.
Victor Stenger, 2000. Timeless Reality: Symmetry, Simplicity, and Multiple Universes. Buffalo NY: Prometheus Books. Chpts. 5-8.
 Veltman, M. J. G., 2003. Facts and Mysteries in Elementary Particle Physics. World Scientific Publishing Company.

Pautan luar
 Takada, Kenjiro, Emeritus professor at Kyushu University,   "Microscopic World -- Introduction to Quantum Mechanics. "
 Quantum Theory.
 Quantum Mechanics.
 Planck's original paper  on Planck's constant.
 Everything you wanted to know about the quantum world. From the New Scientist.
 Quantum Articles. 
 This Quantum World. 
 The Quantum Exchange (tutorials and open source learning software).
Theoretical Physics wiki 
 "Uncertainty Principle," a recording of Werner Heisenberg's voice.
Single and double slit interference 
Time-Evolution f a Wavepacket in a Square Well An animated demonstration of a wave packet dispersion over time.
Experiments with single photons An introduction into quantum physics with interactive experiments
Hitachi video recording of double-slit experiment done with electrons. You can see the interference pattern build up over time.

 
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