Kanan Dan Kiri Memang Beda

KANAN DAN KIRI MEMANG BEDA Oleh: Jum’an Tentu saja, dari dulu kanan dan kiri memang beda bahkan saling berlawanan. Kanan adalah arah kalau kita berjalan kebarat lalu berbelok keutara. Kiri adalah arah bila kita berjalan kebarat lalu berbelok ke selatan. Atau, kiri adalah letak tangan yang sepihak dengan jantung dan kanan adalah letak tangan yang sepihak dengan hati. Kecuali bagi bayangan anda dalam cermin. Kalau benarbenar ada orang seperti itu, jantungnya ada disebelah kanan. Anda menghadap kebarat, jantung anda disebelah selatan sedangkan bayangan anda dalam cermin menghadap ketimur tetapi jantungnya disebelah selatan juga. Seorang tukang bubut dengan mudah memahami instruksi untuk membuat sebuah sekrup dengan ulir yang arah putarannya kekanan atau kekiri. Untuk melihat hasilnya keliru atau tidak, sesuaikan saja dengan pengertian kiri dan kanan seperti diatas. Tetapi instruksi sederhana itu tidak mudah difahami oleh misalnya (ini fiksi) seorang tukang bubut dari planet Mars, yang utara- selatannya berbeda dengan bumi dan letak jantung tukang bubut itu belum tentu didada kiri seperti kita. Ternyata tidak mudah membuat istilah yang bisa difahami secara universal – karena bahasa yang kita miliki memang sekedar bahasa manusia bumi. Robert Frisch, ahli fisika atom dan Professor Filsafat dari Universitas Cambridge dapat menerangkan bagaimana memberi instruksi membuat sekrup ulir kanan yang mudah difahami oleh tukang bubut dari Mars itu. Ilustrasi itu merupakan bagian dari komentarnya mengenai penemuan yang menggemparkan dari ahli fisika nuklir yang termasyhur Dr. Chien Shiung Wu (1912 - 1997) dari Columbia University. Dalam eksperimennya ditahun 1957, wanita pemenang Nobel dan penerima 40 penghargaan ilmiah internasional ini mendapati bahwa elektron-elektron yang dipancarkan oleh zat radioaktif Cobalt 60 menyebar tidak sesuai dengan kaidah symetri hukum alam yang merupakan keyakinan dasar para ahli fisika saat itu. Dalam eksperimen itu Cobalt 60 diletakkan diantara dua kutub magnet yang sangat kuat. Elektron yang dipancarkan, pada suhu super-dingin, bukannya meyebar kesemua arah sebagaimana seharusnya, tetapi justru menuju kesatu arah yaitu kekutub utara magnet. Para fisikawanpun tercengang dan tidak menduga hal itu bisa terjadi dan secara serentak mengumandangkan adzan: ”Ini kitab suci baru, ini sabda baru. Bagaimana dengan kitab suci kita yang lama.............. kita tinggalkan?”

Dr. Chien Shiung Wu atau Madame Wu atau “First Lady of Physics” atau “Madame Curie of China” telah membuktikan bahwa alam ternyata tidak tunduk kepada akal sehat . Intuisi para fiskawanpun tergoncang menhadapi dilemma seperti ini. Kenapa hukum alam membeda-bedakan antara kiri dan kanan. Kenapa elektronelektron itu memilih untuk tunduk kepada kutub utara? Bukankah seharusnya tidak boleh begitu? Madam Wu telah membuka pintu ke era post modern dalam ilmu fisika, karena asas symetri bagi hukum alam telah runtuh. Masih mau mendengar instruksi Robert Frisch untuk membuat sekrup ulir kanan berapapun biayanya? Minta saja tukang bubut Mars kita untuk melaksanakan eksperimen Wu. Kutub maknit tempat berkumpulnya elektron dari Cobalt 60 itulah yang namanya kutub utara. Sesudah dapat menandai kutub utara, mari kita ajari dia mengenal mana kanan mana kiri. Itu mudah. Ikutilah petunjuk praktikum siswa STM Listrik untuk membuat elektomagnet. Mereka tahu hubungan antara arah lilitan kumparan yang mereka buat dengan kutub-kutub magnet yang akan terbentuk. Untuk membuat sekrup ulir kanan, contoh saja arah lilitan kumparan itu. Begitu saja kok repot.... (Sumber: Everything about Madame Wu)

Symmetry: " A 'thing' is symmetric if one can subject it to a certain 'operation' and it appears exactly the same after the 'operation' "

There are symmetries in the basic laws which govern the physical world. But how can a law be "symmetrical"? According to Feynman we should adopt the definition of Hermann Weyl who says a thing is symmetrical if one can subject it to a certain operation and it appears exactly the same after the operation. She is best known, however, for her 1956 experiment that disproved the conservation of parity and won the Nobel Prize the following year for the two theoretical physicists who had first doubted it, Lee of Columbia and Chen Ning Yang, who is now at S.U.N.Y-Stony Brook.

She conducted the experiment at the National Bureau of Standards in Washington, D.C., which provided a cryogenics laboratory where the necessary low temperatures could be maintained. The basis for the experiment was a salt of radioactive cobalt-60 and her considerable expertise in beta decay, or the emission of electrons from radioactive nuclei. Her method was to place the cobalt in a strong magnetic field to line up the north-south magnetic poles of its nuclei, supercool it to minimize the atoms' random thermal motions, and then watch where the electrons it emitted went. She found that a majority of the tens of thousands of electrons emitted by the cobalt every second were ejected primarily in one direction. The discovery stunned scientists, for it showed that the laws of nature are not always symmetrical with respect to right and left. Among her many honors and awards were the Research Corporation Award in 1958, the Industrial Research Scientist of the Year in 1974, the National Medal of Science in 1975, the first Wolf Prize in Physics in 1978 and Columbia's Pupin Medal in 1991. She was elected to the National Academy of Sciences in 1958, the Royal Society of Edinburgh in 1969 and the American Academy of Arts and Sciences in 1972. In 1973, she was chosen the first woman to head the American Physical Society. Wu received numerous honorary degrees from universities in the United States and abroad

Masalahnya utara-selatannya bumi tidak sama dengan utara selatannya planet Mars misalnya, karena dia mempunyai kutub-kutub sendiri. dan perputaran yang bebedai.

A Brief Introduction to Madame Dr. Chien-Shiung Wu World-renowned physicist Dr. Chien-Shiung Wu graduated from the National Central University in Nanjing, China, and then went to the United States for advanced study specializing in physics. She received her Ph. D. degree from the University of California at Berkley in 1940. During the Second World War, she was invited by the U.S. government to participate in the top-secret Manhattan Project. The purpose of the

project was to develop the atomic bomb. The success of the project greatly shortened the war against Japan. Owing to her involvement in this highly secretive war project, she was unable to return to China and serve her country. 　　Consequently, she turned to teaching and research in the U.S., serving at several universities, such as Smith College, Princeton University, and Columbia University. Among these institutions, she spent most of her time, over 40 years, at Columbia University, where she published a large number of scientific papers and trained many top students from around the world. It was in the specialized field of nuclear weak interactions that she performed many crucial experiments, including the one in 1956 that demonstrated the validity of the theory of "parity non-conservation in weak interactions" which was proposed by Dr. Lee and Yang. Not only did this experiment win the praise and respect of physicists world-wide, it also resulted in Dr. Lee and Yang receiving the Nobel Prize for their theory. 　　In the course of her prestigious career, Dr. Wu was the recipient of the U.S. National Science Medal and the Comstock Prize from the U.S. Academy of Sciences. She was the first female president of the American Physical Society as well as the first woman to receive an Honorary Doctorate of Science degree in the 107-year history of the graduate school at Princeton University. Furthermore, she was the recipient of the highest scientific honor in the U.S., the Pupin Medal from Columbia University. Dr. Wu received more than 40 honors and honorary degrees from around the world in recognition of her accomplishments. 　　Following her retirement from Columbia University in 1985, the university named part of the new Physics and Engineering Research Center building the Wu Chien-Shiung Physics Laboratories in commemoration for her outstanding contributions. Located next to the old Pupin Physics Building, the Madame Dr. C. S. Wu Physics Laboratories will serve as a lasting tribute to her and an honor to Chinese people all over the world.