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Sabtu, 29 September 2007

Einstein, the universe, and God

Chosen by Time magazine to be their 'Person of the Century',1 Albert Einstein2 is famous for many things (apart from his shaggy visage). His theories of special and general relativity and his formula for the equivalence of mass and energy, E = mc2, changed forever our views on time and space, light and gravity, matter and energy. He is somewhat less well-known for his remark 'God does not play dice with the universe.' But what did Einstein really mean by 'God'? Was his 'God' anything like the God of the Bible ?

ildhood influences

Although born in 1879 of German-Jewish parents, Albert was not brought up in the Jewish faith. He attended a nearby Catholic elementary school in Munich and then the local high school. A rather slow and dreamy student, Albert was bored with non-scientific subjects,3 and learned little under the harsh military-style 19th century German education system. He grew up with an aversion to discipline, and a life-long suspicion of all authority.

At age 11 he went through an intense religious phase during which he ate no pork and composed songs to God, which he sang to himself on the way to school.4

From age 12 Albert read popular books on science, taught himself algebra, geometry and calculus, and studied Immanuel Kant's anti-theistic Critique of Pure Reason. Concerning this time in his life, Albert later wrote, 'Through the reading of popularscientific books I soon reached the conviction that much in the stories of the Bible could not be true. The consequence was a positively fanatic (orgy of) [sic] freethinking coupled with the impression that youth is intentionally being deceived by the state through lies; it was a crushing impression. … It is quite clear to me that the religious paradise of youth, which was thus lost, was a first attempt to free myself from the chains of … an existence which is dominated by wishes, hopes, and primitive feelings.'4

Albert's anti-authoritarianism, and probably also his desire to escape compulsory military service at age 17, led him to renounce his German citizenship. On January 28, 1896 he became a stateless person at the age of 16. His application for Swiss citizenship was approved February 21, 1900.

Tertiary studies, fatherhood and marriage

From 1895 to 1900 Albert attended the Zurich Polytechnic in Switzerland,5 then the finest technical school in Europe. He seldom attended lectures, but spent much of his time doing his own experiments in the excellent physics laboratory, and reading about the latest advances in physics by Hertz, Helmholtz, and other pioneers in science. He also learned about revolutionary socialism from his friend, Friedrich Adler (who in 1918 achieved fame by assassinating the Prime Minister of Austria).

Albert fell in love with Mileva Maric, a Hungarian and the only woman student in his class who, though rather plain, afflicted with a limp, and not in the least flirtatious, knew enough physics to be able to have intelligent conversations with him. In 1901 he fathered an illegitimate child with her. He married Mileva in 1903, after he had secured a job as patent examiner at the Swiss Patent Office in Berne.6

In 1905, the prestigious Berlin journal Annalen der Physik published four papers written by Albert between March 17 and June 30 of that year in his spare time!7 The first, for which he received the Nobel Prize 16 years later, described how light could behave as both a wave and a stream of particles. The second, on the size of atoms, earned him a doctorate from Zurich University.8 The third, on Brownian motion, is the foundation of modern statistical mechanics, and the fourth became the basis for his Special Theory of Relativity. This was based on Albert's 'thought experiments', such as what he might or might not see if he were in a space ship travelling at the speed of light.

In 1916 Albert published 'The Foundation of the General Theory of Relativity'. This was based on more 'thought experiments' that gravity and acceleration produce identical effects, and that this is a consequence of gravity warping (distorting) both space and time. Scientists were both bedazzled and bewildered. Then the theory appeared to be confirmed during an eclipse of the sun in the West Indies, on May 29, 1919.9 The world's press started referring to Albert as 'the greatest genius on earth'.

Albert and Elsa

Albert and Mileva's marriage had gradually fallen apart and in 1914 they had separated. In 1918, divorce proceedings were set in motion, based on the adultery of Albert with his divorced cousin Elsa Löwenthal,10 who had cared for him during a period of illness. The Zurich court granted the divorce on February 14, 1919, and ordered inter alia that Albert should give the monetary reward from a Nobel Prize, if and when he should receive it,11 to Mileva.12

Albert married Elsa on June 2, 1919, but again he was unfaithful.13 He wrote that he admired a deceased friend for having lived for many years in peace and 'lasting harmony with a woman—an undertaking in which I twice failed rather disgracefully.'14

The Nobel Prize

In 1922 Albert received official news that he had been awarded the 1921 Nobel Prize for Physics for his work in theoretical physics and his photoelectric law. Relativity, still highly controversial, was specifically excluded.15

People now wrote to Albert from all over the world; some of his answers revealed his wry sense of humour. In Berlin, he received a letter from New York asking, 'Would it be reasonable to assume that it is while a person is standing on his head—or rather upside down—that he falls in love or does other foolish things?' Albert wrote, 'To fall in love is by no means the most stupid thing man does—gravitation cannot be held responsible, however.'16

On another occasion, he was asked his formula for success. He replied, 'If A is success, I should say the formula is A = X + Y + Z, X being work and Y being play.' 'And what is Z?' 'Keeping your mouth shut.'17

In 1933, after Adolf Hitler had come to power, the Nazis launched a campaign against 'Jewish science' and offered a 20,000-mark reward for Albert's assassination.18 He emigrated to the USA and settled in Princeton, New Jersey, a scientific super-celebrity, becoming a US citizen on October 1, 1940.

Albert and 'the bomb'

For most of his life Albert was a gentle pacifist. However, on August 2, 1939, after learning that German scientists were working on splitting the uranium atom, he signed a letter to President F. D. Roosevelt which stated, 'This new phenomenon would also lead to the construction of bombs,' and urged 'quick action' on the part of the United States in atomic bomb research.19

The Manhattan Project, which produced the world's first atomic bombs, got under way two years later. Albert, regarded as a security risk, was excluded from participation in this.20 After the bombs had exploded on Hiroshima and Nagasaki, he considered this letter one of his greatest mistakes.

In November 1952 Albert declined an offer by David Ben-Gurion, Prime Minister of Israel, to be that country's president.21

For most of the last 30 years of his life, Albert tried, unsuccessfully, to establish a mathematical relationship between electromagnetic forces (such as light) and gravity. His aim was to find a single formula to explain the behaviour of everything in the universe, from electrons to stars, called a Unified Field Theory. He died in his sleep on April 18, 1955, from a ruptured defect in the main abdominal artery.

Einstein and 'God'

Albert Einstein was not a Christian. He had no concept of the God of the Bible or trust in Jesus Christ as his Lord and Saviour. His views on religion and 'God' were evolutionary and pantheistic.

He wrote, 'I cannot conceive of a God who rewards and punishes his creatures, or has a will of the kind that we experience in ourselves. Neither can I nor would I want to conceive of an individual that survives his physical death; let feeble souls, from fear or absurd egoism, cherish such thoughts.'22

'The desire for guidance, love, and support prompts men to form the social or moral conception of God. … The man who is thoroughly convinced of the universal operation of the law of causation cannot for a moment entertain the idea of a being who interferes in the course of events. … A God who rewards and punishes is inconceivable to him … .'23

'During the youthful period of mankind's spiritual evolution human fantasy created gods in man's own image. … The idea of God in the religions taught at present is a sublimation of that old concept of the gods. … In their struggle for the ethical good, teachers of religion must have the stature to give up the doctrine of a personal God … .'24

Answering a Japanese scholar who asked him about 'scientific truth', Albert wrote, 'Certain it is that a conviction, akin to religious feeling, of the rationality or intelligibility of the world lies behind all scientific work of a higher order. This firm belief, a belief bound up with deep feeling, in a superior mind that reveals itself in the world of experience, represents my conception of God. In common parlance this may be described as "pantheistic" (Spinoza).'25

It is thus clear that when Albert mentioned 'God', e.g. 'God does not play dice with the universe', and 'The Lord God is subtle, but malicious he is not',26 he was referring to something like rationality in the universe. He is recorded as saying that a 'deeply emotional conviction of the presence of a superior reasoning power, which is revealed in the incomprehensible universe, forms my idea of God'.27 However, he certainly was not referring to anything like the God of the Bible, who is Creator, Lawgiver, Judge and Saviour.

Addressing Princeton Theological Seminary on May 19, 1939, Albert said, '[A] conflict arises when a religious community insists on the absolute truthfulness of all statements recorded in the Bible.'25,28

Christian apologist Dr Hugh Ross claims that, despite not believing in the biblical God, 'Einstein held unswervingly, against enormous peer pressure, to belief in a Creator.'29 However, in the normal meaning of these terms, Einstein believed no such thing (see aside below on starlight and time). Thus, Christians who inappropriately invoke Einstein in their preaching, writing or witnessing do so to the detriment of their cause.

Note: As Einstein wrote his scientific papers and most of his correspondence in German, translations used above vary slightly among his biographers.


Bagaimana mekanisme Bleaching Earth terhadap pencegahan kerusakan minyak?

Dewasa ini memang penggunaan Bleaching Earth (BE) banyak digunakan dalam aplikasi bleaching (pemucatan/penjernihan) CPO atau juga CNO dan minyak-minyak yang lainnya. Tujuan utama dari BE memang untuk menjernihkan CPO (katakanlah contohnya) dengan cara mengadsorpsi zat-zat warna dalam CPO. Dalam CPO sendiri zat warna yang biasa ditemukan adalah antosianin, klorofil, xanthofil dan beta karoten.

Proses bleaching juga bisa mencegah kerusakan minyak karena selain zat warna tadi, BE jg dapat mengadsorpsi pengotor-pengotor lain yang terdapat dalam CPO seperti sisa tandan, sejumlah kecil logam, dan pengotor hasil oksidasi minyak yang biasanya berwarna gelap. Akan tetapi, harap diingat pula, untuk CPO biasanya proses bleaching dilakukan dengan menggunakan suhu yang relatif tinggi (100-120 derajat celcius). Sudah tentu dengan suhu sedemikian tinggi dapat menyebabkan CPO menjadi teroksidasi walaupun untuk skala lab, biasanya proses oksidasi minyak bisa diminimalisasi atau bahkan dihindari dengan mengkondisikan set alat bleaching dalam kondisi vakum untuk mencegah adanya oksigen atau juga, lebih baik lagi, sebelum dilakukan proses bleaching oksigen yang ada dalam set alat bleaching diusir terlebih dahulu dengan gas nitrogen.

Proses bleaching dengan menggunakan BE jg punya kelemahan terhadap kualitas CPO karena banyak sekali zat-zat yang justru diperlukan seperti beta karoten maupun vitamin E yang ikut teradsorpsi oleh BE.. Berdasar pada pengalaman yg telah saya lakukan, ada kondisi optimum dari BE agar proses bleaching berlangsung dengan baik. Baik disini adalah warna CPO yang jernih dan kandungan zat yang diinginkan seperti beta karoten juga tidak berkurang terlalu banyak.

Untuk masalah yg terakhir, ada pertanyaan yang kadang terus menggelitik di kepala tapi sampai saat ini belum terpecahkan, bagaimana caranya agar BE yang digunakan memiliki kemampuan mengadsorpsi yang selektif, dimana hanya pengotor yang tidak diinginkan saja yang terserap sedangkan beta karoten dan vitamin E (misalnya) tidak ikut terserap?

Apa Yang Dimaksud Dengan 'Spektrum Infra-merah'

Latar belakang spektrokopi infra-merah

Bagaimana sebuah spektrum infra-merah terbentuk


Anda mungkin tahu bahwa cahaya yang bisa kita lihat itu terdiri dari gelombang elektromagnetik dengan frekwensi yang berbeda-beda, setiap frekwensi tersebut bisa dilihat sebagai warna yang berbeda. Radiasi Infra-merah juga merupakan gelombang dengan frekwensi yang berkesinambungan, hanya saja mata kita tidak bisa melihat mereka.

Jika anda menyinari sebuah senyawa organik dengan sinar infra-merah yang mempunyai frekwensi tertentu, anda akan mendapatkan bahwa beberapa frekwensi tersebut diserap oleh senyawa tersebut. Sebuah alat pendetektor yang diletakkan di sisi lain senyawa tersebut akan menunjukkan bahwa beberapa frekwensi melewati senyawa tesebut tanpa diserap sama sekali, tapi frekwensi lainnya banyak diserap.

Berapa banyak frekwensi tertentu yang melewati senyawa tersebut diukur sebagai 'persentasi transmitasi' (percentage transmittance)

Persentasi transmitasi dengan nilai 100 berarti semua frekwensi dapat melewati senyawa tersebut tanpa diserap sama sekali. Pada kenyataannya, itu tidak pernah terjadi, selalu akan ada penyerapan, walaupun kecil, mungkin transmitasi sebesar 95% adalah yang terbaik yang bisa anda peroleh.

Transmitasi sebesar 5% mempunyai arti bahwa hampir semua frekwensi tersebut diserap oleh senyawa itu. Tingginya penyerapan seperti ini akan membuat kita mengerti tentang ikatan-ikatan yang ada dalam senyawa tersebut.

Bagaimana bentuk sebuah spektrum Infra-merah

Grafik di bawah ini menunjukkan bagaimana nilai persentasi transmitasi berubah jika frekwensi dari radiasi Infra-merah yang diberikan itu dirubah.

Catatan: spektrum Infra-merah pada halaman ini dibuat berdasarkan data yang diambil dari Spectral Data Base for Organic Compounds (SDBS) di National Institute of Materials and Chemical Research di Jepang.

Ada kemungkinan bahwa kesalahan-kesalahan kecil mungkin timbul dalam proses perubahan dari data tersebut untuk digunakan dalam situs ini, tapi itu tidak akan mempengaruhi argument ini sedikitpun.

Anda harus memperhatikan bahwa besaran untuk mengukur frekwensi yang ada pada sumbu horizontal adalah bilangan gelombang, yang didefinisikan sebagai berikut:



Jangan kuatir dengan hal ini, hanya perlu diingat saja!

Hal lainnya yang perlu diperhatikan adalah pergantian skala pada sumbu horizontal bagian tengah. Anda akan melihat bahwa ada spektrum infra-merah yang mempunyai skala yang sama dari awal-akhir, ada juga spektrum yang skalanya berubah pada nilai sekitar 2000 cm-1, dan walaupun jarang, ada juga yang berubah lagi pada skala sekitar 1000 cm-1.

Hal-hal diatas bukanlah masalah yang besar, karena pada waktu kita ingin mengartikan spektrum infra-merah, anda hanya perlu hari-hati dalam membaca skala pada sumbu horizontal.

Apa yang menyebabkan beberapa frekwensi itu terserap?

Setiap frekwensi sinar (termasuk infra-merah) mempunyai energi tertentu. Apabila frekwensi tertentu diserap ketika melewati sebuah senyawa tersebut diselidiki, maka pasti energi dari frekwensi tersebut ditransfer ke senyawa tersebut.

Energi pada radiasi infra-merah sebanding dengan energi yang timbul pada getaran-getaran ikatan.

Pergerakan ikatan

Pada ikatan kovalent, atom-atom tidak disatukan oleh ikatan yang kaku, kedua atom berikatan karena kedua inti atom tersebut terikat pada pasangan elektron yang sama. Kedua inti atom tersebut dapat bergetar maju-mundur dan depan-belakang, atau menjauhi masing-masing, dalam posisi yang memungkinkan.



Energi yang terlibat pada getaran ini tergantung pada hal-hal seperti jarak ikatan tersebut, massa kedua atom. Ini berarti bahwa setiap jenis ikatan akan bergetar dengan cara yang berbeda pula, yang melibatkan energi dengan jumlah yang berbeda-beda pula.

Ikatan-ikatan selalu bergetar, tapi jika anda menyinarkan energi dengan jumlah yang tepat sama dengan yang dipunyai ikatan tersebut, anda bisa membuat getaran-getaran itu ke tingkat yang lebih tinggi. Jumlah energi yang diperlukan untuk melakukan ini tergantung pada ikatan masing-masing, karenanya setiap ikatan-ikatan yang berbeda, akan menyerap frekwensi (energi) infra-merah yang berbeda-beda pula.

Pembelokan ikatan

Tidak hanya bergerak, ikatan-ikatan juga dapat berbelok.



Sekali lagi, ikatan-ikatan akan selalu bergetar seperti ini setiap saat dan jika anda menyinari ikatan itu dengan jumlah energy yang tepat, maka anda bisa membuat getaran itu ke tingkat yang lebih tinggi. Karena energi yang terlibat pada pembelokan ini juga berbeda-beda pada setiap jenis ikatan, maka setiap jenis ikatan akan menyerap sinar infra-merah dengan frekwensi yang berbeda-beda pula untuk membuatnya meloncat ke tingkat yang lebih tinggi.

Mencoba semuanya.

Lihat lagi spektrum infra-merah sebuah n-propannol, CH3CH2CH2OH:



Pada diagram diatas, 3 contoh penyerapan itu dipilih untuk menunjukkan kepada anda getaran-getaran ikatan yang membuat penyerapan itu terjadi. Perhatikan bahwa pergerakan ikatan dan pembelokan ikatan menghasilkan lembah yang berbeda dalam spektrum tersebut.

Ahmed H. Zewail, peraih nobel yang mencerahkan proses reaksi kimia

Ahmed H. Zewail terserang demam sepanjang akhir pekan. Ketika beliau menerima telepon dari Royal Swedish Acedemy of Sciences, penyakit demamnya mendadak hilang. Siapakah Ahmed H. Zewail?

Ahmed H. Zewail adalah seorang Professor di California Institute of Technology yang mendapatkan hadiah Nobel dalam bidang Femtokimia. Beliau menemukan teknik dan kamera laser untuk memantau pergerakan atom atom dalam reaksi kimia. Kamera ini bekerja pada kecepatan femtodetik, suatu skala kecepatan dimana reaksi reaksi kimia terjadi. 1 Femtodetik adalah 10-15 detik. Penelitian Professor Zewail telah melahirkan cabang baru di bidang kimia yaitu Femtokimia.

Kamera laser hasil penemuan Professor Zewail bekerja dengan memadukan 2 sinar yang dihasilkan molekul molekul dalam sebuah ruang vakum. Laser tersebut kemudian menginjeksikan 2 sinyal. Pertama, sinyal pompa, mengeksitasi molekul ke tingkat energi yamg lebih tinggi.Kedua,sinyal sampel,mendeteksi molekul berdasarkan panjang gelombangnya. Peneliti dapat memvariasikan waktu interval antara dua pulsa untuk menetapkan berapa lama waktu yang dibutuhkan oleh molekul untuk berpindah.

Sebelum perkembangan femtokimia, kita hanya dapat berteori tentang bagaimana atom atom bertemu dan bergabung. Kamera laser hasil penemuan prof. Zewail memungkinkan para peneliti untuk mengamati reaksi reaksi kimia dalam gerak lambat. Hal ini memungkinkan para ilmuwan tersebut untuk menjawab beberapa pertanyaan penting seperti bagaimana temperatur mempengaruhi reaksi dan faktor-faktor apa saja yang mempengaruhi terjadinya suatu reaksi.

Ini neh Hasil pencarian Kamu baca ya..!!!!