Earth and Planetary Astrophysics

Planetary science encompasses the study of the physical and chemical nature of planetary bodies, both in the Solar System and in extrasolar systems. The formation of planets, the forces that sculpted their orbits, the processes that shaped their interiors, surfaces, and atmospheres, and the development of life all fall under its rubric. Understanding these complex phenomena requires knowledge of astronomy & astrophysics, earth science, meteorology, atmospheric science, space science, plasma physics, chemistry, and biology.

Kumpulan Kalimat-Kalimat wejangan dari Albert Einstein {Stanford University}

A[Note: This list of Einstein quotes was being forwarded around the Internet in e-mail, so I decided to put it on my web page. I'm afraid I can't vouch for its authenticity, tell you where it came from, who compiled the list, who Kevin Harris is, or anything like that. Still, the quotes are interesting and enlightening.]

Collected Quotes from Albert Einstein

• "Any intelligent fool can make things bigger, more complex, and more violent. It takes a touch of genius -- and a lot of courage -- to move in the opposite direction."
• "Imagination is more important than knowledge."
• "Gravitation is not responsible for people falling in love."
• "I want to know God's thoughts; the rest are details."
• "The hardest thing in the world to understand is the income tax."
• "Reality is merely an illusion, albeit a very persistent one."
• "The only real valuable thing is intuition."
• "A person starts to live when he can live outside himself."
• "I am convinced that He (God) does not play dice."
• "God is subtle but he is not malicious."
• "Weakness of attitude becomes weakness of character."
• "I never think of the future. It comes soon enough."
• "The eternal mystery of the world is its comprehensibility."
• "Sometimes one pays most for the things one gets for nothing."
• "Science without religion is lame. Religion without science is blind."
• "Anyone who has never made a mistake has never tried anything new."
• "Great spirits have often encountered violent opposition from weak minds."
• "Everything should be made as simple as possible, but not simpler."
• "Common sense is the collection of prejudices acquired by age eighteen."
• "Science is a wonderful thing if one does not have to earn one's living at it."
• "The secret to creativity is knowing how to hide your sources."
• "The only thing that interferes with my learning is my education."
• "God does not care about our mathematical difficulties. He integrates empirically."
• "The whole of science is nothing more than a refinement of everyday thinking."
• "Technological progress is like an axe in the hands of a pathological criminal."
• "Peace cannot be kept by force. It can only be achieved by understanding."
• "The most incomprehensible thing about the world is that it is comprehensible."
• "We can't solve problems by using the same kind of thinking we used when we created them."
• "Education is what remains after one has forgotten everything he learned in school."
• "The important thing is not to stop questioning. Curiosity has its own reason for existing."
• "Do not worry about your difficulties in Mathematics. I can assure you mine are still greater."
• "Equations are more important to me, because politics is for the present, but an equation is something for eternity."
• "If A is a success in life, then A equals x plus y plus z. Work is x; y is play; and z is keeping your mouth shut."
• "Two things are infinite: the universe and human stupidity; and I'm not sure about the the universe."
• "As far as the laws of mathematics refer to reality, they are not certain, as far as they are certain, they do not refer to reality."
• "Whoever undertakes to set himself up as a judge of Truth and Knowledge is shipwrecked by the laughter of the gods."
• "I know not with what weapons World War III will be fought, but World War IV will be fought with sticks and stones."
• "In order to form an immaculate member of a flock of sheep one must, above all, be a sheep."
• "The fear of death is the most unjustified of all fears, for there's no risk of accident for someone who's dead."
• "Too many of us look upon Americans as dollar chasers. This is a cruel libel, even if it is reiterated thoughtlessly by the Americans themselves."
• "Heroism on command, senseless violence, and all the loathsome nonsense that goes by the name of patriotism -- how passionately I hate them!"
• "No, this trick won't work...How on earth are you ever going to explain in terms of chemistry and physics so important a biological phenomenon as first love?"
• "My religion consists of a humble admiration of the illimitable superior spirit who reveals himself in the slight details we are able to perceive with our frail and feeble mind."
• "Yes, we have to divide up our time like that, between our politics and our equations. But to me our equations are far more important, for politics are only a matter of present concern. A mathematical equation stands forever."
• "The release of atom power has changed everything except our way of thinking...the solution to this problem lies in the heart of mankind. If only I had known, I should have become a watchmaker."
• "Great spirits have always found violent opposition from mediocrities. The latter cannot understand it when a man does not thoughtlessly submit to hereditary prejudices but honestly and courageously uses his intelligence."
• "The most beautiful thing we can experience is the mysterious. It is the source of all true art and all science. He to whom this emotion is a stranger, who can no longer pause to wonder and stand rapt in awe, is as good as dead: his eyes are closed."
• "A man's ethical behavior should be based effectually on sympathy, education, and social ties; no religious basis is necessary. Man would indeeded be in a poor way if he had to be restrained by fear of punishment and hope of reward after death."
• "The further the spiritual evolution of mankind advances, the more certain it seems to me that the path to genuine religiosity does not lie through the fear of life, and the fear of death, and blind faith, but through striving after rational knowledge."
• "Now he has departed from this strange world a little ahead of me. That means nothing. People like us, who believe in physics, know that the distinction between past, present, and future is only a stubbornly persistent illusion."
• "You see, wire telegraph is a kind of a very, very long cat. You pull his tail in New York and his head is meowing in Los Angeles. Do you understand this? And radio operates exactly the same way: you send signals here, they receive them there. The only difference is that there is no cat."
• "One had to cram all this stuff into one's mind for the examinations, whether one liked it or not. This coercion had such a deterring effect on me that, after I had passed the final examination, I found the consideration of any scientific problems distasteful to me for an entire year."
• "...one of the strongest motives that lead men to art and science is escape from everyday life with its painful crudity and hopeless dreariness, from the fetters of one's own ever-shifting desires. A finely tempered nature longs to escape from the personal life into the world of objective perception and thought."
• "He who joyfully marches to music rank and file, has already earned my contempt. He has been given a large brain by mistake, since for him the spinal cord would surely suffice. This disgrace to civilization should be done away with at once. Heroism at command, how violently I hate all this, how despicable and ignoble war is; I would rather be torn to shreds than be a part of so base an action. It is my conviction that killing under the cloak of war is nothing but an act of murder."
• "A human being is a part of a whole, called by us _universe_, a part limited in time and space. He experiences himself, his thoughts and feelings as something separated from the rest... a kind of optical delusion of his consciousness. This delusion is a kind of prison for us, restricting us to our personal desires and to affection for a few persons nearest to us. Our task must be to free ourselves from this prison by widening our circle of compassion to embrace all living creatures and the whole of nature in its beauty."
• "Not everything that counts can be counted, and not everything that can be counted counts." (Sign hanging in Einstein's office at Princeton)

Copyright: Kevin Harris 1995 (may be freely distributed with this acknowledgement)

Terima Kasih Semoga Bermanfaat

Arip Nurahman

Pendidikan Fisika, FPMIPA. Universitas Pendidikan Indonesia

&

Follower Open Course Ware at MIT-Harvard University, Cambridge. U.S.A.

Nobel Fisika Indonesia

Central for Research and Development for Winning

Nobel Prize in Physics at Indonesia

"Pada penemuannya mengenai hukum penentuan radiasi panas."

The Nobel Prize in Physics 1911

"for his discoveries regarding the laws governing the radiation of heat"

Wilhelm Wien

Wilhelm Wien
Born	Wilhelm Carl Werner Otto Fritz Franz Wien 13 January 1864(1864-01-13) Fischhausen, East Prussia
Died	30 August 1928(1928-08-30) (aged 64) Munich, Germany
Nationality	German
Fields	Physics
Institutions	University of Giessen University of Würzburg University of Munich RWTH Aachen
Alma mater	University of Göttingen University of Berlin
Doctoral advisor	Hermann von Helmholtz
Doctoral students	Karl Hartmann Gabriel Holtsmark
Known for	Blackbody radiation Wien's law
Notable awards	Nobel Prize for Physics (1911)
Spouse	Luise Mehler (1898)

Wilhelm Wien (13 Januari 1864 - 30 Agustus 1928) adalah fisikawan berkebangsaan Jerman yang memenangkan Penghargaan Nobel di bidang fisika pada tahun 1911.

Wien was born at Gaffken near Fischhausen (Rybaki), Province of Prussia (now Primorsk, Russia) as the son of landowner Carl Wien. In 1866, his family moved to Drachstein, in Rastenburg (Rastembork).

In 1879, Wien went to school in Rastenburg and from 1880-1882 he attended the city school of Heidelberg. In 1882 he attended the University of Göttingen and the University of Berlin. From 1883-85, he worked in the laboratory of Hermann von Helmholtz and, in 1886, he received his Ph.D. with a thesis on the diffraction of light upon metals and on the influence of various materials upon the color of refracted light. From 1896 to 1899, Wien lectured at the prestigious RWTH Aachen University. In 1900 he went to the University of Würzburg and became successor of Wilhelm Conrad Röntgen.

Career

In 1896 Wien empirically determined a distribution law of blackbody radiation, later named after him: Wien's law. Max Planck, who was a colleague of Wien's, did not believe in empirical laws, so using electromagnetism and thermodynamics, he proposed a theoretical basis for Wien's law, which became the Wien-Planck law. However, Wien's law was only valid at high frequencies, and underestimated the radiancy at low frequencies. Planck corrected the theory and proposed what is now called Planck's law, which led to the development of quantum theory. However, Wien's other empirical formulation λ_maxT = constant, called Wien's displacement law, is still very useful, as it relates the peak wavelength emitted by a body (λ_max), to the temperature of the body (T). In 1900 (following the work of George Frederick Charles Searle), he assumed that the entire mass of matter is of electromagnetic origin and proposed the formula m = (4 / 3)E / c² for the relation between electromagnetic mass and electromagnetic energy.

While studying streams of ionized gas, Wien, in 1898, identified a positive particle equal in mass to the hydrogen atom. Wien, with this work, laid the foundation of mass spectrometry. J. J. Thomson refined Wien's apparatus and conducted further experiments in 1913 then, after work by Ernest Rutherford in 1919, Wien's particle was accepted and named the proton.

Presentation Speech

Presentation Speech by the Librarian of the National Library, Dr. E.W. Dahlgren, President of the Royal Swedish Academy of Sciences, on December 10, 1911

Your Majesty, Your Royal Highnesses, Ladies and Gentlemen.

The Royal Academy of Sciences has awarded the Nobel Prize for Physics, for the year 1911, to Wilhelm Wien, Professor at the University of Würzburg, for his discoveries concerning the laws of heat radiation.

Ever since the beginning of the last century and, in particular, since spectrum analysis reached an advanced stage of development as a result of the fundamental work by Bunsen and Kirchhoff, the problem of the laws of heat radiation has occupied the attention of physicists to an exceptionally high degree.

The solution of this problem has presented immeasurable difficulties both

in the theoretical and experimental respects, and it would hardly seem possible to solve this task without a knowledge of certain laws which embrace a wide diversity of radiating bodies.

One of these is the famous Kirchhoff law of the relationship between the ability of substances to emit and to absorb radiation energy. It relates the laws of radiation of all bodies so far as their radiation is dependent on temperature to those laws which are valid for the radiation emitted by a completely black body.

The search for the latter laws has therefore been one of the most fundamental problems of radiation theory. These laws have been discovered in the last decades and, by virtue of the great importance that attaches to them, belong to the major achievements of modern physics.

The difficulty in investigating the laws of radiation of black bodies was, firstly, that no completely black body exists in nature. In accordance with Kirchhoff's definition, such a body would reflect no light at all, nor allow light to pass. Even substances such as soot, platinum black etc. reflect part of the incident light.

This difficulty was only removed in 1895, when Wien and Lummer stated the principles according to which a completely black body could be constructed, and showed that the radiation which issues from a small hole in a hollow body whose walls have the same temperature behaves in the same manner as the radiation emitted by a completely black body. The principle of this arrangement is based on the views of Kirchhoff and Boltzmann and had already been applied in part by Christiansen in 1884.

With the assistance of this apparatus it now became possible to investigate black body radiation. In this manner, Lummer, together with Pringsheim and Kurlbaum, succeeded in substantiating the so-called Stefan-Boltzmann law which indicates the relationship between the quantity of heat radiated by a black body and its temperature.

This solved in a highly satisfactory manner one of the major problems of radiation theory, i.e. that which touches total black body radiation.

However, the thermal energy that radiates from a body contains rays of different wavelengths whose intensities differ and change with the temperature of the body. It therefore remained to investigate the manner of change in intensity with wavelength and temperature.

An important step towards the solution of this question had been taken as early as 1886 by Langley who, with his famous spectrobolometer, investigated the distribution of radiation in the spectrum of a number of heat sources of high and low temperature. Inter alia these classical researches showed that the radiation had a maximum for a certain wavelength and that the maximum shifted in the direction of the shorter waves with increasing temperature.

In 1893 Wien published a theoretical paper which was destined to acquire the utmost importance in the development of radiation theory. In this paper he presented his so-called displacement law which provides a very simple relationship between the wavelength having the greatest radiation energy and the temperature of the radiating black body.

The importance of Wien's displacement law extends in various directions. As we shall see, it provides one of the conditions which are required for the determination of the relationships between energy radiation, wavelength and temperature for black bodies, and thus represents one of the most important laws in the theory of heat radiation. Wien's displacement law has however acquired the greatest possible importance in other contexts as well. Lummer and Pringsheim have shown that the radiation of bodies other than black bodies obeys the displacement law, with the sole difference that the constant which forms part of the formula has a different value.

Thus it became possible to determine the temperature of bodies, within fairly narrow limits, simply by seeking the wavelength at which radiation is greatest. The method has successfully been applied to the determination of the temperature of our light sources, of the sun and of some of the fixed stars, and has yielded extremely interesting results.

The Stefan-Boltzmann law and the Wien displacement law are the most penetrating statements on a secure theoretical foundation that have been discovered with respect to thermal radiation. They do not solve the central problem, i.e. the question as to the distribution of radiation energy over the various wavelengths at different black body temperatures. We can however say that Wien's displacement law provides half the answer to the problem. We have one condition for determining the desired function. One more would be sufficient for solving the problem.

It was only natural that Wien who had contributed so much to the advancement of radiation theory should make an attempt to find an answer to the last remaining question also, i.e. that of the distribution of energy in radiation. In 1894 he indeed deduced a black body radiation law. This law has the virtue that, at short wavelengths, it agrees with the above-mentioned experimental investigations by Lummer and Pringsheim.

By a different approach from that used by Wien, Lord Rayleigh also succeeded in discovering a law of radiation. By contrast with that discovered by Wien, it agrees with experiment for long wavelengths.

The problem now became to bridge the gap between these two laws each of which had been shown to be valid in a specific context. It was Planck who solved this problem; as far as we are aware, his formula provides the long sought-after connecting link between radiation energy, wavelength and black body temperature.

These remarks show that we now know, with considerable accuracy, the laws that govern thermal black body radiation.

A magnificent and unique task has thus been undertaken and brought to a certain conclusion- a task which has claimed the liveliest interest and energy of the leading physicists of our time.

Among the researchers in this field now living it was Wilhelm Wien who made the greatest and most significant contribution, and the Academy of Sciences has therefore decided to award- to him the Nobel Prize for Physics for the year 1911.

Professor Wien. The Swedish Academy of Sciences has awarded to you this year's Nobel Prize for Physics for your discoveries concerning the laws of thermal radiation. You have devoted your researches to one of the most difficult and spectacular problems of physics, and among the researchers now living it is you who has succeeded in making the greatest and most significant contributions to the solution of the problem. In admiration of the completed task and with the wish that further success may be granted to you in future work, the Academy now calls upon you to receive the prize from the hands of his Majesty the King.

From Nobel Lectures, Physics 1901-1921, Elsevier Publishing Company, Amsterdam, 1967

Copyright © The Nobel Foundation 1911

Ucapan Terima Kasih;

1. DEPDIKNAS Republik Indonesia

2. Kementrian Riset dan Teknologi Indonesia

3. Lembaga Ilmu Pengetahuan Indonesia (LIPI)

4. Akademi Ilmu Pengetahuan Indonesia

5. Tim Olimpiade Fisika Indonesia

Sumber:

Wikipedia

Nobel Prize Org.

Disusun Ulang Oleh;

Arip Nurahman

Pendidikan Fisika, FPMIPA. Universitas Pendidikan Indonesia
&
Follower Open Course Ware at MIT-Harvard University, Cambridge. USA.

Semoga Bermanfaat dan Terima Kasih

Nobel Fisika Indonesia

Central for Research and Development for Winning

Nobel Prize in Physics at Indonesia

"Untuk pekerjaannya pada persamaan tetapan gas dan cairan."

Johannes Diderik van der Waals

Born	23 November 1837(1837-11-23) Leiden, Netherlands
Died	8 March 1923(1923-03-08) (aged 85) Amsterdam, Netherlands
Nationality	Netherlands
Fields	Physics
Institutions	University of Amsterdam
Alma mater	University of Leiden
Doctoral advisor	Pieter Rijke
Doctoral students	Diederik Korteweg
Known for	Equation of state, intermolecular forces
Notable awards	Nobel Prize for Physics (1910)

Johannes Diderik van der Waals (23 November 1837 – 8 Maret 1923) ialah ilmuwan Belanda yang terkenal "atas karyanya pada persamaan gas cairan", sehingga ia memenangkan Penghargaan Nobel dalam Fisika pada 1910. van der Waals adalah yang pertama menyadari perlunya mengingat akan volume molekul dan gaya antarmolekul (kini disebut "gaya van der Waals") dalam mendirikan hubungan antara tekanan, volume, dan suhu gas dan cairan.

Biografi

van der Waals lahir di Leiden, Belanda, sebagai putera Jacobus van der Waals dan Elisabeth van den Burg. Ia menjadi guru sekolah, dan kemuian diizinkan belajar di universitas, karena kurangnya pendidikan dalam bahasa-bahasa klasik. Ia belajar dari 1862 hingga 1865, mendapat gelar dalam matematika dan fisika. Ia menikah dengan Anna Magdalena Smit dan memiliki 3 putri dan 1 putra.

Pada 1866, ia menjadi direktur sekolah dasar di den Haag. Pada 1873, ia mendapatkan gelar doktor di bawah Pieter Rijke atas tesisnya yang berjudul "Over de Continuïteit van den Gas- en Vloeistoftoestand" (Pada Kontinuitas Keadaan Gas dan Cair). Pada 1876, ia diangkat sebagai profesor pertama di Universitas Amsterdam.

van der Waals meninggal di Amsterdam pada 1923.

The Nobel Prize in Physics 1910

Presentation Speech

Presentation Speech by the Rector General of National Antiquities, Professor O. Montelius, President of the Royal Swedish Academy of Sciences, on December 10, 1910

Your Majesty, Your Royal Highnesses, Ladies and Gentlemen,

The Academy of Sciences has resolved to award this year's Nobel Prize for Physics to the world-famous Dutch physicist, Johannes Diderik van der Waals for his studies of the physical state of liquids and gases.

As far back as in his inaugural dissertation "The relationship between the liquid and the gaseous state". Van der Waals indicated the problem to which he was to devote his life's work and which still claims his attention today. In the dissertation to which I have referred he sought to account for the discrepancies from the simple gas laws which occur at fairly high pressures. He was led to the assumption that these discrepancies are partly associated with the space occupied by the gas molecules themselves, and partly with the attraction which the molecules exert on one another, owing to which the pressure acting on the interior of the gas is greater than the external pressure.

These two factors become more and more pronounced with increasing compression of the gas. At a sufficiently high pressure, however, the gas becomes liquid, unless the temperature exceeds a certain value, the critical temperature as it is termed. Van der Waals showed that it is possible to apply the same considerations and calculations to liquids as to gases. When the temperature of a liquid is raised to beyond the critical temperature without the liquid being allowed to volatilize, it is in fact converted continuously from the liquid to the gaseous form; and close to the critical temperature it is impossible to distinguish whether it is liquid or gas.

The force preventing the separation of the molecules in a liquid is their mutual attraction, owing to which a high pressure prevails in the interior of the liquid. Van der Waals calculated this pressure, the existence of which had already been vaguely perceived by Laplace, for water. It amounts to not less than about 10,000 atmospheres at normal temperature. In other words the internal pressure, as it is called, of a drop of water would be about ten times greater than the water pressure at the greatest depth of the sea known to us.

However, this was not the most important result of Van der Waals' studies. His calculations led him to consider that once we are acquainted with the behaviour of a single type of gas and the corresponding liquid, e.g. that of carbon dioxide, at all temperatures and pressures, we are able by simple proportioning to calculate for any gas or liquid its state at any temperature and pressure, provided that we know it at only one, i.e. the critical, temperature.

On the basis of this law of what are known as "corresponding states" for various gases and liquids Van der Waals was able to provide a complete description of the physical state of gases and, more important, of liquids under varying external conditions. He showed how certain regularities can be explained which had earlier been found by empirical means, and he devised a number of new, previously unknown laws for the behaviour of liquids.

It appeared, however, that not all liquids conformed precisely to the simple laws formulated by Van der Waals. A protracted controversy arose around these discrepancies which were ultimately found to be attributable to the molecules in these liquids not all being of the same character; the older Van der Waals laws apply only to liquids of uniform composition. Van der Waals then extended his studies to mixtures of two or more types of molecules and here too he managed to find the laws and these, of course, are more complex than those which apply to substances composed of molecules of a single type. Van der Waals is still occupied with working out the details of this great investigation.

Nevertheless, he has successfully surmounted the difficulties that were initially in his path.

Van der Waals' theory has also been brilliantly successful through its predictions which made it possible to calculate the conditions for converting gases to liquids. Two years ago Van der Waals' most prominent pupil, Kamerlingh Onnes, in this way succeeded in compelling helium-the last previously uncondensed gas - to assume the liquid state.

Yet Van der Waals' studies have been of the greatest importance not only for pure research. Modern refrigeration engineering, which is nowadays such a potent factor in our economy and industry, bases its vital methods mainly on Van der Waals' theoretical studies.

Professor Van der Waals. The Royal Academy of Sciences has awarded you this year's Nobel Prize for Physics in recognition of your pioneering studies on the physical state of liquids and gases.

Hamurabi's and Moses' laws are old and of great importance. The laws of Nature are older still and even more important. They apply not just to certain regions on this Earth, but to the whole world. However, they are difficult to interpret. You, Professor, have succeeded in deciphering a few paragraphs of these laws. You will now receive the Nobel Prize, the highest reward which our Academy can give you.

From Nobel Lectures, Physics 1901-1921, Elsevier Publishing Company, Amsterdam, 1967

Ucapan Terima Kasih;

1. DEPDIKNAS Republik Indonesia

2. Kementrian Riset dan Teknologi Indonesia

3. Lembaga Ilmu Pengetahuan Indonesia (LIPI)

4. Akademi Ilmu Pengetahuan Indonesia

5. Tim Olimpiade Fisika Indonesia

Sumber:

Wikipedia

Nobel Prize Org.


Disusun Ulang Oleh;

Arip Nurahman

Pendidikan Fisika, FPMIPA. Universitas Pendidikan Indonesia
&
Follower Open Course Ware at MIT-Harvard University, Cambridge. USA.

Semoga Bermanfaat dan Terima Kasih

Nobel Fisika Indonesia

Central for Research and Development for Winning

Nobel Prize in Physics at Indonesia

"Dalam pengakuan kontribusi mereka terhadap pengembangan telegraf tanpa kabel".

"in recognition of their contributions to the development of wireless telegraphy"

Guglielmo Marconi	Karl Ferdinand Braun
1/2 of the prize	1/2 of the prize
Italy	Germany
Marconi Wireless Telegraph Co. Ltd. London, United Kingdom	Strasbourg University Strasbourg, Alsace, then Germany
b. 1874 d. 1937	b. 1850 d. 1918

Titles, data and places given above refer to the time of the award.
Photos: Copyright © The Nobel Foundation

The Nobel Prize in Physics 1909

 

Presentation Speech

Guglielmo Marconi (25 April 1874 – 20 Juli 1937) adalah seorang insinyur listrik Italia dan peraih hadiah Nobel, terkenal setelah mengembangkan suatu sistem telegrafi tanpa kabel yang dikenal sebagai "radio". Ia menerimanya bersama Karl Braun tahun 1909.

Guglielmo Marconi lahir di Bologna, Italia pada tanggal 25 April 1874, anak laki-laki kedua dari Giuseppe Marconi, seorang pria Italia kaya raya dan Annie Jameson yang berdarah Irlandia. Dia menyelesaikan pendidikannya di Livorno.

Guglielmo Marconi menikah dengan Maria Cristina Bezzi-Scali pada tanggal 15 Juni 1927 dan mempunyai seorang anak perempuan yang bernama Maria Elettra Elena Anna Marconi.

Marconi wafat pada tanggal 20 Juli 1937 di Roma, Italia.


Guglielmo Marconi (1874-1937) Lahir pada tahun 1874 di Bologna, Itali. Penemu radio ini dapat pendidikan privat dari seorang guru. Tahun 1894 tatkala usianya menginjak dua puluh, Marconi baca percobaan-percobaan yang dilakukan oleh Heinrich Hertz beberapa tahun sebelumnya. Percobaan-percobaan ini dengan gamblang mendemonstrasikan adanya gelombang elektromagnetik yang tak tampak oleh mata, bergerak lewat udara dengan kecepatan suara.

Marconi lantas tergugah dengan ide bahwa gelombang ini bisa dimanfaatkan mengirim tanda-tanda melintasi jarak jauh tanpa lewat kawat yang menyediakan banyak kemungkinan berkembangnya komunikasi yang tak bisa dijangkau telegram. Misalnya, dengan cara ini berita-berita dapat dikirim ke kapal di tengah laut.

Tahun 1895, hanya setahun kerja keras, Marconi berhasil memprodusir peralatan yang diperlukan. Tahun 1896 dia memperagakan alat penemuannya di Inggris dan memperoleh hak paten pertamanya untuk penemuan ini. Marconi bergegas mendirikan perusahaan dan "Marconi" pertama dikirim tahun 1898. Tahun berikutnya dia sudah sanggup kirim berita tanpa lewat kawat menyeberang selat Inggris. Meskipun patennya yang terpenting diperolehnya tahun 1900, Marconi meneruskan pembuatan dan mempatenkan banyak penyempurnaan-penyempurnaan atas dasar penemuannya sendiri. Di tahun 1901 dia berhasil mengirim berita radio melintasi Samudera Atlantik, dari Inggris ke Newfoundland.

Makna penting dari penemuan barunya secara dramatis dilukiskan di tahun 1909 tatkala kapal S.S. Republic rusak akibat tabrakan dan tenggelam ke dasar laut. Berita radio amat membantu, semua penumpang bisa diselamatkan kecuali enam orang. Pada tahun yang sama Marconi berhasil meraih Hadiah Nobel untuk penemuannya. Dan pada tahun berikutnya dia berhasil mengirim berita radio dari Irlandia ke Argentina, suatu jarak yang lebih dari 6000 mil.

Semua berita ini dikirim lewat tanda-tanda sistem kode Marconi. Sebagaimana diketahui, suara itu dapat dikirim lewat radio, tetapi hal ini baru bisa terlaksana sekitar tahun 1915. Penyiaran radio dalam skala komersial baru mulai awal tahun 20-an, tetapi kepopulerannya dan arti pentingnya tumbuh dengan amat cepatnya.

Sebuah penemuan yang hak patennya punya harga tinggi dengan sendirinya menimbulkan pertentangan di pengadilan. Tetapi, rupa-rupa tuntutan lewat pengadilan sirna melenyap sesudah tahun 1914 tatkala pengadilan mengakui hak-hak Marconi. Pada tahun berikutnya, Marconi melakukan pula penyelidikan penting di bidang gelombang pendek dan komunikasi microwave. Dia menghembuskan nafas terakhir di Roma tahun 1937.

Selain Marconi menjadi kesohor selaku penemu, jelas pula pengaruhnya tak diragukan dalam hal arti penting radio dan hal-hal yang berkaitan dengan itu. Marconi tidak menemukan televisi. Tetapi, penemuan radionya merupakan pembuka jalan penting buat televisi, karena itu adalah layak menganggap Marconi punya saham juga dalam pengembangan televisi.

Jelas, komunikasi tanpa kawat punya makna teramat penting dalam dunia modern. Ini bermanfaat amat buat pengiriman berita, untuk hiburan, untuk keperluan militer, untuk penyelidikan ilmiah, untuk tugas-tugas kepolisian, dan lain-lain keperluan. Meskipun untuk beberapa hal telegram (yang sudah diketemukan orang lebih dari setengah abad sebelumnya) boleh dibilang punya kegunaan juga, penggunaan radio secara besar-besaran betul-betul tak tertandingkan. Dia bisa mencapai mobil, kapal di lautan, pesawat yang sedang mengudara, bahkan pesawat ruang angkasa. Jelas merupakan penemuan lebih penting ketimbang tilpun karena berita-berita yang dikirim via tilpun dapat pula dikirim lewat radio, lagi pula pesan-pesan lewat radio dapat dikirim ke tempat-tempat yang tak bisa dicapai tilpun.


Karl Ferdinand Braun (lahir di Fulda, 6 Juni 1850 – meninggal di New York, 20 April 1918 pada umur 67 tahun) adalah seorang fisikawan Jerman.

Braun belajar di Universitas Marburg dan menerima gelar di Universitas Berlin pada tahun 1872. Ia menjadi direktur di Lembaga Fisika dan profesor fisika di Strasbourg (1895).
Pada tahun 1897, ia membuat oskiloskop tabung sinar katoda pertama. Teknik ini digunakan oleh sebagian besar peralatan TV dan monitor komputer. Tabung katode masih disebut "tabung Braun" (Braunsche Röhre) di negara penutur bahasa Jerman (dan di Jepang: Buraun-kan).

Pada tahun 1909 Braun menerima Penghargaan Nobel dalam Fisika dengan Guglielmo Marconi untuk "sumbangan pada pengembangan telegrafi nirkabel."

Pada awal Perang Dunia I Braun pindah ke Amerika Serikat untuk mempertahankan stasiun nirkabel Jerman yang terletak di Sayville (Long Island) terhadap serangan oleh Marconi Corporation yang dikendalikan Inggris (saat itu Amerika Serikat belum terjun dalam perang).

Braun meninggal di rumahnya di Brooklyn sebelum perang berakhir, pada tahun 1918.

Karier dan Perjalanan Hidupnya

Karl Ferdinand Braun dilahirkan pada tanggal 6 Juni 1850 di Jerman. Ayahnya seorang pegawai pengadilan di Fulda (Jerman).

Braun memiliki sifat skeptis dan serba ingin tahu yang kuat tentang kejadian-kejadian alam yang dijumpainya. Dia sangat tertarik dengan ilmu fisika dan filsafat. Setelah menamatkan sekolah menengah, ia cenderung mempelajari filsafat dan berhasil meraih gelar doktor dibidang itu. Namun hobinya di bidang fisika tidak dia tinggalkan.

Pada tahun 1872-1885, sembari menggeluti bidang fisika, dia menjadi guru fisika di sekolah menengah di Leipzig, kemudian menjadi dosen di Marburg, Strasbourg dan Karlsruhe. Selain mengajar, dia juga gemar menulis artikel ilmu pengetahuan modern dalam mingguan Die Fligenden Blatter.

Selain itu, dia juga menulis buku yang berjudul Der Junge Mathematiker und Naturforscher. Braun senantiasa menemukan hal-hal yang baru, diantaranya, ia mengembangkan sejenis pirometer listrik guna mengukur suhu yang tinggi, menetukan kenaikan suhu bumi melalui lubang-lubang galian yang dalam dan menemukan dampak pelurus pada pada semikonduktor yang merupakan dasar bagi elektronika modern. Berkat jasanya pula, maka transistor dan dioda dapat berfungsi. Selama hidupnya di Eropa (Jerman) ia jarang berada dirumah dalam waktu yang lama.

Braun menikah pada tahun 1885 dan setelah pernikahannya, ia melakukan riset keliling Eropa, Amerika dan gurun Sahara di Afrika. Sepulang dari beberapa negara pada tahun 1897, ia menayangkan temuannya yang cukup modern saat itu.

Temuan itu tak lain adalah tabung gambar yakni tabung yang mampu menyerap sinyal-sinyal yang diwujudkan dalam bentuk gambar. Temuan itu ia populerkan dan di publikasikan di depan para mahasiswa Universitas Strasbourg.

Penjelasan mengenai tabung gambar ini adalah bahwa tabung gambar tersebut dapat menampilkan arus bolak-balik dari pusat pembangkit listrik Strasbourg secara langsung berupa gelombang sinus yang kemudian hari diterima sebagai lambang arus bolak-balik, muncul pada permukaan suatu Polygon (bersegi banyak) berputar yang memantul. Sinar datang dari sebuah tabung berbentuk alat pemukul, dari katoda atau elektron tabung sinar. Kekuatan magnetis mengarahkan elektron-elektron yang terkumpul, yaitu partikel-partikel inti yang sangat cepat, yang pada saat itu tampak tidak dapat dikendalikan, melalui tabung gelas. Titik-titik sinar di ujung tabung kemudian secara otomatis membentuk garis-garis gelombang menghasilkan gambar yang persis sama dengan arus sinkron bidang-bidang magnetis yang menggoyangkan cahaya elektron. Sesungguhnya itulah sistem bekerjanya televisi dewasa ini yakni elektron-elektron dengan kecepatan tinggi disalurkan melalui tabung yang hampir kosong, memantulkan cahaya membentuk titik-titik secara otomatis kemudian dipusatkan oleh bidang-bidang magnetis untuk membentuk gambar, inilah yang kita sebut televisi.

Jadi, tabung yang ada intinya merupakan arus bolak-balik merupakan elemen pokok dan esensial bagi teknologi pertelevisian. Sampai kini tabung tersebut masih dikenal sebagai Tabung Braun. Selain untuk televisi, juga digunakan untuk berbagai perlengkapan medis, komputer bahkan perlengkapan radar.

Dengan beberapa temuannya itu pula Braun mendirikan perusahaan Braun-Siemens Gesellschaft dan Telefunken di Berlin. Kecenderungannya pun kembali ia buktikan pada tahun 1905 ia mampu memanfaatkan hipotesis yang dikembangkan oleh Maxwell bahwa untuk mendeteksi semua karakter unsur gelombang listrik dalam cahaya yang terlihat mungkin saja dapat dilakukan. Pada tahun 1905-1909 ia bersama ilmuwan Italia bernama Yuglielmo Marconi membantu mengembangkan telegraf tanpa kawat dimana telegraf sebelumnya ditemukan oleh Marconi hanya dapat menyampaikan osilasi (getaran) yang terendam yang sangat membatasi jangkauan siarannya.

Maka, dengan kepiawaiannya, Braun akhirnya berhasil memecahkan masalah tersebut dengan dua kondensor dan sebuah gulungan kawat induksi dalam sirkuit osilasi tertutup guna mencegah getaran-getaran elektromagnetik yang hilang dalam perjalanan udara. Hal ini mendorong osilasi-osilasi yang juga dikenal sebagai umpan balik. Temuan itu membuat pemancar menjadi lebih kuat dibandingkan dengan temuan Marconi sebelumnya.

Atas jasanya dala dunia telegraf, maka pada tahun 1909 Braun bersama Marconi memperoleh hadiah Nobel. Sebetulnya Braun patut memperoleh Nobel pada tahun-tahun sebelum ia menemukan sistem Telegraf, namun dunia pada saat ini belum secara pasti memandang bahwa temuan tabung gambar merupakan nenek moyang televisi dan perlengkapan lainnya. Namun begitu, hadiah Nobel yang disandang atas jasa temuan bidang telegraf membuat dirinya kokoh sebagai ilmuwan sejati.

Pada tahun 1911 ia membangun sebuah stasiun di Sayville. Pada tahun 1914 ia bekerja sama dengan Count Zeppelin, mengembangkan sambungan-sambungan radio untuk navigasi penerbangan. Pada bulan Desember 1904 ia melawat ke Amerika Serikat untuk tujuan bisnis alat-alat teknologi temuannya. Sayangnya selang beberapa waktu kemudian Perang Dunia I meletus. Braun terpaksa menetap di Broklyn (USA), ia tidak bisa pulang ke negaranya. Setelah menetap di Amerika Serikat selama empat tahun, Braun meninggal dunia dalam usia 68 tahun tepatnya tanggal 20 April 1918. Sebelum wafat ia sempat menulis sebuah buku yang berjudul Fisika untuk Wanita.

Presentation Speech by the former Rector General of National Antiquities H. Hildebrand, President of the Royal Swedish Academy of Sciences, on December 10, 1909

Your Majesty, Your Royal Highnesses, Ladies and Gentlemen.

Research in physics has provided us with many surprises. Discoveries which at first seemed to have but theoretical interest have often led to inventions of the greatest importance to the advancement of mankind. And if this holds good for physics in general, it is even more true in the case of research in the field of electricity.

The discoveries and inventions for which the Royal Academy of Sciences has decided to award this year's Nobel Prize for Physics, also have their origin in purely theoretical work and study. Important and epoch-making, however, as these were in their particular fields, no one could have guessed at the start that they would lead to the practical applications witnessed later.

While we are, this evening, conferring Nobel's Prize upon two of the men who have contributed most to the development of wireless telegraphy, we must first register our admiration for those great research workers, now dead, who through their brilliant and gifted work in the fields of mathematical and experimental physics, opened up the path to great practical applications. It was Faraday with his unique penetrating power of mind, who first suspected a close connection between the phenomena of light and electricity, and it was Maxwell who transformed his bold concepts and thoughts into mathematical language, and finally, it was Hertz who through his classical experiments showed that the new ideas as to the nature of electricity and light had a real basis in fact. To be sure, it was already well known before Hertz's time, that a capacitor charged with electricity can under certain circumstances discharge itself oscillatorily, that is to say, by electric currents passing to and fro. Hertz, however, was the first to demonstrate that the effects of these currents propagate themselves in space with the velocity of light, thereby producing a wave motion having all the distinguishing characteristics of light. This discovery - perhaps the greatest in the field of physics throughout the last half-century - was made in 1888. It forms the foundation, not only for modern science of electricity, but also for wireless telegraphy. But it was still a great step from laboratory trials in miniature where the electrical waves could be traced over but a small number of metres, to the transmission of signals over great distances.

A man was needed who was able to grasp the potentialities of the enterprise and who could overcome all the various difficulties which stood in the way of the practical realization of the idea. The carrying out of this great task was reserved for Guglielmo Marconi. Even when taking into account previous attempts at this work and the fact that the conditions and prerequisites for the feasibility of this enterprise were already given, the honour of the first trials is nevertheless due, by and large, to Marconi, and we must freely acknowledge that the first success was gained as a result of his ability to shape the whole thing into a practical, usable system, added to his inflexible energy with which he pursued his self appointed aim.

Marconi's first experiment to transmit a signal by means of Hertzian waves was carried out in 1895. During the 14 years which have elapsed since then, wireless telegraphy has progressed without pause until it has attained the great importance it possesses today. In 1897 it was still only possible to effect a wireless communication over a distance of 14-20 km. Today, electrical waves are despatched between the Old and the New World, all the larger ocean-going steamers have their own wireless telegraphy equipment on board, and every Navy of significance uses a system of wireless telegraphy.


The development of a great invention seldom occurs through one individual man, and many forces have contributed to the remarkable results now achieved. Marconi's original system had its weak points. The electrical oscillations sent out from the transmitting station were relatively weak and consisted of wave-series following each other, of which the amplitude rapidly fell-so-called "damped oscillations". A result of this was that the waves had a very weak effect at the receiving station, with the further result that waves from various other transmitting stations readily interfered, thus acting disturbing at the receiving station. It is due above all to the inspired work of Professor Ferdinand Braun that this unsatisfactory state of affairs was overcome.


Braun made a modification in the layout of the circuit for the despatch of electrical waves so that it was possible to produce intense waves with very little damping. It was only through this that the so-called "long-distance telegraphy" became possible, where the oscillations from the transmitting station, as a result of resonance, could exert the maximum possible effect upon the receiving station. The further advantage was obtained that in the main only waves of the frequency used by the transmitting station were effective at the receiving station. It is only through the introduction of these improvements that the magnificent results in the use of wireless telegraphy have been attained in recent times.

Research workers and engineers toil unceasingly on the development of wireless telegraphy. Where this development can lead, we know not. However, with the results already achieved, telegraphy over wires has been extended by this invention in the most fortunate way. Independent of fixed conductor routes and independent of space, we can produce connections between far-distant places, over far-reaching waters and deserts. This is the magnificent practical invention which has flowered upon one of the most brilliant scientific discovery of our time!

From Nobel Lectures, Physics 1901-1921, Elsevier Publishing Company, Amsterdam, 1967

Copyright © The Nobel Foundation 1909

Ucapan Terima Kasih;

1. DEPDIKNAS Republik Indonesia

2. Kementrian Riset dan Teknologi Indonesia

3. Lembaga Ilmu Pengetahuan Indonesia (LIPI)

4. Akademi Ilmu Pengetahuan Indonesia

5. Tim Olimpiade Fisika Indonesia

Sumber:

Wikipedia

Nobel Prize Org.

Disusun Ulang Oleh;

Arip Nurahman

Pendidikan Fisika, FPMIPA. Universitas Pendidikan Indonesia
&
Follower Open Course Ware at MIT-Harvard University, Cambridge. USA.

Semoga Bermanfaat dan Terima Kasih

Indonesian Space Sciences & Technology School

Indonesian Space Sciences & Technology School

BASICS OF SPACE FLIGHT

Added & Edited

By: Arip Nurahman
Department of Physics Education, Faculty of Sciences and Mathematics

Indonesia University of Education

and

Follower Open Course Ware at Massachusetts Institute of Technology
Cambridge, USA
Department of Physics 
http://web.mit.edu/physics/
http://ocw.mit.edu/OcwWeb/Physics/index.htm
&
Aeronautics and Astronautics Engineering
http://web.mit.edu/aeroastro/www/
http://ocw.mit.edu/OcwWeb/Aeronautics-and-Astronautics/index.htm

Part I - Rocket Propellants

In this page we classify and describe the types of chemical propellants typically used in rocketry.  Included are tables listing the properties of the most frequently used fuels and oxidizers.

• Liquid Propellants
• Solid Propellants
• Hybrid Propellants
• Tables of Properties

Part II - Rocket Propulsion

In this page we describe how a rocket works by introducing and explaining the physics of rocket propulsion.  We will explain how a rocket engine accelerates the hot gases generated by the combustion of propellant to produce thrust.  Engine types and thrust chamber design equations are presented.  As we introduce the necessary formulae, example problems are provided to demonstrate their use.

• Thrust
• Conservation of Momentum
• Impulse & Momentum
• Combustion & Exhaust Velocity
• Specific Impulse
• Rocket Engines
• Power Cycles
• Engine Cooling
• Solid Rocket Motors
• Monopropellant Engines
• Staging

Part III - Orbital Mechanics

In this page we define an orbit and describe the various types.  We will then introduce Newton's laws of motion and Universal Gravitation and explain how they apply to the motions of planets and satellites.  We will examine how the Earth, Moon, Sun, and atmosphere affects a satellite's orbit.  We then conclude with a discussion of some common orbital maneuvers and maintenance.  Along the way we will introduce many basic formulae and provide example problems illustrating their application.

• Conic Sections
• Orbital Elements
• Types of Orbits
• Newton's Laws of Motion and Universal Gravitation
• Uniform Circular Motion
• Motions of Planets and Satellites
• Launch of a Space Vehicle
• Position in an Elliptical Orbit
• Orbit Perturbations
• Orbit Maneuvers
• Escape Velocity

Appendices
The following are the appendices referenced in Parts I, II and III above.

• Example Problems
• Basic Constants
• Atmosphere Properties
• Drag Coefficients
• Propellant Combustion Charts
• Supplement #1: Optimizing Expansion for Maximum Thrust
• Units of Weights and Measures

Source:

Braeuning