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Thread: Anti Materi: Apa dan untuk Apa


  1. #1
    Senior Contributor dudulz's Avatar
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    Lightbulb Anti Materi: Apa dan untuk Apa

    Trit untuk membahas anti materi, apa, bagaimana, dan potensi pemanfaatannya di masa depan.

    silahkan jika ada yg ingin share



    ps: bukan trit pseudoscience lho


  2. #2
    Senior Contributor dudulz's Avatar
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    Re: Anti Materi: Apa dan untuk Apa

    anti materi? bagaimana mungkin ada yg semacam itu? ini mungkin bisa menjawab: (sumber:http://livefromcern.web.cern.ch/live...ter/index.html)

    If you could convert all of the energy contained in 1 kg of sugar, or 1 kg of water, or 1 kg of any other stuff, you could drive a car for about 100,000 years without stopping!
    Why? Albert Einstein, in 1905, wrote down the famous equation E=mc2. It says that mass is a very concentrated form of energy.
    Energy is like the 'money' of nature; it comes in two different currencies, and with an enormous exchange rate - the square of the speed of light .
    1 kg corresponds to 25,000,000,000 kWh of energy; 1 gr would be enough to supply energy to a medium-sized town for a whole day!
    But how can energy be transformed into matter, or vice versa?

    Big meteorites traverse our solar system with a typical speed of about 30 km/sec. If such a meteorite enters the Earth's atmosphere, its energy of movement is converted into heat, reaching 100,000 Co or more and melting most of its material ('shooting star').
    We do not have the technology to make a space ship go at the speed of light (300,000 km/sec), but it is possible - using accelerators at CERN - to make single particles (like a proton, the nucleus of a hydrogen atom) go that fast.
    If a particle moving with this speed hits a block of material, its energy is also transformed, producing 'temperatures' of 10,000,000,000,000 Co or more. Under these extreme circumstances, the energy set free in the collision will transform into matter.
    But: what kind of matter do I produce in such collisions?

    In a coin factory, hot metal is pressed into coins. They only come in specific sizes and values, as 1p, 2p, 5p, 10p, 50p and 1 pound.
    Similarly, nature does not allow energy to be converted into just any kind of matter. Nature has provided us with 'moulds', corresponding to a precisely defined amount of energy, as well as having some other particular properties.
    These moulds are analogous to particles, the most important ones in our daily lives being the proton, the neutron and the electron. They have very precisely defined properties, such as their mass, their electric charge or the way they interact with other particles.
    So can I transform energy into a single proton or a single electron?

    Imagine a hot metal sheet in a coin factory ('energy'). When you stamp out a coin from a metal sheet, you are left with a coin and a hole in the sheet.You could call this hole an "anticoin".
    This is similar to what happens when energy transforms into matter. Many experiments have shown that you can only produce a pair of particle and its mirror image, called 'antiparticle', at the same time. Nobody has ever observed the production of only particles, or only antiparticles.
    That example also shows another feature observed with particles and antiparticles. To create them, it takes energy, and when you bring them back together ('annihilation', because they disappear into a flash of energy), this energy is released. It is like putting the coin back into the hole, leaving the original metal sheet.
    Last edited by dudulz; 16-02-09 at 10:50 AM.


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    Senior Contributor dudulz's Avatar
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    Re: Anti Materi: Apa dan untuk Apa

    Anti materi, kemana mereka pergi?

    obrolan santai 2 remaja berikut mungkin bisa menjelaskan ttg antimateri (sumber: http://livefromcern.web.cern.ch/live...matter/academy)

    Ellen ( Teen-age girl scientist)
    So, Tim - do you find the atom interesting?
    Tim (Teen-age boy) Great! It's fascinating that everything is made of just three particles - electron, proton, and neutron.
    Ellen Did you know that protons and electrons are immortal - well, we know that both live much longer than the age of the Universe.
    Tim So my body is made of particles that will never die? How old are these particles?
    Ellen About 15 billion years … the same as our Universe.
    Tim Wow! I don't feel that old … But: how were these particles made?
    Ellen They were created from energy in the first instants after the Big Bang. Remember your training course?
    Tim Yes, E = mc2 - mass is concentrated energy. But I also learned that particles and antiparticles are always created together. So there must be the same amount of antiparticles around. Where is all this antimatter?
    Ellen You're right - at the very beginning, there must have been equal amounts of particles and antiparticles. But somehow, the Universe became 'lopsided' during the first instants - and matter won the fight against antimatter.
    Tim That sounds interesting. Can you explain that a little slower?
    Ellen OK, let's take a trip back to the Big Bang in my time machine!

    (mereka melihat ke teleskop)
    Tim I thought you wanted to take me in your time machine?
    Ellen Tim, this is a time machine.
    Tim Why? It only makes the stars and the galaxies appear bigger.
    Ellen Yes. But think - when do you see the stars and the galaxies?
    Tim Now, of course.
    Ellen Only if light traveled with infinite speed- but it does not. The speed of light is 300,000 km per second, but in space all distances are enormous. It takes light about 4 years to cross the space to our neighboring star.
    Tim OK - but I still don't get your point about the time machine.
    Ellen Looking into space is like looking back into the past. The deeper we look into space, the further we look back in time. The light we see from a star on the other side of our galaxy was emitted about 100,000 years ago - when we were still sitting in caves and hurling clubs.

    Ellen Look, the Andromeda galaxy is our nearest neighbor - 'only' 1.5 million light years away.
    Tim Its light set off when the first human-like creature walked on two legs!
    Ellen So when we look into the remote corners of our Universe, we see what happened a very long time ago.
    Tim Now I see why you called it a time machine. Although we're not really traveling back in time, we're seeing things which happened a long time ago.
    Ellen Looking at pictures from the Hubble Space Telescope, astronomers have discovered a galaxy so far away that its light started to travel more than 8 billion years ago - that was even before our Earth had formed! So do you grasp why I called the telescope a 'time machine'?
    Tim Yes, but I don't understand how you can tell that this little red dot there is a galaxy 8 billion light years away?
    Ellen We owe that to Mr. Hubble: he observed that all galaxies move away from each other - the further away from us, the faster! And when a source of light moves away, its waves get 'stretched', and its color is shifted towards red.
    Tim So we are sitting in the middle of the Universe and all the galaxies are moving away from us?
    Ellen No - although people in the olden days would have liked the idea! Imagine a huge black balloon which is being blown up. Place a few white spots on its surface, and see how they all move away from each other. The further they are apart, the faster they separate.
    Tim I get it. The balloon is our Universe. Its diameter increases, and so does the distance between everything inside - stretching like rubber.
    Ellen This is one of the strongest arguments in favor of a violent start of the Universe - the Big Bang. It is of course possible to calculate at what time all these galaxies occupied the same position - and the answer is somewhere between 10 and 15 billion years.
    Tim Wow, I wonder what the Universe was like then…

    Ellen Ten billionths of a second after the Big Bang, the entire Universe would have fitted into your living room. Inside, energy and matter were completely exchangeable - the temperature was billions of billions of billion degrees. New particles and antiparticles were created all the time - and then annihilated back into energy.
    Tim So - at that time there were still equal amounts of matter and antimatter?
    Ellen No, the symmetry between matter and antimatter was already broken. We don't yet understand why. Somehow a small surplus of matter appeared: for every billion antimatter particles, there were a billion plus one matter particles.
    Tim The Universe got a kick which made it tip to the 'matter side'! Where did all the antimatter go?
    Ellen The antimatter part of the Universe was doomed - it took only about a second to wipe it all out. While expanding, the temperature in the Universe continued to drop rapidly. Particles and antiparticles annihilated in pairs. But after one second, the temperature had dropped too low to create new particle-antiparticle pairs. Only the small amount of 'leftover' matter particles remained - the rest had disappeared into radiation.
    Tim Pheww! So without that tiny surplus of matter there would be no stars, no planets, no humans? The universe would consist only of light in an empty space?

    Ellen Yes, it seems that we owe our existence to a very small asymmetry between matter and antimatter. That's why physicists are trying to find out more about antimatter. But did you know that we still observe the echo of this battle between matter and antimatter? The radiation produced in the annihilations is called the 'Cosmic Background Radiation', and it fills the whole Universe uniformly. I will show you a picture of it at our next stop.
    Ellen A satellite named COBE (COsmic Background Explorer) has taken a picture of the cosmic background radiation. Imagine: this picture shows the whole Universe! It is one of the great successes of the Big Bang model that it actually can explain the existence of this radiation. It comes from all directions, with very similar intensity.
    Tim Isn't that radiation dangerous? It must be very energetic!
    Ellen Only at the beginning. But now, the Universe has become more than a thousand times bigger since the time when this radiation was emitted. The waves have been 'stretched', and the energy of the light is now 1000 times less than before.
    Tim I see. The cosmic background radiation is the leftover from the matter-antimatter annihilations. And we're all made from the leftover matter.


  4. #4
    Senior Contributor dudulz's Avatar
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    Re: Anti Materi: Apa dan untuk Apa

    sejarah riset ttg anti materi (bag 1)
    (sumber:
    The History fo Antimatter - from 1928 to 1995)

    1928: the beginning
    The history of antimatter begins with a young physicist named Paul Dirac and the strange implications of a mathematical equation...
    It was the beginning of the 20th century, an exciting time when the very foundations of physics were shaken by the appearance of two important new theories: relativity and quantum mechanics.
    In 1905 Albert Einstein unveiled his theory of Special Relativity, explaining the relationship between space and time, and between energy and mass in his famous equation E=mc2. Meanwhile experiments had revealed that light sometimes behaved as a wave, but other times behaved as if it were a stream of tiny particles. Max Planck proposed that each light wave must come in a little packet, which he called a "quantum": this way light was not just a wave or just a particle, but a bit of both.
    By the 1920s, physicists were trying to apply the same concept to the atom and its constituents, and by the end of the decade Erwin Schrodinger and Werner Heisenberg had invented the new quantum theory of physics. The only problem now was that quantum theory was not relativistic - meaning the quantum description worked only for particles moving slowly, and not for those at high (or "relativistic") velocity, close to the speed of light.
    In 1928, Paul Dirac solved the problem: he wrote down an equation, which combined quantum theory and special relativity, to describe the behaviour of the electron. Dirac's equation won him a Nobel Prize in 1933, but also posed another problem: just as the equation x2=4 can have two possible solutions (x=2 OR x=-2), so Dirac's equation could have two solutions, one for an electron with positive energy, and one for an electron with negative energy. But in classical physics (and common sense!), the energy of a particle must always be a positive number!
    Dirac interpreted this to mean that for every particle that exists there is a corresponding antiparticle, exactly matching the particle but with opposite charge. For the electron, for instance, there should be an "antielectron" identical in every way but with a positive electric charge. In his Nobel Lecture, Dirac speculated on the existence of a completely new Universe made out of antimatter!

    1930: nature's helping hand
    From 1930, the hunt for the mysterious antiparticles began...
    Earlier in the century, Victor Hess (Nobel Prizewinner in 1936) had discovered a natural source of high energy particles: cosmic rays. Cosmic rays are very high energy particles that come from outer space and as they hit the Earth's atmosphere they produce huge showers of lower energy particles that have proved very useful to physicists.

    In 1932 Carl Anderson, a young professor at the California Institute of Technology, was studying showers of cosmic particles in a cloud chamber and saw a track left by "something positively charged, and with the same mass as an electron". After nearly one year of effort and observation, he decided the tracks were actually antielectrons, each produced alongside an electron from the impact of cosmic rays in the cloud chamber. He called the antielectron a "positron", for its positive charge. Confirmed soon after by Occhialini and Blackett, the discovery gave Anderson the Nobel Prize in 1936 and proved the existence of antiparticles as predicted by Dirac.
    For many years to come, cosmic rays remained the only source of high energy particles. A steady stream of discoveries was made but for the next sought-after antiparticle, the antiproton (antipartner of the proton and much heavier than the positron), physicists had to wait another 22 years...

    1954: power tools
    The search for antiprotons heated up in the 1940s and 1950s, as laboratory experiments reached ever higher energies...

    In 1930, Ernest Lawrence (Nobel Prizewinner in 1939) had invented the cyclotron, a machine that eventually could accelerate a particle like a proton up to an energy of a few tens of MeV. Initially driven by the effort to discover the antiproton, the accelerator era had begun, and with it the new science of "High Energy Physics" was born.
    It was Lawrence that, in 1954, built the Bevatron at Berkeley, California (BeV, at the time, was what we now call GeV). The Bevatron could collide two protons together at an energy of 6.2 GeV, expected to be the optimum for producing antiprotons. Meanwhile a team of physicists, headed by Emilio Segre', designed and built a special detector to see the antiprotons.
    In October 1955 the big news hit the front page of the New York Times: "New Atom Particle Found; Termed a Negative Proton". With the discovery of the antiproton, Segre' and his group of collaborators (O. Chamberlain, C. Wiegand and T. Ypsilantis) had succeeded in a further proof of the essential symmetry of nature, between matter and antimatter.
    Segre' and Chamberlain were awarded the Nobel Prize in 1959. Only a year later, a second team working at the Bevatron (B. Cork, O. Piccione, W. Wenzel and G. Lambertson) announced the discovery of the antineutron


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    Senior Contributor dudulz's Avatar
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    Re: Anti Materi: Apa dan untuk Apa

    sejarah riset ttg anti materi (bag 2)
    (sumber:
    The History fo Antimatter - from 1928 to 1995)

    1965:antinuclei
    By now, all three particles that make up atoms (electrons, protons and neutrons) were know to each have an antiparticle. So if particles, bound together in atoms, are the basic units of matter, it is natural to think that antiparticles, bound together in antiatoms, are the basic units of antimatter.
    But are matter and antimatter exactly equal and opposite, or symmetric, as Dirac had implied? The next important step was to test this symmetry . Physicists wanted to know: how do subatomic antiparticles behave when they come together? Would an antiproton and an antineutron stick together to form an antinucleus, just as protons and neutrons stick together to form an atom's nucleus?
    The answer to the antinuclei question was found in 1965 with the observation of the antideuteron, a nucleus of antimatter made out of an antiproton plus an antineutron (while a deuteron, the nucleus of the deuterium atom, is made of a proton plus a neutron). The goal was simultaneously achieved by two teams of physicists, one led by Antonino Zichichi, using the Proton Synchrotron at CERN, and the other led by Leon Lederman, using the Alternating Gradient Synchrotron (AGS) accelerator at the Brookhaven National Laboratory, New York.

    1995: from antiparticles to antimatter
    After making antinuclei, naturally the next question was: can antielectrons stick to antinuclei to make antiatoms?
    In fact the answer was only revealed quite recently, thanks to a very special machine, unique to CERN, the Low Energy Antiproton Ring (LEAR). Contrary to an accelerator, LEAR actually "slowed down" antiprotons. Physicists could then try to force a positron (or antielectron) to stick to an antiproton, making an antihydrogen atom, a real antimatter atom.
    Towards the end of 1995, the first such antiatoms were produced at CERN by a team of German and Italian physicists. Although only 9 antiatoms were made, the news was so thrilling that it made the front page of many of the world's newspapers.
    The achievement suggested that the antihydrogen atom could play a role in the study of the antiworld similar to that played by the hydrogen atom in over more than a century of scientific history. Hydrogen makes up three quarters of our universe, and much of what we know about the cosmos has been discovered by studying ordinary hydrogen.
    But does antihydrogen behave exactly like ordinary hydrogen ? To answer this question CERN decided to build a new experimental facility: the Antiproton Decelerator (AD).
    Last edited by dudulz; 16-02-09 at 11:00 AM.


  6. #6
    Contributor Swan's Avatar
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    Re: Anti Materi: Apa dan untuk Apa

    busyet dulz, lha kamu tanya sendiri malah kamu jawab sendiri, dari data yang aku punya malah nggak ada apa2nya sama data punyamu...

  7. #7
    Senior Contributor dudulz's Avatar
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    Re: Anti Materi: Apa dan untuk Apa

    Quote Originally Posted by Swan View Post
    busyet dulz, lha kamu tanya sendiri malah kamu jawab sendiri, dari data yang aku punya malah nggak ada apa2nya sama data punyamu...
    di share aja swan.. sama belajar kita

    mungkin ada yg mau share ttg penggunaan anti matter?

    oh ya pengunaan anti materi yg paling terkenal dan umum dilakukan adalah PET scan..


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    Re: Anti Materi: Apa dan untuk Apa

    Kalau antimateri menurutku itu antipartikel yang berasal dari penyusun partikel biasa, Bila sebuah partikel dan antipartikelnya menyentuh satu sama lain, keduanya saling memusnahkan, artinya keduanya diubah menjadi partikel-partikel lain dengan energi yang sama menurut persamaan Einstein E=mc˛.
    terus antimateri itu kayaknya jarang banget ditemukan ya dulz? (maksudku nggak ditemukan secara alami dibumi, kecuali hanya dalam waktu sangat singkat dan dalam jumlah sangat sedikit karena peluruhan radioaktif atau sinar kosmik), tapi kalau dijagat raya kita ya mungkin aja ada. bingung dulz, mau menjelaskan gimana lg, haha...

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    Re: Anti Materi: Apa dan untuk Apa

    Quote Originally Posted by Swan View Post
    Kalau antimateri menurutku itu antipartikel yang berasal dari penyusun partikel biasa, Bila sebuah partikel dan antipartikelnya menyentuh satu sama lain, keduanya saling memusnahkan, artinya keduanya diubah menjadi partikel-partikel lain dengan energi yang sama menurut persamaan Einstein E=mc˛.
    terus antimateri itu kayaknya jarang banget ditemukan ya dulz? (maksudku nggak ditemukan secara alami dibumi, kecuali hanya dalam waktu sangat singkat dan dalam jumlah sangat sedikit karena peluruhan radioaktif atau sinar kosmik), tapi kalau dijagat raya kita ya mungkin aja ada. bingung dulz, mau menjelaskan gimana lg, haha...
    sebuah anti hidrogen tersusun dari 2 anti atom hidrogen, anti atom hidrogen isinya anti nukleon (=anti proton dan anti neutron), dan anti elektron.

    anti hidrogen yg dibuat tahun 1995 saat direaksikan dengan hidrogen jadi 100% energi, ini menguatkan penjelasan "plat dan koin" di postingan ke dua gw di atas...


  10. #10
    zxc
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    Re: Anti Materi: Apa dan untuk Apa

    jika materi dan anti materi saling memusnahkan, apakah ada zat atau materi lain yang terbentuk? atau ia hilang begitu saja atau berubah bentuk menjadi energi, seperi foton?

    sambungan dari thread saya tentang materi dan anti materi di sebelah..

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