Does anybody know about nuclear fusion in sun?
443833
yes in its simplest form two hydrogen atoms fuse together to make a helium
128958
To simply, the sun is basically a gigantic collection of hydrogen gas that is being pushed together by an enormous force of gravity (each particle of hydrogen gas attracts each other).  When those atoms are forced together, they interact to form a continuious nuclear reaction which effectivly acts as a counter-force to the force of gravity.  So: Gravity pushes in, a nuclear explosion pushes out and the particles come to an equilibrium giving the sun a particular size.\n\nAs a star grows older, it begins to exhaust its supply of hydrogen fuel for the nuclear reaction and increases in size while decreasing in temperature.  At some point in the lifecycle of our sun, its size will actually expand to include the current position of the Earth.  However, current models indicate that Earth will move farther out in orbit, preventing its engulfment and destruction.\n\nAt any rate, as _our_ star (the Sun, sometimes called "Sol") continues to grow older, it will eventually shed these outer layers (thus creating a nebula) and condense into a very dense core and over time radiate away its energy.\n\nVery large stars can form black holes or neutron stars, regions of extreme gravitational forces, but our sun is small enough that it will form neither of these and just cool down into an inert ball of chemicals, no longer shining after it has radiated away its energy.\n\nHope that is helpful.
324432
Quick summery:\n\nFusion produces energy by taking very light elements, like hydorgen, and combining them together to form heavier ones like helium.  4H -> 1He.  If you take a look at the mass of 4 hydrogen atoms you will find that they have more mass than 1 helium atom.  This extra mass is converted into energy in fusion (E = mc^2).\n\nNow this produces a ton of energy (it is what powers the sun), but you need extream conditions (high temperature and pressure) to do it.  In order to make a hydrogen bomb, that is a bomb that uses fusion to generate the energy to do its dirty work, we need a source of intense heat.\n\nThat is why typically we trigger our hydrogen bombs with a small atomic bomb.  An atomic bomb generates energy through breaking large elements (uranium) into lighter ones.  Just like fusion, there is a mass difference between what you start with, and what you end with.  That missing mass goes into eneregy.  Fission is easy to strat, just get enough fissionable material together and presto.\n\nSo, you use the energy/heat produced by the little atomic bomb to super-heat your fusion fuel (hydrogen isotopes), and bang -> hydrogen bomb.\n\nTo be specific it is actually a three-stage detonation.  You use a conventional bomb to set off the fission (atomic) bomb, which in turn sets off the fusion (hydrogen) bomb.
837108
The sun "burns" on the concept of nuclear fussion, where hydrogen is converted to helium. Once all hydrogen has been converted it then produces lithium and all other elements in the periodic table until iron.\n\nThis process creates energy and is what you are referring to as "burning".\n\nNuclear fussion is a nuclear reaction. Processes like creating a fire are chemical reactions involing oxygen
619024
sun has huge amt of hydrogen atom which under the high temp. undergo nuclear fussion reaction to produce helium ion with emission of huge amount of light & heat......so becoz of this light it always shine...& bcoz of that heat the nuclear reaction keep to continue......
324460
Oxygen is required for combustion, not for nuclear reactions.\nIn Sun, the tremondous amount of energy is released by nuclear fusion reaction in which two hydrogen atoms combine to give a helium atom. A very small mass is converted into large energy, given by the famous equation: E=mc^2, where m is the difference in mass and c is speed of light.
1076020
Through some ridiculous idea, scientists have been able to continue their ridiculous campaign to convince you that the core of the Sun is the hottest even though the Sun's halo-like  corona is 300 times hotter.  Sunspots show us an interior of the Sun that is even cooler than the surface, so how can this be if the core is supposed to be even hotter?  Well it isn't, and that's not where light is created and that's not where fusion takes place.\n\nLook into the "electric universe." Do a search for it.
402973
Carrying out a nuclear fusion reaction at room temperature.  Stars, such as the Sun, have fusion chain reactions, but at temperatures exceeding 10000 deg C.
794246
Absolutely.  In fact, there have been several different approaches, including zapping little pellets with a monster laser (NOVA), which are then immersed in water.  These minuscule nuclear bombs fuse and release their energy into the water, creating steam and turning turbines.\n\nThe most promising method, however, is a fusion reactor; a magnetic bottle which traps plasma.  Fusion occurs when the electromagnetic forces of nuclei (which are positive) are overcome.  In order to get nuclei, atoms are injected into the reactor and brought to immense temperatures.  The individual atoms, which are neutral, become so energetic that the electrons are stripped from the nuclei, creating plasma.  Plasma is simply free electrons (negatively charged and unbounded to a nucleus) and the positively charged nuclei.  Because these are positively and negatively charged, the plasma is contained within magnetic field lines.  This is the proverbial "magnetic bottle".\n\nThe nuclei smash into each other, creating helium nuclei and excess neutrons.  These neutrons are EXTREMELY energetic (14 MeV), and are neutrally charged.  Therefore, these neutrons zip right past the magnetic field lines.  The charged plasma remains, continuing the fusion process; and the neutrons are captured in water, where elastic collisions with H2O molecules transfers the energy from the neutrons to the water, heating the water, turning it to steam, and turning the turbines.\n\nThere are a couple of major problems.  First, the sun is very big and very hot.  Getting similar temperatures and pressures on Earth is next to impossible.  Although the energy released is several orders of magnitude greater than the energy put in when the process is going a full capacity, getting it started has been very difficult.  However, through TFTR and the new ITER, already the plasmas have generated more energy than were used to start the process.  This is a big step.\n\nAlso, the magnetic bottle and the plasma can experience some strange instabilities and wave functions.  Any time a harmonic resonance-like phenomena occurs, the fusion can break down, the plasma cools, and the process slows or stops.  As the test reactors continue to gather data, these phenomena are better understood.\n\nFinally, those 14 MeV neutron zip through the magnetic bottle and the water, and interact with impurities in the concrete and building materials, creating radioactive waste.  This waste is not insignificant - huge amounts of concrete becomes low-level waste.  Low level waste is NOT a measure of how dangerous it is - this stuff can be very dangerous - but it will only remain dangerous for about 100 years or so.  It's not the stuff that remains deadly for thousands of years.\n\nSo solve the instabilities, be able to sustain a plasma and reaction long enough to become self-sustaining, and be prepared for the low level waste, and fusion will become an almost unlimited energy supply.
380249
Burn evokes the idea that there is oxygen involved, and fire consuming carbon-based materials like wood. Not so. It is all at extremely high temperatures, and nothing solid or liquid would exist at those temperatures. \n\nThe reaction is nuclear fusion. Atoms of hydrogen (1 proton and 1 electron) (possibly its deuterium isotope with an extra neutron) or its tritium isotope (2 extra neutrons) fusing together to form atoms of helium (2 protons, 1 neutron, 2 electrons). Energy is released in the process in the form of heat and light, as mass is destroyed (Einstein's e = mc^2 equation).\n\nThe sun isn't larger than other stars. It is just nearer to us (8 light minutes away) than any other star is (Alpha Centauri is 4 light years away and is the nearest). So it LOOKS bigger. That doesn't mean it IS bigger.
944935
There's not much question that the sun is a nuclear fusion machine. You don't need this direct evidence
540178
I am proud to say that I have witnessed this event on countless occasions as it took place. As lighting falls from the sky, it carries an enormous quantity of energy. It is enough energy to bring together two Oxygen molecules. The ultimate result is a molecule of Ozone. This process is commonly called Nuclear Fusion because the nuclei of the participants come together and a portion of matter is turned into energy in the process.
1187203
The Fate of the Sun:\n\nAbout 5 billion years from now, the hydrogen fuel in the center of the Sun will begin to run out and the helium that has collected there will begin to gravitationally contract, increasing the rate of hydrogen burning in a shell surrounding the core. Our star will slowly bloat into a red giant -- eventually engulfing the inner planets, including the Earth. \n\nAs the helium core continues to contract under the influence of gravity, it will eventually reach the temperatures and densities needed to fuse three helium nuclei into a carbon nucleus. Another nuclear reaction will compete for the available helium nuclei at the same temperature: the carbon can fuse with an additional helium nucleus to form oxygen. The amount of oxygen produced during this process is largely determined by the relative rates of these two competing reactions. Since the Sun is not very massive by stellar standards, it will never get hot enough in the center to produce nuclei much heavier than carbon and oxygen. These elements will collect in the center of the star, which will then shed most of its red giant envelope -- creating a planetary nebula -- and emerge as a hot white dwarf star. \nOnce a white dwarf star forms and the nuclear reactions have ceased, its structural and thermal evolution is dominated by cooling, and regulated by the opacity of its thin atmospheric outer layers. It will slowly fade as it radiates its residual thermal energy into space -- eventually cooling through a narrow range of temperatures that will cause it to vibrate in a periodic manner, sending gravity-driven seismic waves deep through the interior and bringing information to the surface in the form of brightness variations. This is fortunate, because a detailed record of the nuclear history of the star is locked inside, and pulsations provide the only known key to revealing it. \n \n\n\nAbout 99 percent of all stars in the galaxy will end their lives as white dwarfs. By studying the stars that have already gone through this process, we can learn about the ultimate fate of our own Sun. \n\nhttp://www.whitedwarf.org/index.html?education/sunwd/&0\n\nFate of the Sun\nThe sun has been shining for about 4.5 billion years. It has enough hydrogen fuel to "burn" for about 10 billion years. The size of the sun is a balance between the outward pressure made by the release of energy from nuclear fusion and the inward pull of gravity. When the core runs out of hydrogen fuel, it will contract under the weight of gravity; however, some hydrogen fusion will occur in the upper layers. As the core contracts, it heats up and this heats the upper layers causing them to expand. As the outer layers expand, the radius of the sun will increase and it will become a red giant. The radius of the red giant sun will be just beyond the Earth's orbit, so the Earth will plunge into the core of the red giant sun and be vaporized. At some point after this, the core will become hot enough to cause the helium to fuse into carbon. When the helium fuel has exhausted, the core will expand and cool. The upper layers will expand and eject material. Finally, the core will cool into a white dwarf and then eventually into a black dwarf. This entire process will take a few billion years. \nAs you can see, our sun is quite complex and interesting, and now you know more about how it produces the light and heat that all life on Earth depends on. \nhttp://science.howstuffworks.com/sun5.htm
555978
Nuclear Fusion is when nuclei of smaller atoms combine to make a bigger nucleus and release energy. For example, 4 hydrogen atoms can combine to make one helium atom. A hydrogen atom weighs slightly than 1/4 of a helium atom though. In other words the helium that is produced weighs less than the hydrogen that we started with. That lost mass has been converted into energy according to Einstein's famous equation, E=MC^2.
156733
Sun has a nuclear reaction (fission of Hydrogen gas)to radiate energy. Theoratically as much as Hydrogen is being used in the process of energy production the net quantity of hydrogen is being reduced and so net amount of reacting atoms is decreasing. Thus energy of sun is being reduced. However, the rate of decrease in the active mass is so slow that it can not be measured in course of few centuries.\n\nThe much referred worming of air or global worming, as replied here by one other, is due to increasing pollution of air or green effect.
721125
fusion is when two elementary particles collide and combine or fuse to make -- even temporarily -- a new particle. In the graphic below, a form of the hydrogen nucleus -- Tritium -- collides with another form of the hydrogen nucleus -- Deuterium -- to form a new particle. (Deuterium and Tritium are isotopes of hydrogen -- a form of water.) The fused particle is not stable, and quickly decays via the split decay mode into a neutron -- moving very fast, i.e., "hot" -- and a helium neucleus -- also know as an "alpha" particle and energy.\nThe radioactive by-products from fission are undeniably bad. They last for tens of thousands of years and can cause untold problems, the worst of which is through terrosists using the waste products for weapons. The fast neutron from fusion can potentially interact with metals a cause them to become radioactive. This process can be minimized by have neutron shielding between the fusion burn and any metals in the reactor. However, the radioactive metals produced -- and any ash from the fusion burn itself -- is a low-level radioactivity that is not considered dangerous, with half-lives in the tens of years. There is no comparison -- radioactive waste from fission is very dangerous, radioactive waste from fusion is not very dangerous.\nIt is hard for most people to understand where this energy comes from, and how much it is. Most people have heard of Einstein's famous equation:\n\nE = mc2\n\nWhen the fusion reactions listed above occur, a small amount of mass disappears. The small amount of mass is converted into a large amount of energy. How much is large? A typical chemical reaction in which hydrogen and oxygen combine to produce water, releases about 1 eV of energy. The fusion process typically releases 1,000,000 times as much energy. Historically, when people talk about the benefits of nuclear fusion, they refer to how much fuel must be burned to equal to each other.\nNuclear fusion takes water, burns it, releases helium (and a small amount of radiation in the form of neutrons), and converts the missing mass into massive amounts of energy.
399933
The answer is: the sun doesn't burn.  What you are thinking of is combustion, the process of combining oxygen with something to release energy (fire).  What is happening in the sun is nuclear fusion.  Two hydrogen atoms smack into each other with such force that they join together to make a helium atom.  During this process, some of the mass is turned into energy, which is heat and light.  It has nothing to do with oxygen.