What and nuclear fusion help keep the suns shape?
953138
Gravity, because the sphere is the most economical shape in the universe.  It holds the most mass in the smallest area.  It is why planets have their shape as well, I was not aware that Nuclear fusion had any effect on the shape of the sun...\n\nmay you forever learn and forever ask
337972
Mostly Hydrogen.\n\nAt the center of the Sun, where its density reaches up to 150,000 kg/m3 (150 times the density of water on Earth), thermonuclear reactions (nuclear fusion) convert hydrogen into helium, releasing the energy that keeps the Sun in a state of equilibrium. About 8.9 ×1037 protons (hydrogen nuclei) are converted into helium nuclei every second, releasing energy at the matter-energy conversion rate of 4.26 million tonnes per second, 383 yottawatts (383 ×1024 W) or 9.15 ×1010 megatons of TNT per second. The fusion rate in the core is in a self-correcting equilibrium: a slightly higher rate of fusion would cause the core to heat up more and expand slightly against the weight of the outer layers, reducing the fusion rate and correcting the perturbation; and a slightly lower rate would cause the core to shrink slightly, increasing the fusion rate and again reverting it to its present level.\n\nHydrogen 92.1%\nHelium 7.8%\nOxygen 0.061%\nCarbon 0.030%\nNitrogen 0.0084% \nNeon o.0076%\nIron 0.0037%\nSilicon 0.0031%\nMagnesium 0.0024%\nSulfur 0.0015%
419301
The sun is actually made up of hydrogen gas. The "burning" you speak of is the fusion of hydrogen in to helium, which emits extreme amounts of light and energy.
640490
Up until the time that the earth started forming, the sun had time (I can't speculate, but probably a few billion years) to begin it's nuclear fusion and begin burning. Sol would have been surrounded by thick clouds of dust, ice and gases (see planetary nebulae). The particles of gas and dust began to clump together into larger and larger pieces and began spinning around the sun either falling in their maintainable orbits or falling back into the sun. These clumps continued to come together and the planets were formed in their respective distances around the sun.
744404
The Sun is the most prominent feature in our solar system. It is the largest object and contains approximately 98% of the total solar system mass. One hundred and nine Earths would be required to fit across the Sun's disk, and its interior could hold over 1.3 million Earths. The Sun's outer visible layer is called the photosphere and has a temperature of 6,000°C (11,000°F). This layer has a mottled appearance due to the turbulent eruptions of energy at the surface. \nSolar energy is created deep within the core of the Sun. It is here that the temperature (15,000,000° C; 27,000,000° F) and pressure (340 billion times Earth's air pressure at sea level) is so intense that nuclear reactions take place. This reaction causes four protons or hydrogen nuclei to fuse together to form one alpha particle or helium nucleus. The alpha particle is about .7 percent less massive than the four protons. The difference in mass is expelled as energy and is carried to the surface of the Sun, through a process known as convection, where it is released as light and heat. Energy generated in the Sun's core takes a million years to reach its surface. Every second 700 million tons of hydrogen are converted into helium ashes. In the process 5 million tons of pure energy is released; therefore, as time goes on the Sun is becoming lighter. \n\n \n\nThe chromosphere is above the photosphere. Solar energy passes through this region on its way out from the center of the Sun. Faculae and flares arise in the chromosphere. Faculae are bright luminous hydrogen clouds which form above regions where sunspots are about to form. Flares are bright filaments of hot gas emerging from sunspot regions. Sunspots are dark depressions on the photosphere with a typical temperature of 4,000°C (7,000°F). \n\nThe corona is the outer part of the Sun's atmosphere. It is in this region that prominences appears. Prominences are immense clouds of glowing gas that erupt from the upper chromosphere. The outer region of the corona stretches far into space and consists of particles traveling slowly away from the Sun. The corona can only be seen during total solar eclipses. (See Solar Eclipse Image). \n\nThe Sun appears to have been active for 4.6 billion years and has enough fuel to go on for another five billion years or so. At the end of its life, the Sun will start to fuse helium into heavier elements and begin to swell up, ultimately growing so large that it will swallow the Earth. After a billion years as a red giant, it will suddenly collapse into a white dwarf -- the final end product of a star like ours. It may take a trillion years to cool off completely.
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......
944935
There's not much question that the sun is a nuclear fusion machine. You don't need this direct evidence
949723
Jupiter was never quite large enough for nuclear fusion to start. If it would have been larger it would have started nuclear fusion and become a star.\n\nA little about nuclear fusion and the sun.\n\nThe Sun, like most stars, is a main sequence star. This means that it generates its energy by nuclear fusion of hydrogen nuclei into helium and is in a state of hydrostatic balance, neither contracting nor expanding over time. About 3.6×1038 protons (hydrogen nuclei) are converted into helium nuclei every second, releasing energy at the matter-energy conversion rate of 4.3 million tonnes per second, 380 yottawatts (3.8×1026 W) or 9.1×1010 megatons of TNT per second. The rate of nuclear fusion depends strongly on density, so the fusion rate in the core is in a self-correcting equilibrium: a slightly higher rate of fusion would cause the core to heat up more and expand slightly against the weight of the outer layers, reducing the fusion rate and correcting the perturbation; and a slightly lower rate would cause the core to cool and shrink slightly, increasing the fusion rate and again reverting it to its present level.
586906
God doesn't exist.  The Sun creates energy through nuclear fusion.  \n\nNuclear power is the only thing left to power the Sun for as long as it has been shining. There are two types possible: fusion and fission. They both transform the nucleus of an atom into another type of nucleus. Fission produces energy by breaking up massive nuclei like uranium into less massive nuclei like helium and lead. Fusion produces energy by fusing together light nuclei like hydrogen to make more massive muclei like helium. Atomic power plants and the Atom Bomb use fission to get the energy. Stars (like the Sun) and Hydrogen bombs use fusion.
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
7997
The result is there for all of us to see. The stars and other celestial objects are the result of many such nuclear reactions. The sun is a big fusion reactor. Beginning with the lightest elements like helium and hydrogen the process of fusion gives rise to heavier and heavier elements. Some times stars are overcome by their own mass and implode to become a black hole or explode as a supernova releasing enormous amounts of matter and energy into space. In comparison the worlds biggest nuclear bomb will appear like a pop-gun. Will the sun implode or explode. Luckily  - no. But over time it will swell into what is called a red giant, swallowing Mercury and Venus. But I think by the time that happens we would have colonised Mars!
387463
This question could be interpretted two different ways: (1) What drives the sun to produce heat/enegery? and (2) Describe the process of using the solar energy to power modern conventions.\n\nSomebody else already attempted the latter, so I'll go for #1.\n\nThe sun, right now, is fusing hydrogen into helium to produce its energy.  It's been doing this for a long time, and will continue to do so until it runs out of hydrogen.  When this happens, it'll start fusing the helium, and so on.\n\nHope this helps.
476232
A star shines because it is undergoing nuclear fusion (from hydrogen to helium), producing energy (light).
70587
The Sun is not 'on fire'.  It is a giant ball of plasmsa that is undergoing a constant fusion reaction at the core.  In the Sun, there is so much preasure (because of its mass) that hydrogren atoms are fused together to make helium.  Occassionally the preasure is so intence that fusion occurs between heavier elements as well, but right now the Sun is in a point of its life-cycle where the reaction rate is stable.  However, the Sun will eventually 'run out' of easily fusable materials.  As a result, it will attempt to fuse heavier and heavier elements, which is less efficent, and the Sun will eventually stop 'burning'.  Though this will take billions, not hundres, of years.
401857
The sun gives us light because of nuclear fusion-two atoms of Hydrogen are combining in huge quantities to form one atom of Helium. The mass of two atoms of Hydrogen are slightly more than one atom of Helium, which is mono atomic.The difference in this mass is converted to energy in the form of Heat and Light, rays of which don't need a medium to travel.
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.
162981
Stars use nuclear fusion to liberate the energy we perceive as light and heat.  When a star runs out of Hydrogen to fuse, it begins to fuse Helium.  This continues up the chain of elements up until Iron.  A star cannot make the jump in energy needed to go beyond this point.  With each change in fusion matter, the stars energy output increases, more heat causes the star to expand more and more.  If the star is massive enough, when it "runs out" of fuel, it will collapse upon itself in one final massive explosion of energy.  We call these Nova, or Super Nova.  The remnants of smaller Nova are Pulsars, or Neutron Stars.  The only matter left are Neutrons, no protons or electrons, no electron cloud.  Tightly packed, the material from a Neutron star is the most dense substance known.  If the star is too massive to form a Neutron star, it forms a Black Hole instead.  Stars that are not massive enough to go Nova, just burn out and cool to a brown dwarf.