How old is the sun?  Why is it not burnt out all these years? How long is it expected to remain in existence?
95335
Astronomers will tell you the Sun is dated at 4.5 billion years old\n\nhttp://www.astro.uiuc.edu/~kaler/AstroBrief/chapter12/sunage.html\n\nThe Sun will one day become a white dwarf and be the fiery death the Bible claims God will bestow upon us.\n\nhttp://imagine.gsfc.nasa.gov/docs/science/know_l2/dwarfs.html\n\nPersonally, I think it's all a farce:\nhttp://www.celestialproducts.com/BA.asp\n\nor maybe I'm just angstrom's away from reality. hmm. I wonder, but not for too long as I may contract Homer Simpson syndrome.
731384
The sun does go through an eleven year cycle where sunspots and electromagnetic storm activity peaks every 11 years or so.  I don't know if it's getting stronger every time, though.  It does affect mankind more every cycle, but thats because we have more and more satellites in orbit all the time, so there's more hardware to be affected.  It won't cause too much trouble on the ground, though.  The Van Allen radiation belts and the ozone layers block most of it.  Mostly it would affect communications, and cause radio static, etc.  I wouldn't get your knickers in a knot over it.
336535
Total life span=8billon+yrs.\nIt may last for another 4.5 billion years.....(and counting)
619304
You asked for it! Ha ha ha ha!\n\nWhat is the sun? Read this.....\nI  INTRODUCTION \n\nSun, closest star to Earth. The Sun is a huge mass of hot, glowing gas. The strong gravitational pull of the Sun holds Earth and the other planets in the solar system in orbit. The Sun’s light and heat influence all of the objects in the solar system and allow life to exist on Earth. \n\nThe Sun is an average star—its size, age, and temperature fall in about the middle of the ranges of these properties for all stars. Astronomers believe that the Sun is about 4.6 billion years old and will keep shining for about another 7 billion years. \n\nFor humans, the Sun is beautiful and useful, but also powerful and dangerous. As Earth turns, the Sun rises over the eastern horizon in the morning, passes across the sky during the day, and sets in the west in the evening. This movement of the Sun across the sky marks the passage of time during the day (see Sundial). The Sun’s movement can produce spectacular sunrises and sunsets under the right atmospheric conditions. At night, reflected sunlight makes the Moon and planets bright in the night sky. \n\nThe Sun provides Earth with vast amounts of energy every day. The oceans and seas store this energy and help keep the temperature of Earth at a level that allows a wide variety of life to exist. Plants use the Sun’s energy to make food, and plants provide food for other organisms. The Sun’s energy also creates wind in Earth’s atmosphere. This wind can be harnessed and used to produce power.\n\nWhile it lights our day and provides energy for life, sunlight can also be harmful to people. Human skin is sensitive to ultraviolet light emitted from the Sun. Earth’s atmosphere blocks much of the harmful light, but sunlight is still strong enough to burn skin under some conditions (see Burn). Sunburn is one of the most important risk factors in the development of skin cancers, which can be fatal. Sunlight is also very harmful to human eyes. A person should never look directly at the Sun, even with sunglasses or during an eclipse. The Sun influences Earth with more than just light. Particles flowing from the Sun can disrupt Earth’s magnetic field, and these disruptions can interfere with electronic communications.\n\nII  PHYSICAL CHARACTERISTICS \n\nThe Sun is large and massive compared to the other objects in the solar system. The Sun’s radius (the distance from its center to its surface) is 695,508 km (432,169 mi), 109 times as large as Earth’s radius. If the Sun were hollow, a million Earths could fit inside it. The Sun has a mass of 1.989 × 1027 metric tons. This number is very large. Written out, it would be the digits 1989 followed by 24 zeroes. The Sun is 333,000 times as massive as Earth is. Despite its large mass, the Sun has a lower density, or mass per unit volume, than Earth. The Sun’s average density is only 1.409 g/cu cm (1.188 oz/cu in), which is a quarter of the average density of Earth.\n\nThe Sun produces an enormous amount of light. It generates 3.83 × 1026 watts of power in the form of light. In comparison, an incandescent lamp emits 60 to 100 watts of power. The temperature of the outer, visible part of the Sun is 5500°C (9900°F). \n\nFrom Earth the Sun looks small, because it is far away. Its average distance from Earth is 150 million km (93 million mi). Light from the Sun takes about eight minutes to reach Earth. This light is still strong enough when it reaches Earth, however, to damage human eyes when viewed directly. The Sun is much closer to Earth than any other star is. The Sun’s nearest stellar neighbor, Proxima Centauri (part of the triple star Alpha Centauri), is 4.3 light-years from our solar system, meaning light from Proxima Centauri takes 4.3 years to reach the Sun. The Sun is so much closer to Earth than all other stars are that the intense light of the Sun keeps us from seeing any other stars during the day.\n\nA  Importance to Earth \n\nEarth would no
970270
it won't be for a long time from now, like 1000s of years, but it will happen.  Planets are basically stars and stars burn out sooner or later.  If it isn't earth that ends first, it'll be the sun that burns out and we can't survive without the sun.
184263
100,000 years ago according to the bible and scientists because the sun is decreasing at 5 ft per hour so if you would add all that up, it would have started 100,000 years ago , it is not a million or billion or else the sun would have been too big for the earth to have survived.
475816
I actually did hear about that in my college Astronomy class. I think it's pretty awesome. I mean, what if our sun burnt out. Maybe we could still have a significant amount of solar energy and radiation that could help us survive. I'm not sure if the star is old enough to develop life or not. It could have already developed it, and we just have no knowledge of it.
214368
I'm going to focus on the word "producing" here.  The sun produces heat and light through thermonuclear reactions in its core.  If those reactions were to stop tomorrow, it would take hundreds of thousands of years for us to find out.  Maybe scientists who study the sun would know sooner.  Energy that is produced in the core has to collide with an immense number of particles on its way to the surface -- so many particles that it takes about one million years for this light to make it to the surface.\n\nEven if the reactions that power the sun stopped tomorrow, it would go on shining for roughly a million years.  No one in our lifetime, or for many generations to come, would be the wiser.
976309
not millions of years, as the previous answers say.  try about five billion years from now.  at that time, the sun will have used up its supply of hydrogen fuel.  it will try to burn off the helium that now fills its core, and expend so much energy in the process that its outer layers will expand beyond the orbits of mercury and venus, and making earth's surface semi-molten (if it doesn't destroy the planet).  it will thus become a red giant.  as it slowly cools and fades, it will shrink to become a white dwarf, and finally die out as a black dwarf.  hopefully before then, we'll have long since been gone, if we haven't destroyed each other by then.
1023696
No there are far older stars. \nThe sun wasn't born it condensed out of nebulous gas and dust.\nThe universe is so large it is possible to see back in time ( and space) to objects like quasars that have not existed for billions of years.\nGod doesn't exist hence never said anything
372861
In around 4 to 5 Billion years when the Sun is swollen in its death throes before it collapses into star known as a white dwarf . In fact the whole Earth will be vapourised.\n\nIf you mean by your question when will it be destroyed environmentally, then that's upto the caretakers of this planet wether that is humans or some other species.\n\nOtherwise the Earth will always have an atmosphere of one kind or another until the Sun begins to die.\n\nJules
364727
Nope...The sun still has plenty of hydrogen, and the only Earth smashing asteroid that we know of is still over 800 years away. Everybody Party!!
161565
Because it has been darkest for longest at this time. Why is the high at around 6:00 pm? same reason. The sun has been at its peak for longest then.
611962
How hot is concentrated light, what is the temp of the sun?\n\nWELL WE HAVE A ENERGY SHORTAGE, ONLY AT SUNSET.\n\n I read about Solar collection in power plants like Solar One.  In these plants the where they make molten salt, for heat transfer for running steam generator. At the reciever of Solar One plant or concentrated light point temperature reachest approximately 1,050 Fahrenheit.\n    \n      THIS LINK IS ABOUT YOUR SUN AND THE TEMPS ARE HOT.\n         SO HOW MUCH LIGHT CAN WE CONDENTRATE MORE  \n           DEVELOPMENT IN SOLAR SAILS\n\nhttp://hyperphysics.phy-astr.gsu.edu/hbase/hframe.html \n\n Earth's Sun is a medium-sized star which lies on the main sequence with 90% of the known stars. It has a effective surface temperature is 5780 K, putting it in spectral class G2. Its mass is 1.989 x 1030 kg and its mean radius is 6.96 x 108 meters. The mass of the sun is over 99.8% of the mass of the entire known solar system, leading de Pater and Lissauer to refer lightly to the solar system as "the Sun plus some debris". \n\nThe sun radiates energy at the rate of 3.85 x1026 watts. Just outside the earth's atmosphere solar energy is received, assuming normal incidence, at the rate of 1340 watts per square meter. \n \n\nThe orbit of Earth ranges from 1.47 to 1.52 x 1011 meters from the Sun. The average light travel time to the earth is 8.3 minutes. \n\nThe radius of the sun at 696,000 km is 109 times the Earth's radius. Its surface gravity is 274 m/s2 or 28.0 times that of the Earth. Its mean density is 1410 kg/m3 or 0.255 times the mean density of Earth. \n\nThe composition of the sun is 71% hydrogen, 27.1% helium and less than 2% of all other elements. \n\nThe center temperature is modeled to be 15.5 million K. The Sun is fueled by the proton cycle of nuclear fusion.\n\nEscape velocity = 618 km/s\n\nSO
851319
The sun’s history \n\n5 billion years ago, a small cloud of gas and dust began to compress under its own weight, or if your a creationist 5000 years ago. As more and more gas began to be crushed on the weight of gravity, hydrogen within the core began to fuse together. This fusion processes, one still sought by earth's scientist makes hydrogen into helium, and release’s incredible amounts of energy. This energy is converted into tremendous amounts of heat and light, which forms the energy source for our planet. Imagine the power you could amass if you were able to corner the market on the amount of sunlight hitting the earth. The cloud from which the sun is formed, fortunately for us, did not use all of its gas and dust to make the Sun; that which was left over, less than one percent of the original material, formed the 9 planets. Incidentally Jupiter could be considered a failed sun, that didn't have sufficient mass to start the fusion process. \n\nLuckily for us in the real estate business the sun has 3 to 4 billion years more of prime building time. As the sun begins to age more and more of its interior will be converted into helium. Once the sun exhausts its source of fuel, it will begin fusing helium into heavier elements. The heaver element carbon, the primary new fusion product, gives off a lot more energy than the similar production of helium. This excess energy will make your property on the sun even more valuable, since the excess energy could be harvest for your use. In fact as the sun pumps out more energy it cause the outer layer of the sun to expand and will engulf the inner core planets up to Mars. This lost of prime real estate will make your investment in the sun even more valuable, since the available area for building will be reduced. Not to mention but the sun's color will change to a pleasing Red color, a nice change of pace from the current yellow/orange hue our sun currently has. .
19839
Brian is right, but I have to add a smart-ass remark that sun will burn up and go out in a few million years, but by then the humankind will either destroy itself, or find a way to move on to other stars.
1113828
The sun will burn out in 4.5 - 5 billion years.  But our planet will die way before that because sun will start dying in 3 billion years... that is if we dont' kill each other waaaaaaay before that.