how many years for heat generated in the sun's core to reach its outer layer,the photosphere?
817631
Nobody really knows, but it may be as much as 50 million years or as little as 17,000 years.
190329
A sunspot is a region on the Sun's surface (photosphere) that is marked by a lower temperature than its surroundings and intense magnetic activity, which inhibits convection, forming areas of low surface temperature. Although they are blindingly bright, at temperatures of roughly 4000-4500 K, the contrast with the surrounding material at some 5700 K leaves them clearly visible as dark spots. Next year is expected to be a cyclical peak in the sunspot cycle
663516
150000000 kilometres from the sun\n\nSo, that comes to 166666.67 hours\n\nThat is 6944.44 days\n\nwhich is 19 years, so f.
1018347
The surface of the Sun, called the photosphere, is at a temperature of about 5800 Kelvin/ 5 526 degree Celsius/ 9 980 Fahrenheit.\n\n\nErm guys, the lithosphere is the brittle uppermost shell of the earth, not the sun.  *just to clarify out things a bit*
527742
The sun is a star.  All stars eventually burn out.  See facts below:\n\nThe Sun will last about 5 billion years as it is now, a so called Main Sequence Star, and burns 700 billion tonnes a second. This may look like a lot but the Sun actually burns Hydrogen, a gas, and it turns it into Helium, another gas. This happens in the central part of the Sun, its Core, through a process called nuclear fusion. A side effect of fusion is that light and heat are created. So only a small amount of this Hydrogen, only a few Billion tonnes a second, is actually burned off to create light. I would not worry that so much Hydrogen is burnt every second as the sun has a mass of 1.989 times 1030Kg. That is 1,989,000,000,000,000,000,000,000,000,000,000 Kg, or one million nine thousand, eight hundred and nine billion, billion, billion Kg. So the odd few Billion tonnes will not be missed. \n\nWhat is really interesting is what happens after the Hydrogen has been used up in the Suns core. At this point in our Sun's life the central part of the Sun, its core, shrinks and heats up and its atmosphere will expand to cover the Earth, and possibly Mars. The Sun is now called a Red Giant Star. If you can find the constellation Orion, the bright red star in the upper left hand corner is a Red Giant called Betelgeuse. After only a few million years the core will shrink again and the our Suns atmosphere will be blown off into space to become Planetary Nebulae. What will be left is a type of Star called a White Dwarf. This will last for many tens of billions of years, slowly cooling and getting dimmer. So, our star, the Sun, will last for 5 Billion years as it is, a few million years as a Red Giant, and finally tens of Billions of Years as a White Dwarf.
698399
we still have about 4 billion years to go on that\n\nhttp://en.wikipedia.org/wiki/Sun
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.
1140436
The earth moves around the sun at a mean distance of 93,000,000 miles.\nAnother point of interest, the earth is more than 4500 million years old.
417138
On it's axis I presume. I'm afraid it's not definitive at all:\n\n25 days at the equator\n27 days 35 degrees of latitude from the equator.\n33 days 75 degrees of latitude from the equator.\n\nThis is for the "surface" of the sun.
805940
The people who said it is closer to 4.5 to 5 *billion* years, are correct.\n\nThe sun is a class G star, which has a lifespan of about 10 billion years (the main part of it's lifespan ... after 10 billion years, it expands and goes through a second, larger but shorter-lived phase).  The sun is about 4.5  to 5 billion years old, which means that it's about halfway through its main lifespan.   So it will be here a little bit more than it has been here already ... which is a *very* long time.\n\nIf the earth hasn't been physically destroyed by an asteroid, or some man-made catastrophe we cannot imagine yet, I am quite sure that life will still be going strong on the earth at that time .. but that humans will be long gone.   Either we will have left after making the planet uninhabitable for ourselves, or we will have killed each other off, or we will go extinct through natural causes (like an asteroid that doesn't destroy the planet, but does wipe out most life).  But in all cases, some life forms will survive, and will do quite fine without us.\n\nEven if we blew each other to pieces with nuclear weapons, and wiped out almost all life on the planet due to radiation, some life would survive the radiation (e.g. in the deep oceans) and life would eventually bounce back ... and would begin the process of evolution all over again.  That's what life does.
425682
The Core: The Sun's core has a tremendously high temperature and pressure. The temperature is roughly 15 million °C. At this temperature, nuclear fusion occurs, turning four hydrogen nuclei into a single helium nucleus plus a LOT of energy. This "hydrogen burning" releases gamma rays (high-energy photons) and neutrinos (particles with no charge and almost no mass). \n\nThe Radiative Zone (or radiation zone): The next layer out from the core is this zone which emits radiation. This radiation diffuses outwards. The temperature ranges from 15 million °C to one million °C. It may take photons of radiation millions of years to pass through the radiative zone, as they gradually make their way outwards. \n\nThe Convective Zone: In this next layer, photons continue to make their way outwards via convection (towards lower temperature and pressure). The temperature ranges from one million °C to 6,000 °C. \n\nThe Photosphere: This is the lower atmosphere of the Sun and the part that we see (since it emits light at visible wavelengths). This layer is about 300 miles (500km) thick. The temperature is about 5,500 °C. \n\nThe Chromosphere: This reddish layer is an area of rising temperatures. The temperature ranges from 6,000 °C (at lower altitudes) to 50,000 °C (at higher altitudes). This layer is a few thousand miles (or kilometers) thick. It appears red because hydrogen atoms are in an excite state and emit radiation near the red part of the visible spectrum. \n\nThe Chromosphere is visible during solar eclipses (when the moon blocks the Photosphere). \n\nThe Corona: This is the outer layer of the Sun's atmosphere. The corona extends for millions of miles and the temperatures are tremendous, reaching one million °C. \n\nHoles in the corona occur where the Sun's magnetic field loops out into space. These coronal holes may be the source of the solar wind, a stream of energetic particles that permeate the Solar System.
551301
The interior of the Earth reaches temperatures of 5650 ± 600 kelvins [3] [4]. The planet's internal heat was originally generated during its accretion (see gravitational binding energy), and since then additional heat has continued to be generated by the decay of radioactive elements such as uranium, thorium, and potassium. The heat flow from the interior to the surface is only 1/20,000 as great as the energy received from the Sun.
865349
Energy in the form of photons is generated in the sun's core. Photons like to take off at the speed of light, so they do. But they move only 1micron before running into(being absorbed by) a gas molecule. That's because the gas atoms at the center of the sun has a pressure of 250 billion times the earth atmosphere's sea level pressure. That is why gas atoms are so hard for photons to miss. But the gas atom gets so excited with the extra energy it carries from that hot photon that it lets go of another photon, that promptly runs into another gas atom. This emitting & absorption occurs 100 million trillion times PER YEAR.  You'd think all this elbowing going on that it would get to the sun's surface fairly quickly. But this radiative process takes from 30,000 to 200,000 years to make it only about 55% of the way to the sun's surface. But once it makes it to this higher convective layer of the sun(like the earth atmosphere's lower convective atmosphere), then the energy is transported fairly quickly to the sun's surface.
845575
Well, the solar energy received by Earth is considered a constant. The heat from residual internal sources is considered to be minimal compared to the amount received by the Sun. Also the idea of a constant temperature is relative to the scale of time and space you choose. I'm not going into variations possibly due to sunspot occurrence, orbital, precession, axis wobble, volcanic, meteor impacts, nor seasonal changes.\nHere is a general model of energy transfers, heating and temperature.\nThe amount and wavelength of energy absorbed by a substance or blackbody causes it to heat to a particular temperature and radiate at a particular wavelength. Though the atmosphere is of a layered, mostly permanent composition and the Earth surface is not contiguous, this helps understand the effect of radiant energy on Earth. The reactions of the Sun make it so hot the radiant energy is essentially short wave (high frequency). Consider 100 units of solar sw received by the Earth (insolation), the atmosphere absorbs 25 (mostly due to ozone in the stratosphere) and reflects or scatters 25, while the water/terrain at the surface absorbs 45 and reflects 5. As the terrain and atmospheric gases absorb the sw energy they heat, but not too hot, and radiate long wave energy (low frequency).\nThe Earth surface radiates 104 units of lw - 100 to the atm and 4 out to space. The atm radiates 154 units - 88 back to Earth and 66 out to space. How can this happen and where does the additional energy come from?\nThere are several parts of this development.\nPart of the reason is the atm is a layered, mostly gaseous composition that exchanges energy amongst the layers, the Earth surface, and out to space. Another part is the other ways energy is transferred, such as the convection and turbulent flow of gases that transfer latent and sensible heat between the surface and atmosphere. You experience this when water is transported and goes through its various phases to develop the local weather.\nLets give these processes values. Convective processes values account for 22 units of latent heat and 7 of sensible heat.\nNow tally the total energy absorbed by the surface as 45 + 88 = 133 and the atm as 100 + 25 = 125. The convective processes ensure the energy balance by transferring 29 units of energy from the surface to the atm to obtain the 104 units and 154 units mentioned earlier. This leads to development of a mean global temperature as we know it at 15 deg C.\nNotice how much the atm is relied upon to transfer energy out to space? Changing the atm composition with additional variable/ long term gases, particulates, and aerosols can alter the events.\nParticulates and some gases can cause more reflection at the top of the atm resulting in less insolation, less heating, and lower temperature. Addition of some gases into the atm can increase the absorbtion of lw radiation or prevent it from being transferred to space. When it comes back to the surface, additional heating and a temperature increase will result if the convective processes cannot adjust for the increased energy.
281067
Source  The mean surface temperature of the Sun is 5506°C (9944°F) \nThe mean core temperature of the Sun is 15,000,000°C(27,000,032°F)
1142458
Our sun will expand and engulf the earth and turn it into a ball of molten rock, then vapor.  Run... this will happen in about 5-6 billion years.
899150
Barring one of these, http://www.livescience.com/technology/10ways_destroyearth.html in about 5 billion years the sun will have exhausted most of it's hydrogen and will swell up to a red giant, engulfing the earth. As our blackened, burned-out cinder of a planet orbits inside the sun, it will be plowing through solar material, and will gradually spiral into the core, where it will fly apart shortly before impact and be smashed into it's base elements with little fanfare.