Could our sun become a white dwarf sooner than we believe?

As was suggested above we can well constrain the lower age limit of the Sun based on the age of Earth.

To do much beyond that you have to start probing the fields of stellar evolution theory and also Helioseismology.

In a nutshell: you take the current luminosity of the sun which represents a quantifiable amount of fusion reactions (on average) in the core, primarily the hydrogen p-p chain which liberates energy at an efficiency of something like .7% of rest mass energy (don't let that low number fool you, fusion is the second most efficient energy release we know of, the first being accretion power).

This gives you a sort of fuel expenditure reading. If you assume that the Sun has been burning more or less constant since it was born (which is reasonable, it can't vary dramatically or life would not have evolved), then you can figure out the amount of fuel spent versus reserved. You can do this by measuring fist the total mass of the Sun by planets in orbit around it (pretty easy) and then by constraining the radius of the core via seismological waves which propagate through the star and give you a reading of the size of the core.

From stellar evolution theory and nuclear physics you can figure out the 'average' density of the core, and if you know the radius from the above method, then you now have a way to quantify the mass in the core.

The fuel expenditure rate can also be read from the solar neutrino flux which is a more accurate current reading of conditions in the core of the Sun. All the numbers here should match pretty well at each stage.

Anyway if you know the fuel burning rate and the rough estimate of the remaining fuel then you can estimate the remaining lifetime of the Sun.

Astronomers can tell how old it is by studying the wavelengths (colors) of light being given off by the sun. Different elements burn different colors, this means that we can see the percentage of each element in the sun, or a rough estimate. They can also tell how fast the sun's nuclear fusion is occurring. It's like an hour glass, just reverse this rate and you get how old the sun is, give or take 500,000,000 million years. Besides, the sun will either consume us as it expands, burn us to a crisp as it expands, obliterate and possibly vaporize earth if it explodes, and pretty much kill us before we get to see it become a white dwarf.

a million would desire to existence re-start up on an inner planet? No, by using fact there does no longer be an inner planet. in spite of the shown fact that the planets closer to the solar than the earth, and probable the earth itself, may be swallowed by employing the pink standard solar and vapourised, so the question does not upward push up. 2 would desire to the scorched earth restart existence itself? No back, i'm afraid. The earth because it extremely is replace into formed by employing, between different issues, huge and prolonged bombardment by employing smaller bits and products of the photograph voltaic nebula - which comprise, we have faith, comets bringing our water to earth over a protracted era. the unique water the earth had while it forst formed could have been lost into area in the process its mo;ten area. There may be no equivalnet bombardment after the solar grew to become a white dwarf, so the ineffective. baked earth might stay that way.

The Sun and the Earth formed at much the same time and we can reliably date the Earth using radiometric dating on the oldest rocks.

Because astronomers specialize in this subject. They compare our sun's size, flares, and many other traits to other suns in the universe. IF 2012 were to be true, it will not be because of the sun exploding.

even if they are off by a billion years and it is only 3 billion years old, who cares? i'll be alive for about 100 years max. the chances of it going in my lifetime are microscopic. i'll take my chances.

i wouldn't worry about, you'll be dead then anyway.