We're all gonna die!

The Sun Will Eventually Engulf Earth--Maybe
Researchers debate whether Earth will be swallowed by the sun as it expands into a red giant billions of years from now
By David Appell

The future looks bright—maybe too bright. The sun is slowly expanding and brightening, and over the next few billion years it will eventually desiccate Earth, leaving it hot, brown and uninhabitable. About 7.6 billion years from now, the sun will reach its maximum size as a red giant: its surface will extend beyond Earth’s orbit today by 20 percent and will shine 3,000 times brighter. In its final stage, the sun will collapse into a white dwarf.

Although scientists agree on the sun’s future, they disagree about what will happen to Earth. Since 1924, when British mathematician James Jeans first considered Earth’s fate during the sun’s red giant phase, a bevy of scientists have reached oscillating conclusions. In some scenarios, our planet escapes vaporization; in the latest analyses, however, it does not.

The answer is not straightforward, because although the sun will expand beyond Earth’s orbit, or one astronomical unit (AU), it will lose mass along the way. As a result, Earth should drift outward as the gravitational tug lessens over time. (At its maximum radius of 1.2 AU, the sun will have lost about one third of its mass, compared with its current heft.) In this way, Earth could escape solar envelopment.

But other factors complicate the analysis. Drag on the planet from the sun’s outermost, tenuous layers will cause Earth to drift inward. Smaller forces from the other planets—all in turn reacting to the same reducing, expanding sun—are even more difficult to account for completely.

Earlier this year two teams reported different kinds of calculations indicating that Earth will be swallowed up by the sun. In a calculation that would thrill any college junior studying classical mechanics, Lorenzo Iorio of Italy’s National Institute of Nuclear Physics used perturbation theory. It simplifies analyses by dropping relatively small factors, thereby making complex equations of motions that describe the interactions between the sun and Earth mathematically manageable. Assuming that the sun’s yearly mass loss (currently about one part in 100 trillion) remains small for the duration of its evolution to the red giant phase, Iorio calculates that Earth will move outward at about three millimeters a year, or only 0.0002 AU by the sun’s red giant phase. But at that point the sun will balloon up, in only a million years, to 1.2 AU in radius, thus vaporizing Earth.

more:
http://www.sciam.com/article.cfm?id=the-sun-will-eventually-engulf-earth-maybe

Overheated: Researchers debate whether Earth will be swallowed up by the sun as it expands to its red giant state billions of years from now.

be devoured by a black hole created by the LHC, so all this business about the sun destroying us 7 1/2 billion years from now is irrelevant. :sarcasm:

(Seriously, thanks for the article excerpt and the link. Interesting read!)

We should all start worrying in about 7.59999999 billon years.

What will I do with it all? :P

...will realize that the invisible hand of the free market isn't going to make things all better. However, "expanding sun deniers" will spend billions (and billions) proving that the massive fireball covering a quarter of the sky isn't really there and that the sun is still really only ½º wide.

I suppose if the period of time were long enough, it would heat up some of the planets further away and spark life in places where it's now cold. Would that be possible?