So you think the human race is going to survive the next billion years?
We once considered the Sun a planet, and it took finding Uranus to decide that moons should really be their own category of thing. These are all the places in our solar system that were once planets—but now have far more suitable names.
If you mean simply "is not visible" then very little, we'd have a second of darkness, not unlike an eclipse, and then we'd be back to normal. If on the other hand, you mean "ceases to exist momentarily" then you're talking about something else entirely.
Trying to watch the sun's explosions with your naked eyes is a recipe for blindness, but luckily NASA has a couple of telescopes that can show you all that fusion glory with none of the permanent ocular damage. Take, for instance, this 200,000-mile long canyon of fire.
For as long as we've bothered to care about heavenly bodies other than our own, we've thought that the size of the Sun varies throughout its 11-year solar cycles. Intense magnetic forces, the theory went, rendered it as malleable as a sturdy stress ball. That was a good theory, backed up by decades of data.
You might have had a peaceful day here, but up above, some serious solar violence just went down: an ejection of scorching plasma just erupted from the Sun. Enough to burn its away across ten Earths.
The fruits of today's Sun UK hack are starting to dangle down: LulzSec (out of retirement?) and Anon are tweeting logins of some serious British media brass. Foremost? Rebekah Brooks, the epicenter of England's voicemail hacking scandal. Update: phone numbers!
Fact: Space is a freak show. But that link goes to a post about deep space, beyond our solar system. Thanks to the IBEX probe, however, we're quickly learning that our own backyard is rife with the freaky-deaky too.
Just remember, it could happen to any of us—at any time. Perhaps it will be the draw of soft Barry White playing on our alluring RED Nano, or a particularly revealing angle as Lara Croft illuminates our smooth, curvy, porcelain-white Xbox 360. Indeed, the question is really less "how" than "when".