[RightWhale]

can't just "go out".

There was some cafeteria speculation a couple years ago that the sun has already gone out. It is dark inside and the surface is glowing from residual heat. Won't be long until we notice, maybe a few thousand years.

[Ernest_at_the_Beach]

Geeezzzz:

Everyone needs to read this book:

___________________________________________

100 Billion Suns: The Birth, Life, and Death of the Stars
by Rudolf Kippenhahn "The earth revolves around the sun at a rate of 30 kilometers per second in an almost circular orbit measuring 300 million kilometers in diameter..." 

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

Review
An admirable introduction to the difficult subject of stellar evolution accurately aimed at the general reader.

Product Description:
How are the nuclear power plants we call "stars" formed? Where do they get their energy and how do they die--and what does this suggest about the future of the universe? One of the most popular books written on astrophysics, 100 Billion Suns provides an exhilarating and authoritative life history of the stars.

[clyde asbury]

Won't be long until we notice, maybe a few thousand years.

Missing solar neutrinos were the problem, IIRC. I wonder if they've been found.

[Phsstpok]

As Rightwhale mentions in post 39:

There was some cafeteria speculation a couple years ago that the sun has already gone out. It is dark inside and the surface is glowing from residual heat. Won't be long until we notice, maybe a few thousand years.

This is not just cafeteria speculation but a current topic of debate among astrophysicists, particularly trying to find explanations why there are fewer neutrinos being detected from the sun than are predicted by the prevalent theories.  A paper on the University of Toronto Physics web site raises this possibility:

There are two possible explanations for the solar neutrino deficit.  The first, and simplest, is that the sun is producing fewer neutrinos than we think. One dramatic possibility is that the sun has stopped burning at its core and is already in the final phases of the stellar life cycle. Fortunately for us, it would still take several million years before the energy output of the sun would be noticeably reduced.

Note that they say it would "still take several million years" for us to notice the change.

Another possibility is that the sun's nuclear fusion is cyclical and that we are going through a "downtime" in solar fusion.  Whether it is permanent or not, the possibility exists that the sun has already 'gone out.'

By the way, my favorite SF story about the sun messing up, in my mind, is Larry Niven's "Inconstant Moon," which was made into an episode of the revived Outer Limits TV show.  In this case it's a massive solar flare event which occurs while Los Angeles is on the far side of the Earth from the sun.  He does a great job speculating about the first telltales and then the growing affects of the event.  His characters are a bit less convincing (which is typical of his stories) but still fun.