The problem with the /. lead-in and the SD article quoting an astronomer is that THEY ARE BOTH PROBABLY WRONG! I have this problem all the time when I see shows on the Discovery Channel or the Science Channel where they explain how the sun *will* die in 5 billion years (The implicit assumption is that the current natural laws of physics will apply for that period -- and within an intelligent species framework that may be completely false. What they SHOULD be saying is "The sun, if allowed to continue on its natural evolutionary course, will die in 5 billion years." But qualified it, of course, sounds less dramatic. IMO, the probability of that occurring, is nearly zero. Why? Because our solar system is inhabited by an intelligent technological species and if we could stop talking about the next great iPhone app or global warming [1] for just a minute we might begin a discussion about how to develop real molecular scale nanotechnology [2] and the best way to approach dismantling the sun so it never becomes a red giant.
For the unaware, we are "dismantling" planets *now* -- what do you think launching satellites to explore foreign bodies (that don't return to earth) or crashing them into foreign bodies (where some of the material ejected may reach escape velocity for said body) is??? Now given the influx in asteroid/comet/solar ion debris I suspect the Earth is still in a net mass gaining state -- but we know how to invert that situation should we choose to do so. We do understand the physics involved and have the technology to manage it.
What most people are unaware of is that there has been some thought devoted to planetary dismantlement. Freeman Dyson did some (in discussing in 1960 in Science the dismantlement of Jupiter to create a Dyson shell) [1]). David Criswell [3] thought of some more/better paths to dismantlement.
So the answer is very clear -- we dismantle the sun at a rate which slows its aging -- so the 5 Billion years number becomes ENTIRELY fictional -- we cannot predict what a technological civilization would do. But there are significant odds that it might dismantle the sun to the point where its lifetime is on the order of that of a red dwarf (several hundred billion years or more with no red giant phase). Ample time to decide when and how to move to a new star with a new lease on life.
1. In a molecular nanotechnology enabled world, there isn't really a "global warming" perspective to worry about. It is too simple to take the CO2 out of the atmosphere and store it in some inert form. People who are in the hard-core "global warming" camp should ask themselves why when I wrote the paper "Sapphire Mansions" in 2001, did I not instead call them "Diamond Mansions"? [4] It was because I did not wish to encourage the sucking of CO2 out of the atmosphere to the extent that all plants would DIE!
2. Molecular scale Nanotechnology has been defined and reviewed since 1992 (Drexler, Nanosystems) -- over 15 ago!. During that period nobody has said it is "incorrect", nobody has said it violates "laws of physics", at the most people may have said it is "hard". But if I can point out 4+ paths to get there -- so one has to wonder if it is simply not a lack of technological imagination that keeps us from already being there (and as a species having such methods in our technology toolbox).
3. David R. Criswell from Interstellar Migration and the Human Experience, Eds.: Ben R. Finney and Eric M. Jones, University of California Press, 1985, Chapter 4, pp 50-87.
4. It may be worth noting that the "Sapphire Mansions" phase of human development I consider to probably be limited to a few decades -- while the "Matrioshka Brains" phase lasts the life of our engineered sun (or longer).
