SableWyvern said:
Unfortunately, even if there is an excellent basis for that sort of claim, it would require either blind faith or years of study to be able to rely on it. It's one thing to say to the layman, "This is the truth as we know it, and you should work on the assumption we're correct." I take a lot of scientific opinion at face value, on that basis. It's another entirely to expect someone to accept that, "We'll never be proven wrong in any significant fashion."
Well the basis for that claim is in the solidity of the science. There's plenty of areas of science where the uncertainties are such that one simply can't say "this is never going to change". Relativity was proposed because there were a a few major uncertainties and oddities about Newtonian gravity, and it solved those problems... but there are still a few more nagging issues with relativity even though they're a lot more obscure and much less obvious to anyone who isn't a deep student of the field. So maybe one day someone will come up with a testable theory that will extend the relativistic universe and reveal new possibilities to us that for all we know may include more options for FTL travel (and as I said, there are already options for FTL travel, like wormholes).
But stars? There are no such
fundamental uncertainties there (at least, none that are remotely credible. You get the odd wacko claiming that all stars are powered by black holes or something, but there's no evidence for that whatsoever and a lot of reasons why they can't be). We went through the "uncertainty" stage there a couple of centuries ago (e.g. when Kelvin proposed that stars were powered by
gravitational contraction alone, but that generates far too little heat on its own), but now we KNOW how they're powered and how they work. They fuse hydrogen atoms in their core to make helium, and that releases energy. When that hydrogen fuel is used up, we know how the structure of the star changes because we know how the interplay between gravity and pressure works in the star. So we know it'll get bigger and cooler when it burns hydrogen in a shell around the helium core, or when it starts to burn helium and so on. We know there's a lot less helium than hydrogen, and so we know the stage where it burns helium can't last for long, which is how we know the red giant phases are short.
All of this follows on from what came before. It's well known and well understood, and it's not going to change on a general level, any more than our understanding of what fire is, or what liquids are is going to change. While there are mysteries on an specific level - for example, why does one star act a certain way while others act differently (probably down to differences in chemical makeup), or how do shockwaves travel through stars - the knowledge about their general evolution is rock solid.
Ditto for planets - there's a lot of specific mysteries, but we know that a planet with a given mass and radius needs to be at a certain temperature to be able to hold onto specific gases, and if those conditions aren't met then it will lose them. Again, specifics can change that - strong solar wind could strip atoms off faster than anticipated, or maybe some chemical effects in the atmosphere or a strong planetary magnetic field can delay the atmospheric loss - but all things being equal, the general details are solid.
And all of it is based on observation and experimentation. When the theories of relativity or radioactivity came along they didn't change reality itself - just our understanding of it. Planets continued to move around their orbits as they had always done before, and radioisotopes continued to decay and emit particles just as they'd done before. The only difference was that we had a better idea of what was going on (and in some cases had learned to actually recognise what we were seeing for the first time). We didn't suddenly throw away Newtonian Gravity and declare that things like F=Ma weren't valid anymore, because they still worked and still agreed with what was observed in general situations.
So even if a new theory of stellar evolution was to come along, it wouldn't change anything I've said about it here. Stars will still shine by the fusion of light elements into heavier ones in their interiors, and they'll still expand and contract based on how quickly they burn their fuel and what they're burning. Any brand new theory of stellar evolution still has to explain everything we've already observed, after all.
Perhaps I overstated it by saying that it'd
never change, but I am extremely, supremely confident that the general picture of stellar evolution that I described in my article is valid and that sequence of events will not be changed even if any new theories come along and supplant what we know already.
I am not, however, anywhere near as confident that Relativity is anywhere near as inviolate and that it will remain unchallenged in the future, and in fact I am quite sure that something better will probably come along to expand on it within the next century. For example, we don't have a unified "theory of everything" yet, where gravity is wrapped in with the other unified forces - if relativity was so inviolate and so certain then we surely wouldn't be searching so hard for such a theory and investigating all these exotic membranes, string theories and multidimensional sub-quantum knots in the process. If and when we do pull it all together then the resulting theory may tell us that yes, actually it is possible to circumvent the speed of light in certain circumstances. Or it may not - but the "fundamental principle" that captainjack claimed is inviolate clearly has a question mark hanging over it. Whereas we know exactly how much energy one gets out of fusing hydrogen to helium and how that works, so it isn't so dubious.
Maybe part of the problem is that while the statement "This is the truth as we know it, and you should work on the assumption we're correct." is perfectly valid, a lot of laymen that I've seen appear to twist that into "This is the truth as we know it, but you should work on the assumption that we're wrong" with no good reason to do so, and then use that as an excuse to toss science out of the window on general principle because they don't like the implications. That might be part of the reason why I come out as so defensive about it.