Fact is, the Sun's life cycle based on what we currently observe, on what we've do ented so far, and on observations of other stars in their respective life cycles... is all driven by nuclear physics...
The Sun's nuclear reactions have slowed down over time (measurable fact)... as they do the amount of hydrogen that is consumed also decreases... if today's consumption rates bear any relevance to the past, logic would dictate that past hydrogen consumption rates were faster... meaning the Sun had to be more massive. If the Sun was more massive, it had to be larger in size... any extrapolation model attempting to pin point that exact size, however, would contain its fair share of speculation. I know that... nevertheless we can come to that conclusion based on what we've come to learn about our studies of the Sun. What is poignantly clear based on Earth's distance from the Sun, then, is that a 4 billion year model would have irreparably scorched earth's surface, completely evaporated it's atmosphere and all sources of liquid water... Earth would essentially look like Mercury or our very own moon...
That observation aside.... there is a strong ideological rift between what most people think science is capable of achieving and what it actually can...
In fact, most people don't really question the natural processes that led to earth's current state... the common 'educated man' simply accepts them and moves on because they acknowledge that science has affected all of our lives in positive, practical ways...
that tangible impact, however, has biased our view on what science is able to accomplish...
While the scientific toolset has been a very powerful tool in developing useful technologies... and is extremely methodical at explaining today's processes it does have limits... the common 'educated man' however rarely confronts that question... In their mind, if science can explain today's natural phenomena with accurate precision, then we can allow those same scientific principles to accurately explain the past... no?? Science doesn't quite work that way... The past isn't always reproducible... it can't be tested on... retrivable data is incomplete and paints only partial pictures... ultimately, the past can only be observed forensically. The scientific criteria and standards we apply to studying say a tangible set of chemical reactions, or some atmospheric phenomenon, isn't fully transitive to measuring the past.... Especially when we start tossing around staggering numbers that are completely incompatible with our personal experience... I mean a million years is a very long time! How about 250 million years? 1.2 billion years? 4.6 billion years? 13 billion years?

. Those numbers have little relevance to the human mind... and so we've blindly embraced them... after all, we percieve that the scientific establishment has our best interests at heart... or better, that it's completely objective on all such matters... we're duped into thinking Science can never have an agenda... (although the global warming debate seems to have opened a few eyes on that one)...
Ultimately however, we've violated the scientific principles we've established in attempting to quantify processes that supposedly existed millions and billions of years ago. The scientific establishment has errected a house of lies when pertaining to their explanation of our past... they've intricately layered that lie to encompass all fields of study even though more "holes" are poked into a multibillion-year model the more they try to extend that envelope... Ah... But feel free to think what you want... I'm not attempting to change your mind.
After all, you've never once admitted to being wrong about anything... at least not on this forum. Your perspective is completely full-proof, I know... So rather than belittling my own perspective... ignore it... and move on. I don't want to enter another back-and-forth argument with someone who has been incapable of conceding or budging on anything...