Thoughts & Theories on our Sun

[Spiderrific]

I been reading about the sun and how it'll affect our Earth later on. Not a lot but some. And if what I read is true, our sun will be our ultimate demise. It's most likely that our sun will go from a yellow dwarf star to a red dwarf star and expand and will be more hot than it already is. And since we're not too far from the sun, we'll disappear long with Mercury and Venus. The sun is already half way through it's stable cycle of life, too.

This is just tid bits on what I gathered from reading about our Sun.
Feel free to share your thoughts or theories about our Sun.
Friendly debates are welcomed.

[elf rights activist]

astrophysicist in the making here. given what we know of star life cycles, it's more than likely the sun is going to expand into a red giant. this is a result of it collapsing when its hydrogen is depleted, meaning nuclear fusion of hydrogen into helium is no longer possible. as it collapses, its outer layers expand, hence why it gets so much bigger.

whether or not the sun will consume earth in this phase is up for debate. we arent sure exactly how big it will get, so earth may be spared. mercury and venus wont survive though, and even if the earth does, it will be so close to the sun that it will likely be pulled into it thanks to tidal deceleration.

but lets say earth as a body survives past all that somehow. first, the odds of humanity being around that long (on earth, at any rate) are fairly low in my opinion. the sun still has billions of years left in its main sequence phase, which is the one it's in now. if we survive that long, chances are we'll be far away from earth. several moons in our solar system are good candidates for life beyond earth, and their odds of being suitable of humans would only increase with time. unfortunately the sun wont last forever, red giant or otherwise, and by the time it reaches its red giant phase it wont have much life left. so any outer planets & moons that warm up and are welcoming to life as we know it wouldnt have enough time to produce evolved life of its own, or prove to be a long-lasting home for our own species.

so as the sun begins expanding, the odds of human life still being on earth seem a little bleak, but hopefully by choice. the sun will double in luminosity before it even leaves its main sequence stage, which means earth's temperature will be unsuitable for life as we know it, and most of its atmosphere and water sources will evaporate or be boiled away.

so yes, the sun will ultimately be earth's demise as a planet, provided the earth is not hit by a celestial body that breaks it apart before then. but what will be left of earth before that time remains up to us. i'd be surprised if civilisation didnt destroy itself long before the sun starts to die.

even if it somehow didnt, we'd have to leave the solar system at some point. the sun is a pretty vital part of our way of life. the nearest star from us (proxima centauri) is less than 5 light years away, and it will probably outlive our sun on the basis that it is smaller. that being said, though 4.24 light years doesn't seem like a lot, we don't travel in light years. that's over 25 trillion miles away, so that's tens of thousands of years of travel as we know it. the only viable way to get there without making it a generations-long trip (which would require an astronomical amount of resources) is via nuclear pulse propulsions, but that's just a theory right now.

forgive my tangent, i like talking about this stuff. in any case, youre right, the sun is likely going to kill us if we dont kill ourselves first. our only hope is further space exploration - something we'd have to keep up with as stars continue to die out.

[Spiderrific]

elf rights activist

Well I have read something not too long ago about five Super-Earths that might be habitable for "alien life" back in April 2013.

I've also heard that there are few scientists that are working on a way to build space ships like the ones from Star Trek. Though, I'm not quite sure if they are making any breakthroughs yet.

It's cool, no worries. I like talking about this stuff too. I love hearing theories and or opinions about stuff like this. Great chance to learn what you can and also share your own input.

[elf rights activist]

no doubt there are inhabitable planets nearby somewhere, but we have to consider what "nearby" means in terms of the universe. like i said, proxima centauri is close, but still thousands of lifetimes away from us without better technology. with the nuclear pulse propulsion theory, we could reach proxima centauri in as little as 85 years. still a lifetime away, but still better than the aforementioned tens of thousands of years.

we should have that technology (provided it works as proposed) fairly soon. maybe not in the next few decades - especially with funding being constantly cut - but relatively soon nonetheless. so i have absolutely no doubts that we'll be able to colonise other nearby stars before humanity is wiped out. but it's also a constant process of star-hopping as they burn out and die. and thats not just for humanity, but for any life form that wants to survive past the lifetime of their home star(s).

[Masiakasaurus]

Sinful Ways

I've also heard that there are few scientists that are working on a way to build space ships like the ones from Star Trek. Though, I'm not quite sure if they are making any breakthroughs yet.

The Alcubierre drive you're referring to has a number of pretty serious theoretical flaws, such as "once inside the warp bubble you can't steer" and "you can't generate enough energy to make one in the first place."

It's still very exciting, but we're a long, long way from making it work.

[Armchair Academic]

We typically make the assumption that we have until the Sun's entire lifetime to figure out how we're going to survive a cataclysm on a cosmic scale. This notion is indeed as false as they come; the Sun is getting hotter over time and we've only got ~1 billion + so years until this haven of ours becomes a smoldering furnace of death (at least in climate terms). But hey, the good news is there's at least a shot in hell that Mars will become warm enough due to this heating for us to inhabit it for the remaining ~3.5 billions years or so, at which point the Sun will expand into a red giant and destory any hope of ever living on the terrestrial planets indefinitely.

If we're still too nervous to move far from home, there's always the interiors of the Jovian moons to consider, such as Saturn's Enceladus or Jupiter's own Europa. Enceladus spews forth geysers (of water, woo!) from it's core, indicating there are sufficient temperatures to sustain liquid water beneath the surface. Europa, on the other hand, backhands the notion of needing a star or radioactive molten core for heat. Give it some good-ol fashion tidal forces (exerted on it by Jupiter-Ganymede/Callisto tug-of-war) and you've got frictional forces that generate sufficient heat to theoretically sustain liquid water beneath the surface.

So basically we've got a lot of options when it comes to cosmic real-estate, and that's of course presuming that we won't even at least be capable of figuring out how to get to Proxima Centauri, Alpha-Centauri, or Sirius A by those times (which are actually ideas already being considered).

[Masiakasaurus]

Kyojy

We typically make the assumption that we have until the Sun's entire lifetime to figure out how we're going to survive a cataclysm on a cosmic scale. This notion is indeed as false as they come; the Sun is getting hotter over time and we've only got ~1 billion + so years until this haven of ours becomes a smoldering furnace of death (at least in climate terms). But hey, the good news is there's at least a shot in hell that Mars will become warm enough due to this heating for us to inhabit it for the remaining ~3.5 billions years or so, at which point the Sun will expand into a red giant and destory any hope of ever living on the terrestrial planets indefinitely.

I think you're pretty optimistic here in terms of the human species' collective lifespan. A billion years is longer than animals have existed on our planet. Humanity will not exist that far from today. Maybe one of our descendants, but they will be as unlike us as we are from fish. Who's to say that in the far future Earth isn't inhabited by subterranean mole people who built an artificial haven from their dying sun? Or it might not be inhabited anymore at all, the last sapient beings having long ago adapted themselves to survive in raw vacuum. A billion years from now Earth might as well be another planet.

Bear in mind that humanity has only been around for an extremely brief period on the geologic scale. Even by the standards of the animals around us, we're newcomers. Bears have been around for over 30 million years. Deer aren't much younger. Anatomically modern humans have been around for a few hundred thousand years, and the split between the line of descent that would eventually become humans and the lines that became the other apes was less than 10 million years ago. Our society has happened overnight. We have no idea how stable our existence really is. A few more thousand years, barring our own self-destruction, seems plausible. Beyond that it's pretty much anyone's guess.

I guess what I'm saying is that humanity won't have to worry about the sun kerploding because we'll be long gone by that point, and whatever comes after us will be as alien to us as, well, aliens.

[CuAnnan]

Kyojy

We typically make the assumption that we have until the Sun's entire lifetime to figure out how we're going to survive a cataclysm on a cosmic scale. This notion is indeed as false as they come; the Sun is getting hotter over time and we've only got ~1 billion + so years until this haven of ours becomes a smoldering furnace of death (at least in climate terms). But hey, the good news is there's at least a shot in hell that Mars will become warm enough due to this heating for us to inhabit it for the remaining ~3.5 billions years or so, at which point the Sun will expand into a red giant and destory any hope of ever living on the terrestrial planets indefinitely.

We're going to destroy the atmosphere long before then.

[calgarian]

it could be true, but we shouldn't worry...



we're all mortal lol