Hal

Forgetting about colonization, Venus should definitely not be regarded in the same way as Saturn. While Venus' atmosphere is hellish, it has a definite end where it hits something different, the rocky ground. Gas giants are just the same thing all the way down, you'll never "hit" something, you'll just sink to where you can float (or, more likely, be crushed horribly). Colonization is a whole other can of beans. If/When we do get to the point where we're seriously considering expanding onto Venus and the gas giants beyond something like a research outpost, technology will probably be so different that making plans to either settle in the air or on the ground now will be kind of pointless. It's a fun way to pass the time though, and there's no harm, so go ahead, just keep reality in mind.

It's a thought experiment people, try to have some fun. Do you really want to be the guy who goes up to Plato and tell him about how his cave allegory makes no sense because the cave's inhabitants would have to be fed? Deliberately missing the point only works if you're being really funny. As for me, I would be screwed. I guess I would try to hide out somewhere kind of remote and stockpile supplies, but I highly doubt my survival skills are good enough for me to last long. I would try to download as much of, say, Wikipedia as I could onto some safe hard drives. I'd also try to collect important books (sciencey stuff, mostly), and keep them with me. While I might not last long, hopefully I could help to preserve some knowledge for rebuilding after the collapse (although chances are many people or organizations will do something like this and my personal effort may be pointless).

The rover's going to be 660 meters tall? Bravo, ESA, I had no clue we could land something like that on Mars. On a more serious note, on top of the physical changes to the wheels, the rover drivers now know just how dangerous some kinds of terrain can be, and will probably be as careful as they are now of Curiosity from the beginning for Mars 2020, which should help too. Or at least the damage won't be a surprise.

Hmmm. I find it a little odd that he says that 100 billion years from now, there will be no photons our eyes could detect. Maybe that's true if it's all averaged out over the whole volume of the universe, but smallish red dwarf stars are supposed to have lifetimes of up to 10 trillion years, according to Wikipedia. While that is a high bound, even if they only lasted 1 percent of that time, stars that are already formed would still be around, to say nothing of future generations. Also this is probably just a problem of the article itself (not the scientist), like many popular news articles on science, it doesn't convey the doubt very well. While I am speaking entirely out of my posterior here, not being anything like a cosmologist, I get the impression that when it comes to the overall energy balance of the universe, there's a lot that we don't really get (hence dark matter and energy). I wouldn't take it as gospel. It is cool though, thanks for sharing.

I could be very mistaken here, as I feel like I'm forgetting some basic part of orbital mechanics, or maybe just some basic part of logic. But wouldn't the aliens only be able to find where Voyager had come from by backtracking if it hadn't made any extra burns? They wouldn't have any particular reason to assume that the probe didn't, say, perform a 200 dV burn (and then detach the propulsion stage) after reaching a light-year from Earth, or any other one of infinite possibilities that would throw off tracking through simple gravity. I do feel like I'm missing something though, so take that with a big grain of salt.

It would definitely be nice if there was more coverage (and better coverage) of science in the news, although I'm not sure if the LHC turning on is enough for anything but a slow day. However, if you can't talk about the things you like without dumping on other people for liking different things, you need to rethink a little bit. People have different interests, and while some may be more worthy than others ("mine" are best, according to everybody), you're not going to change anyone's mind for the better by insulting them. It's also just bad manners, which aren't good (they're bad!).

The thing is, while there might be some kind of life on Titan, it would have to be fundamentally different than Earth life, and much better adapted to its environment. Titan is so different from any part of Earth that contamination isn't really an issue. Europa or Mars, on the other hand, are problematic for precisely the reason we're so interested in them: they seem like they could possibly host Earth-like life. Because they're so similar (they have some kind of liquid water, or once did), we have to be more careful, as it's more possible that Earth life brought on our probes could actually survive and thrive there, possibly even outcompete whatever life is there. At least this is what I think. I could be way off the mark.

I think the point that's trying to be made is that even if the atmosphere is going to get blown away in a billion years or so, and isn't technically self-sustaining, it's good enough. If humans (or some descendant of us, obviously very different) are still around a billion years from now, terraforming a single planet is going to be laughably easy, if we aren't all artificial and don't even care about the atmosphere at that point. If we're not around then who cares? If it would actually work to substantially improve the Martian atmosphere, I don't see why we shouldn't go for it (once/if we actually get serious about colonization). The lack of magnetosphere might be an issue though, like magnemoe said. I don't know enough to say what kind of an issue, though. But anyway, an atmosphere's probably not going to hurt.

That is really cool. It does have a bit of an unrealistic PR spin, but that's the price for looking awesome I guess. This is a pretty ignorant question, since I really have no idea how fast the central stage is going besides "really fast," but would it be feasible for them to just try to land it on the other side of the Atlantic? I would guess not, because there doesn't seem to be an easy way to ship it back, but someone who actually knows what they're talking about shedding some light on the matter would be nice. Also, what's with the payload? You'd think it would be a Dragon with some kind of transfer stage, but it's not. Is that just a generic commercial satellite?

Hehe. Seriously though, that moon can't be that stable. You'd think even the force from the light of the sun (that they thought was causing the Pioneer Anomaly, I think) would overpower that feeble gravitational attraction soon enough. Maybe even tiny variations in drag from space dust. Cool though.

To answer the OP without resorting to reality, you're forgetting that there may be no way for the universe to end. Then, with your logic, the infinite universe's very existence proves the fact that nothing can happen to end that existence. In reality though, we don't really have any reason to think it's infinite, and we might (I don't know a whole lot on the topic) have good reason not to (big bang model seems to imply that it was limited at some point). I'm pretty sure that it's mathematically possible to have infinities of different sizes, so the universe's size could just be infinity +1 over and over, if that makes any sense. When things get this abstract, we don't really have to assume that it's expanding into anything, it could be expanding into complete nothingness. There's really no way to know what's outside though, so it's all guesswork. Also, if there's a 1 in 5 billion chance for someone to turn into a whale, even if it's over the course of a lifetime, there would be about 1.5 people swapped with whales on the planet right now. Teehee.

I'm not really sure if this belongs in here or the Space Lounge, but it's close enough I guess. Also, this isn't quite news, I just was reminded of it by randomly finding the article that first informed me of its existence, but it's been true for at least a couple of years. There was actually a post on these forums about a month ago on a specific part of it, but it only had 2 responses and didn't really communicate the idea, so here we go. With the boring disclaimers out of the way: MIT course materials are free online! Anyone can have unlimited free access to all sorts of lectures and assignments (and probably videos, I haven't looked around yet much) without so much as even signing up for an account. You can learn things, it's great! And now for the KSP link (meaning the first thing I went to), the Introduction to Propulsion Systems class. While I know a lot of people on these forums don't yet have a full education of tricky physics and mathematics, Wikipedia can be helpful for a lot of things, and you can take your own time. It's also not perfect for sure, learning is (hopefully) a lot more difficult without a teacher and in some of these cases, the book they expect you to be looking at (replaced by Wikipedia?), but it's still a nice thing to have around. There are literally hundreds of courses, it's just... really cool. Also, it's a good several dozen thousand dollars per year cheaper than the real thing, which certainly doesn't hurt. What are you waiting for?

I don't quite want this thread to die yet, it's a nice thing to have around (says the guy who practically only lurks, but's that's neither here nor there). Anyway, I have a couple of questions: 1. What type of radiation is primarily responsible for endangering astronauts (and flight hardware) both inside and outside the Van Allen belts? Is it mostly gamma rays or other high energy photons or different particles? Or, alternatively, am I completely misunderstanding the situation? 2. What's up with the sublight Alcubierre drive? It seems like it could be pretty crazy helpful for traveling around the solar system at least, but always gets kind of brushed over. I've heard that it wouldn't require negative energy densities, but also that it would (in this very thread), so a little clarification would be nice. Is there some reason it would be tricky?

You're right. I was just trying to make a juvenile joke that only made sense to me because I'm American, and hilarious would have been too strong anyway. My bad, I tend to forget how the internet is international. On a different note, I wonder how successful this movie is going to be. While people on this forum obviously are really into it, do you think the general, less science-minded/crazed populace will like it? I hope so, but have no clue.

I don't post here often, but I feel like this is the kind of movie that the people on this forum would love. Here's the trailer that came out today: https://www.youtube.com/watch?v=OXwichuGW28 It's directed and co-written by Neill Blomkamp, who not only has a hilarious name, but directed District 9 and Elysium. Elysium was... alright, but District 9 was one of the best sci-fi movies I've seen (if you haven't seen it, find a way, it's amazing). He seems to be really good at blending a great emotional story with a bit of optimistic but realistic sci-fi. There's not a whole lot to say about the movie yet, but is anyone else excited? I'm excited.

"The use of any equipment or facility necessary for peaceful exploration of the Moon and other celestial bodies shall also not be prohibited." Hmmm. I wonder if you could argue that, in order to peacefully explore the moon and other celestial bodies, it is necessary to send a nuclear weapon to destroy an asteroid, as a crippled human civilization wouldn't have a chance. Alternatively, it could possibly be said that, if sent up with absolutely no intent to harm anything living (in fact the opposite) the nuke wouldn't count as a weapon. Those are both some pretty extreme stretches, but if there's one thing politicians are good at, it's stretches of logic. I imagine an agreement to break the treaty or amend it would be easier and give less leeway for weapons in future cases, though.

I'm not really commenting on whether I agree (but mostly yes), I just think it's kind of funny that this is really similar to a situation in I, Robot (by Isaac Asimov, of course). Basically, there's a mining robot that consists of one "head" that is properly sapient and controls the 6 "fingers," which do the grunt work and don't have the fleshed out emotions and personality of the head. It's a really good book, and this also leads somewhat into my actual point... I might be misunderstanding something here (and you might be to), but where do you draw the line for programming it to love its job? What if you simply made a slightly inferior AI, which was mostly sapient but instead of needing to find pleasure in interaction with others (like people, but which would be useless for its job) it finds pleasure in doing what it needs to? This is a little tricky to state properly, but the general idea is that instead of making a human mind and imposing limitations of a sort so it only loves its job, you're building up from nothing to being able to enjoy something. Would you not consider that a valid AI, or just not what we're talking about here? If it's never a person in the first place, is it bad to make it something less?

I don't really think this is the right way to approach climate change, while reducing power use is nice on a personal level to save money, you can't really expect everyone to do it to save the world. It would certainly be nice if, as a species, we could cut our power usage enough to stop any climate change, but since a large part of the world is coming into the electronic age (at risk of sounding like something from the 90s) and we'll need to use a lot more power in order to advance technologically, it's unrealistic. That being said, this thread kind of got crazy off topic. Everyone except for maybe one or two people who have refused to be persuaded in the past agrees that climate change is happening, so continuing to pound on the dissidents is fun, but not particularly useful. The OP mentioned something pretty interesting, I was also confused when reading it earlier today. Does anybody who knows more about this topic have any ideas on what could be absorbing so much energy/heat?

Cool, I figured it was something like that, but it's nice to know for sure. I didn't think of the power generating... things decaying themselves. Thanks.

To start this off, I want to apologize for any painful ignorance I have on this topic, radiation isn't something I know an awful lot about. What I do know, though, is that the Chernobyl disaster left a good deal of land uninhabitable for hundreds if not thousands of years, and the inside of the reactor that melted down is still incredibly radioactive. I also know that this is ionizing radiation, which is much more powerful than the normal radiation we get from the sun (duh, that's why it kills people). I'm sure there's some rather obvious explanation to this, but why can't we try to harness the energy from all that radiation? Inside the reactor, there's enough to kill a person very quickly, which (I think) takes a pretty non-insignificant amount of energy, so why isn't this possible? Or if it's possible, why isn't it done? Is it not actually worth it?

Darnok, Mars' atmospheric pressure is, on average, 600 Pa compared to Earth's average of 101,300 Pa. That, combined with being much farther from the sun than the rest of the terrestrial planets, is the reason that its high CO2 concentration doesn't make it boiling, because it actually has very little CO2. You say there's just extreme weather for a short transition period (I'm assuming you mean while the Earth warms up), but if we keep pumping CO2 into the air the world will keep heating up, and even if it stopped 100 years from now for some magical reason, the weather would still more extreme on average (more energy in the system). While more CO2 is good for plants, technically speaking, we don't need more oxygen (too much is actually harmful), and the effects of CO2 on the climate are far worse. You also seem to be getting climate and weather confused. We kind of suck at predicting day-to-day weather (I think a coin toss for rain over the next 3 days is better than our predictions), but we have a pretty good grip on how climate works. While weather is just day-to-day stuff, climate is the general weather of an area over long periods of time (years or more), and is a completely different deal for prediction compared to weather. Climate includes weather, in a way. Lastly, although this is getting somewhat off topic, governments being in debt is a pretty natural thing (the USA has been for most of its history, and it's done well enough). Also, just because a country has bad economic policies does not mean you should ignore what it says on scientific matters. Being skeptical is good, but ignoring facts from some of the most reliable sources you can find is not.

Great, now I can't stop thinking of the end of Prometheus. THERE ARE 2 DIMENSIONS YOU CAN TRAVERSE OVER THE GROUND! JUST RUN 20 FEET TO THE LEFT! In all seriousness, this is pretty silly. Although I guess this kind of thing is a lot rarer on Mars, what with the thinner air and lack of water for erosion.

I've decided to introduce myself for reasons that are no longer clear to me, so hello. I lurked around the forums (especially the science labs, that place is great/awful) for a few months before buying the game, then made an account and promptly proceeded to not post. I might be changing that now, I'm really not sure, but the main lesson to take away is that I'm a bit creepy (hence the extended lurk). Regarding the game, I managed a few Mun-and-return landings in the demo before buying the game, and quite a few more Mun-stranded landings. I want to thank pretty much anyone who's ever posted in the gameplay questions forums, as I never would have landed on either moon or Duna and Eve without you. So... thanks, I guess, and hello. By the way, what's the minimum number of posts needed before they no longer need to be approved and I can choose an avatar and signature? I'm guessing 10, but I'm guessing​ 10.

Like WestAir said, there are two kinds of immortality, never dying of old age but able to be killed by other means, and living forever, with your existence unable to end. To clarify things for Arran a little, I think he is talking about the second one, while most others are talking about the first (unless they specify something else, or I'm entirely wrong, which is very likely). As for my own opinions, I think I'm agreeing with everyone when I say the first kind is great. Coupled with advanced medical care and/or computer memory storage, this would lead to most people living hundreds of years at least, unless society was particularly violent. The second kind, though, is kind of weird. First of all, there's no way I know of (not that that's saying much) that it could be possible, as life requires some sort of physical component, and that can't really be invincible. Assuming it was though, I would never want to accept it or condemn anyone else to it. As fun as living through all of human history would be, and even assuming we magically branch out and colonize the whole universe, even finding a way to combat entropy, the end of humanity is essentially inevitable. Even if there's only a tiny chance of something going wrong, given an infinite amount of time, it will eventually happen, and you would have to spend an even longer eternity after that going crazy (which might actually be pretty fun after a while, living forever in the empty dark with a few other madmen to talk to). That's all assuming you can't shutdown the super-immortality when you choose to, however. If I could end myself when the universe(s) finally went out or when existence tired me, then I would go for it in a heartbeat. I think what makes us human is our ability to ignore the natural order of things, and screw with it as we please.

What I hope? Like most of the people here (as far as I can tell), we go to space, at least the moon or Mars if not further. What I expect? Something unexpected. A hundred years is a long time. At the end of the US Civil War, who could have predicted that in a hundred years the entire world would be threatened with destruction by unbelievably powerful weapons? At the turn of the 20th century, who could have predicted that in a hundred years millions of people would communicate across the globe using unbelievably powerful machines? It would be nice if that unpredictable advance was in the direction of space, though. Maybe an Alcubierre drive working at sub-light speeds or something (I feel like I saw someone saying that wouldn't require exotic matter). I'm not going to pretend I'm educated enough on the subject to make a real guess, though.