K^2

It'd be bad for business, yes. But yeah, distinguishing between effective weight and mass is kind of important. Although, an effect similar to buoyancy may exist for mass. Casimir Effect comes to mind.

You use almost half of your fuel during that first minute, as you combat aerodynamic drag.We are talking about 1.5-2km/s of extra dV accumulated as you traverse that layer. A rocket that could cut that overhead in half is nothing to sneeze at. Especially for SSTO design.

Actual lasers, yes, because coherent light is not good for dumping heat. But beam cooling is absolutely viable if you have an adequate energy source. The basic idea is that a radiator at 1,000K will have over 100x the heat output of one at 300K. So if you want your craft at 300K, but you have a huge heat flux coming in, say, from a nearby star, you can set up a heat pump to raise the temperature of the radiator, and beam the heat away in near-visible IR. It is a significant energy drain, though, so you need either very good solar panels or a very efficient reactor to stay in the net gain.

Scientists aren't without bias, and unfortunately, climate research is highly politicized right now. We should consider this as a serious warning sign, and it should impact our policy decisions, but we should not consider it a proven matter and jump to any drastic actions. Most of all, what this calls for is more research.

Stop it, both of you are completely wrong. At equilibrium temperature, there is equilibrium between incoming and outgoing energy. By definition of equilibrium. What greenhouse gas does is alter the thermodynamic balance of short and long wavelengths at different altitude, establishing higher equilibrium temperature on the surface. It's a very complex process, which includes thermal radiation, absorption, and convection to make it work. All of the typical explanations of "it works like a greenhouse" are completely wrong, and serve only for illustration. And even our best models have limited capacity of describing the full process. But the net effect is higher surface temperature with higher concentration of greenhouse gasses. How much higher and where saturation points lie is still somewhat debated. The most powerful greenhouse gas on Earth, and one with by far the highest contribution to global temperature is water vapor. Most IR channels are saturated with the GH effect of water vapor. The problem with other greenhouse gasses is that they block IR at wavelengths that water vapor does not. If you want to learn actual physics behind all of that, I would need to point you to several thermodynamics texts to get you started on the basics first.

Not at all. Energy conservation is consequence of Noether's Theorem, and in Classical Mechanics it is pretty simple. So long as Hamiltonian is time-independent, energy is conserved. For orbital mechanics, it boils down to the statement that if you include all of the sources of gravity in your energy considerations, then total energy is conserved. For example, if you consider just the ship's energy during a fly-by, it is not conserved, because there are moving sources of gravity. If you consider energy of craft and the planet it flies-by, then energy is conserved.

I don't think we'll ever see these sort of oil prices again. Like any prediction about oil prices, I could be way off on this, but I really don't see a mechanism. After we're done with current oil wars, it might climb back to $50/$60, but by that point, every step oil makes up will just rocket-boost all of the electrics and renewables. The demand just isn't going to climb like it has, and we'll have more and more ways of extracting oil in more economical ways. I suppose, a civil war in Russia could, potentially disrupt the supply sufficiently, but that seems unlikely. Even with a gov't collapse over there, oil supply is unlikely to suffer a bigger disruption than it did after USSR collapse, and oil never topped $30/barrel then.

Both statements are completely wrong. You cannot use Newtonian physics to properly describe objects of negative mass, but it does not mean that we do not have adequate description of these. Objects of negative mass (e.g. virtual particles,) are commonplace in field theory. Also, having people vote on something that's common knowledge in theoretical physics is kind of like having a vote on whether or not gravity works. A little silly.

Nice Model. As in city in France. Solar System formation comes out all sorts of wonky with just four giants. Adding a fifth giant, which gets knocked out of the early Solar System makes the simulation evolve pretty much into a replica of Solar System. So in that regard, the model is, actually, quite nice. Given that Nice Model and latest research point to an ice giant of roughly the same size, it's not a stretch to assume that they are one and the same. At any rate, that's way more likely than a rogue capture.

I never said it would be in shortage. I'm saying there would be low demand, and consequently, low use of it.

Most of our natural gas is also a byproduct of the oil industry. Methane's bound to get far more expensive once oil demand drops. But you might still be right. Either way, our CO2 output is bound to start going down soon.

That... That could actually work. Twenty years is still a bit optimistic. I'm only getting a 70km/s escape from a Jupiter dive and a 10km/s burn. Diving from higher up would work, but that would still add to trip time. But decades instead of centuries? I'll take that.

I don't think we are going to run out of oil. Not only have we found tons and tons more of it that we can tap into, but also electric cars and solar power are catching up really fast. It's already cheaper to put up solar panels than to burn coal in some places. Yes, thanks in part to reasonable environmental regulations. We are well on our way to phasing out oil. Peak oil will still happen, but it will be due to dropping demand, not dropping supply. But yeah, I agree. Nuclear is a fantastic option for a lot of places. We can't switch to 100% nuclear for an array of reasons, not least of which availability of nuclear fuel, but we don't need to, either. Running nuclear along side renewables will give us clean energy and a good safety margin on supply. Edit: By the way, peak oil will have an exciting side-effect. We are currently relying on oil industry by-products for a lot of our carbon polymer supply. When gasoline consumption starts to drop, we'll suddenly be experiencing a shortage. Which will lead to carbon-capture as an economically viable way to supplement this supply. In the end, it will be economic forces that will get us to clean up the environment. Not that economy isn't in need of a guiding hand of policy, but certainly not a throttling one.

That's precisely the alarmist attitude I'm talking about. When driving on icy road, the last thing you want to do is slam the brakes. Even if you're certain you can't make the turn ahead. You're much better off tapping the brakes gently and try to minimize the damage on impact. So far, we have established that global temperatures are climbing, that it will almost certainly have major negative impact on climate if the trend continues, and that we are contributing. But that's not the bad news. The bad news is that we don't yet know how much we are contributing, and whether we've hit a runaway point yet. Suppose we contribute only a little, and temperatures keep climbing almost as rapidly even if we put on major brakes on the industry. What do we do then? What if it's actually all our fault, but we are past the point of no return already? In both of these scenarios, the last thing you want to do is hurt the industry right now. Sure, left unchecked, maybe it will bring about the catastrophic outcome a decade sooner. But if it's inevitable, I'll take it if it means we can be prepared for it. One way or another, drastic climate change will happen on this planet. We all hope it won't happen during our life time, and maybe we can have impact on that. But we don't know. We might be heading for disaster either way. And I'm far more interested in making sure we can actually survive it. That my children and their children will be able to survive it. And the only way we can do that is with better technology. We have no idea what set off major climate change in the past. We aren't certain about causes of changes we see today. But we do know what the consequences will be. Large temperature variations, flooding, droughts, and subsequent food shortage. None of it is pleasant, but all of it is something we have learned to manage. We have learned to heat and cool our houses. We have learned to irrigate dry land. We have learned to make fresh water out of sea water. We have learned to manage the floods. And we have learned to genetically engineer our crops to withstand all sorts of adverse conditions. We've not always been successful with these things, and we've never done it on this scale. But it's something we understand, and it's something we know how to manage. We can survive a runaway global warming on the scale that the most pessimistic prognosis holds. We can do it if we do our homework and prepare for it. We will need very strong infrastructure for dealing with water distribution. We will need a power grid that can handle the additional demand. And we'll need to get people to get over the GMO fear. Which, by the way, is just another example of alarmists making life worse for everyone. While we are doing all of that, we'll also learn a lot more about climate, and learn to rely on renewable resources instead of fossil fuels. And if that helps us not have to deal with catastrophic climate change this century, or maybe even this millennium, that would be absolutely fantastic. But if all we do is simply slam the brake, we'll just ruin our infrastructure and have no hope of saving ourselves from what's coming if it is already inevitable. I don't wish to gable the entirety of civilization on chance. Do you?

You are thinking of Nemesis hypothesis of periodic mass extinctions, which is ruled out by the fact that the entire outer system would be thrown into disarray over time. Nobody has ever ruled out Planet X, because that's absolutely impossible to do. We can rule out a very large planet, and we can rule out a bunch of orbits. But you can't rule out something of planetary size in the entirety of trans-Neptunian space. That's worse than finding needle in the haystack. It's like trying to prove it's not there. Nine, on the other hand, has pretty decent support by now. It's more likely that we'll find it than that we do not.

Do you know what we need to make a better world? A ton of resources put into research. Do you know who funds most of the research? Private companies trying to get ahead of the competition. Do you know which departments get the ax first when profits drop? R&D. Because R&D makes profits tomorrow, all other departments make profit today. Any environmental regulations we put in place put additional burden on the industry. We definitely need them, because we've learned that industry won't regulate itself. But we also need to be reasonable. Status quo is that we are relying on burning fossil fuels. People won't stop driving their cars just because glaciers are melting. They just won't. If you don't realize it, you must not be from this planet. The only way we are going to make things better is by getting people off gasoline cars and onto electric. And to do that, we need to make electric cars cheaper, more convenient, and more reliable. And this isn't going to happen without corps willing to dump a ton of money into research. Which is happening right now, and the progress has been amazing. I know it's been going slower in the rest of the world, but in Cali, every fifth car I see is a hybrid and electrics have stopped being an oddity. This is very different from even a decade ago. And the situation is the same across the board. Take a look at the charts for renewables. Many states are heading towards wind and solar dominating their grid before the decade is over. That's huge. That's fantastic. And we need to be very careful about not stomping on this progress, even if it means that we don't get to enact some strict carbon regulations for a while. It's good that companies are afraid of this happening and investing into greener research, but we also want them to have the funds to invest into that research. For that reason, I urge everyone to make very careful considerations before making any leaps. We shouldn't enact draconian regulations just because we've heard a scary talk about global warming or because we saw that picture of a polar bear on a melting iceberg. These aren't good reasons to enact policy. We need to weigh the consequences. If something is a problem in a short term, it needs to be fixed immediately. If something is a problem on the long term, we need to make sure we fully understand the dynamics, weigh all the options, and make balanced decisions. And as I've said above, the right decision isn't always going to be to limit pollution. If we expect fossil fuel use to drop naturally in the future, and we do, there is no reason to strangle the economy.

We are talking specifically about a spike in temperature at the end of Minoan period. The general trend of a spike about every 1k years is very persistent. Although, there are definitely a bunch of other things going on, so it's hard to insist that we're absolutely seeing another spike coming up. Nonetheless, insisting that this absolutely couldn't be the dominant cause of the temperature trend is likewise premature. I am absolutely in favor of reasonable policy change to help us reduce impact on climate to be on the safe side, but we seriously don't understand the beast yet. And a lot of alarmists are calling for drastic measures, because they insist these are dire circumstances. And all I'm asking is that we don't shoot ourselves in the foot out of sheer panic. We're not even close to catastrophic damage yet, this planet's been through far worse without our effort, and the general trends have been good already.

I'm going to put my two cents in, as a nuclear physicist. Launching an Orion-like craft from Earth using nuclear pulse propulsion would be stupidly irresponsible. Orbital assembly is pretty much the only way to go with one of these, and even then, we want to be well clear of LEO before engaging NPP.

Maximum Entropy. Given no other information, probability distribution that maximizes entropy under known constraints is the best guess. So if something happened every X years in the past, even if we don't know why it happened, our best guess is that it will keep happening with roughly the same intervals. To give a banal example, people knew that sun will rise the next day long before they've learned about orbital mechanics. That's not to say that we can't be wrong about this, but that's true of all knowledge. Best we can do is put some statistical bounds on how likely it is. Given observation of 3 events that fit the pattern and no known events that do not, the odds of pattern holding are estimated at 80%.

There are a lot of "Flat Earthers" that are just trolls who make good living from all the YouTube views. Some are genuine nutcases, of course, but ti's hard to tell the difference.

Geometry in KSP needs to have separate collision data in order for you to be able to interact with it. There were parts of the "KSC 2" that you could walk through and couldn't land on. Likewise, in order to see an object from great distance, or on the map, it needs to have appropriate LOD models. If a model has neither, then you'd only be able to see it when you get close, and you wouldn't be able to land on it.

Binary is a term for stars. The corresponding term for planets is Double Planet. Otherwise, yeah, there is no reason these wouldn't exist.

Given that humans have been humans for less than a million years, and 100 million years ago we were tree-climbing rodents, even if we don't go extinct, expecting anything like humanity to exist 100 million years from now is silly.

Oh, you could totally take the transfer orbit around galactic center. It'd take over 100 million years, but you could do it with modern rockets. Fact that no human will ever learn if mission was a success puts a damper on things, though.

Very unlikely to be glitches. More likely geometry forgotten behind. Happens frequently enough in game dev.