pavelcherepan

If you want to convert it to electricity you'd definitely need metal for the generator. I believe it might be possible to use plastics for blades and some other parts of steam turbine. On the other hand, if there's really no metal to be had, it should be still possible to make use of mechanical energy in some ways. For example, one could use rotation of the turbine to generate heat through friction and use that energy to melt ice and heat water and pump it around to heat "dwellings" and "factories". Or some other weird things can be done. EDIT: Come to think about it and I believe some metal should still remain dissolved in water and not drift down to the core, because what would make, for example, iron ions completely precipitate from water in absence of oxygen or other oxidizers? If there's still some metal dissolved in water it would be a huge undertaking but should still be possible to extract some via chemical means.

That's correct, but Titan may have cryovolcanism similar to what is being investigated at Enceladus. In these areas the crust would be thinner and could potentially be used for energy generation. https://en.wikipedia.org/wiki/Titan_(moon)#Cryovolcanism_and_mountains

Also Titan is supposed to have a liquid water ocean under the crust, so potentially (depending on the thickness of the crust) you could get geothermal energy from drilling down through the crust. Although, I'm not exactly sure if that's going to work, because water is very likely to freeze before it reaches to top of the bore hole, but still potentially could be done especially in regions with lower thickness of the ice.

Cheaper for one. A large rocket like planned SLS works on the very edge of technology and everything in it is extremely expensive. For example, Falcon 9 costs ~$70 million per launch and can take ~13 tonnes to LEO. SLS is predicted to have a launch cost anywhere from $500 million and up to several billion. We can safely assume that the lowest estimate is for the lowest payload version that can take about 70 tonnes to LEO. Then using 5 launches of Falcon 9 we can send the same amount of cargo at a cost of some $350 million, which is only 70% of the cost of SLS launch. Additionally, smaller rockets like Falcon 9 or Soyuz or Ariane 5 are built in relatively large numbers which lowers the cost of any single vehicle. SLS, on the other hand is likely to be relatively rare (there are not many uses for a launcher with such a great payload) and that will keep prices up. Falcon 9 also have recently finally managed to safely return the first stage back and if that becomes a norm it will drop prices by a lot. Also a larger rocket will either experience higher losses due to drag (if accelerating fast) or higher gravitational losses (if accelerating slower). It will probably have to use a less energy efficient trajectory with a later gravity turn compared to smaller rockets, which can start turning very early on. As far as boil-off of cryogenic fuels is concerned, some tank designs allow very low rates of boil-off of like 0.13% per day for LH2 and as low as 0.016% per day for LOX. Obviously, there is option of using non-cryogenic fuels like rocket-grade kerosene or hydrazine. http://www.sciencedirect.com/science/article/pii/0360319988900559 https://tfaws.nasa.gov/TFAWS01/NASA/13Spacecr/dHULL.PDF EDIT: Also, if you're going on a long mission, such as a trip to Mars or outer Solar system, you wouldn't use cryogenic fuels anyway, because if you travel to Mars in 6 months then by the time you get there even with best tanks available you'd lose somewhere between 22-30% of your original H2.

This has puzzled me for a while - why haven't space refueling and orbital fuel depots become widespread? It seems like a no-brainer, especially for long missions and putting satellites on GSO. Also for deep space manned exploration it should be much easier to send fuel and the craft separately using a couple smaller rockets rather than a proposed monstrosity of SLS (in a sense that it's huge and super-duper expensive).

Just like I said before - probably electricity and some means of melting ice.

If some life did develop there and if its a complex life then it's probably reasonable to say that it will be much better adapted to the conditions and as such they probably won't need as much heating or fire as we'd have to use. I'd say a technological civilization on Titan will be eating chemically processed hydrocarbons and building structures out of ice and plastics. If they do develop technologies for electricity fire shouldn't be a problem - there's frozen water everywhere and if you melt it you can run electrolysis and get as much oxygen as you want and fuel is abundant too (and also the hydrogen we've just produced), but obviously the civilization would have to develop a few perquisite technologies to get fire going.

Personally I think that mountain ranges most of the time separate different ethnic groups because of the following: often different climates on opposite sides of mountain range and within the range itself, mountains stop propagation of people, they reduce the chances of communication between peoples living on opposite sides, terrain and climate have a major effect on culture and language if you define ethnic group as a "group of people linked by common ancestry and/or culture". I'm very surprised that historians wouldn't know that. Probably these are not the droids you're looking for forums you should go to.

You're asking about two things that sort of work against one another. High TWR with the current technology is achieved in very powerful engines (rocket engines), while high efficiency engines are very low thrust. So you really need to define what exactly you want. Looking at this chart from Wikipedia (Thrust-to-weight ratio article) you can see that from the currently known technologies for rocket engines nuclear fission and liquid/solid fuel engines are the best. Obviously, there are no current fission rocket engines but from initial studies back in 1970s to 1990 show that they can have really good TWR combined with very high Isp.

In general I do agree with you, Ophiolite, that lifestyle, diet, lack of exercise and obesity levels have greatest impact on Type 2 diabetes incidence rates, but there have been quite a few studies on genetical predisposition to getting it. For example: http://www.nature.com/ng/journal/v38/n3/abs/ng1732.html http://www.sciencedirect.com/science/article/pii/014067369291958B http://link.springer.com/article/10.1007/s00125-007-0827-5 But also, drinking a lot of sweet beverages, not exercising and watching Oprah are also really bad: http://jama.jamanetwork.com/article.aspx?articleid=196345&resultclick=1

I'm pretty sure that it's not only influenced by genetics and probably in most cases it's due to incorrect development and early walking habits, footwear and other external factors, for example see below the study that children wearing sandals (or any footwear for that matter) in early age have a higher chance of developing flat feet compared to ones who often walk barefoot. Specially designed orthopedic footwear is sometimes recommended for children to help properly develop the foot. http://www.bjj.boneandjoint.org.uk/content/74-B/4/525.full.pdf

Up to a point. After that we get into very early stages of the Universe and our current theories break down, so I'd agree with studiot, that essentially we still don't know where atoms and molecules came from.

This is beautiful, but still my winner for the best ever pictures of volcanic eruption goes to Kawah Ijen volcano in Indonesia. I mean, c'mon! The lava is blue! http://www.cbsnews.com/news/volcano-erupts-in-bright-blue-flames-stunning-photos/

It looks like the whole concept of habitable zone is going out of the window, which is a good thing - more aliens! Although with this Fermi paradox is getting more and more paradoxical and annoying.

First of all both the initial and resulting mercury compounds are very toxic so I don't recommend performing this reaction unless you're qualified and have carefully perused relevant MSDS and taken all necessary precautions. To get mercury nitrate you would need to react HgCl with silver nitrate in an aqueous solution, but yet again, it's dangerous. P.S. Silver nitrate is toxic too, and so is the resulting silver chloride. Basically everything in this reaction is toxic. Fun times.

What about most other elements? Say, a red giant will produce a lot of elements up to iron but most of that will be in the core which will form the white dwarf. How enriched would the outer layers, that it will inevitably shed, be? (Obviously, apart from helium enrichment).

It's a grey area. For starters there's still no universally accepted theory as to how plate tectonics started here on Earth. I'll post some links to papers later when I get to a computer.

That's mostly because Mars doesn't seem to have or ever had plate tectonics. On Earth either plate moves over I "hot spot" like in case of Hawaiian volcanoes and this creates a linear stretch of volcanoes, or in subduction zones due to change of subduction regime over time (for example the angle of subduction) the area where molten material encounters the surface shifts over time and then you have a series of volcanic ranges, like in case with Kamchatka peninsula in Russia.

You could just use a CO2 detector which are about $50 apiece on eBay.

Thanks for your reply, and I guess there are a few things that I need to clarify. First off, I've never claimed to be an expert in the topic, but I come to this forum to learn new things and participate in meaningful discussions, and this discussion seemed interesting. Obviously, when looking up my "Google-Fake-Knowledge" I couldn't get all the information that you seem to know, but what I've seen was enough to form some sort of opinion on the matter. I'm happy to be proven wrong but unfortunately the OP didn't stay to discuss further. Secondly, while I think that your comment is rather interesting and informative it could do with a little less condescension and appeal to authority. Lastly, the Solutrean hypothesis is not a generally accepted idea and I can play devil's advocate as much as I please. Again, it's unfortunate that OP didn't stay for longer so that we could discuss it more. I'll have a bit more read on the topic and will come back with more discussion points if you're keen to keep going.

Good points. Also, its very important to note that in eastern regions of Syria and northern Iraq the clan system is still dominant, where lot of small groups are more inclined to follow their clan leader rather than any other authority and they can change their allegiance in a blink of an eye towards whichever side seems to offer more to the particular group in question. China, too has its own interests in Syria and has repeatedly blocked UN SC resolutions and is allegedly planning military intervention too. Damn you Middle East! Why do you have to be so complicated?

Well, the thing about human rights is that those are a very volatile thing. They seem to be changing a lot in a relatively short time. Also, what was that about 11th century? Allan Turing disapprovingly stares at you from his grave. So, let me get this straight - all the time everyone is screaming that there's no democracy in Russia, but when it comes down to a highly populist topic of LGBT rights, suddenly everyone says that Russia should go against the democratic procedure and the vox populi? And here I thought that not all people in the world shall share the same ideals and world views. You are very misguided if you think that everyone should be exactly the same.

I have close friends in LGBT community in Russia so I don't like recent laws on that topic, but may I ask: why do you think you or anyone else should decide things for Russian people? AFAIK all recent polls show overwhelming support of anti-LGBT-propaganda law from general populace in Russia, something over 80%, so if we used democratic procedures and had a referendum on this question, the law would still stand. Could you clarify what exactly you're referring to? Well, propaganda is one of the cornerstones of any government whether you like it or not. Whichever country you live in I can assure you that you regularly get significant amounts of propaganda through media. Also this: https://en.wikipedia.org/wiki/Ministry_of_propaganda

If we take this definition for explosion: And knowing that radiation (including light) can exert pressure on matter (see Radiation pressure article) you can potentially create an explosive device that will generate and extremely high intensity radiation that would push whatever matter surrounds it away like the normal explosion would.

Good idea, because if you don't just need elementary ones, there's also about ~140 mesons. So all-in-all, a lot of particles to choose from.