Ken Fabian

National 'suicide' is what results from ethno-nationalists getting what they want. Or what they think they want. It isn't a well thought out position and those doing it the fiercest are not showing themselves to be competent. Not to govern and keep prosperity and peace within a mixed society - and few nations are or have ever been actual monocultures. A unified monoculture was and is more myth than reality - I suspect more a consequence of prior more apartheid-like societies; differences aplenty but kept apart. Those promoting it now are mobilising grievance and resentment without much real consideration of social complexity and the unintended consequences of their policies - which are simplistic and unrealistic. Being so susceptible to alarmist fears and simplistic solutions they are susceptible to being played. Press those hot buttons and the ability to take in information and think things through goes out the window. I think simplistic policies to enforce imaginary monoculture done hard - intended to enforce more homogeneous (and supposedly better) society - will rebound to exacerbate social divisions and make tensions worse, effectively forcing people to fall back on their ethnic social links to find a sense of belonging.

I am one who thinks it isn't endless, that, at least for fundamental physics, it can approach an endpoint. The endpoint may not be the same as knowing it all. It is just an opinionated bloke's opinion of course. There may be some unknowables (does it count as knowable if it takes AI to know but no humans can understand what the AI says?) but I do think we will get more of the fundamental physics correct over time and shrink the 'unknowns' down and may well end up able to distinguish the knowable from the unknowable. And I suspect less answers are needed than the proliferation of unanswered questions might suggest - that getting the fundamentals right for some crucial ones will give solutions for others. Outside fundamental physics, where complexity is rife - life sciences especially - there may forever be more to describe and understand. With most of the universe beyond our physical reach to observe there will be unknowables.

There haven't been any posts that disprove energy conservation.

I found myself wanting to upvote everyone. To the OP - it seems reasonable and even normal for a proposed industry expansion with high energy or water or other requirements to cooperate in planning processes, including potentially to have to contribute to the expansions of the services and infrastructure they require. For an industry promoting intelligence as their product there seems to be a distinct shortage. It seems to me the same imperatives and considerations that are making RE the most built new energy around the world apply to data centres - cost, convenience, time to build. Being the cynical sort that I am I suspect partisan elements within politics see them as disruptive to the RE growth trajectory as well as a raised finger to environmentalism (as most visible proxy for broader community concerns and calls for regulation - and a partisan button to press). Massive growth of data centres are presenting an opportunity for partisan politics to dictate what energy choices that new demand should use.

Whilst the size/mass seems small compared to Earth's mass the crust itself is relatively thin and sits on top of magma. I would expect seismic consequences around the world - if nothing else, enough of a shake to trigger some earthquakes and volcanoes where fault lines and volcanoes had existing, unrelieved stresses. I would expect tsunami to be triggered on the Pacific Ocean side of Mexico from where it hit as well as (more extreme) Atlantic ones; I would be surprised if they weren't effectively global. Dust and smoke doing the initial sunlight blocking with a long tail of sulfates - from anhydrite rock under the impact zone, rather than from the impactor itself was what I got from prior reading. A lot of limestone meant a lot of CO2 released, causing warming, but after the smoke and dust causing global cooling settled. Smoke because the hot debris rained down around the globe; just the radiant heat from it reentering the atmosphere was thought to be enough to spontaneously start fires. (From https://www.lpi.usra.edu/science/kring/Chicxulub/discovery/ ) But I haven't closely followed more recent studies.

A comprehensively capable advanced industrial economy.

EV batteries do seem likely to be dominated by NMC type for the near future, possibly to be supplanted by solid state lithium, lithium/air or even something different. Nonetheless there is a lot of LFP used for EV's - less range but still adequate for a lot of vehicles, with other advantages. Less high value materials means less incentives to recycle. Sodium batteries are starting to enter the picture too. Some - I expect not for EV's - have potential to exceed 100,000 cycles, ie very long lasting as well as benign chemicals. Benign wastes may be more important than recyclability for global abundance of batteries. I've also read of a way aged NMC batteries can be restored to near their original condition - although that seems to require batteries designed to enable electrolytes to be drained, flushed with a 'conditioner' and replaced. My own view is that with less corruption the fears of bad governance - or of governance itself - diminish. But I do wonder if it will take socialist or at least social democratic tendencies (government for the people? Radical notion!) to advance energy technologies to make an abundant sufficiency for everyone with minimal climate and environmental harms achievable. Such technologies, whilst used at enormous scales, may not be especially profitable - or be suited to cost effective recycling. I'm very-not an expert but I suspect that for China - that defies the stereotype for dogmatic and corrupt shoot-self-in-foot incompetence usually applied to communist autocracy - the overarching fear for their leadership isn't of foreign influence and invasion but of a deeply dissatisfied citizenry rising up. Raising people out of poverty may be less about ideology and more about pacifying and appeasing, but does appear to be a genuine commitment. But I think such things, like addressing climate with decarbonising (and legal accountability) and eliminating poverty, seems a legitimate role for government-for-the-people. When eliminating poverty becomes purely a side-effect of appeasing capitalists and perpetual economic growth - from not successfully preventing all tricking down? - that won't be good enough. Like choosing RE and EV's because they are cheaper won't be enough. We need governance that can have big, overarching roles and goals - like decarbonising, like poverty elimination. Insisting the biggest energy and energy technology companies deliver cheap and abundant - enough for a billion plus people irrespective of commercial profitability - could play a significant role in China's policy making that is absent in other nations.

I do think some kind of pre-paid safe disposal/recycle levy would be worthwhile - necessary even, given that the shift to lower cost batteries without high value materials to recover is ongoing. But I think something like that needs to apply to fossil fuels - full responsibility for the problem wastes - and much more urgently. Imposing strong conditions on disposal of batteries or other RE equipment whilst allowing amnesty in perpetuity for fossil fuel wastes - which vastly exceed them in both expected physical quantities per MWh and with greater and harder to manage ongoing harms - would be a mistake.

That is fair, but you did suggest a magnetic sail scoop to collect Hydrogen. I think that faces the same problems achieving magnetic fields large enough and strong enough as Bussard 'scoops', with the added issue of magsail design being inherently different. Yes, I admit I am inclined to add more to my comments than specific responses, including to other possibilities and suggestions that may not have come from you. But I think I will refrain from further comments on this thread.

Theoretically we can't. Too few hydrogen atoms - hydrogen ions? - and magnetic fields lose strength rapidly with distance; the cross section of a magnetic field 'scoop' will be small. There are good reasons why Bussard ramjets are not considered feasible, no matter their ongoing popularity within science fiction. Popular much the way FTL is popular. Even apart from not yet having successfully developed useful controlled fusion without any mass restrictions a proton-proton type appears significantly more difficult than the types being attempted. The onboard capability to produce deuterium or tritium from such collected ions or onboard stores adds yet more dry mass. Produced from lithium within the reactor means carrying lithium in sufficient quantities. And I remain doubtful of the durability of hypothetical fusion or fission hardware - as I am for the durability of everything. As for passing through planetary atmospheres and scooping up gases? By a ship in orbit going around and around again, combining deceleration and refueling - at relatively low speeds - that seems vaguely possible enough to seem possible (but I seriously doubt that it is close to feasible) but faster than orbital speeds, let alone at interstellar velocities in a single pass, no. Like hitting a solid wall I would think. You would have to already have done almost all the deceleration.

A good thing taking a lot of work that should not have been necessary. Unfortunately there can be no assuming the science programs doing the fundamental observations and producing the underlying data will continue intact; clearly the current US Administration, including Congress continue to seek to hamstring climate science. But it appears there is serious intent, commitment and organisation to put politically partisan flunkies in charge of every US government agency and thoroughly vet their activities for political correctness. The extent that climate monitoring and climate science conducted elsewhere can replace the US contributions isn't clear - they have been the largest contributors and the gold standard for more than half a century.

As Australians are wont to say - tell 'em they're dreaming. As thought experiment it can be fun considering possibilities and exposing the impossibilities. As a serious goal to commit vast resources too... in an age where our overuse of Earth resources and carelessness are turning around to bite us? No. And perhaps the most essential thing for keeping such possibilities possible is a healthy, wealthy Earth society. I would be concerned for its mental health if interstellar expansion became an obsession. As threads grow longer the older posts get overlooked and a lot of what DanMP is suggesting has been discussed and I'm probably reiterating some of my own by saying - Saving humanity from extinction is to my mind one of the most unrealistic reasons for interstellar travel. We'll go to space and succeed there from the economic opportunities that require on-site human labour and without them succeeding in delivering more back than the investments they will whither. I am still struggling to see what those opportunities could be. If surviving extreme disasters is the overarching intent then artificial habitats closer to hand, beginning with bunkers before space colonies and space habitats before planets and within the solar system before other stars makes more sense - if you can really call it sense. (Switzerland has (had?) nuclear war bunkers for the entire population - using their abundance of tunnels - but I would find it objectionable for my nation's government to commit to them for only a select few.) Try building a bunker that can last a thousand years without outside resources and see how that works out. I'm more inclined to being 'philosophical' about species mortality; I don't like my impending mortality and putting up a good fight against it is in our nature but so is acceptance of the inevitability. Making the best of what we get and not spending the best of it chasing dreams of immortality is sane and reasonable too. And I think any worlds with existing life are far more likely to be uninhabitable than present as colonial opportunities - nothing makes more varieties of poisons, toxins, allegens than biochemistry and it is big stretch to assume compatibility, even aside from potential for predators and plagues; for most of Earth's living history humans would find Earth's atmosphere un-breathable. I would think if it were somehow possible to go there such living alien life and biochemistry, uncontaminated, is worth more to humanity for what we can learn from it - from an in-space habitat, deploying robotic sampling - than as something to displace and extinct on purpose or by accident with Earth life in pursuit of dreams of land ownership. I hope humanity can rise above such self indulgence.

Not really - societies and economies face some serious problems over the not entirely foreseeable future. If high levels of funding and support continue to flow to fundamental physics without discontinuities I expect more puzzles will get solved. I'm not entirely convinced that will be the case.

Not that he remains as the pre-eminent authority on evolution, but Darwin had some insightful things to say about human societies - not all I would consider correct but he never subscribed to the view that human evolution was driven by individual fitness alone. Somewhat ironic with the rise of Christo-Fascists that detest 'Darwinism' in the US (and to a lesser extent here in Australia) that he considered Euro-Christian societies the superior form. My own view is that we are getting more variation within the population due to our nurturing of the 'weak' but that should circumstances change and our technology dependency break down we will see a lot more natural selection. Yet I think it will be the survival and adaptations of societies that largely determine who does best and which physical traits are lost and which persist and become more common within subsequent populations.

I stand corrected that there are a lot of puzzles within physics that are unsolved. Yet I still think there will be a finite number of them and if not yet more answers than questions as long as we keep trying the proliferation of new question will diminish whilst those answered will increase. Identifying the puzzles is a big step to solving them. Like many truisms, I think it will prove incorrect that the more we learn, the more we realize how much we don't yet know. More specifically to the OP I'm not convinced solving the known unknowns is going to lead to FTL or other workarounds to the physics underpinning the time and resources issues for interstellar travel and I remain skeptical the set of unknown unknowns will reveal any. I would not be disappointed to be wrong - but possibly alarmed with it. I will add that I think that for some of these puzzles resolving one may provide resolution to others - that the number of solutions needed will be less than the number of questions.