Ken Fabian

All individual humans are different... therefore we don't have an absolutely precise definition of a human there is no such thing as a group of humans - just one and all the rest are flawed imitations... No, this discussion looks like a problem with words and their definitions - and the aspects shared are the unifying characteristics that make "human"; the differences between individuals (even identical twins) don't negate what is shared. The potential for abiogenesis in the universe isn't going to go away with a redefinition of what "abiogenesis" means.

Turn it the other way around - if healthcare workers refuse vaccination and they become a vector for Covid transmission, should they be legally liable for medical/funeral/other expenses of those who get sick as a result? Should their employers face legal sanctions for failure to insist on vaccination? Seems to me there are duties of care that override any personal "free" choice.

Push or pull, pressure or suction, either way can do that - the earliest steam engines sucked (from steam condensing in the chamber) rather than blew; depends on the design whether such a piston would push or pull. It would work either way. I note that my bicycle pump pumps air both pushing and pulling. But what is the piston connected to? A crankshaft like a reciprocating engine? Or will it pump air, say, through a turbine? The first example above ditches the piston and uses the water column itself as the piston to pump air past a turbine - much simpler. The second example could have wave motion pull up some kind of piston in a cylinder in place of the reeling of cable in and out - closest to the OP suggestion that way - with the same question of what then? It could pull up a piston in a cylinder but it looks like there is no advantage; a whole lot of engineering issues are sidestepped by not using pistons. I also note that hypothetically such things could be driven by tide rise and fall - just very slowly and delivering very little power.

This would be a wave generator, not a tidal generator. Rather than a piston but working along these lines... I've encountered - systems where air is drawn in and pushed back out past a turbine as waves pass. Also the use of the cables of a buoyant object aka a buoy, reeling in and out and driving a generator.

I suspect humans are innately - or initially - "weak-wired" sexually; the potential for attraction and arousal is broad. I note that arousal does not even require the participation of anyone else, let alone specific pheromones or specific seasons; fantasizing alone can do it. I also suspect that absence of seasonality made a strong but non-specific sex drive more important. I think the power of the plasticity of the developing pubescent human brain is able to reinforce the triggers and responses humans experience - creating (usually lifelong) "hard-wiring". A wide variety of them. And we are a social animal where sex is both bonding and cause of rivalry and conflict; rules and customs around it have probably always been essential for the group's health. Most preferences will arise from observation and mimicry and experiences. And varying levels of enforcement of conformity within the group can determine what those will be. Those that are missing out on early sexual experiences - perhaps denied them by tribal rules and/or polygamy from power - just guessing - may result in higher incidence of homosexuality.

I don't think what I said does read like that - assuming you mean the "faster horses" are the other options and nuclear fusion is the "electric car", (I think). Analogies don't always work - I don't think yours does. I never said pull the money out of fusion, I said give more money to other options that have potential. My optical rectenna example was just that, one example - like fusion I think it is looks very difficult but has potential for big rewards. I thought my point was that plenty of other kinds of clean energy are also deserving of being well funded, including existing ones that do already work - breeding better batteries and lower cost solar and tidal and geothermal and nuclear fission, because we don't know that fusion will ever be as cheap. Betting on it being a big contributor to emissions reductions in the time frames we are dealing with for climate change looks... overly optimistic. We need those other technologies - much more certainly than we need fusion. Truisms, like analogies, don't always work either; the greatest losses can also come from taking the greatest risks - I suspect risk taking more reliably results in losses than in big rewards. But wealthy nations aren't really risking much, even with 10's of $billions thrown at fusion that fails to realise it's promise; even if these efforts don't work there is usually a lot of new knowledge built that has value. That may be a truism too, but I think a better, truer one. However, where the R&D funding pool is limited (and it always has limits) we do pick and choose what gets support and what doesn't; I don't see that fusion development that isn't working should get special treatment forever if other R&D is being sacrificed to fund it. But even pulling back levels of funding support doesn't mean we cannot come back to it later - where ongoing R&D in other areas will continue to come up with new techniques and technologies that can be applied to the problems controlled fusion pose. I think the entirety of R&D is as essential to success of fusion in the long term as the specific programs currently working.

Beecee, there is the possibility costs just do not come down enough, even that it will be made to work but be too expensive to be our clean energy solution. Worst might be to forever be just out of reach. All our clean possibilities come with problems and doing R&D is about identifying and solving them. I wouldn't want to cut fusion energy funding prematurely, I'd like more overall funding that supports some things I think deserve to be better funded. With a US$20 Billion budget could optical rectennas aka nantennas - that ought to be an innately superior clean energy solution even to fusion - be made to work? I'd be surprised if this is something, that despite the potential for something that can harvest thermal energy from the environment and waste heat and turn it to electricity, has ever gotten single digit millions. I suspect we will increasingly be able to model the things we want to do before we do them and know a lot before we try them. I suspect what ITER is building is in part the product of that kind of process. Is that something only their kind of budget can afford or is that something that others can tap into?

- from the quote, not said by beecee. Safe maybe; the fusion reaction isn't self sustaining so most things that might go wrong will result in cessation of fusion energy production, unlike fission where it keeps making heat for years after the control rods bring it below critical. Which doesn't mean fission has stopped, just been reduced. Fusion will stop. Still some radioactive waste to deal with but potentially less waste than almost any other energy option. How much waste we will tolerate is not always rational; heavy metals contaminated coal ash for example is not usually classed as a toxic waste... mostly because the industries involved have fiercely resisted it, to avoid the costs of safe disposal, and those industries are deemed essential by lawmakers. The potential for serious disasters with fusion is probably still there - lots of energy there that might be released in unwanted ways, like explosions and fires, with possible releases of toxic materials (eg coolants?) but they seem more likely to be localised. If they are large, few in number and whole nations depend exclusively on them the economic consequences of failures may exceed the direct damage. Carbon-free? In the same sense that renewables must initially rely on energy and materials with carbon footprints to get established and will not be zero emissions until their use fully replaces fossil fuel energy and inputs across manufacturing and transport - zero emissions potential, using fossil fuels as the starter fluid. Economic? No. Current price of power from fusion power stations is approaching infinity - you need to be making power that can be sold to even assess if it is economic. It may be fair to socialise the development costs of technologies deemed important and not expect them to be repaid by those building them if commercial plants are built - but whether that is taxpayer money well spent is a real question; there are lots of potential clean energy technologies that could use levels of R&D funding ITER gets. Seems to me if it is this hard to do fusion at all it is unlikely to be easy to make it low cost as well.

Not just those who think life was created have a problem with the idea Life exists in order to moderate planetary energy flows. It seems to presume a purpose. It looks more purposeless and opportunistic to me; energy differences made opportunities for chemical reactions. The just right combinations of chemical reactions. A long way from the Big Bang to a world with the just right non-biological chemicals (not quite the same as "inorganic"). It does sound like the Big Bang was when the potential for such worlds with such chemistry was set. We don't yet know if the emergence of life was inevitable; if we find other emergent examples of Life or, by indirect methods, show that the chemical pathways that would lead to life are likely to be common on worlds similar to Earth, it might be a reasonable conclusion that Life was inevitable all along.

In evolutionary biology there is no "evil" but there is a lot of thinking about cheating and how that plays out. Wikipedia has a reasonable summation, but if you are serious you will look to the linked sources. Social organisms often have ways of "policing" cheaters.

Seems to me the success of a group of hominids depends on the combination of varied abilities, with varied personality types suiting different roles. I suspect there is no ideal personality and too much uniformity would reduce the group's capabilities.

There were solar updraft towers proposals around, warming the air in a flared "hothouse" base. Is that what Revl has in mind? Other ways of using low grade heat to make mechanical movement or electricity include stirling engines and thermocouples.

I don't think I can address all the arguments from multiple people in one session and some probably deserve their own thread - and I won't keep at this endlessly - but fwiw - We have a growing capacity to assess the scale of the challenges we face before we face them, to know the theoretical and practical limits we can expect to come up against, to model them. I expect we will get a top to bottom theoretical understanding of the physics of our universe and thus of limits of material properties and processes - and I don't expect it to include magical outcomes. That will allow us to better recognise what is physically possible and what is not. We can also get better at assessing benefits and cost and what is achievable and what is not. We are already good at that and Mars colonies don't stack up. Previous rounds of natural philosophers and scientists getting it wrong doesn't preclude final iterations getting it right; science is already circling in on those final truths. I don't accept the possibilities for ever better technological capabilities are open ended. And some will be hypothetically possible and demonstrable but in practice impossible to exploit due to absence of commercial viability. Like possible Mars colonies. I no doubt don't have the right attitude - I think the commercial viability is absolutely essential to shift from being a taxpayer funded loss making activity to profitable for growth and any inevitability to kick in. Requiring commercial viability is the right attitude. 1, We (US or China, not my nation) probably will send crewed missions to the moon, for national pride. There are credible plans and commitments from the US to do so and abandoning them will look weak. 2, I see no compelling reason to do so - national pride and one-upping China isn't a compelling reason. 3, I doubt there will ever be a colony on the moon - nothing there of value, no commercial base, no way to pay it's way. 4, I see no compelling reason to do so. 5, I think it is unlikely, but possible we will send crewed missions to Mars. For national pride. Or perhaps billionaire's pride. 6, I see no compelling reason to do so. 7, I strongly doubt there will ever be a colony on Mars - because there is nothing there of value, no commercial basis and no way to pay it's way. Without a sound economic basis it fails. 8, I see no compelling reason to do so. 9a, I think it is possible we will establish self supporting civilisations in space but as an emergent outcome from enduring commercial success at asteroid mining for Earth markets - more likely if doing so actually turns out requiring in-space crews and the whole enterprise is not automated and operated remotely. As a goal in and of itself, no. 9b, if 9a then just possibly habitats that thrive entirely on asteroid/cometary resources - if abundance of reliable fusion energy that is readily and reliably copied is achieved, ie energy apart from solar - then they might survive in the Kuiper and Oort. I don't think humans will ever explore other solar systems, even with probes - not unless successive generations build out new habitations ever further out and keep doing so reliably for a few hundred thousand years. 10, I don't believe generation ships will ever be viable. I don't expect exotic reactionless or FTL ships will ever be possible - and if our current Earth civilisation doesn't implode I think we will achieve a complete understanding of the fundamental physics of our universe in this century and will achieve the ability to know for sure. Mining bulk physical commodities for the Earth market - accessing the abundance of iron and nickel and the more valuable elements mixed in with them - has a compelling basis. Success will probably depend on NOT involving astronauts working in space. Meteor defense looks like a good motivation for taxpayer funded space capability. Colonising, as goal in and of itself? No, I don't think it is compelling. If somehow it can be done easily, where it presents economic opportunity, sure, but it looks anything but easy or presenting commercial opportunity. I don't think is possible to compartmentalise any company's finances like that - too opaque and too much overlap. Direct funding for Starship? Offhand I only recall "just" $80M to assist testing rocket engines that appears directly related. The $2.9M moon lander funding has apparently been suspended. I don't have a special issue with companies bidding for government contracts - which by their nature will include profitability for the contractor - but with misrepresenting it as a private enterprise industry and private industry ambition that stands on it's own feet. SpaceX PR seriously understates the difficulties of grand goals like Mars colonies and hypes unrealistic outcomes. I don't believe they will be capable of doing Mars landings as purely private enterprise ventures, let alone colonies. If they do get to Mars "independently" it will be because of enduring profitability in servicing government contracts - and will probably be a poor business decision. I don't believe space tourism can prop it up and make it commercially viable - something of tangible value has to flow back to Earth. I don't believe it is the role of governments to prop such speculative ventures - but concede that others disagree. I am not stopping anyone but SpaceX is popularising Mars missions with unrealistic hype and do engage in lobbying for government support for funding them.

But I expect that is not as big a graveyard as for those who thought something could be done but it turned out it couldn't. Seriously, these kinds of arguments around having the right attitude don't answer the fundamental problems. Take it for granted that there will be visionaries and risk takers and that they will be admired for it. And some will get it right and change the course of human history and all but the spectacular failures will be forgotten. But I'd like to hear something more substantive about how the risks and problems are to be dealt with than cliches and slogans. It will 100 years of the world changing out of recognition. A century of coming up against hard resource limits and dealing with climate change impacts. Advances in technology and industry, yes, especially near term, but I think there are limits to those too. R&D and continuing advances depend on healthy, wealthy economies and no matter the appearance of continuing advancement as an inevitability I don't believe that it is. Communications looks like the exception that has developed a commercial foundation and can generate sufficient income to pay it's own way. But the entire industry outside of communications and observation is propped up one way or another by taxpayers and even those mostly are too, so it becomes a question of the goals of those space agencies and their governments and what they ought to be supporting. Mars is not a commercial opportunity but servicing government contracts to go to Mars can be, if governments can be induced to support it; the private money invested in developing SpaceX capabilities included capabilities that overlap with Mars ambitions, but always depended on getting rockets that can service governments to be a viable business. I think that expectation of taxpayer funding helping, if not outright paying them to go to Mars was always there. Even more so than most government contract servicing businesses, that may have significant commercial business outside contracting, these "private" space ventures depend on taxpayers. What looks clear to me is there is zero chance of private enterprise going to the moon or Mars without it being mostly if not fully government supported. And I do not think there will be any tangible benefits to Earth or even to advancing Grand Space Dreams in these Mars ambitions. An order of magnitude reduction in launch costs is an astonishing achievement and will benefit Near Earth (Earth oriented) space activities (which we can hope will not be weaponising near Earth space) but it is not nearly enough to make the moon or Mars viable for colonisation. Another one or two orders of magnitude might get us commercially viable asteroid mining, but still leave Mars colonies as unviable. Which colonies I believe will require a substantial Mars economy and population - with no way to pay their way during establishment and facting extinction level dangers on a constant basis. Optimising current rocket technologies to achieve another 10 fold cost reduction looks a lot harder than the first time around and there aren't any promising exotic new technologies that look capable of bringing space shipping costs down anywhere near shipping costs within the main economy. Earth based open ended R&D - that works just as well without a specific space colonisation focus is where that will come from, if that is actually possible. Ultimately understanding the depths of the challenges and limits of materials and technology can tell us if we are wasting efforts on unreachable goals - we will know that throwing yet more effort into it in "obstacles are opportunities" style won't work.

SpaceX income and commercial viability depends heavily on government contracts and it is a long way short of beng fully funded privately; it receives a lot of government funding, which comes tied to particular projects and outcomes. I am not sure what it is but it is not "private enterprise" as it is usually understood. Even Starlink is getting funding. By operating a business which has the US government as the principle customer SpaceX can't just do as it pleases - and without the strong US government support I think current SpaceX capabilities would be much more modest and big ambitions like Mars missions look a lot less likely. Not that I think colonies will be possible even with strong government commitment. Will the Lunar lander they are being funded to develop be the prototype for the Mars landers that don't yet exist? I think they will keep up the science fiction inspired Mars Colony hype but with a timeline reminiscent of Zeno's Paradox, whilst hoping that sufficient popular support leads to a crewed Mars mission as a government funded venture, like with the moon. As contractors they would be well placed to make the profits but avoid the financial risks. Doing it as a wholly private venture? I don't think they are anywhere near being capable of even doing a crewed orbit of Mars and return, let alone landings.

I am not endorsing IDNeon's combative contributions. I remain interested in discussing and debating the real prospects for colonising Mars. I see fundamental problems and am not impressed with "Problems are opportunities" type truisms as responses to them. Those problems are not due to a lack of an optimistic attitude; they need much more substantive solutions than additional optimism. At this point "plans" to colonise Mars are little more than wishful thinking and adding more wishful thinking won't do it.

There is no viable plan for colonising Mars and the improvements SpaceX have made to rocketry are not nearly sufficient to make Mars colonies possible. I suggest Rockets capable of taking missions to Mars part are just one unresolved issue amongst a plethora. Are we not supposed to point out the problems with Mars ambitions? Sorry but the optimistic enthusiasm looks more like Belief and Faith that Elon the Prophet will lead the way to the Promised Land than it being a rational and reasonable ambition for a worthwhile goal that is within reach. At every point the arguments in favor revert to variations of "Planet B", "Lifeboats for escaping a world with no future", "inevitable", "Destiny", "builds hope", "just like Columbus", "Once there people will thrive" and "new tech will make it easy". None of those address concerns raised about fundamental economics or what it takes to be self sufficient under such circumstances. I should just share the enthusiastic hope and refrain from criticising? Sorry, no. I think the subject needs a healthy round of scepticism; people who otherwise appear reluctant to accept extraordinary claims on trust sound a lot like dogmatic Religionists on this.

Some manufacturers like Tesla already include provisions for taking back batteries for recycling/disposal in the purchase price. It is a serious consideration but I don't think it is being neglected. I fully expect more and better recycling and safe disposal Also I think we need some perspective - projections for battery waste for Australia indicate a rise to above 100,000 metric tons per year by 2050. Not sure what global projections are. It is also projected that by then most of that waste will be recycled. I am inclined to think that the quantities of battery waste is an underestimate, but by comparison coal burning in Australia currently produces 12.5 million metric tons per year of heavy metals contaminated and chemically reactive coal ash. Then there is CO2, which exceeds all other waste more than 5 times over. In Australia, 20 times more of that than coal ash waste, which is a lot, lot more than we expect from battery waste. Yes, battery and other RE waste needs to be dealt with but the shift to RE will greatly reduce overall amounts of toxic waste.

People can believe and promote whatever beliefs they like but I do think there are or should be obligations for people holding positions of responsibility and trust, including journalists to investigate and report factually and news editors to make clear the difference between reporting and opinion. We have large parts of communities disbelieving the existence or seriousness of the climate problem - profoundly important to our future - because people we rely on to know the difference between fact and fiction chose to promote conspiratorial BS. The US experienced an attempted coup, because organisations that promote themselves as the Fourth Estate, the essential guardians of Truth and Democracy promoted conspiratorial BS. These were not grass roots movements of people holding their own beliefs but conspiracy theories presented and promoted as factual by people holding positions of trust as , with fiduciary duties, who should and mostly did know better. Journalists and news editors, like people holding high Offices, should have and abide by minimum standards - and be held accountable.

I don't think History tells us that at all. This is the popular retelling of colonial history by space dreamers but I don't see any real substance to it, not adventure as the initial motivation for exploration nor the searching for places to put down roots. What History tells me is that colonies depended on trade and the use of cost effective existing technologies - the gap to bridge between expensive to normal was relatively small. There was an abundance of readily available exploitable resources both for basic survival and for trade. Once provided with maps and rutters plenty of ships could get there and back - and do it profitably. But the gap between expensive to go to Mars and normal remains such a huge gulf that even the superficial resemblance to Europeans colonising The Americas breaks down. It won't be bold adventurers but meticulous planners - and bean counters - that will make any expansion into space possible; the bold adventurer type will be low on the list of preferred crew characteristics.

I don't agree. The resources needed for putting those boots on the ground can do multiple missions and multiple rovers, and can not just deliver and examine a very few samples within close proximity to the lander but do thorough surveys and mapping across vast areas. The data can be on the monitors of teams of the world's best geologists in short time. And in any case I expect any crews will sit within the safety of their base and send out rovers! We've visited Mars by proxy and it offers no path forward to the stated grand dreams of expansion into space I am reading. There are no shortages of better ways to push and celebrate human limits than pointless ones like Mars and most frontiers that matter are still on Earth, frontiers of science. The alleged motivations of Columbus don't even appear to be true - Columbus sought different route to a well known region of rich trade and potential plunder and found an unexpected region to plunder, one with fewer defenses. Any comparison of the opportunities Mars presents to modern humans and the opportunities The Americas offered - unparalleled opportunities to advanced raiders with ships, steel and gunpowder - looks ridiculous. Look at The Americas. Look at Mars. The Americas offered real opportunities to Europeans using everyday technology in common use. Mars offers no real opportunities without technologies that do not exist, technologies that would probably bypass Mars. Space is nothing like the explorations and colonisations of the past and such comparisons offer nothing but illusion; the Grand Space Dreams will be advanced by Earth's economy being sustainable, by using spin off tech from what Earth develops and makes and uses for itself.

We are exploring and better than ever. 21st century humans do space exploration from swivel chairs in front of computer monitors on Earth - it is the in-person explorer thing that is anachronistic. With roots in Astronomy and science, space exploration done from a distance, remotely, is normal and works extraordinarily well, whilst the gloves-on, in-person human space explorer is wishful thinking. Leaving out the crew part simplifies any space mission, extends it's reach and reduces costs enormously. We still do space exploration and we share in it through remote machines and their feeds, in different ways to crewed missions of the Apollo era. But the claim that humans do space exploration better is bunk, with probes and rovers already having explored far beyond the reach of the most ambitious crewed missions. There are some worthwhile taxpayer funded goals in space beyond Earth orbit, eg meteor defense - but Mars colonisation is a poor one. It isn't the spirit of adventure that will carry space enterprises over the line into self supporting viability but commercial viability and Mars doesn't have any.

The quoting from SF may be making my point for me. It IS corny, sorry and I don't accept that it is true; machines are doing it better at this point, already going where Man cannot go boldly or at all. We are way short of stagnation and the disparagement of our blue orb is not called for; nothing in our solar system can compare, not even close. Our harshest deserts are more hospitable. And I think the Grand Space Dreams that science fiction inspires absolutely depend on an enduring, prosperous and wealthy Earth economy. Should we manage to achieve some kind of colonising of space I think it will arise from servicing Earth's needs for resources - at this point the standout resource is nickel-iron and Mars would not be the place to try and mine it. And to succeed, will have to ruthlessly eliminate the need for astronauts wherever possible; nothing adds more costs and complications to doing things in space than including people. Mars is interesting if you are a planetologist or we want to look for evidence of life apart from planet Earth but it's a terrible place for people and I do think sending crewed missions there is pointless as well as extraordinarily wasteful. Also very high risk. It is hyper expensive theatre with a high likelihood of turning to tragedy. If people want to do it out of their own resources, sure, but I don't want taxpayers funding it.

I am of the view that the problem must be addressed at the energy industry level, through government policy planning and regulation inducing a transition to very low to below zero emissions. To be effective clean energy abundance such that even people with extravagantly wasteful lifestyles who do not care will have low emissions is necessary. Personal choices to avoid waste, choose lower emissions options and otherwise reduce personal emissions are helpful - and necessary for our sanity and self respect - but without that fundamental shift to clean energy they cannot solve the problem. Going stone age by choice is not a viable choice and failing to go stone age by choice is no more hypocritical than justifying no efforts to reduce emissions through economy wide policy on the basis of a choice to deny or ignore climate science or just not caring. We can mostly agree that stealing is wrong but it takes laws and enforcement to discourage it - and still stealing is widespread; relying on that in-principle agreement that it is wrong is insufficient. I think the climate problem is like that - something widely agreed should be addressed but relying on that in-principle agreement or personal choice will always be insufficient; people are people and still do things despite knowing better. The issues of social and economic equity can't be set aside but it looks clear to me that failure on emissions will overwhelm any short terms "gains" for the poor by deferring or preventing that transition. Good governance is essential, including for poverty alleviation and should include measures to insulate the most vulnerable from short term economic harms from policies to shift to low emissions. In my experience it is primarily people who can afford such measures that are the ones making the strongest objections that they should not be done because it will hurt the poor, speaking of hypocrisy.

I don't think that makes it better. Starlink has a huge potential revenue stream that can be reinvested in commercial opportunities and makes commercial sense but trips to Mars do not. There is still no potential future revenue stream from spending all that money going to a dead end destination and will be a bad investment. I think Mars only looms large in popular imagination because of generations of overly optimistic popular fiction.