Ken Fabian

Some thought has been put into what signatures we might look for - from one side of that question there are efforts like Sara Seager et al to build a comprehensive list of possible volatile compounds. The presence of chemicals that are not in thermodynamic equilibrium - some active process needed to sustain them - seems to be a major criteria, but a lot of chemicals made by life on Earth are unlikely to occur without life. Determining what can or is likely to occur without life is another aspect. What astronomy requires to detect them and how far out is another question. Planets crossing their parent stars visible from Earth and near space will only be a small fraction. https://www.saraseager.com/wp-content/uploads/2020/07/Seager2016.pdf

How much interstellar exploration can a few grams do? What instruments can each carry? How about interstellar data transmissions? Even lots of them strung out as relays - receivers and transmitters and power source along the way needed in that case - I think not. Von Neumann machines look more likely to be successions of complexes of mining, refining, manufacturing machines than machines that can eat asteroid dirt and excrete copies of themselves - I think not. But tech that is thousands and millions of years ahead of us can overcome the obstacles suggests Time somehow erodes the laws of physics to allow magical technologies; we are closing in on a complete theory of everything and it doesn't look like it will support faster than light or time suspension or other magical shortcuts. I see science and tech development as S-curve not exponential or open ended. To the Question - echoing some other comments, vast distances and the limits the laws of physics impose - the difficulties in detection or travel across them - stand out as the most obvious and likely reasons we haven't found any aliens and why aliens have not found us. Any suggestion that we are being deliberately left alone requires evidence they are within range but are avoiding us - we don't have any. I think there is nothing but baseless conjecture to think that; I think not.

This isn't going to work, sorry. If something is turning CO2 into pure carbon, where is the oxygen going? What is powering the process? You can't make carbon from CO2 without using as much energy as carbon burning to make CO2 produces. Hydrocarbon combustion includes hydrogen becoming H2O but most of the energy is from carbon becoming CO2; any reverse process will use at least as much energy as burning the fuel produces with none left over for driving the car. Any collection of CO2 itself - leaving out any making it solid or conversion to "carbon flakes" - would accumulate around 3 times the weight of fuel burned, without considering the weight of the liquid metal and hardware required and the extra fuel consumption running it plus running a car that is much heavier. Battery electric cars powered by low/zero emissions energy are now a proven, viable low/zero emissions option. Major vehicle manufacturers are already committing to it.

I suspect modern physics is circling in on a complete understanding of the underlying physical nature of our universe - and I don't expect it to include opportunities for these kinds of technologies. Of course I would be pleased to be wrong. I see science and technological development following S-curve type progressions and think appearances of being exponential and open ended are illusory. I think that still leaves it open for a lot more technological progress, but probably not the giant leaps in spacecraft propulsion required to open up the possibility of interstellar travel.

I thought Einstein sought empirical evidence that his theory was correct; if it were true the bending of light by gravity would be demonstrated. If it were not correct that would be demonstrated too, but I don't think it was proposed as an attempt to disprove. Other people probably did see it like that. It works as Falsifiable in Popper's terms but not by any intent to conform to Popper's terms; Popper's ideas didn't get published until a couple of decades after the observations that showed Einstein was correct.

Assuming "ice age" refers to glacial maximum within this current ice age - Earth currently being in a glacial minimum within an ice age... No-one knows but climate history and understanding of climate change suggest thousands to tens of thousands of years and with it possibly delayed or even prevented by long term persistence of raised CO2. Not within the lifetimes of any person now living, unless some extreme and enduring rise in volcanic activity occurs first, that is sufficient to induce and sustain large scale expansion of global snow cover. That kind of volcanic activity would be a very strong hint.

I think the dispute becomes about creation versus abiogenesis, rather than versus evolution.

How powerful is the ray? Unless extraordinarily powerful no photons from it will hit that place - they'll scatter too far... and that specific galaxy will have moved, both after the light we detect from it was emitted and after the ray we send in return was emitted.

Since I don't think any past rate of crewed space missions projected into the future can properly represent genuine expectations for technological advancement - and the sufficient motivations for ever more distant crewed missions (allegedly colonisation) are assumed and assumed to be sufficient - I remain deeply dubious that these kinds of studies can tell us anything useful. I think space exploration will continue to be best done remotely with machines and the motivations for and benefits of crewed missions aren't entirely clear to me, beyond feel-good human interest; it isn't because they will do mapping, surveying, sampling better. Including them will reduce, not expand the overall mission capability, with astronaut safety and comfort coming at the expense of other, more useful payload and capabilities.

We will get samples from within the solar system but it looks unlikely in the extreme that we will ever get to examine samples from exoplanets, ever - so we will have to make do with what astronomy can detect. If we want evidence of ETL within our lifetimes it has be either artificial emissions - intentional and unintentional - or biosignatures, not samples. I am not sure what is meant by "theory of life" - observed and hypothetical biological chemistries? I suspect there will be limited chemical pathways for abiogenesis to make life and that determining what those are (and how limited) will be primarily a matter of modeling. Of course we will need to know what signatures abiotic processes can produce, to reduce the possibility of misreading signatures that are ambiguous.

A breakdown of the available nutrients seems appropriate; as others point out getting seeds to sprout is not indicative of an adequate growing medium. About the best it does is indicate an absence of toxicity to plants, or was the "soil" washed or otherwise modified? Mars "soil" would definitely need to have the perchlorates washed out as a preparatory step. NPK are just the big ones where plant nutrients are concerned and for a great many plants the presence of soil biota is critical, including for making usable nutrients from raw rock and mineral material. But I am not convinced this kind of experiment has much value and suspect it is more about keeping the hype about desirability and inevitability of human occupation alive; being able to grow plants in Moon or Mars "soil", when suitable soil, with it's mineral abundances and mineral absences is just one of a great many requirements for viable agriculture will give a misleading impression - almost inconsequential compared to some of the difficulties. On Earth the kinds of construction costs of suitable habitat like the moon needs would send farmers broke before they ever planted anything. And doing it here would be much easier and less costly. Economics is not inconsequential - if providing basic needs takes more economic resources than what the available labour can produce the enterprise will fail; some very big payoff is needed to justify Earth's subsidies.

Coming into this a bit late but - I think cannabis should be fully legal for adults - like alcohol it is widely used and widely accepted and I think prohibition causes more harms than it prevents. A significant number of people who are otherwise law abiding see the police as enemy because cannabis (and other drug use) is illegal. Counseling and rehab as well as education make better use of taxpayer funding than policing cannabis. Other drugs should be legal to use and possess (in small amounts), with efforts to limit availability, but supplying them outside of medical supervision (which may be indicated for confirmed addiction, as harm reduction) should probably not be legal, although I suspect education and harm minimising for users will still give better outcomes than harsh policing. Anecdotally crackdowns on cannabis supply tended to be followed by increased use of other drugs that have more significant medical and social harms, including alcohol. I remain a bit skeptical of significant increase in society wide incidence of psychosis and mental illness from cannabis, suspecting it is one trigger amongst many for susceptible people rather than being a specific cause. The reality around here (rural Eastern Australia) is that policing of cannabis is sporadic and the police don't have their hearts in it, and the penalties are minimal - to the point where Magistrates have actually berated the police for wasting the courts time with arrests of people growing a few plants. The helicopter raids on growers are ineffective - occasionally a very large crop is found but most of that policing is of small crops - a tiny fraction of them - and the police presence is for appearances sake.

PS - I do wonder if they'd have done it differently if they were planning that farm now - solar PV with battery storage instead of solar thermal and thermal storage, powering reverse osmosis rather than evaporative desalination. Most new solar desalination is PV + reverse osmosis. But unless your water needs are low or the demand is high value it won't be cost effective.

Reality is different - skilled labor and existing technologies, construction techniques and supply streams for materials like glass already grows significant amounts of vegetable crops with desalinated water in Australia. Sundrop Farms - It is an example of concentrated solar thermal power being used cost effectively, providing on-site power as well as desalination. Without the climate controlled greenhouses it probably wouldn't work; the local climate would not support outdoor growing and they reduce overall water requirements. It has contracts with one of the largest (the largest?) supermarket chains in Australia. These chains are ruthless with keeping supplier costs low; if it weren't cost competitive with other growers that wouldn't happen. Even the "climate responsible" PR benefits wouldn't be enough. "We use the sun’s energy to produce freshwater for irrigation. And we turn it into electricity to power our greenhouse to heat and cool our crops."

I wonder if this is the most common sort of atheism - people who don't know and don't care. And the most common sort of theism is going along with and repeating the common beliefs of those around us, without much thinking about it.

Like others here I tend to set aside the spooked reaction in favor of more rational explanations. We have a much more comprehensive knowledge of the world around us to draw on than at any time in our evolution, giving confidence in (the more mundane) explanations over the supernatural. I think our capacity for dreaming and imagining is both a strength and a vulnerability - and the imaginary can be spoken or sung or otherwise communicated in ways that affect us emotionally, which I suspect amplifies or reinforces. When the explanations we imagine are close to reality it helps us solve mysteries and real world problems. When the real world responses we make to what we imagine is going on advantage us rather than disadvantage us it helps us. In the presence of imaginary dangers we may do things that help against real dangers - staying near each other and patrolling the camp perimeters for fear of imaginary predators can protect against real ones.

Yet it is currently smaller in extent than at any time since records were kept. Big swings, from record high to record low over a short period. https://www.scientificamerican.com/article/antarctic-sea-ice-hit-a-record-low-now-scientists-think-they-know-why/ The recent extraordinary record high temperatures in Antarctica - coincidentally at the same time as breaking temperature records in the Arctic - came after the record low ice extent, so was not a factor. Antarctica's ice sheets are also losing about 200 billion metric tons of ice a year.

At the household level - it is looking more cost effective for us personally to replace our dying solar hot water system with a heat pump hot water system and run it off the rooftop solar. Note, I'm in Eastern Australia with a mild climate and good solar availability. The power used wouldn't deprive us of any, but the amount of electricity exported back to the grid would be reduced, foregoing a small return payment. The upfront costs are similar, with heat pump costs declining but solar hot water systems struggling to achieve further cost reductions. Why a very simple, direct heating method with no moving parts should be more expensive than a heat pump isn't clear to me but I suspect material costs account for a lot of it - a lot of stainless steel, copper, aluminium and glass in a domestic solar hot water system. Installation of heat pump hot water at ground level is easier too. Durability matters but assumptions that - having no moving parts - direct solar will last longer isn't clear. The repeated heating and cooling of the collectors takes it's toll - it is leaking now at a joint within the collector part and more hassle than it is worth to attempt repair. That part has it's own fluid, originally glycol but now just water, being topped up regularly until we can replace the system. For electricity grids photovoltaics have significant advantages over solar thermal regardless of energy conversion efficiencies. The panels don't need precise alignments or tracking. Little maintenance is needed. They are lower cost per watt hour compared to high temperature Solar Thermal - enough lower that it is cheaper to add more area of panels than use tracking. Finding room for more isn't an issue. Solar thermal's mirrors are technically demanding - precise surfaces and precise solar tracking for each mirror are essential. Steam turbine efficiency in general is rarely above 50% - more like around 30% - but I'm not sure what they are for working solar thermal plants. The capability to store energy as heat - molten salt usually - should be one of the significant advantages but I think including it has actually made the economics worse, not better; attempting to be some kind of drop in replacement for 'baseload' fossil fuel plants was a mistake I think. It added costs but without a clear market and grid demand for stored energy the grid managers just call on lower cost power from elsewhere and the storage component of these plants fail to earn money. Photovoltaics pass off the load leveling role to other elements of an electricity grid, which is normal foer how grid managers deal with the ups and downs of supply and demand. Calling on power from somewhere else has, so far, been cheaper and easier than each generator providing it on site. The economic of solar thermal storage may change as the value of stored energy becomes more explicit within electricity markets.

I think the definition of "therefore" is presenting real problems too. Too many misunderstandings backed by faith rather than evidence or reason. Throw enough doubts around about abiogenesis and evolution amongst people who know little about either and even the most outlandish hypothesis - a supernatural being did it - can sound reasonable. It doesn't work with people with even a basic understanding of biology and evolution.

Peterson will use his keen perception for which hypocrisies of liberals presses conservatives' buttons - showing almost as much contempt by that for those unthinking conservatives as the "hypocritical" progressives - to relentlessly criticise appointments by US Democrats for being politically motivated but, being a politically partisan voice, will refrain from and deflect criticism of brazenly political appointments by US Republicans; despite not being a US citizen he has chosen his side. Of course I'm disappointed that any US President or political party feels it is necessary to stack their highest court with partisans or choose candidates for the sake of public perceptions, but that is the way many of them "play the game". I suspect the new Supreme Court judge - not being white and male and watched hawkishly by conservatives - is more likely to be scrupulous than some of the ones there already, such as Trump appointed.

They stop being atheists with that belief. Taking up religion because other people appear more contented or happy with it could be a rational choice, especially if atheists face persecution, even to wanting to believe and at times feel like they do. And at other times, not. Is that an in between state or a switching between theist and atheist? People are complicated and even the rational are not always rational.

Those that live by the truism will die by the truism. I daresay Alexander made good tyrannical use of fear, both to motivate his nation(s) and armies and to weaken the responses of his enemies. .

The political players who thought branding their legitimate political opponents as traitors was a good idea probably saw it simply as a small but effective way to build a reluctance to change sides in their voter base. The larger consequences of that probably didn't concern them - winning at all costs was the point. But political discourse and democratic elections are the principle ways to avoid deciding things by violence - ie to avoid winning at all costs turning everyone into losers.

I expect some attempts at doing so - parents wanting children who are better than they are in places where that kind of choice is allowed and available, or authoritarian regimes wanting workers and soldiers more capable than their rivals (but probably wanting them to be more obedient and content with their place too). But I think the former depends on developing the means using comprehensive and reliable modeling of the results rather than experimenting on humans - parents will want confidence the changes won't cause unexpected harms but likely won't support trying it out on human subjects as the means to find out. The powerful people who want better soldiers, servants and slaves won't care about the human costs. They will likely want control too much to allow too much super free thinking. Practicing eugenics to enhance or inhibit various traits is possible but I'm not convinced that the end can justify the means. I also suspect a society that is ordered enough to support long term eugenics within it's population may be intrinsically unhealthy. Sorry Beecee, I'm not going to watch an hour and a quarter to get to the "virtually said yes" bits. Hawking was an amazing man with an amazing mind who had big ideas and shared your enthusiastic optimism about humanity expanding into space but his expertise was theoretical physics, not predicting the future. Whilst bio-engineering humans for exotic environments appears a way to make successful colonisations of such environments more likely it takes a whole lot of unlikely hypotheticals on top of hypotheticals to get there. Most proposals for people in space start with making artificial environments close to what humans evolved with, with technologies ordinary humans are capable of mastering. Whilst isolated small populations will end up sharing traits, enough to be recognisably different to other populations I don't see how that would lead to becoming superhuman. Survival in space is unlikely to be easy so being well ordered is probably essential but that degree of order may ultimately be an impediment - any adventurous or rebellious urges may need to be channeled or suppressed to prevent them being counterproductive.

Not sure what is meant by "the energy crisis". I thought first you meant the climate change challenge of replacing dirty energy with clean but suspect it may be the short term shocks from Russia's Ukraine invasion you are referring to. I have no doubt that European nations are quantifying near term available energy resources and requirements in mathematical terms - something nations tend to do anyway, just with more urgency at the moment. But whilst finding the optimum based on those factors may be possible there is politics and balancing various interests to complicate things. EG - clearly it is given that German Greens will oppose extending the lives of nuclear plants - but Germans apart from Greens have misgivings too or the agreement to close them would not have happened. Some of those are more about the poor cost effectiveness of keeping them going given they are expensive and they need a lot of work. Other Germans don't care about climate or nuclear and want returns on their brown coal and gas investments. A study showing other options would be better than nuclear will not be welcomed and would face opposition, just as studies showing doing upgrades to existing nuclear plants would help will face opposition. Given we've had more than 3 decades of consistent science based studies showing we need to get out of fossil fuels the growth of their use was (and is) widely supported by the same governments that commissioned and funded those studies - it is clear that doing studies isn't the biggest problem.