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sethoflagos

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Everything posted by sethoflagos

  1. Somewhat. I find it quite 'Little England-ish'. Rather like Lord of the Rings, it has a grain of optimistic truth here and there. @exchemist is correct. Processes may feature negative feedback promoting stability, positive feedback (eg Agent Smith-like autocatalysis) promoting instability, or quite often a combination of the two. A stable global state is dominated by negative feedback loops at it's heart. A large enough disturbance my drive the system towards the boundary where positive feedback loops are more influential. Ultimately, the latter take over and drive the system towards a different equilibrium state. One perhaps where biochemistry can no longer occur rendering all consideration of photosynthesis etc. moot. Post scriptum. I meant to mention Le Chatalier's principle. It colours much of my thoughts on this regarding the local primacy of negative feedback.
  2. There are many potential states of relative long-term global stability embedded as islands within a sea of relative instability: During the Cryogenian epoch ('Iceball Earth') the planet was near fully ice covered for hundreds of millions of years whereas it was pretty well ice free for most of the Mesozoic. Hopefully we're a very long way from a tipping point towards a Venus-like climate, but that state would be remarkably stable. Much depends on the relative movements of the continental masses and, in very recent times, human activity. Both are pretty random phenomena.
  3. Aren't air-conditioners, heat pumps and refrigerators all fundamentally the same thing from a basic physics standpoint? The differences seem only to be on PoV focus: which bit connects to ambient and whether the desired product comes from the heat source (cooling) or heat sink (heating) Perhaps not relevant to a domestic application, but industrially it is common practice to 'daisy chain' refrigeration cycles. For instance a methane cycle can extract heat at -175 0C exhausting to the cold end of an ethylene cycle at -100 0C which in turn exhausts to the cold end of a propane cycle at -15 0C which exhausts to ambient. This temperature can be (and often is) extended with say a cryogenic nitrogen cycle at the cold end. While the final exhaust is simply regarded as 'waste heat', each additional cycle of the chain significantly reduces overall efficiency. But what if we added additional high temperature cycles to the upper end? Domestic heating has been already discussed, and this recovers not just the thermal energy extracted in the low temperature cycles, but also the electrical energy consumed in compression. This turns around the economic balance appreciably since the thermal exhaust now has value comparable to that of combustion heating, and easily beats electrical resistance heating. Water/steam heat pump cycles could achieve temperatures of ~550 0C before metallurgy becomes a real issue, and low cost thermal energy at these temperatures could substitute at an industrial scale for fossil fuels in globally important endothermic reactions like nitrogen fixation, catalytic cracking, drying, etc. etc. but perhaps that's a topic for a different thread. The key point is that if value is created from both ends of a refigeration cycle, then the economics is drastically improved. Scale it up to provide hot water/space heating for a group of apartment blocks or similar densely populated area, then the challenge is less economic, more political (in certain less community oriented jurisdictions).
  4. I understand it correlates with the Riemann zeta function of spin value (?). Some detail at https://mathoverflow.net/questions/414594/scattering-amplitudes-and-the-riemann-zeta-function
  5. Then leadership of the free world must pass by default to the EU. The US is clearly unable to deliver leadership to match Scholtz and Macron.
  6. Most of you seem to regard this as a US internal matter and of no one else's concern. But it was watched with interest in one bar in Lagos at least, by a bunch of not-much-younger- than-them expats of various nationalities. The consensus was that it amounted to a slanging match between the pub gobshite and the drunk in the corner who'd been there since yesterday. If that is the best that the USA can offer at this critical time then heaven help us all - which for an atheist doesn't give a great deal of hope.
  7. Including Pongo, Pan, Gorilla and forebears? Just looking at late Homo erectus, adult brain sizes varied between 550 cc and 1250 cc depending on physical size and local environment due in major part to phenotypic plasticity - different populations adapting quickly to highly divergent habitats. Add to that the extreme rarity of good fossil crania and consequent large statistical uncertainty, you can imagine almost any trend pattern you like. But the data is just too scant and variable to justify it.
  8. Villmoare et al (2022) have yet to see a serious challenge to their summary:
  9. ... is to accept that it isn't your prerogative to do the picking. Try relocating to somewhere where you stand out from the crowd and don't remind potential partners of an irritating sibling. Novelty provokes interest. After that, all you need to do is make them feel like their interest is worthwhile and reciprocated. Resist talking about yourself. It isn't rocket science.
  10. As the OP specifically mentioned a tardigrade level of complexity, this would both push the timeline on by a couple of billion years and demand that those bio-friendly conditions persisted for this period without interruption by e.g. interaction with an active galactic centre (or indeed any galactic centre). The combined requirement for adequate metallicity and long duration stability may conceivably advance the timeline to a couple of billion years after the emergence of large, quiescent spiral galaxies: perhaps >50% of the current age of the universe. Ward & Brownlee and others have pursued these avenues through the Rare Earth Hypothesis. Not sure what you mean here. Something more advanced than tardigrades?
  11. The temperature range 4000K to 60K corresponds to a period called the 'dark ages': after recombination but before the birth of the first generation III stars. The hydrogen + helium 'chemistry' of that era is not conducive to biology.
  12. ... or have both parties check whether a long pendulum suspended from a swivel precesses clockwise or anticlockwise. Difficult to explain how two points on a rigid plane could rotate in opposite directions without ripping apart.
  13. Except the conflagration at Grenfell was due to burning of the exterior cladding so no escape route that way.
  14. ... so some say. I'm in no position to defend the concept at a deep technical level, however, others are and do so. Admitting the advanced wave solutions seems to offer neat solutions to some otherwise seemingly intractable phenomena such as EPR. Perhaps more pertinently, the apparent and 'unlikely' flatness of our universe just shouts 'negative feedback - asymptotic approach' to me. Okay, that sense implies some sort of retrocausal effect. It's a tough call, but I'd sooner trust to Feynman's gut feel than the dim designer of the OT.
  15. Perhaps in the sense that the time evolution of the universe is 'just' thermodynamics. However, it's apparent preference for universes similar to ours, amenable to the evolution of life without appeal to either the anthropic principle or a 'creator', seems a valid enough point.
  16. As I understand it (I may not), Feynman-Wheeler absorber theory postulates that every emitter is coupled to a future absorber. If this is the case, then it introduces an interesting aspect to the teleological argument: that there exists in the (possibly far distant) future, sufficient, and sufficiently diverse structures to provide all necessary absorbers. This suggests that the past is influenced by the consequences of its state and dynamics on its future evolution.
  17. Just a poorly worded afterthought. I intended to say that in the absence of a ram pump or equivalent, the only driving force to hand is the velocity head of the source. On the other hand a ram pump could use a waste flow head drop of a metre, say, to generate surge pulses of up to 15 bar or so albeit for a much lower flowrate.
  18. Yes, I'm well aware of how ram pumps work. But there was no ram pump in the system described, and therefore no means of channeling the input kinetic energy preferentially into the vertical output stream.
  19. The 'logic' seems to be that running water out of a sealed header tank creates a partial vacuum (true so far) that can be used to suck up water from a lower elevation than the discharge. Seconded. Just another PM dream. As for the ram pump idea, if the incoming velocity head was higher than the required lift, the flow would climb the bank of it's own accord.
  20. I'm sure some supermarkets must stock it, but I don't recall seeing peanut butter in Nigeria. It's very much a US product. Here, processed peanuts yield peanut oil and the dry product kuli-kuli which is mixed with various peppers to yield our signature barbeque spice mix suya. Peanut oil and suya pepper have a pretty well indefinite unrefrigerated shelf life even in our climate.
  21. And yet despite being one of the master race, you ended up in your sixties shuffling round Walmart wondering who's fault it was you were still at the bottom of the heap. Oh dear, how sad. Time for you to head back to your cold lonely pond and crawl beneath your stone I think.
  22. This has been tested in South African courts. In what I consider to show a remarkably conciliatory attitude, the San and associated peoples stated that they didn't object to the term 'Bushman' providing it was framed in a positive context. Obviously our racist little troll falls way short of that requirement.
  23. I SO want your dream to be realised as a dung beetle in elephant country. A nice little lesson in humility though I'm sure it would be lost on you.
  24. Why do you pick on Africans? Their impact on climate change has been negligible in comparison to those accustomed to riding in modern air-conditioned automobiles.
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