sethoflagos

My thoughts exactly. The OP appears determined that this is problematic, yet seems incapable of stating exactly what those problems may be.

All species have metabolisms. Not my job. Your's is to provide the evidence.

So? We've found a way of maintaining genetic diversity, and hence our adaptability to meet the challenges of rapid environmental change more so than competing species. What point are you trying to make?

I too have a profoundly deaf uncle (German measles) who was able to forge a valued place in society through being a skilled carpenter and very entertaining company. Caring for the 'weak' is far from unknown in the natural world, particularly if the individual is closely related. See how parents across a host of genera will fight to protect their offspring. Perhaps you should consider more the individual's potential contribution to the society they live in than their vulnerability as an isolated individual. ...and how it may be that I can guess your nationality without checking your profile.

You've never visited Nigeria, have you? Screwdrivah? Wetin be dat?

The early stages might be quite straightforward: a pioneer probe to determine if the target was ripe for exploitation; a secondary wave of chemotrophic microbe based units for basic raw materials extraction; a tertiary wave of bespoke enzyme based purification units... At some point there will be a rate controlling step: possibly the reduction of diatom generated silica to silicon; or the subsequent purification of impure silicon to the 99.9999999% purity required for efficient semiconductor performance. But we know such steps are possible because we've done them ourselves: we cracked the Czochralski process (or rather Czochralski did) over a century ago. Beyond that, most of the complexity is software driven, and software is energetically cheap. Perhaps it takes eight generations, perhaps ten to produce a self sustaining system (rather like the hierarchy of symbionts in terrestrial life). But I don't see this as an impossibility. Yet.

Okay, a word on thermodynamic equilibrium and my cryptic invitation: The thermodynamic Free Energy path leads ultimately to the well known partition function of an equilibrium canonical ensemble: Z = sum(states) exp(-Estate/(kBT)) The Lagrangian path leads to the general quantum path integral, which after Wick rotation can be expressed as: Z = integral(paths) exp(-Spath/h) D(path) The similarity is striking, and suggests some inverse correspondence between temperature and imaginary time along the lines of: 1/(kBT) ~ it/h I suspect this may be behind the recently announced unification of quantum and classical statistical mechanics though I've yet to get around to downloading that paper to confirm or otherwise. Intriguing though. (The embedding of maximum system entropy into the realms of quantum field theory, that is). By definition, thermal equilibrium at temperatures approaching absolute zero. I'll buy it. Since I'm not going to buy into proton decay, then the very occasional collision of structures may continue indefinitely.

I'm insisting that these energy states that the hadrons of the Earth could be redistributed in, are simply not available states, because the hadrons would require an input of energy to move to those infinitely many states. Consider a book with 1000 pages. There are many more ways to arrange the pages of that book so that they are not in order, than the one way in which they are ordered. Yet when the book is 'bound', only the ordered state is available; to access the other state you need to supply energy, and rip out all the pages. Firstly, good response! Game on! You introduced the term 'Maximal Entropy' without specifying what exactly you meant by this. There are as many different interpretations as there are permutations of possible constraints on system development, and external influence. When @swansont interprets it as the maximum possible entropy available to ni=1,k free particles of k different species at some arbitrary V, T, you challenge my response to him on the grounds that it is inconsistent with your preferred interpretation, which seems to constrain the system to one of bound particles in an effectively closed system. This is hardly fair argument. You are trying to have your cake and eat it. Please explain exactly what you intended by the term 'Maximal Entropy' so we can make some positive progress. If you like, we can digress on the apparent symmetry of the evolutionary paths of system Free Energy and system Lagrangian. I don't have a good fix on that one and would appreciate a clear explanation from someone.

No. At least it's certainly not adiabatic: except for black holes (within limits), thermal energy is free to escape the system. Follows naturally from the above. If it were thermodynamically available (for reasons given in my last post, I can't see how it can be) then one would (depending on where you're prepared to draw the line of incredulity) have to accept that all subsystems upstream of that line would dissipate. There are near-infinitely more ways of redistributing the hadrons of the earth-moon system than their current state. If as @MigL insists, even the hadrons are up for grabs, then we're in some sort of featureless Penrose land.

I also omitted Black Holes for simplicity (and also they're not in my field). However, I see them as a special kind of structure where the heat generated by infalling matter cannot escape the event horizon making them rather skin to miniuniverses of their own. Of course, I've come across Hawking radiation which rather muddies this comfy little rationalisation, but then one has the apparent loss of quantum information to explain. I suspect the 2nd Law will survive intact. Do you gain spiritual comfort from the thought? 😄

Love this. A metathesis combining Darwinian evolution with cosmological thermodynamics! Perhaps we have the beginnings of an explanation for that image of a broken transistor radio at the end of a block universe that's haunted me since H2G2 first aired. Gravitational stratification occurs without this surplus free energy as it releases enough heat to activate the process on its own. Decaying nucleides merely help accelerate the process. I omitted them for brevity. We're saying the same thing. Here's the paradox: The universe as a whole progresses through states of ever increasing entropy in conformance with the 2nd Law. Bound matter progresses through states of ever decreasing free energy into low entropy structures. Conformance with 1st & 2nd Laws requires that theoretical 'Maximum Entropy' states are eternally unavailable. That broken transistor radio remains viable.

That scenario was correctly introduced by @studiot as an example of long term low entropy structure in the universe. Entropy is central to the OP, so one may wonder whether a lossless classical n-body system has any relevance. It appears to be a thermodynamic dead end. What I'm attempting to do is argue for the thermodynamic relevance not only of the path toward the minimum free energy classical ideal, but also the relevance of such structures as 'eternal' reservoirs of 'negentropy' (despite an aversion to that term). A parallel, but very much faster evolutionary path has been made for the condensation of protons from a primordial quark gluon plasma: another low entropy, minimum free energy structure created with a truly enormous generation of thermal energy to maintain consistency with the 2nd Law. CERN may well suggest that breaking protons is commonplace, if one turns a blind eye to their need to create energy densities coequal to those of the early universe in order to achieve it. Taken together the 1st and 2nd Laws suggest that one cannot reverse the arrow of time in this way on a cosmological scale as proton decay implies. I'd sooner buy into astrology. Quite. +1

Really ? Is that the lowest energy state ? Really. All particles would be free to diffuse to any location within a planet of uniform composition. And no. The lowest energy state would see the planet in an onion structure of concentric shells of pure components sorted by density. But this doesn't happen either. (Glossing over issues rnvolving chemical potential: reaction, phase change, etc.) The direction of planetary evolution is towards a state of lowest free energy, which is a hybrid of these two forces (H = U - TS) The U component drives differentiation of the planetary interior into shells of differing densities; the S component ensures that some degree of mixing always remains, especially among components of similar density. Well, you've obliged me to think through in detail something that I'd only a vague hand-wavy picture of before, so thanks for that. ...where TdS again characterises the minimum heat shed by the system due to tidal forces as the two bodies exchange angular momentum on their journey to becoming a fully tidally locked single structure. Wouldn't this now become effectively a single isolated body?

Yup, currently inaccessible states need a free energy boost to access them. No disagreement here. Now how about properly addressing my comments on structure? Or am I just wasting my time?

A 'maximal entropy' planet Earth would have no atmosphere-ocean-crust-mantle-core structure. It would be all mixed up into a homogenous blob (which is roughly how it started out). Clearly, this was unstable as the denser components had way too much gravitational potential energy for underlying lower density material to support and they sank towards the centre despite the long-term reduction in (ISOTHERMAL) entropy that implied. The 2nd Law wasn't broken:: the large negative dU component of Free Energy was released as more than sufficient entropy increasing heat to offset the entropy reducing TdS drop in thermodynamically available states. But ultimately that heat, and its associated entropy, would be radiated off into space. Far from evolving into an unstructured body of maximal entropy, it evolves toward a highly structured body of minimal free energy. (Since you're a physicist, I'm using Helmholtz Free Energy here 😉) Similarly, life uses the surplus free energy of other 1st Law energy sources (sunlight, chemical energy) to convert high entropy water and carbon dioxide into highly structured lower entropy cells and multicellular bodies. I use the word 'structure' here as a preferred alternative to 'negentropy' or 'complexity', both of which I think are easily misunderstood. But they are effectively synonyms for reservoirs of APPARENTLY negative entropy. I say 'apparently' since the negative residue is more than balanced by a corresponding radiation of heat from the system. Clearly these must be accounted for in any discussion of cosmological entropy budgets. Proton decay with a 1034 year half-life would clearly obliterate all familiar structures within 1035 years. I half suspect that the concept was invented by some physicist who couldn't be bothered to account for cosmological structures in his calculations. Let him demonstrate an unambiguous and spontaneous proton decay, and I might begin to take the possibility seriously. Until then, I shall remain commitedly atheist about it.

Wherever you feel the urge to use the word 'randomness' in relation to entropy, try replacing it with 'diversity': diversity of position; diversity of momentum; diversity of type; and you will be much closer. The 'diversity of type' (or 'entropy of mixing') is a much underappreciated aspect as it permits the creation of novel structures due to the low entropy ordering of the structure being offset by its high entropy contribution to diversity. Hence stars can ultimately produce the heavier elements; which beget life; which begets the broken transistor radios and other miscellaneous items of space junk that continue to populate a cold universe at the end of time. @MigL can possibly explain how all this structure can be eroded away in the apparent absence of the necessary activation energy - though I can't see it.

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Consider why motorists are so heavily shielded from charges of recklessness simply for bringing an inherently dangerous piece of machinery into an environment shared by others. The origin of 'jaywalking' is instructive: If a man takes his imported pet leopard for walks down the village street, and every so often it bites a lump out of a passing yokel, who is morally responsible for this? The leopard? The yokel? Pray explain why there should be any difference regarding machinery whether AI controlled or not. Indeed this argument seems to render the AI factor irrelevant.

A topical one courtesy of Private Eye

Such a lofty idea it's gone and flown right over my head (was it a bird? was it a plane? ....)

Good points. Reading between the lines, different interest groups are all pulling in different directions, competing for limited governmental attention and development budgets. What's clearly lacking at national levels globally is holistic long-term power supply planning covering: Projected regional power demand Capacity and distribution of base load generation. Capacity and distribution of hot-standby generation. Capacity and distribution of cold standby generation. Capacity and distribution of deep power storage units. Transmission capacity. Stable environmental impact criteria. Stable and flexible grid supply-demand management. Grid voltage and synchronisation management. Stable grid frequency control Power factor control. Rigorous transient and fault protection. Progressive stable and fair power pricing policy (both internal and external) Progressive stable and holistic investment policy Rational accommodation of technological advances. Failure to address any one of these appropriately will adversely impact grid performance as a whole. The free market will always cherry pick the fastest ROI, neglecting the rest, so the central dilemma is how to achieve all of the above through stable, integrated state-level control for the next 50 years. (Where's Stalin when you need him!)

For the same unit power output per unit volume of fluid, a denser fluid needs: less elevation difference; shorter pipe runs; lower fluid velocity. Without knowing the exact nature of the fluid, it's impossible to say whether losses would rise or fall. For some dense fluids (e.g. mercury) I imagine that losses could fall significantly. There is potential to increase power output per unit volume of fluid, but now losses would rise in rough proportion (also to square of velocity) though this does seem to imply that efficiency doen't take a serious hit. Key algebra is h = v2/2g = 'velocity head'

The main advantage IS being able (potentially) to locate high capacity gravity storage in areas of lower relief, perhaps locating them closer to regions of high demand cutting distribution losses. A secondary benefit maybe the lower liquid head to volume flow ratio may better facilitate the use of mixed flow (Francis vane type) pumps and turbines which may help hydraulic efficiency. No mention of the high rates of mechanical wear typically associated with slurries though.

The thermodynamics of a 'photon gas' is well established and quite real. Very similar to the thermodynamics of a molecular gas, but slightly different equations: (there is no conservation of photons etc.) On second thoughts, that's not what you're saying is it. You're referring to that unheard falling tree in a forest malarkey. Never really gone in for that viewpoint. Bit too solipsistic for my taste.

They will suffer an ''absence of heat" death. No more stars (or radioactivity etc.) to keep local temperatures much above absolute zero. Chemistry ceases to be a thing. Or at least chemical reactions grind to a halt. No food; no respiration; no metabolism. Periodically launch probes into deep space and carefully watch their red shift? Long term experiment, but what else are you going to do for a googol-year?