sethoflagos

Sort of. But let's get real. Your reservoir is also supplied by groundwater springs and rainfall runoff from the surrounding hills. Consumer demand is variable, subject to diurnal and various other cycles. The reservoir is 400 miles away and your level readings are supplied by some old bloke who plods up there and back each morning, and sends you the results by carrier pigeon.

Say we wanted to control the average surface temperature of the planet to 1.5oC above pre-industrial levels on a long term basis. Whatever we do, we are denied immediate access to the resulting output that may take many decades to fully present itself. So any attempt at pure feedback control is almost certain to swing chaotically between too-little-too-late and whoops!-too-much. You simply cannot dial in a significant gain value and maintain stability (I have the tee-shirt). The only real option available is some form of feedforward control of the Smith Predictor type. But that requires a really accurate climate model; full knowledge of all influencing factors; and ruthless elimination of... let's call it 'noise'. Thinking about it, yes, there are some philosophical issues to address.

You're not answering the question I asked. Feedforward control requires a model (or implicit model) that predicts the effect of a change in input signal on the output. Since there isn't a hint of retrocausality here, why would a philosopher have any interest in it from a causality perspective? Chapter and verse at: Feed forward control ... and Smith Predictor control where feed forward is a significant component in a system with major industrial relevance (control of distillation towers, paper machines etc)

I've tried accessing the site from a few different VPN locations, and some are giving Error 503: Backend fetch failed. Googling this seems to suggest the website server may be experiencing unusually high traffic.

I can see the relevance of feedback (both +ve and -ve) but what is the context for 'feedforward' here? Let me illustrate with a current topic. Our new short term resident 3i/Atlas is a potential causal factor for a number of possible events. Its disturbance of the local gravitational field may disturb some small orbiting satellite. If that orbit is inherently stable due to say orbital resonance, then the system will tend to generate reaction forces that oppose and possibly reverse any change in satellite trajectory. These reaction forces would be an example of negative feedback. A weakly bound satellite whose orbit is merely metastable may find that the disturbance is enough to send it spiralling out of its orbit at an ever increasing rate as the reduction in gravitational attraction with distance is effectively a repulsive force acting in concert with the initial transient. This is a positive feedback response. So far so good. However, a feedforward response (afaik) implies foreknowledge of a future disturbance from equilibrium which maybe countered by creating an opposing disturbance in advance. So if our best models of solar system mechanics had predicted that 3i/Atlas was going to plough into earth head on, we could potentially launch some countermeasure to deflect the object and reduce its effect. This would be an example of feedforward control. Nature does do feedforward, but only in living systems afaik. A spooked gazelle may run for its life to avoid becoming dinner. A stranded octopus may 'sprint' over rocks to find a deeper pool. Or is that just an inborn reflex? The inanimate parts of the universe seem content just to let stuff happen.

... or at least a quasi religious emotional reaction to ideas that seemed even slightly contrary to his world view. https://vevmo.com/sites/default/files/upload/not-listening-gollum.gif

Ah, we're back to the teleology you mentioned in the OP. What do you expect from such people? Rationality? Rather reminds me of the 1948 Zhdanov decree where Shostakovich, Prokofiev, Khachaturian, Myaskovsky, and others were castigated for formalism (as opposed to Socialist Realism). This, of course, spilled across the border into Poland where Lutoslawski and Panufnik were similarly censured plus Kodaly in Hungary. Other than Krakus gherkins, these were some of the finest products to come out of the Eastern bloc in the mid-20th century and should have been paraded as major achievements. Though I admit that Lutoslawski's concession to Socialist Realism, his Concerto for Orchestra is one of my all time favourites. But then, I also like Wagner. There's no accounting for taste, is there.

No, not at all. The economic analysis of capitalist production in Das Kapital is just objective algebra. The dialectics stem from the class conflict over who gets to pocket the surplus value and the subjective moral judgments associated with that. As @Otto Kretschmer states, these two aspects are quite separable. Your bible stories seem utterly irrelevant. Drivel. DM is a philosophical approach to the resolution of conflict through creation of a new 'synthesis'.

Just for an update, the okra ferment I tried with a version of your suggestion (close fitting glass cup as a 'floating roof') worked a treat with not a hint of yeast pellicle. So thanks for that. And the surface vegetable oil barrier I used on a jalapeno brew worked fine too. I scooped out the now quite spicy oil for recycling prior to refrigeration and the peppers are just right. No oily texture or off-taste that I can detect. Might still work on the fermentation air-lock though: I've got the ginger beer plant up and running...

Me too. And also I believe the current UK government. This is from their Action Plan for achieving Nett Zero by 2030 published on the UK government website: This gets little media attention due to their bias, but I think it's very hard to fault. Far from compromising the implementation of RE, the OP project is clearly an integral part of a much bigger picture that puts RE at the heart of UK power generation. It deserves our general support even if we have some small qualms about individual elements of it. Let's leave the mindless mudslinging to the wealthy vested interests and their lackeys in the right wing media.

Bad kahma all round, I'd say

I guess. Must have forgotten to plug the empathy simulation chip into the autism socket this morning. Apologies @Ken Fabian , it was an unfair comment. I do have a positive view of this project due as much to its local socioeconomic significance as its role in carbon disposal. There's no reason for you to see it in the same light.

... or advising me to stop wearing tights.

You don't seem to have taken on board a single point I made. Fine. Apparently, that's how discourse works these days.

I can assure you that my pickle does not have thrush.

I find this guy very good. https://youtu.be/ZGFpBU37riM

Yup. Acres of greenhouses using the waste heat in the cooling water. Just to put this CCS project in perspective, some back of envelope calculations. 12 million tonnes per annum of CO2 is: 1 million tonnes per month, ~36,000 tonnes per day, 1,500 tonnes per hour, 25 tonnes per minute, ~400 kg/s. Picking a liquid CO2 density of 800 kg/m3 off the top of my head, that's 0.5 m3/s. For a pipeline velocity of 1 m/s, internal x-section of 0.5 m2 sounds very much like bog standard 36" ND pipeline. 200 bar sounds like a reasonable pressure, so 2*107 N/m2 * 0.5 m3/s = 10 MW Couple of Siemens multistage barrel pumps? In the greater scheme of things, this is a very typical pipeline job. A single operating company could easily take this in their stride. For a G7 nation? Peanuts.

Me too. But forgive me if I go on to play devil's advocate for what follows Are you seriously suggesting that going beyond nett zero and removing CO2 out of the atmospheric cycle is undesirable? Why? Why are you introducing this neoliberal BS? Unlike a household economy, the UK government has the Royal Mint. If it needs money for capital investment, it can print it. For wood chips? How do you arrive at these figures? The UK no longer produces power from coal (and please give them credit for that landmark achievement). How does the project in question impact fuel transport costs or combustion efficiency? There are no ongoing CCS costs. What fuel costs are ongoing remain unchanged by the project and are therefore irrelevant to the topic. What point are you trying to make here? Over 250 million years of self-evident containment of the southern North Sea gas fields not long term enough? This is no more than an argument from incredulity. And flies in the face of hard geological evidence. After decades of neoliberal economic austerity and the severe negative impact on growth of Brexit, some would argue that this is a good thing. Another neoliberal mantra. More of a Keynesian myself. Right now, the UK is paying for wind farm capacity simply as rolling reserve to offset the recent large reductions of power generation rotating mass to maintain mains frequency and keep the grid stable. This will become an even more critical issue as the transition to EV proceeds. A holistic approach isn't just a matter of preference; under the circumstances, it's obligatory. Sorry for taking you to task a little here, but do you think the 'other side' would be less robust in their arguments?

A tetrahedral stack of 35 spheres?

A couple of pieces where I think the viola gets some of the best lines (and that's coming from a brass player!) I think they're both gorgeously played, though the AI may disagree.

😄 I understand that it means 'colourful' in the German source name Buntsandstein. It may well be over there, but the bits we dug up in the subsoil at Askham Bryan were just a uniform buff.

The Zechstein actually outcrops 10 miles west of York as magnesian limestone at Tadcaster (Latin name Calcaria) where I went to secondary school. It's an excellent building stone used in the construction of York's Roman walls and the Minster. Our history, geography, and chemistry courses all referenced it to some degree as a relevant local feature, and being fascinated by geology from primary school days, the Zechstein and overlying Bunter sandstone sequences are my 'home turf'.

I was rather impressed that the first thing I saw on emerging from the railway station was a Chinese takeaway called the 'Kerry Oot'. Mind you, that was close on fifty years back.

... chooses to keep quiet about being born within 10 miles of Stamford Bridge (1066), Towton (1461), and Marston Moor (1644) 🤐 The real battles are fought at Winterfell... And winter is coming!

I can't claim to be an expert but l can tell you a little about the southern North Sea gas fields and the importance of the crucial Zechstein Group that caps them. Most of the gas is contained at a depth around 2,500 feet (I think) within permeable Permian strata called the Rotliegend which was marks a low lying depositional area where a sea was starting to form. The area was near the equator at the time, and the sea was either landlocked, or perhaps had a limited connection to the Tethys Ocean in the south around southern Poland. Evaporation rates were high, leading to an overlying deep series of evaporites extending beyond the areal limits of the Rotliegend as the proto North Sea increased in size. This is the Zechstein Group. It's mainly halite, continuous, highly impermeable, and within broad limits, immune to faulting as it self-heals. Things are a little different further north as the salt becomes diapiric and tends to migrate upwards where it forms the cap rock for the younger oil fields. Having said that, the report didn't say how deep the 'saline aquifer' was that they were going to use for storage, or exactly where it was. So that's important info to look out for. If they're putting it under the Zechstein, then there isn't really an issue here I think. A very timely report of an about turn in Dutch policy wrt wind farms.