Chapter 5 of the report focuses on the challenges to NEM system reliability caused by increasing VRE penetration, and on possible reforms to the system to accommodate these changes. Price signals, bidding, and market cap prices and floors, as well as many other terms dealt with in this chapter, are definitely outside my sphere of knowledge or interest, but I feel duty bound to try and make sense of them. For a useful beginner’s guide to the NEM, check out this ABC site, though it dates from 2010, and it’s fascinating to note how things have changed since then. The AEMO was only established in 2009.
The NEM is an ‘energy-only’ market, rather than a capacity market. An energy-only market is one in which the companies generating energy are paid for the electricity they sell. In a capacity market they would be paid for keeping generation capacity available to cover what might be a fluctuating demand. With an energy-only market, producers would presumably be focused on demand, not wishing to provide more of something they can’t sell when demand is down, as it has been in recent times. However, base load demand, which is intermittent and unpredictable, becomes a particular problem when investment in the kind of generators that provide base load power is low. The report has this to say on the matter:
The NEM relies on price signals (subject to market price caps and floors), performance standards and market information to incentivise the development and retirement of generation infrastructure. When there is sufficient baseload supply, average prices tend to be low, signalling that no new investment in base load generation is needed. When base load supply tightens, average prices increase, signalling that investment in base load generation is needed. Peaking generators respond to similar patterns but look to higher price periods associated with peak demand.
I don’t really understand this, especially the bit about peaking generators, which sounds as if there are separate generators for peak demand, but that can’t be right. In any case, what this chapter tells me is that the economics of electricity generation in a transforming and uncertain market are fiendishly difficult to comprehend and control. The review ends the chapter, and all other chapters, with consultation questions which help concentrate the mind on the issues at stake. These include questions about the NEM’s reliability settings, liquidity in the market for forward contracts to ensure supply for business and commercial enterprises (and the effect of increasing levels of VRE on forward contracts, and how this can be catered for), and other questions about creating or ensuring future investment.
Chapter 6 deals with the problem of the seemingly ever-increasing cost of electricity to the consumer. The chapter divides itself into sections on wholesale costs and retail pricing. It seems Australia no longer experiences low electricity costs by OECD standards. Network investments have recently driven prices up, and further rises are expected due to generator closures, the international price of gas, and constraints on gas supply. Again the report emphasises the role of gas, at least in the interim:
Gas has the potential to smooth the transition to a lower emissions electricity sector. Gas generation provides the synchronous operation that is key to maintaining technical operability with increased renewable generation until new technologies are available and cost-effective. Furthermore, gas is dispatchable when required.
It seems there’s an intergovernmental understanding that reform is desperately needed to develop and incentivise the local gas market. There are many roadblocks to successful reform, which are currently affecting wholesale costs which will lead to higher retail prices.
Some 43% of current residential electricity prices are made up of network charges, mostly for distribution. Many network renovations were necessary to meet revised standards. A 2013 Productivity Commission inquiry criticised ‘inefficiencies in the industry and flaws in the regulatory environment’ in respect of the planning of large transmission investments and management of demand. Consumer concern about rising prices is driving reform in this area, but we’re yet to see any clear results. Also, there is a difficult balance to be struck between system reliability and cost. A significant proportion of consumers have expressed a willingness to live with reduced reliability for reduced cost.
There has been a difficulty also in forecasting demand, and therefore the spread of cost. Reduced peak demand in the period 2008 to 2013 wasn’t foreseen. The reduction, likely driven increasing electricity costs, was a result of many factors, such as solar installations, energy efficiencies and reduced consumption. There’s a plan to introduce ‘cost reflective pricing’, which means ‘charging prices that accurately reflect the cost of providing network services to different consumer groups’. This is expected to reduce peak demand overall, as will increasing use of solar and, in the future, battery storage.
Retail pricing is another matter, and according to the report there is a lack of transparency in the retail market. Retailing electricity is obviously complex and involves covering wholesale costs as well as billing, connections, customer service, managing bad debts, marketing, return on investment, inter alia. We can only determine whether the retail market is operating fairly when these costs are open to scrutiny.
Chapter 7 deals with energy market governance from a national, whole-of-system perspective. The report stresses urgency on this, though given the complexity of the system and the divided views of policy-makers, it’s unlikely that decisions on integrating the system and making it more flexible will be forthcoming in the immediate future. The governance of the NEM is divided between policy-maker (the COAG Energy Council), rule-maker (AEMC), operator (AEMO) and regulator (AER, the Australian Energy Regulator). None of these bodies, the report notes, are integrated with bodies advising on emissions reduction. Again, the report doesn’t advance a plan for an improved governance system, but posts consultation questions for how improvements might be made. These include amendments to various rules and guidelines, methods for improving accountability and transparency, and expedited decision-making in a rapidly transforming market.
The report includes a number of appendices, the first and most important being a comparison of the NEM with other energy systems and markets worldwide, including those with a large market share of VRE, such as Denmark and Ireland. It is noted that the transformation of these markets, as well as larger markets in Spain and Germany, is being managed apparently without compromising energy security. However, the variety and complexity of many overseas markets and systems makes comparisons well-nigh impossible for someone as uninitiated as myself. Suffice to say that the role of interconnectors for system security is very important in many European regions, and support from governments for a more flexible system to accommodate VRE is more widespread.
Canto: So what’s the latest on SA’s statewide blackout of September 28 last year, who’s to blame, who’s blaming who, and what solutions are in the offing, if any?
Jacinta: Well the preliminary report on the NEM, which we’ve been reading and writing about, has a few things to say about this, and they’re based on the findings of the Australian Energy Market Operator (AEMO) in its own preliminary report.
Canto: He said she said.
Jacinta: Well maybe sort of. So the SA blackout is presented as a case study. Here in SA we have a very high proportion of VRE (variable renewable energy) generation – one of the highest in the world. Our peak demand as a region is 3300 MW, and our supply capacity is almost 2900 MW of gas, almost 1600 MW of wind, and 700 MW of installed solar. We’re connected to the rest of the NEM by two interconnectors, an AC connector with a capacity of 600-650 MW, and a DC connector with a capacity of 220 MW. With electricity demand here declining, or at least not growing, synchronous generation and supply have reduced, with a resultant reduction in system inertia.
Canto: I presume by system inertia you mean the tendency for a machine, a vehicle, or a generator, whatever, a system to keep going once the power’s switched off. Like the QE2 has a lot of system inertia.
Jacinta: Right, but it’s a particularly important term in reference to power generation. There are some neat explanations of this online, but I’ll give a summary here. Coal-fired power stations work through the burning of coal which generates steam to turn a turbine, putting energy into the grid, and being massive, it has a lot of spinning inertia. Slow to fire up, slow to wind down. Solar, though, doesn’t work that way. It has no spinning or even moving parts. When the sun’s off, it’s off, but when it’s on it’s on. There’s really no inertia at all in a conventional solar PV system.
Canto: And wind? That’s the principal renewable energy here.
Jacinta: Yes that has inertia, certainly, but it’s variable and not as significant as perhaps it could be. So anyway on the morning of the blackout weather forecasts were grim, but not enough for AEMO to put out alerts for a ‘credible contingency event’. As it turned out there were at least seven tornadoes in the north of the state that day, as well as numerous lightning strikes and high winds which caused structural damage to transmission lines. At blackout time electricity demand in the state was a little over 1800 MW, with nearly half of it being supplied by wind farms, and of the rest about a third came from gas-fired generators, and the other 600 or so megawatts came through the interconnectors from Victoria. The main Heywood connector was approaching its operating limit. Short circuits to the transmission lines, caused by lightning, were the probable proximal cause of the blackout. Thirteen wind farms were in operation at the time, and eleven of them experienced ‘voltage dips’. What happens in these circumstances is that ‘fault ride-though’ responses are invoked. However, nine of the eleven farms had a lower pre-set limit for the ride-through response to proceed, and after a number of dips those nine wind farms cut their connection. The other two had higher pre-set limits and continued operation.
Canto: Ahh, so those preset limits were set too low?
Jacinta: Maybe – that’s one for further investigation. So the lack of generation from the wind farms caused an overload on the Heywood interconnector, and it was disconnected as per protection systems, resulting in frequency failure on the grid, and blackness fell upon all the land.
Canto: Right, so how did things get restarted? What’s the normal procedure?
Jacinta: Well, there’s this contracted service, called the System Restart Ancillary Service, which in SA is contracted to two major electricity generators (unnamed in the report), who can supposedly restart regardless of the grid situation, and provide power to the transmission network, but these servers failed for unexplained reasons, and power was finally restored through the Heywood interconnector together with the Torrens Island power station.
Canto: Okay, so now the fallout. How could things have been done differently?
Jacinta: Some near-term fixes have been implemented already. Firstly, having to do with frequency rates which I won’t go into here, and secondly in relation to wind farms. Five of them have made changes to their fault ride-through settings, and AEMO is looking at this issue for wind farms across the NEM. The Australian Energy Regulator, another bureaucratic body, will have completed a full analysis of the blackout by early next year to determine if there were any breaches of regulations. Obviously it’ll be looking at the conduct of AEMO throughout, as well as that of the transmission operator, ElectaNet. It’ll also look at these fault ride-though settings of wind farms and the failures of the System Restart Ancillary Service. It all sounds as if everything’s being done that can be done, but the major problem is that grid security as it stands can only be provided by large generators. The report again mentions gas-fired generators as the best solution, at least in the short to medium term.
Canto: So, as the grid, and the general provision of electricity, undergo these transformations, we’ll no doubt experience a few more of these hopefully minor setbacks, which we can learn from as we develop security for a more diverse but more integrated system…
Jacinta: Greater integration might require less squabbling about the future of energy. I can’t see that happening in the near future, unfortunately.
Australia’s Chief Scientist, Alan Finkel, who also happens to be a regular columnist for Cosmos, Australia’s premier science magazine, of which I’m a regular reader, has released his panel’s preliminary report on our national electricity market (NEM), and it has naturally received criticism from within the ranks of Australia’s conservative government, which is under pressure from its most conservative elements, led by Tony Abbott amongst others, who are implacably opposed to renewable energy.
The report confirms that the NEM is experiencing declining demand due to a range of factors, such as the development of new technologies, improved energy efficiency and a decline in industrial energy consumption. It makes a fairly reasonable assumption, but one unwelcome to many conservatives, that our electricity market is experiencing an unprecedented and irreversible phase of transition, and that this transition should be managed appropriately.
The NEM has been in operation for over 20 years, and the recent blackout here in South Australia (late September 2016) was its first real crisis. The issue as identified in the report is that variable renewable energy (VRE) sources are entering and complicating the market, which heretofore has been based on the synchronous generation of AC electricity at a standard system frequency. VRE generation is multiform and intermittent, and as such doesn’t sit well with the traditional system.
There are a number of other complicating issues. Improvements in building design and greater public awareness regarding emissions reduction have led to a decrease in overall energy consumption, while high peak demand on occasion remains a problem. Also the cost of electricity for the consumer has risen sharply in recent years, largely due to network investment (poles and wires). It’s expected that prices will continue to climb due to the closure of coal-fired power stations and the rising cost of gas. Interestingly, the report promotes gas as a vital energy source for this transitional period. It expresses concern about our overseas sales of gas, our low exploration rates, and negative attitudes to the fuel from certain states and territories. Rooftop solar systems, numbering more than 1.5 million, have further complicated the market, as the Australian Energy Market Operator (AEMO) understandably finds it difficult to measure their impact. System integration, which takes solar and wind energy system contributions into account, is clearly key to a successful NEM into the future.
The report also stresses Australia’s commitment to emissions reductions of 26-28% by 2030. It points out that business investors are turning away from fossil fuels, or what they call ’emission intensive power stations’, and financial institutions are also reluctant to back such investments. Given these clear signals, the report argues that a nationally integrated approach to a system which encourages and plans for a market for renewables is essential. This is clearly not what a backward-looking conservative government wants to hear.
So the report describes an ‘energy trilemma’: provision of high level energy security and reliability; affordable energy services for all; reduced emissions. More succinctly – security, affordability and the environment.
In its first chapter, the report looks at new technology. The costs of zero-emission wind turbines and solar PVs are falling, and this will maintain their appeal at least in the short term. Other such technologies, e.g. ‘concentrated solar thermal, geothermal, ocean, wave and tidal, and low emission electricity generation technologies such as biomass combustion and coal or gas-fired generation with carbon capture and storage’ (p13), are mentioned as likely technologies of the future, but the report largely focuses on wind and solar PV in terms of VRE generation. The effect of this technology, especially in the case of rooftop solar, is that consumers are engaging with the market in new ways. The penetration of rooftop solar in Australia is already the highest in the world, though most of our PV systems have low capacity. Battery storage systems, a developing technology which is seeing cost decreases, will surely be an attractive proposition for future solar PV purchasers. Electric vehicles haven’t really taken off yet in Australia, but they are making an impact in Europe, and the AEMO has projected that 10% of cars will be electric by 2030, presenting another challenge to an electricity system based largely on the fossil fuels such vehicles are designed to do without.
The management of these new and variable technologies and generators may involve the evolution of micro-grids as local resources become aggregated. Distributed, two-way energy systems are the likely way of the future, and an Electricity Network Transformation Roadmap has been developed by CSIRO and the Energy Networks Association to help anticipate and manage these changes.
In chapter 2 the report focuses on consumers, who are becoming increasingly active in the electricity market, which was formerly very much a one way system – you take your electricity from the national grid, you pay your quarterly bill. With distributed systems on the rise, consumers are becoming traders and investors in new forms of generation. The most obvious change is with rooftop PV. The national investment in these systems has amounted to several million dollars, with the expectation that individual households will be generating electricity more cleanly, more efficiently, and also more cheaply, notwithstanding the traditional electricity grid. Developments in battery storage and other technologies will inevitably lead to consumers moving off-grid, likely creating financial stress for those who remain. The possibilities for developing micro-grids to reduce costs will further complicate this evolving situation. Digital (smart) metering and new energy management software empower consumers to control usage. And while this is currently occurring mostly at the individual level, industrial consumers will also be keen to curb usage, creating added pressure for a more flexible and diverse two-way market. The report emphasises that the focus should shift more towards demand management in terms of grid security. One of the obvious problems from the point of view of consumers is that those on low incomes, or renters, who have little capacity to move off-grid (or desire in the case of passive users), may bear the burden of grid maintenance costs at increasing rates.
Chapter 3 deals with emissions. In reference to the Paris Agreement of 2015, which has been ratified by Australia, the report makes this comment which has been picked up by the media:
While the electricity sector must play an important role in reducing emissions, current policy settings do not provide a clear pathway to the level of reduction required to meet Australia’s Paris commitments.
The current Renewable Energy Target does not go beyond 2020 and national policy vis-à-vis emissions extends only to 2030, causing uncertainty for investors in an already volatile market. Clearly the report is being critical of government here as it has already argued for the primary role of government in developing policy settings to provide clarity for investment. The report also makes suggestions about shifting from coal to gas to reduce emissions at least in the short term. The report discussed three emissions reduction strategies assessed by AEMO and AEMC (Australian Energy Market Commission): an emissions intensity scheme, an extended large-scale renewable energy target, and the regulated closure of fossil-fuelled power stations. The first strategy is basically a carbon credits scheme, which was assessed as being the least costly and impactful, while an extended RET would provide greater policy stability for non-synchronous generation, so adding pressure to the existing grid system. Closure of coal-fired power stations would reduce low-cost supply in the short to medium term. Base load supply would be problematic in that scenario, so management of closures would be the key issue.
Chapter 4 looks at how VRE might be integrated into the system. It gets a bit technical here, but the issues are clear enough – VRE will be an increasing part of the energy mix, considerably so if Australia’s Large-scale renewable energy target is to be met, along with our international commitment vis-a-vis the Paris Agreement. However, VRE cannot provide spinning inertia or frequency control, according to the report. Basically this means that they cannot provide base load power, at a time when coal-fired power stations are closing down (nine have closed since 2012) and eastern states gas is being largely exported. The Hazelwood brown coal power station, Australia’s largest, and one of the most carbon intensive power stations in the world, will cease operation by April next year.
The difficulty with non-synchronous, distributed, intermittent and variable energy generation (e.g. wind and solar PV) is that these terms seem to be euphemisms for ‘not effing reliable’ in terms of base load, a problem currently being encountered in South Australia and likely to spread to other regions. The report identifies frequency control as a high priority challenge.
Frequency is a measure of the instantaneous balance of power supply and demand. To avoid damage to or failure of the power system the frequency may only deviate within a narrow range below or above 50 Hertz, as prescribed in the frequency operating standards for the NEM.
It’s likely that this narrow range of frequency proved a problem for South Australia when it suffered a blackout in September. I’ll look at what the report has to say about that blackout next time.
Jacinta: So it’s been a while, but let’s return to that fascinating movie about identity, ambition, entrapment and dislocation, Limi Girl.
Canto: After this poignant moment when Xiumei and Heigo recognise the difficulty of living independently, of controlling the forces around them, Heigo announces his arranged marriage to Shugio – ‘but it’s you I want to marry.’ When Xiumei rather cruelly ticks him off about this, he apologises, says he was joking.
Jacinta: And he clearly wasn’t, poor fellow. He’s fighting a losing battle.
Canto: Men chase, women choose. Desperately, he warns her that going to college is no guarantee of a good future. But she’s resolute in her irresolute way – it’s the closest thing to her dream. She walks off, leaving him to wonder if the chase is off.
Jacinta: In the next scene we see Shugio at home, apparently mixing farm work with school work – first writing on a blackboard (there appears to be a calculator on the table), then sifting some kind of foodstuff, then reading some paper. It looks she might be learning some basic literacy and numeracy. She looks happy, no doubt dreaming of her marriage, till she sees Xiumei go by at the bottom of the hill, followed by Heigo. It’s more like a funeral procession than a chase, though. Angrily, she throws a basin of water down towards him.
Canto: Poor Heigo’s not too popular with the womenfolk. The next scene is quite obscure for non-Mandarin speakers. Heigo’s home with young Gaidi, having cooked her dinner. He finds her absorbed in watching a Chinese TV program with a lot of people staring at the Chinese flag, with a soothing voice-over. Looks like propaganda. He turns away, looking slightly perturbed.
Jacinta: Yes, don’t know what to make of it. But in the next scene Gaidi is in bed with her aunt, and has woken up in the middle of the night. She says she wants to go to school. To college in Szichuan, like Xiumei. To find her mother and father. So presumably the program she was watching has influenced her. Her aunt isn’t sympathetic. Shugio didn’t go to school and is having a good life. Xiumei, on the other hand… besides, she doesn’t have the money to waste on such things.
Canto: So Xiumei is being denigrated, but the more aspirational, such as Gaidi, see her as an inspiration. In the next scene, Xiumei is out with her fellow-villagers, all female, working in the ‘fields ‘(actually tough, wooded mountainsides) digging up fleece-flower roots (used in TCM – traditional Chinese medicine – and therefore of very doubtful efficacy). One of the girls steals a root that she has dug up, leading to a confrontation. Another girl joins in and they mock the ‘college student’, who finally storms off, vowing to go back to college. Clearly there’s jealousy here, and a fear/dislike of ‘difference’, typical of a traditional culture.
Jacinta: I’m interested in these fleece-flower roots. Apparently they’re used for hair growth by ‘increasing blood circulation’, but that was on a beauty site. A google search turns up numerous sites, none of them particularly trustworthy in my estimation. A Chinese site states this, in quite scientific-sounding, if garbled, language:
Modern researches showed that fleeceflower root has effects in lowering blood lipids and sugar, preventing atherosclerosis, immune enhancement [?], expanding blood vessels, promoting adrenal gland secretion and blood cell productions, smooth heart and brain circulations [?], protecting liver functioning, enhancing neural and bowel transmissions [wow?!], promoting hair growth, anti-septic and anti-aging [?].
All of which sounds absurdly impressive, but the reference it provides takes us nowhere. Still, I hope it really is the good oil, for the Limi people’s sake…
Canto: Yes, there are no reliable scientific treatments of this ‘superflower’ on the search list, and Wikipedia merely tells us that ‘fleeceflower’ is a common name for several different plants, so it’ll be a tough job getting to the truth of it all. And the fact that this somewhat marginalised culture is relying, at least in part, on these doubtful TCM products for survival is another worrisome sign.
Jacinta: I like the way Xiumei stands up for herself when she’s mocked. She’s always feisty. So she heads back home with her donkey, but when she stops to drink at a stream, her donkey jogs off, after shrugging off its load – baskets full of plants. Xiumei has to carry the load herself. Meanwhile Gaidi, who recovers her donkeys, sets out with Haigo to find and help her. They find her struggling uphill with her baskets. Heigo chides her for ‘being like this’ – presumably referring to her stubborn independence. Xiumei, exhausted, complains tearfully that everybody, even the animals, are bullying her. Nevertheless she lets herself be ‘rescued’ by her ‘sister’ and her suitor. They ride off on what appears to be the village motorbike.
Canto: Yes, a most versatile machine, now carrying three people and a couple of hefty baskets. Next we see Shugio, again doing physical work – she appears to have a herbal medicine-type business operating from home – together with some kind of study, as she examines papers. She sees Heigo arrive from her window, with baskets, and looks pissed off. Heigo announces that he has come to sell herbs. Shugio’s angry because she knows the herbs have been harvested by her arch-rival Xiumei. She agrees to buy the stuff but – never again! Heigo then returns with the empty baskets to Xiumei and Gaidi, who are hiding round the corner. He hands Xiumei the money from Shugio, then tries to talk her out of trying to earn money for her education in such a piecemeal, grinding way. This time young Gaidi speaks up, defending her ‘sister’ and announcing that she too will earn money by her hard work, so that she can go to college in Sichuan and find her parents. Still Heigo insists on giving Xiumei some money, which she reluctantly accepts via Gaidi.
Jacinta: And these scenes highlight the interconnectedness of village life, where enemies must still have commercial connections, where one person’s actions influence another’s – everyone is in each other’s way, and co-operation is necessary for survival.
Canto: So the trio ride off again on the motorbike, taking Xiumei home, apparently with Shugio’s blessing, though Heigo claims, probably rightly, that she’s only faking civility.
Jacinta: Next we see that Xiumei and Gaidi have been dropped off, and then the two females separate, at a kind of outdoor entrance constructed of wood. I’m fascinated by the depictions of rural life here – everything is indoor-outdoor, a far cry from our constructed indoor worlds. Anyway, it seems the pair live side by side, but not together. Or maybe Gaidi is just seeing her elder ‘sister’ to the door.
Canto: In the next scene we have book-burning, always a bad sign, and a heavy symbol. Xiumei’s father is angrily tearing up her college books and throwing them into the fire. Her mother rescues some of them, then Xiumei arrives and protests passionately. Her father, half-brought to his senses, half-relents and stomps off. Her mother consoles her, defends her tormented husband, and brings news of the village gossip. She shouldn’t be hanging out with the engaged Heigo, and she should reconsider all this college malarky. Xiumei, devastated and tearful at all these forces arrayed against her, sobs out that she ‘will not submit to fate’.
Jacinta: It’s another powerful yet low-key moment. I want to shout for her and I want to cry. How well this captures the struggles of the poor. No, not the poor, but those trapped in a web of culture, a culture that understandably wants to maintain itself as it has been for centuries, huddled in a sense with its back to the changing, widening and deepening world around it. We often see these cultures, off-handedly, as lacking, smothering – their shared knowledge of soil, seasons and locality irrelevant to the modern world. Xiumei is half-keen to strip off that knowledge and take on modern clothing, but she’ll inevitably be caught between two worlds and may not succeed or be happy in either.
Canto: Well meanwhile life and the movie goes on. In the next scene, Xiumei’s tormented father visits her as she sleeps in her bedroom, tries to make sense of the schoolbooks there, the posters on her wall, and tucks her in gently. Next morning, Heigo is waiting on his motorbike to take Xiumei to the fields, but she ignores him, saddling up her donkey. As she passes him, she says that his fiancée should ‘watch her mouth’ – presumably it’s Shugio who’s spreading the gossip – and her father later shouts to him a reminder that he’s due to be married (the poor sod), and he also reminds him who the motorbike belongs to.
Jacinta: Yes, but without telling the viewers. Who does that bloody bike belong to? Maybe it’s a community bike. Maybe he’s reminding Heigo of the community values he’s apparently trashing as he chases Xiumei while being engaged more or less against his will to Shugio. The cultural web is doing its ensnaring job.
Canto: Well, Karl Kruszelnicki is one of our best science popularisers as you know, and therefore a hero of ours, but I have to say his explanation of the blueness of our daily sky in his book 50 Shades of Grey left me scratching my head…
Jacinta: Not dumbed-down enough for you? Do you think we could form a Science for Dummies collaboration to do a better job?
Canto: Well that would really be the blind leading the blind, but at least we’d inch closer to understanding if we put everything in our own words… and that’s what I’m always telling my students to do.
Jacinta: So let’s get down to it. The day-sky is blue (or appears blue to we humans?) because…?
Canto: Well the very brief explanation given by Dr Karl is that it’s about Rayleigh scattering. Named for a J W Strutt, aka Lord Rayleigh, who first worked it out.
Jacinta: So let’s just call it scattering. What’s scattering?
Canto: Or we might call it light scattering. Our atmosphere is full of particles, which interfere with the light coming to us from the sun. Now while these particles are all more or less invisible to the naked eye, they vary greatly in size, and they’re also set at quite large distances from each other, relative to their size. The idea, broadly, is that light hits us from the sun, and that’s white light, which as we know from prisms and rainbows is made up of different wavelengths of light, which we see, in the spectrum that’s visible to us, as Roy G Biv, red orange yellow green blue indigo violet, though there’s more of some wavelengths or colours than others. Red light, because it has a longer wavelength than blue towards the other end of the spectrum, tends to come straight through from the sun without hitting too many of those atmospheric particles, whereas blue light hits a lot more particles and bounces off, often at right angles, and kind of spreads throughout the sky, and that’s what we mean by scattering. The blue light, or photons, bounce around the sky from particle to particle before hitting us in the eye so to speak, and so we see blue light everywhere up there. Now, do you find that a convincing explanation?
Jacinta: Well, partly, though it raises a lot of questions.
Canto: Excellent. That’s science for you.
Jacinta: You say there are lots of particles in the sky. Does the size of the particle matter? I mean, I would assume that the light, or the photons, would be more likely to hit large particles than small ones, but that would depend on just how many large particles there are compared to small ones. Surely our atmosphere is full of molecular nitrogen and oxygen, mostly, and they’d be vastly more numerous than large dust particles. Does size matter? And you say that blue light, or blue photons, tend to hit these particles because of their shorter wavelengths. I don’t quite get that. Why would something with a longer wavelength be more likely to miss? I think of, say, long arrows and short arrows. I see no reason why a longer arrow would tend to miss the target particles – not that they’re aiming for them – while shorter arrows hit and bounce off. And what makes them bounce off anyway?
Canto: OMG what a smart kid you are. And I think I can add more to those questions, such as why do we see different wavelengths of light as colours anyway, and why do we talk sometimes of waves and sometimes of particles called photons? But let’s start with the question of whether size matters. All I can say here is that it certainly does, but a fuller explanation would be beyond my capabilities. For a start, the particles hit by light are not only variable by size but by shape, and so potentially infinite in variability. Selected geometries of particles – for example spherical ones – can yield solutions as to light scattering based on the equations of Maxwell, but that doesn’t help much with random dust and ice particles. Rayleigh scattering deals with particles much smaller than the light’s wavelength but many particles are larger than the wavelength, and don’t forget light is a bunch of different wavelengths, striking a bunch of different sized and shaped particles.
Jacinta: Sounds horribly complex, and yet we get this clear blue sky. Are you ready to give up now?
Canto: Just about, but let me tackle this bouncing off thing. Of course this happens all the time, it’s called reflection. You see your reflection in the mirror because mirrors are designed as highly reflective surfaces.
Jacinta: Highly bounced-off. So what would a highly unreflective surface look like?
Canto: Well that would be something that lets all the light through without reflection or distortion, like the best pane of glass or pair of specs. You see the sky as blue because all these particles are absorbing and reflecting light at particular wavelengths. That’s how you see all colours. As to why things happen this way, OMG I’m getting a headache. The psychologist Thalma Lobel highlights the complexity of it all this way:
A physicist would tell you that colour has to do with the wavelength and frequency of the beams of light reflecting and scattering off a surface. An ophthalmologist would tell you that colour has to do with the anatomy of the perceiving eye and brain, that colour does not exist without a cornea for light to enter and colour-sensitive retinal cones for the light-waves to stimulate. A neurologist might tell you that colour is the electro-chemical result of nervous impulses processed in the occipital lobe in the rear of the brain and translated into optical information…
Jacinta: And none of these perspectives would contradict the others, it would all fit into the coherence theory of truth…
Canto: Not truth so much as explanation, which approaches truth maybe but never gets there, but the above quote gives a glimpse of how complex this matter of light and colour really is…
Jacinta: And just on the physics, I’ve looked at a few explanations online, and they don’t satisfy me.
Canto: Okay, I’m going to end with another quote, which I’m hoping may give you a little more satisfaction. This is from Live Science.
The blueness of the sky is the result of a particular type of scattering called Rayleigh scattering, which refers to the selective scattering of light off of particles that are no bigger than one-tenth the wavelength of the light.
Importantly, Rayleigh scattering is heavily dependent on the wavelength of light, with lower wavelength light being scattered most. In the lower atmosphere, tiny oxygen and nitrogen molecules scatter short-wavelength light, such as blue and violet light, to a far greater degree than long-wavelength light, such as red and yellow. In fact, the scattering of 400-nanometer light (violet) is 9.4 times greater than the scattering of 700-nm light (red).
Though the atmospheric particles scatter violet more than blue (450-nm light), the sky appears blue, because our eyes are more sensitive to blue light and because some of the violet light is absorbed in the upper atmosphere.
Jacinta: Yeah so that partially answers some of my questions… ‘selective scattering’, there’s something that needs unpacking for a start…
Canto: Well, keep asking questions, smart ones as well as dumb ones…
Jacinta: Hey, there are no dumb questions. Especially from me. Remember this is supposed to be science for dummies, not science by dummies.
Canto: Okay then. So maybe we should quit now, before we’re found out…
‘Why is the sky blue?’, from 50 shades of grey matter, Karl Kruszelnicki, pp15-19
‘Blue skies smiling at me: why the sky is blue’, from Bad astronomy, Philip Plait, pp39-47
Quote of the day/week/month/post:
Better to have questions you can’t answer than answers you can’t question – Max Tegmark (and many others)
Jacinta: So while astrophysicists argue over the likelihood of life elsewhere in our tiny but massive universe, some are focusing on our nearest star neighbour. Some wobbling of the red dwarf known as Proxima Centauri has revealed, upon lengthy observation, that it has a closely orbiting planet, which considering the relative coolness of the star – way too dim to be seen with the naked eye – and the proximity of its satellite, is very much in the habitable zone. While it’s too early to say so much for the naysayers, the discovery of a planet in the Goldilocks zone of our nearest star in a galaxy of billions of possibilities must surely raise hopes and expectations of life abundant.
Canto: This closest possible exoplanet was only discovered in August this year, so we’re desperate to find out more about it. Being in the habzone is one thing, habitability is another. Obvious questions we have no current way of answering are: does it have an atmosphere? Any possibility of water? Is it tidally locked? And of course we’d love to know if we could launch some sort of robotic mission to our nearest star neighbour. Meanwhile is there any other way of gleaning more info from this tantalising object?
Jacinta: It’s not likely to be habitable though. Solar winds are estimated to be some 2000 times those experienced on Earth, though we can’t be too sure. Researchers are trying to work out the size of the planet…
Canto: How do they know about those solar winds?
Jacinta: Oooh, that’s a horribly good question. It’s due to the closeness of the orbit, where you would expect the solar winds to be much stronger, as they are in our solar system. It’s believed that Mercury’s magnetic field, which should be stronger than it’s been measured to be because of its heavy metallic core, is dampened massively by our solar wind. So basically they would’ve inferred Proxima Centauri’s wind by our own. As to how they came up with the figure of 2000 times that experienced on Earth, I’ve no idea, but strong solar winds make it hard to maintain an atmosphere, which is vital for life. You’ve also talked about tidal locking, which is a feature of close orbits, such as the Moon’s orbit of the Earth. So you’ll have a permanently hot day side and a permanently cool night side, and this can be problematic for the creation of an atmosphere, according to modelling.
Canto: Now, all of this sounds very negative, but basing exo-planetary activity on what’s been the case, as far as we can work it out, in our solar system, has been really problematic hasn’t it?
Jacinta: Definitely, that’s why we need to go beyond modelling, if we can, and collect some real data. So we’re looking to the James Webb Space Telescope (JWST), the very exciting successor to Hubble to be launched around November 2018, to garner more info, which it’ll be perfectly equipped to do.
Canto: If by some near-miraculous combination of circs there is an atmosphere on Proxima b, or a reasonable quantity of liquid water, that would help distribute the heat around the planet. With no atmosphere, the difference between day side and night side would be stark.
Jacinta: Exactly, and that’s what the JWST should be able to detect, as the best way to detect the atmosphere is to measure the planet’s infrared heat signature. If the JWST finds a decisive and fixed difference between the planet’s day and night sides, it’s a safe bet that no atmosphere is present. The JWST will be equipped to measure this IR signature on both sides of the planet, and if it doesn’t find that stark difference, that’ll be when we can start speculating about an atmosphere and its constituents.
Canto: Though of course they’ve already started with the speculation. But really, whatever they find – and I don’t expect that everything will line up for life – the fact that we’ve found an exoplanet well worth investigating on the nearest star outside our solar system, with billions of stars yet to be homed in on, one by one – doesn’t that say something to those who argue for the Fermi paradox – where are they? Okay, Fermi and Hart were talking about intelligent life, and that may well be orders of magnitude more difficult to develop than life itself, but I’m sure that Fermi would be unsettled in his skepticism, if he was alive today, by the vast numbers of exoplanets, in other words possibilities for life, we’re discovering now, with so many to come in the near future.
Jacinta: Yes, bliss in this time it is to be alive, but to be young, that would be very heaven!
Cosmos issue 71, pp9-10
Jacinta: Let’s talk about power. Imbecilic and nasty macho rulers have disgraced our planet for centuries, and their female counterparts have been few and far between. Let’s take a look at some current fruitcakes.
Canto: I wouldn’t say imbecilic – people who get to these positions always have smarts, but often not the kind of smarts that we hopeful underlings value. Okay, let’s go to Poland. Andrzej Duda is Poland’s President, though not its King. That title belongs to another dude, who’s been dead for near on 2000 years (and some say he never existed), and that dude’s mum is Queen. Both in perpetuity, presumably. It’s not known exactly what powers have been conferred on this duo, but a recent ceremony installing the new but very old King, and attended by Duda, gives an indication. During the ceremony, this statement was made:
Rule us, Christ! Reign in our homeland and reign in every nation – for the greater glory of the Most Holy Trinity and the salvation of mankind.
I’m not sure how Poland’s neighbours have responded to this clear threat to their sovereignty, but surely the international community should be on high alert about Poland’s intention to conquer the world via this apparently indestructible dictator (it seems their Queen owes her status solely to being the King’s mum). We shouldn’t let the ambitions of ISIS entirely dominate our thoughts at this time. Duda is, needless to say, a devotee of the most patriarchal organisation in the western world, an organisation that has been intent on world domination since its formation.
Jacinta: And many women in the country are going bunta about the Catholic-diseased government’s plan to ban abortion outright and to impose heavy penalties on non-compliance. Though I should point out that the current PM of the ruling ‘Law and Justice’ Party (PiS) is female, and that’s where the real power lies. The President’s position is largely ceremonial.
Canto: Yeah, like the female cheerleaders for cloth bags in Islamic countries.
Jacinta: Yeah, chuck out the muslin, Muslims. Are they made of muslin? That’d be kind of poetic injustice, wouldn’t it.
Canto: Okay, let’s move south south-east now. Recep Erdogan is the current boss of Turkey, and hopes to be so until 2029. He’s a real macho, a former Islamist who saw the error of his ways after a spell in jail in 1998. Professing to be a moderate conservative, he created the Justice and Development Party (ADP) and led it to victory in a number of elections. So, after terms as Prime Minister he became President in 2014 and has since been expanding the power of that position, previously a ceremonial one.
Jacinta: Watch for any party with ‘justice’ and law’ in its title. They tend to be hard-liners. It’s unlikely that Turkey’s disgusting record of violence against women will improve under this bullish nationalist, who of course opposes abortion in all but the most extreme circs. Honour killing, sex slavery and domestic violence are massive problems in this country, where women are under-educated, under-employed, under-paid and under-valued. Turkey is, or was, keen to join the EU, but it’s opposition to admitting the truth about their Armenian genocide is just one of many obstacles. The position of women in Turkey is another. The recent failure to remove Erdogan seems to have hardened his sense of destiny, so he’ll be cracking down on all dissent and boosting his power in a typically macho way.
Canto: So now let’s head north again and vastly east to the supersized nation of Russia, spearheaded by Vlad the Imperator – not to be confused with the historical Vlad the Impaler, as there are some minor differences in their manner of disposing of their enemies.
Jacinta: Yeah, Vlad the Imp is another macho authoritarian leader unwilling to brook criticism or even scrutiny. Reporters without Borders has ranked the country 148th in terms of press freedom, and the deaths and silencings of independent journalists over the past twenty-odd years have underlined the brutal corruption within the Imp’s regime.
Canto: Sounds very Czarish. But at least women aren’t shat on quite so much there – unless they happen to be journalists.
Jacinta: Yes women are highly educated and highly integrated into the workforce, and two income families are the norm, but clearly the Imp’s a social conservative….
Canto: Right, so worse than your common or garden murderer then?
Jacinta: Well, as usual with these macho types, he’s dizzy with homophobia. He’s bosom buddies with a gang of thugs called the Night Wolves, whose principal raison d’etre is to smash the shit out of homosexuals.
Canto: Strange how some people make use of the only life they have on this planet.
Jacinta: So we seem to be in the grip of a wave of macho thuggery, and all we can do, sadly, is patiently chip away at it, through mockery, smart undermining, argument, evidence, and a kind of faith in a better world. Meanwhile, on with the horrowshow.
Canto: So we head south to China. Of course it has a sorry history of foot-binding and other forms of mistreatment, though probably no worse than elsewhere in the partiarchal past. China is now being transformed more rapidly than possibly any other country in history, and the world is waiting for its profoundly anti-communist government to rip apart at the seams, though there’s little sign of it as yet. The current General Secretary of China is Xi Jinping, a conservative hard-liner who relishes the abuse of human rights. Under him are the members of the standing committee of the Politburo, all men of course. While we know virtually nothing about these characters, we have fairly reliable information that the Chinese dictators slaughter more people annually than are killed by government decree in the whole of the rest of the world put together. In fact, I find China’s very lengthy record of human rights abuses too unbearable to read, and the Tiananmen Square massacre is still fresh and raw in my mind.
Jacinta: Okay so let’s reduce it to statistics – where does Reporters without Borders place China in terms of press freedom? And what about the treatment of homosexuals – always a good sign of macho infantilism?
Canto: China’s ranked at number 176 in terms of press freedom, out of 180 countries listed. Just above Syria, North Korea and other such havens. On the other hand, attitudes to homosexuality aren’t particularly hostile, though legal changes have a time lag on the west. Clearly the dictators don’t see it as a major threat – they don’t seem as murderously imbecilic as Vlad the Imp on the subject. So where next?
Jacinta: Well for our final stop let’s head further south to the Phillipines, whose molto-macho leader seems to love the headlines…
Canto: Actually, when I looked up macho Filipino pollies, the list of sites all dealt with one Ferdinand Marcos.
Jacinta: Interesting point – the current Prez of the Phillipines, a macho scumbag by the name of Rodrigo Duterte, is naturally a great supporter of scumbags of the past, and wanted to honour the former dictator – the second most corrupt polly of all time, just behind Scumbag Suharto, according to the anti-corruption watchdog Transparency International – with a state funeral, but due to receiving plenty of blowback in the country he opted to return the dead scumbag corpse in secret. Now, many argue that Duterte is a reformer who doesn’t belong to the any of the super-rich families who basically own the Phillipines, but his murderous war on drugs shows he’s no friend of the poor either. He has obviously given sweeping powers to the police – always a focus of macho brutality everywhere, with the odd honourable exception – with the inevitable corrupting result. Extra-judicial killings are now a daily occurrence in Filipino cities, and who knows what the death toll will end up being. He’s also flirting with martial law, but that’ll have to wait until his power is consolidated. I’ve no doubt, though, that that’s what he wants for his country.
Canto: He’ll sell his soul for total control?
Jacinta: It’s the ultimate macho fantasy, lived out by Attila, Genghis Khan, Nobunaga, Hideyoshi, Leopold II, Stalin, Mussolini, Hitler, Pavelic, Ho Chi Minh, Tito, Mao Zedong, Brezhnev, Kim Il Sung, Pinochet, Suharto, Amin, Pol Pot, Mobuto, Hussein, just to name a few.
Canto: Yeah, but let’s face it, women would be just as bad if they were allowed to live out their macho fantasies…