an autodidact meets a dilettante…

a dialogue/monologue promoting humanism, science, skepticism, globalism and femocracy, and demoting ignorance, patriarchy, thuggery and zero-sum game nationalism

Posts Tagged ‘science

is this the best use of journalism?: attn Katie McBride and Outline magazine

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Rat Park, in colour

Jacinta: Now we’re going to do something slightly unpleasant but wholly necessary: take someone to task, as teachers must occasionally do.

Canto: Yes, it relates to a previous post, a recent one, about Rat Farm and the war on drugs.

Jacinta: In writing that post we happened upon an article entitled  ‘This 38-year-old study is still spreading bad ideas about addiction” – which kind of shocked me with its provocative title. It was written by Katie MacBride and published by Outline, an online magazine. I only skimmed the article at the time, bemused to find the Rat Park experiment still creating such negative vibes after all these years, but some obvious problems in the article stood out, even on the most cursory reading, so I’ve decided to revisit it with a more careful analysis, with Canto’s help.

Canto: Well the first red flag with the article comes with the first words, before even the title. Pop science. In other words, this article, or rather its subject, should be filed in the category of ‘pop science’, as opposed to real science. This is designed to instil prejudice in the reader from the outset, and is clearly a cheap trick.

Jacinta: Yes, and for an immediate antidote to this kind of cheapsterism, I’d advise anyone to read the Wikipedia article on the rat park experiment, which is calmly and reasonably presented, as is usual. And let me here heap praise on Wikipedia for its general reliability, its objectivity and its pro-science approach. It’s one of the greatest gifts the internet has provided to our world, IMHO.

Canto: The next red flag comes with the title – ’38 years old and still spreading bad ideas’…. As if the date of the study is relevant. There are a number of landmark psychology studies even older than Bruce Alexander’s Rat Park, and also ‘flawed’ – of which more later, – which continue to resonate today for obvious reasons…

Jacinta: Yes, for example Stanley Milgram’s electric shock experiments, over fifty years ago now, and the Stanford Prison experiment of 1971. These, and Alexander’s Rat Park experiment, deserve to be regarded as landmark pieces of work because they make you think. And they often overturn previous thinking. They shake our complacency.

Canto: And what about the latter part of the title, that Alexander’s work is still spreading bad ideas?

Jacinta: It’s interesting that she claims this, considering that the main reason Alexander embarked on this study was to combat bad ideas – particularly the war on drugs itself, and the prevailing view, promoted by the likes of Harry Anslinger and his zero tolerance approach to drugs such as cannabis and cocaine, that use of these drugs led inevitably to a kind of madness that was extremely harmful to self and others. Remember the rat adverts of the time, which showed rats dropping dead after regularly imbibing morphene-laced water, with the message ‘this could happen to you’.

Canto: Yes, and the rats may well have been choosing the drug over plain water because, like many lab rats of the time – hopefully things have changed – the conditions they were kept in made their life something of a living hell. What Alexander’s experiment showed was that, given a far more enriched environment, rats made far less simplistic and self-destroying choices. That’s all. So how could this be a ‘bad idea?’

Jacinta: MacBride doesn’t say. But to be fair, Alexander’s thesis may have been that opiates aren’t addictive at all, which is not what his results showed – they showed that environment matters hugely in respect to the willingness to get hooked on drugs. And that’s a really really important finding, not a ‘bad idea’.

Canto: And we’re still on the title of MacBride’s essay, which is followed by a tiny summary remark, ‘The Rat Park study was flawed and its findings have been oversimplified, but it keeps getting cited.’ Any comments?

Jacinta: Yes – as a regular listener to the podcasts of the Skeptic’s Guide to the Universe (SGU) over the years, as well as a reader of Ben Goldacre and other science-based critics of medical/psychological studies and experiments, I can safely say that every piece of research or experimentation, since the dawn of time, is flawed. Or imperfect. Or limited. Some more than others. of course. So to say the study is flawed is to say nothing at all. Every episode of SGU, and I’ve listened to hundreds, features one piece of published research or other, which Steve Novella picks to pieces to determine whether it’s very or mildly interesting, or a piece of rubbish, but even with the best study, the mantra is generally ‘needs more research’. So a critic needs to show how an experiment is flawed, and how those flaws affect the results. And MacBride’s effort to do this is pretty abysmal.

Canto: Okay, before we examine that effort, I’d like to quote something from early on in MacBride’s article:

The Rat Park study undermined one popular misconception about addiction, that chemistry of drugs is the single most important factor in addiction. But instead of pushing the popular understanding forward, it merely replaced that misconception with a new one: that environment is the most important factor.

What do you make of that? Do you think it a fair description of the study?

Jacinta: It’s an odd description, or mis-description, of the study. The first sentence you quoted isn’t problematic. The study did undermine the idea that it was all about chemistry. Or rather it would have, had anyone paid attention to it. It should have, as MacBride implies, but instead of then regretting that the study didn’t have any impact, she presents it as deserving of oblivion. It doesn’t make much sense.

Canto: The quote claims that it’s a misconception that environment is the most important factor in drug addiction. Do you agree?

Jacinta: I don’t know if it’s the most important factor, but it’s obviously an important factor, and the Rat Park experiment provided strong evidence for this. It seems MacBride is confusing Alexander’s possible claims or commentary on the study with the study itself. The study doesn’t prove that environment is the most important factor, but it certainly makes you think about addiction in a very different way from the horrific but dumb rat ads  that prompted it. It makes you think, as all good studies do, and that’s something MacBride seems extremely reluctant to admit. And I wonder why.

Canto: But MacBride does provide cogent criticisms of the study, doesn’t she?

Jacinta: Well, she quotes one particular critique of the study, by a Dr Sam Snodgrass, who found that the Rat Park environment, in which rats were no longer isolated and therefore mated, as rats are wont to do, would have rendered the findings questionable. According to Snodgrass, “You can’t have one group of subjects mating and with pups and compare it to a group that doesn’t engage in these behaviors and say that the difference between the two groups is caused by environmental differences.” But I beg to differ. An environment in which you’re isolated and unable to have sex is obviously very different from an environment in which you breed as normal – especially for rats. As to the rat pups ruining the experiment, I think if you looked closely at any rat study in which rats get to live together and breed, the actual experiment would be more messy than the published results indicate, but I doubt the problems would be so great as to invalidate those results.

Canto: And what about attempts to replicate the experiment?

Jacinta: Well there seem not to have been enough of them, and that’s not Alexander’s fault. Above all, similar experiments should have been conducted with different drugs and different concentrations etc. And of course rats aren’t humans, and it’s hard to bridge that gap, especially these days, as lab testing of other non-human animals (and rats too) is increasingly frowned upon, for good reason. I note that MacBride briefly mentions that others did replicate Alexander’s results, but she chooses to focus almost wholly on those who found differences. She’s also quite brief in describing the obvious parallel, presented in much greater detail in Johann Hari’s Chasing the scream, of American soldiers taking heavily to heroin in the alienating environment of Vietnam and giving them up on their return to what was for them an obviously more enriched environment. The facts were startling – 20 time the heroin addiction in Vietnam, as MacBride admits – but not much is made of them, as she is more concerned to pour cold water on Rat Park, so to speak.

Canto: Yes it’s strange – MacBride admits that the war on drugs has been an abject failure, but her obsession with criticising Rat Park prevents her from carrying through on that with, for example, the alternatives to this American approach in Europe. She mentions the again startling fact, reported by the Brookings Institute, that the combined hardcore user rate for hard drugs was approximately 4 times higher in the US than in Europe, after decades of the US war on drugs, but fails to note that the Rat Park experiment was one of the main inspirations in implementing more humane and vastly more successful policies, not only in Europe but, more recently, in some US states.

Jacinta: Yes MacBride is clearly concerned to get everyone’s facts straight on the opioid epidemic that’s currently gripping the US, and about which I honestly know little, but I think she has gone overboard in seeking to vilify the Rat Park study, which surely has little to do with that epidemic. The Rat Park experiment hardly promotes drug-taking; what it does strongly suggest, as does Johann Hari’s book, is that environment is one of the most important factors in determining a person’s willingness to escape into drugs. My own personal experience tallies with that, having been brought up in a depressed and disadvantaged region, hard-hit in the seventies by economic recession, and watching the illicit drug trade take off around me, as houses and gardens became more and more derelict.

Canto: Yes, it’s hard to understand why she’s focusing so negatively on Rat Park, when the problem is really one of interpretation, insofar as there is a problem. And I don’t know how it relates negatively to the opioid crisis. Maybe we should find out more about this crisis, and do a follow-up?

Jacinta: Maybe, but it’s so hard trying to fix the world’s problems… but of course that’s what we’re here for…

 

Written by stewart henderson

April 13, 2018 at 11:53 am

transporting water in trees – the finale, perhaps

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‘If I do not succeed today, I will attack [the problem] again on the morrow’

Mary Fairfax Somerville (1780-1872), mathematician, physicist, autodidact, genius

 

trees are so interesting… some more than others

So far my journey into this subject has proved fascinating but inconclusive, but a Veritasium video has helped me with the final solution, though it’ll still take a while to get my head around it.

There’s more than one problem involved here, as I’ve mentioned. There’s the transport problem and the ‘knowledge’ problem; how does the tree ‘know’ when it needs to bring up water, and how much to bring up?

Let’s look at transpiration again. Think of it like our perspiration. When we exercise, or even just when we’re in the sun, we sweat. The sweat then evaporates, cooling our bodies, and if we need to, we produce more sweat. It’s not conscious, we don’t have to know how much more sweat, or water, to produce, it’s just a ‘process’, no doubt a very complex one, like the process in trees and plants. However, I’ll come back to transpiration later.

Water can move up the xylem tube to the leaves of a tall tree at a maximum rate of a third of an inch per second, according to Peter Wohlleben (obviously translated into American). That’s around 2.5cms every 3 seconds, or 50cms per minute. Or 30 metres per hour. That’s rather impressive. When I told a friend about this, she said you can hear the water gushing up the trunk if you put your ear to it. Maybe that’s true.

The Veritasium video starts with another fascinating question – how can trees get so tall? And of course it’s worth noting that different species of trees have their own ‘natural’ height limits, levels of ‘bushiness’ and so forth, which is obviously affected by their particular environments as well as their genes. The tallest are around 100 metres. And one major limiting factor is that they need to transport water from roots to topmost leaves. You can’t suck water up a straw for more than ten metres, because you’ll have sucked all the air out, creating a vacuum, a pressure difference of one atmosphere. To suck the water ten times that high would create a difference of 10 atmospheres or more. So even if trees could suck somehow, the task seems impossible…

Back to transpiration – when water evaporates from the leaves, this ‘pulls up the water molecules behind it’, according to the video, though it doesn’t give an account of this ‘pulling’ mechanism, which in any case couldn’t account for the 100-metre movement, again because of the pressure limitations. Interestingly, many websites, including Wikipedia, describe transpiration as the whole process of water transportation in plants, rather than the process of evaporation and replacement in the region of the leaves, so it can be confusing. In any case the ‘pulling’ up of water to replace molecules lost in evaporation is explained by the cohesion-tension theory, as referred to in a previous post. It’s about hydrogen bonding and the adhesive and cohesive properties of water. Yet it seems miraculous that this process can explain such a vast movement against gravity. The xylem inside trees – those dead, hardened, hollowed-out cells – provide an uninterrupted column for water to pass through (the apoplastic pathway), but the distance would seem to cause pressure problems. The video discounts osmotic action, and here I have to take a quick primer on osmosis, because I don’t get it:

If there is more solute in the roots than in the surrounding soil, water would be pushed up the tree. But some trees live in mangroves where the water is so salty that osmotic pressure actually acts in the other direction, so the tree needs additional pressure to suck water in.

I don’t know why that seems counter-intuitive to me. Is it because I don’t think (sufficiently) scientifically?

Right, after a glance at a couple of videos, I think I get it. I remember the mantra that osmosis is the passage through a semi-permeable membrane (and when does a fully permeable membrane stop being a membrane?) from high to low concentration. But of course it’s the concentration of water molecules that passes from higher to lower, not the concentration of the solute. Duh. And its continued movement up the tree would have something to do with the polarity of water, its bonding properties. But anyway, osmosis isn’t the answer, as mentioned. And neither is capillary action, as explained before.

So now, to the actual explanation, which, at this moment, I certainly don’t get, but I’m going to try. It has to do with gases, liquids, vacuums, pressure and the properties of water. The video provides its final solution, so to speak, in less than two minutes of air-time, but for unscientific me, after a few viewings, it raises more questions than answers. So I’m going to analyse it bit by bit, and this may turn out to be the longest single post I’ve ever written.

So first it’s pointed out, by Hank in the video, that the lowest you can go, pressure-wise, is a vacuum. But that’s only for gases. So a perfect vacuum equals zero pressure. You need something to exert pressure – if there’s nothing there, no pressure:

But in a liquid you can go lower than zero pressure and actually get negative pressures. In a solid, we would think of this as tension. this means that the molecules are pulling on each other and their surroundings. As the water evaporates from the pores of the cell wall, they create immense negative pressures of -15 atmospheres in an average tree.

This negative pressure or tension idea doesn’t come easily to me, and it’s the key to the explanation. It’s certainly accepted science, though there are questions about how much negative pressure water can withstand, as this scientific paper explores, before cavitation. The negative pressure of -15 atmospheres is approximately -1.5 Mpa (megapascals). Experiments described in the scientific paper show that, depending on circumstances, liquid water can sustain far greater negative pressures than -1.5 MPa.

I might be wrong, but it seems to me that negative pressure is like pressure from within (hence tension) rather than from without. I’m going to have to accept this as true, and try and make sense of the rest of the explanation:

Think about the air-water interface at the pore [of the cell wall – is he talking about the whole xylem tube as a cell?]. There’s one atmosphere of pressure pushing in and -15 atmospheres of suction on the other side. So why doesn’t  the meniscus break? Because the pores are tiny – only 2.5 nanometers in diameter. At this scale, water’s high surface tension ensures the air-water boundary can withstand huge pressures without caving [cavitation].

So there’s an air-water boundary (the meniscus) at the pore, which presumably means the top of the column of water. But why does he call it a pore, which we usually think of as a hole, e.g. in the skin. This term isn’t explained at all, it’s just suddenly introduced. Does he mean the xylem column is 2.5 nm wide? No, the average xylem diameter is 25 to 75 micrometers, and 1 micrometer is 1,000 nanometers. In botanical terms, we think of the stomata on the underside of leaves. Is this what is meant? It seems so, from what comes next:

As you move down the tree the pressure increases up to atmospheric at the roots. So you can have a large pressure difference between the top and the bottom of the tree because the pressure at the top is so negative.

I’m still not quite sure how this might be so, and perhaps for that reason the rest of the explanation drifts away from me, though I’m sure it’s trustworthy, and it certainly helps explain why transpiration is indeed an essential part of the entire water movement explanation. But I’ll continue the explanation together with any questions I can come up with. Derek Muller, our Veritasium creator, now asks himself, shouldn’t the water boil at this high negative pressure?

Changing phase from liquid to gas (boiling) requires activation energy. What is this? It’s often defined as the minimum energy required to set off a chemical reaction:

And that can come in the form of a nucleation site like a tiny air bubble. That’s why it’s so important that the xylem tubes contain no air bubbles. Unlike a straw they’ve been water-filled from the start. This way, water remains in the metastable liquid state when it really should be boiling.

Slow down, two more terms are introduced here, a nucleation site and a metastable state. A nucleation site is basically a site where a phase change can begin, and start to spread, as in crystallisation from a solution. In order for water to boil, it has to start to boil somewhere – which is a molecular change. At this site, aka the nucleator, the opportunity for another, freer molecular arrangement (a gas) becomes available, and this will communicate itself to surrounding molecules. Okay, not the best explanation, but it helps me. For a better explanation you should go to the Khan Academy – and so should I. A metastable state, and I quote, is an excited state of an atom or other system with a longer lifetime than the other excited states. However, it has a shorter lifetime than the stable ground state. … A large number of excited atoms are accumulated in the metastable state (Optics 101).

This explains why Muller says the water high in the xylem ‘really should be boiling’, or that it should be in a gaseous state, for that would be its ground state under normal circumstances.

So that’s as far as I can go. It’s been an odyssey for me as well as it was for Muller, and I’m definitely not as sure on it as I could/should be, but I’ve made a lot of headway, and it really is amazing to think of what not only trees but the plants on my balcony ‘garden’ are doing all the time – sucking water through their bodies and into the atmosphere…

 

Written by stewart henderson

February 22, 2018 at 9:42 am

How do trees transport water such long distances? Part 2: the mechanism remains a mystery (to me)

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and I still haven’t found what I’m looking for…

So scientists have learned a lot, though not everything, about water’s travels from soil to leaf in a plant or tree. It’s a fascinating story, and I’m keen to learn more. But the real mystery for me is about energy. As the excellent Nature article, upon which I’m mostly relying, points out, animals have a pump-based circulatory system to distribute nutrients, oxygen and so forth, but plants are another matter, or another form of organised matter.

I actually posed two questions in my last post. How do plants – and I think I should specify trees here, because the massive distance between the soil and their top leaves makes the problem more dramatic – move water such large distances, and how do they know they have to transport that water and how much water to transport?

So let’s look at the Nature Education explanation:

The bulk of water absorbed and transported through plants is moved by negative pressure generated by the evaporation of water from the leaves (i.e., transpiration) — this process is commonly referred to as the Cohesion-Tension (C-T) mechanism. This system is able to function because water is “cohesive” — it sticks to itself through forces generated by hydrogen bonding. These hydrogen bonds allow water columns in the plant to sustain substantial tension (up to 30 MPa when water is contained in the minute capillaries found in plants), and helps explain how water can be transported to tree canopies 100 m above the soil surface.

Notice how we’re again returning to the explanations questioned by Wohlleben – transpiration and capillary action. But we’re introduced to something new – the C-T mechanism. The thesis is that water’s cohesiveness through hydrogen bonding creates a tension (the tension that makes for capillary action) that enables water to be shifted up to 100 metres – all because of the minuteness of capillaries found in plants. And trees? Somehow, I just can’t see it. Perhaps the key is in the phrase ‘helps explain’.  There must surely be more to this. The thesis also mentions ‘negative pressure’ generated by transpiration. This is the signalling I wrote about before. Somehow the plant’s chemistry recognises that there’s an imbalance, and of course this happens in all living things, regardless whether they have a complex nervous system. So maybe there’s no need to worry about ‘knowing’. All living organisms respond to their ever-changing environment by altering their internal chemistry, by opening or closing barriers, by selectively adding or subtracting nutrients, and there are unknowns everywhere about precisely how they do that. It’s a kind of organised chemistry that seems like everyday magic from the outside, whether we’re focusing on a beech tree or our own intestines.

The C-T mechanism is only new to me I should add. It can actually be traced back to 1727 and a book by Stephen Hales, in which he pointed out that without what he called perspiration the water in a plant would stagnate, and that it was also required to allow for the capillary movement of water, because ‘the sap-vessels are so curiously adapted by their exceeding fineness, to raise [water] to great heights, in a reciprocal proportion to their very minute diameters’. But this ‘reciprocal proportion’, according to Wohlleben, as quoted in the last post, can only account for a maximum of 3 feet of upward force in ‘even the narrowest of vessels’.

The water transport system, referred to in the last post as the water potential difference or gradient, also has another name, the Soil Plant Atmosphere Continuum (SPAC). I also mentioned something about an ‘apoplastic pathway’. Water enters the tree by the roots, which are divided and subdivided much like branches and twigs above-ground, with the thinnest examples being the fine root hairs. Water enters through the semi-permeable cell walls by osmosis. Cell-to-cell osmosis carries the water deeper into the root system, and thence into an apoplastic pathway. According to this video, this pathway provides an uninterrupted flow of water (no cell wall barriers) which allows a mass flow ‘due to the adhesive and cohesive properties of water’. This is the cohesion-tension theory again. Apparently, due to evaporation, a tension is created in the apoplast’s continuous stream, leading to this ‘mass flow’.

This makes absolutely no sense to me. What I’m so far discovering is that it’s pretty hard to start from scratch as an amateur/dilettante and get my head around all this stuff, and in my reading and video-watching I’ve yet to find a straightforward answer to the how of long distance, fast transport of water in plants/trees – there probably isn’t one.

I’ll try again after a diet of videos – so far I’ve found a large number of videos in Indian English, and their accents defeat me, I’m sad to say. No transcripts available. Meanwhile, I’ve compiled a little glossary (from various sources) to help myself…

apoplast – within plants, the space outside the plasma membrane within which material can diffuse freely. It is interrupted by the Casparian strip in roots, by air spaces between plant cells and by the plant cuticle.

Casparian stripa band of cell wall material deposited in the radial and transverse walls of the endodermis, which is chemically different from the rest of the cell wall – the cell wall being made of lignin and without suberin – whereas the Casparian strip is made of suberin and sometimes lignin.

cortical cells – in plants, cells of the cortex, the outer layer of the stem or root of a plant, bounded on either side by the epidermis (outer) and the endodermis (inner).

exudation – An exudate is a fluid emitted by an organism through pores or a wound, a process known as exuding.

guttation – water loss, when water or sap collects (at times of low evaporation, dawn & dusk), at tips of grass, herbs (not to be confused with dew, caused by condensation).

hydrostatic pressure – the pressure exerted by a fluid at equilibrium at a given point within the fluid, due to the force of gravity. This increases in proportion to depth measured from the surface because of the increasing weight of fluid exerting downward force from above.

lignin – a class of complex organic polymers that form important structural materials in the support tissues of vascular plants and some algae. Lignins are particularly important in the formation of cell walls, especially in wood and bark, because they lend rigidity and do not rot easily.

osmosis – the movement of water from an area of high to low concentration through a semi-permeable membrane. ‘Pumps’ in the cell membrane transport the specific ions into the cell which means water moves in by osmosis thus maintaining hydrostatic pressure.

phloem – the living tissue that transports the soluble organic compounds made during photosynthesis and known as photosynthates, in particular the sugar sucrose, to parts of the plant where needed. This transport process is called translocation.

plasmodesmata – narrow threads of cytoplasm that pass through the cell walls of adjacent plant cells and allow communication between them.

root pressure – the transverse osmotic pressure within the cells of a root system that causes sap to rise through a plant stem to the leaves. Root pressure occurs in the xylem of some vascular plants when the soil moisture level is high either at night or when transpiration is low during the day

sap – a fluid transported in xylem cells (vessel elements or tracheids) or phloem sieve tube elements of a plant. These cells transport water and nutrients throughout the plant.

suberin – an inert impermeable waxy substance present in the cell walls of corky tissues. Its main function is as a barrier to movement of water and solutes.

symplast – the network of cytoplasm of all cells interconnected by plasmodesmata. The movement of water occurs from one cell to another through plasmodesmata

tracheid – a type of water-conducting cell in the xylem which lacks perforations in the cell wall.

vascular (plants) – also known as tracheophytes and also higher plants, form a large group of plants (over 300,000 accepted known species) that are defined as those land plants that have lignified tissues (the xylem) for conducting water and minerals throughout the plant.

xylem – one of the two types of transport tissue in vascular plants, phloem being the other. The basic function of xylem is to transport water from roots to shoots and leaves, but it also transports some nutrients.

 

On the Trump’s downfall. What a memo. One wonders if the DoJ is running out of patience with the wannabe dictator and his imbecilities, which may bring things to a head sooner rather than later. But those in the know say that Mueller is always thorough and unlikely to be distracted, so I shouldn’t project my own impatience onto him. Dog give me strength to suffer the horrorshow for a while longer.

 

Written by stewart henderson

February 5, 2018 at 3:48 pm

Posted in biology, botany

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the battle for and against electric vehicles in Australia, among other things

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Toyota Camry hybrid – hybrids are way outselling pure EVs here, probably due to range anxiety and lack of infrastructure and other support

I’ve probably not been paying sufficient attention, but I’ve just learned that the Federal Energy minister, Josh Frydenberg, is advocating, against the naysayers, for government support to the EV industry. An article today (Jan 22) in The Australian has Frydenberg waxing lyrical about the future of EVs, as possibly being to the transport sector ‘what the iPhone has been to the communication sector’. It’s a battle the future-believers will obviously win. A spokesman for the naysayers, federal Liberal Party MP and AGW-denier Craig Kelly, was just on the gogglebox, mocking the idea of an EV plant in Elizabeth here in South Australia (the town I grew up in), sited in the recently abandoned GM Holden plant. His brilliantly incisive view was that since Holdens failed, a future EV plant was sure to fail too. In other words, Australians weren’t up to making cars, improving their practice, learning from international developments and so forth. Not exactly an Elon Musk attitude.

The electric vehicles for Elizabeth idea is being mooted by the British billionaire Sanjeev Gupta, the ‘man of steel’ with big ideas for Whyalla’s steelworks. Gupta has apparently become something of a specialist in corporates rescues, and he has plans for one of the biggest renewables plants in Australia – solar and storage – at Whyalla. His electric vehicle plans are obviously very preliminary at this stage.

Critics are arguing that EVs are no greener than conventional vehicles. Clearly their arguments are based on the dirty coal that currently produces most of the electricity in the Eastern states. Of course this is a problem, but of course there is a solution, which is gradually being implemented. Kiata wind farm in Western Victoria is one of many small-to medium-scale projects popping up in the Eastern states. Victoria’s Minister for Energy, Environment and Climate Change (an impressive mouthful) Lily D’Ambrosio says ‘we’re making Victoria the national leader in renewable energy’. Them’s fightin words to we South Aussies, but we’re not too worried, we’re way ahead at the moment. So clearly the EV revolution is going hand in hand with the renewable energy movement, and this will no doubt be reflected in infrastructure for charging EVs, sometimes assisted by governments, sometimes in spite of them.

Meanwhile, on the global scale, corporations are slowly shuffling onto the renewables bandwagon. Renew Economy has posted a press release from Bloomberg New Energy Finance, which shows that corporations signed a record volume of power purchase agreements (PPAs) for clean energy in 2017, with the USA shuffling fastest, in spite of, or more likely because of, Trump’s dumbfuckery. The cost-competitiveness of renewables is one of the principal reasons for the uptick, and it looks like 2018 will be another mini-boom year, in spite of obstacles such as reducing or disappearing subsidies, and import tariffs for solar PVs. Anyway, the press release is well worth a read, as it provides a neat sketch of where things are heading in the complex global renewables market.

Getting back to Australia and its sluggish EV market, the naysayers are touting a finding in the Green Vehicle Guide, a federal government website, which suggested that a Tesla powered by a coal-intensive grid emitted more greenhouse gas than a Toyota Corolla. All this is described in a recent SMH article, together with a 2016 report, commissioned by the government, which claimed that cars driven in the Eastern states have a “higher CO2 output than those emitted from the tailpipes of comparative petrol cars”. However, government spokespeople are now admitting that the grid’s emission intensity will continue to fall into the future, and that battery efficiency and EV performance are continuously improving – as is obvious. Still, there’s no sign of subsidies for EVs from this government, or of future penalties for diesel and petrol guzzlers. Meanwhile, the monstrous SUV has become the vehicle of choice for most Australians.

While there are many many honourable exceptions, and so many exciting clean green projects up and running or waiting in the wings, the bulk of Australians aren’t getting the urgency of climate change. CO2 levels are the highest they’ve been in 15 million years (or 3 million, depending on website), and the last two years’ published recordings at Mauna Loa (2015 and 2016) showed increases in atmospheric CO2 of 3PPM for each year, for the first time since recording began in 1960 (when it was under 1PPM). This rate of CO2 growth, apparently increasing – though with variations due largely to ENSO – is phenomenal. There’s always going to be a see-saw in the data, but it’s an ever-rising see-saw. The overall levels of atmospheric CO2 are now well above 400PPM. Climate Central describes these levels as ‘permanent’, as if humans and their effects will be around forever – how short-sighted we all are.

The relationship between atmospheric CO2 and global warming is fiendishly complex, and I’ll try, with no doubt limited success, to tackle it in future posts.

 

Mustn’t forget my update on Trump’s downfall: the Mueller team has very recently interviewed A-G Sessions, who’s been less than honest about his meetings with Russians. Nobody knows what Sessions was asked about in in his lengthy session (haha) with the inquirers, but he’s a key figure when it comes to obstruction of justice as well as conspiracy. Word now is that Trump himself will be questioned within weeks, which could be either the beginning of the end, or just the end. Dare to hope.

 

Written by stewart henderson

January 26, 2018 at 10:26 am

on electrickery, part 2 – the beginnings

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William Gilbert, author of De Magnete, 1600

Canto: So let’s now start at the beginning. What we now call electricity, or even electromagnetism, has been observed and questioned since antiquity. People would’ve wondered about lightning and electrostatic shocks and so forth.

Jacinta: And by an electrostatic shock, you mean the sort we get sometimes when we touch a metal door handle? How does that work, and why do we call it electrostatic?

Canto: Well we could do a whole post on static electricity, and maybe we should, but it happens when electrons – excess electrons if you like – move from your hand to the conductive metal. This is a kind of electrical discharge. For it to have happened you need to have built up electric charge in your body. Static electricity is charge that builds up through contact with clothing, carpet etc. It’s called static because it has nowhere to go unless it comes into contact with a positive conductor.

Jacinta: Yes and it’s more common on dry days, because water molecules in the atmosphere help to dissipate electrons, reducing the charge in your body.

Canto: So the action of your shoes when walking on carpet – and rubber soles are worst for this – creates a transfer of electrons, as does rubbing a plastic rod with wooden cloth. In fact amber, a plastic-like tree resin, was called ‘elektron’ in ancient Greek. It was noticed in those days that jewellery made from amber often stuck to clothing, like a magnet, causing much wonderment no doubt.

Jacinta: But there’s this idea of ‘earthing’, can you explain that?

Canto: It’s not an idea, it’s a thing. It’s also called grounding, though probably earthing is better because it refers to the physical/electrical properties of the Earth. I can’t go into too much detail on this, its complexity is way above my head, but generally earthing an electrical current means dissipating it for safety purposes – though the Earth can also be used as an electrical conductor, if a rather unreliable one. I won’t go any further as I’m sure to get it wrong if I haven’t already.

Jacinta: Okay, so looking at the ‘modern’ history of our understanding of electricity and magnetism, Elizabethan England might be a good place to start. In the 1570s mathematically minded seamen and navigators such as William Borough and Robert Norman were noting certain magnetic properties of the Earth, and Norman worked out a way of measuring magnetic inclination in 1581. That’s the angle made with the horizon, which can be positive or negative depending on position. It all has to do with the Earth’s magnetic field lines, which don’t run parallel to the surface. Norman’s work was a major inspiration for William Gilbert, physician to Elizabeth I and a tireless experimenter, who published De Magnete (On the Magnet – the short title) in 1600. He rightly concluded that the Earth was itself a magnet, and correctly proposed that it had an iron core. He was the first to use the term ‘electric force’, through studying the electrostatic properties of amber.

Canto: Yes, Gilbert’s work was a milestone in modern physics, greatly influencing Kepler and Galileo. He collected under one head just about everything that was known about magnetism at the time, though he considered it a separate phenomenon from electricity. Easier for me to talk in these historical terms than in physics terms, where I get lost in the complexities within a few sentences.

Jacinta: I know the feeling, but here’s a relatively simple explanation of earthing/grounding from a ‘physics stack exchange’ which I hope is accurate:

Grounding a charged rod means neutralizing that rod. If the rod contains excess positive charge, once grounded the electrons from the ground neutralize the positive charge on the rod. If the rod is having an excess of negative charge, the excess charge flows to the ground. So the ground behaves like an infinite reservoir of electrons.

So the ground’s a sink for electrons but also a source of them.

Canto: Okay, so if we go the historical route we should mention a Chinese savant of the 11th century, Shen Kuo, who wrote about magnetism, compasses and navigation. Chinese navigators were regularly using the lodestone in the 12th century. But moving into the European renaissance, the great mathematician and polymath Gerolamo Cardano can’t be passed by. He was one of the era’s true originals, and he wrote about electricity and magnetism in the mid-16th century, describing them as separate entities.

Jacinta: But William Gilbert’s experiments advanced our knowledge much further. He found that heat and moisture negatively affected the ‘electrification’ of materials, of which there were many besides amber. Still, progress in this era, when idle curiosity was frowned upon, was slow, and nothing much else happened in the field until the work of Otto von Guericke and Robert Boyle in the mid-17th century. They were both interested particularly in the properties, electrical and otherwise, of vacuums.

Canto: But the electrical properties of vacuum tubes weren’t really explored until well into the 18th century. Certain practical developments had occurred though. The ‘electrostatic machine’ was first developed, in primitive form, by von Guericke, and improved throughout the 17th and 18th centuries, but they were often seen as little more than a sparky curiosity. There were some theoretical postulations about electrics and non-electrics, including a duel-fluid theory, all of which anticipated the concept of conductors and insulators. Breakthroughs occurred in the 1740s with the invention of the Leyden Jar, and with experiments in electrical signalling. For example, an ingenious experiment of 1746, conducted by Jean-Antoine Nollet, which connected 200 monks by wires to form a 1.6 kilometre circle, showed that the speed of electrical transmission was very high! Experiments in ‘electrotherapy’ were also carried out on plants, with mixed results.

Jacinta: And in the US, from around this time, Benjamin Franklin carried out his experiments with lightning and kites, and he’s generally credited with the idea of positive to negative electrical flow, though theories of what electricity actually is remained vague. But it seems that Franklin’s fame provided impetus to the field. Franklin’s experiments connected lightning and electricity once and for all, though similar work, both experimental and theoretical, was being conducted in France, England and elsewhere.

Canto: Yes, there’s a giant roll-call of eighteenth century researchers and investigators – among them Luigi Galvani, Jean Jallabert, John Canton, Ebenezer Kinnersley, Giovanni Beccaria, Joseph Priestley, Mathias Bose, Franz Aepinus, Henry Cavendish, Charles-Augustin Coulomb and Alessandro Volta, who progressed our understanding of electrical and magnetic phenomena, so that modern concepts like electric potential, charge, capacitance, current and the like, were being formalised by the end of that century.

Jacinta: Yes, for example Coulomb discovered, or published, a very important inverse-square law in 1784, which I don’t have the wherewithal to put here mathematically, but it states that:

The magnitude of the electrostatic force of attraction between two point charges is directly proportional to the product of the magnitudes of charges and inversely proportional to the square of the distance between them.

This law was an essential first step in the theory of electromagnetism, and it was anticipated by other researchers, including Priestley, Aepinus and Cavendish.

get it?

Canto: And Volta produced the first electric battery, which he demonstrated before Napoleon at the beginning of the 19th century.

Jacinta: And of course this led to further experimentation – almost impossible to trace the different pathways and directions opened up. In England, Humphrey Davy and later Faraday conducted experiments in electrochemistry, and Davy invented the first form of electric light in 1809. Scientists, mathematicians, experimenters and inventors of the early nineteenth century who made valuable contributions include Hans Christian Orsted, Andre-Marie Ampere, Georg Simon Ohm and Joseph Henry, though there were many others. Probably the most important experimenter of the period, in both electricity and magnetism, was Michael Faraday, though his knowledge of mathematics was very limited. It was James Clerk Maxwell, one of the century’s most gifted mathematicians, who was able to use Faraday’s findings into mathematical equations, and more importantly, to conceive of the relationship between electricity, magnetism and light in a profoundly different way, to some extent anticipating the work of Einstein.

Canto: And we should leave it there, because we really hardly know what we’re talking about.

Jacinta: Too right – my reading up on this stuff brings my own ignorance to mind with the force of a very large electrostatic discharge….

now try these..

Written by stewart henderson

October 22, 2017 at 10:09 am

Why science?

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why is it so?

Ever since I was a kid I was an avid reader. It was my escape from a difficult family situation and a hatred or fear of most of my teachers. I became something of a quiet rebel, rarely reading what I was supposed to read but always trying to bite off more than I could chew in terms of literature, history, and occasionally science. I did find, though, that I could chew almost anything – especially in literature and history. And I loved the taste. Science, though, was different. It certainly didn’t come naturally to me. I didn’t know any science buffs and in fact I had no mentors for any of my reading activities. We did have encyclopaedias, though, and my random reading turned up the likes of Einstein, Newton, Darwin, Pasteur and other Big Names in science. Of course I was more interested in their bios than in the nature of their exotic researches, but in my idealised view they seemed very pure in their quest for greater understanding of the material world. I sometimes wished I could be like them but mostly I just dived into ‘literature’, a more comfortable world in which ordinary lives were anatomised by high-brow authors like Austen, Eliot and James (I had a fetish for 19th century lit in my teens). I took silent pride in my critical understanding of these texts, it surely set me above my classmates, though I remember one day walking home with one of the smartest kids in my class, who regaled me with his exploration of the electronics of a transistor radio he was pulling apart at home. I remember trying to listen, half ashamed of my ignorance, half hoping to change the subject to something I could sound off about.

Later, having dropped out of my much-loathed school, I started hanging out, or trying to, with other school drop-outs in my working-class neighbourhood. I didn’t fit in with them to say the least, but the situation worsened when they began tinkering with or talking about cars, which held no interest for me. I was annoyed and impressed at how articulate they were about carbies, distributors and camshafts, and wondered if I was somehow wasting my life.

Into my twenties, living la vie boheme in punk-fashionable poverty among art students and amateur philosophers, I read and was definitely intrigued by Alan Chalmers’ unlikely best-seller What is this thing called science? It sparked a brief interest in the philosophy of science rather than science itself, but interestingly it was a novel that really set me to reading and trying to get my head around science – a big topic! – on a more or less daily basis. I was about 25 when I read Thomas Mann’s The Magic Mountain, in which Hans Castorp, a young man of about my age at the time, was sent off to an alpine sanatorium to be cured of tuberculosis. Thus began a great intellectual adventure, but it was the scientific explorations that most spoke to me. Wrapped up in his loggia, reading various scientific texts, Castorp took the reader on a wondering tour of the origin of life, and of matter itself, and it struck me that these were the key questions – if you want to understand yourself, you need to understand humanity, and if you want to understand humanity you need to understand life itself, and if you want to understand life, you need to understand the matter that life is organised from, and if you need to understand matter…

I made a decision to inform myself about science in general, via the monthly magazine, Scientific American, where I learned at least something about oncogenes, neutrinos and the coming AIDS epidemic, inter alia. I read my first wholly scientific book, Dawkins’ The Selfish Gene, and, as I was still living la vie boheme, I enjoyed the occasional lively argument with housemates or pub philosophers about the Nature of the Universe and related topics. In the years since I’ve read and half-digested books on astronomy, cosmology, palaeontology and of course the history of science in general. I’ve read The origin of species, Darwin’s Voyage of the Beagle and at least four biographies of Darwin, including the monumental biography by Adrian Desmond and James Moore. I’ve also read a biography of Alfred Russell Wallace, and more recently, Siddhartha Mukherjee’s The Gene, which traces the search for the cause of the random variation essential to the Darwin-Wallace theory. And I still read science magazines like Cosmos on a more or less daily basis.

These readings have afforded me some of the greatest pleasures of my life, which would, I suppose, be enough to justify them. But I should try to answer the why question. Why is science so thrilling? The answer, I hope, is obvious. It isn’t science that’s thrilling, it’s our world. I’m not a science geek, it doesn’t come easily to me. When, for example, a tech-head explains how an electronic circuit works, I have to watch the video many times over, look up terms, refer to related videos, etc, in order to fix it in my head, and then, like most people, I forget the vast majority of what I read, watch or listen to. But what keeps me going is a fascination for the world – and the questions raised. How did the Earth form? Where did the water come from? How is it that matter is electrical, full of charge? How did language evolve? How has our Earth’s atmosphere evolved? How are we related to bananas, fruit flies, australopithecines and bats? How does our microbiome relate to obesity? What can we expect from CRISPR/Cas9 editing technology? What’s the future for autonomous vehicles, brain-controlled drones and new-era smart phones?

This all might sound like gaga adolescent optimism, but I’m only cautiously optimistic, or maybe not optimistic at all, just fascinated about what might happen, on the upside and the downside. And I’m endlessly impressed by human ingenuity in discovering new things and using those discoveries in innovative ways. I’m also fascinated, in a less positive way, by the anti-scientific tendencies of conspiracy theorists, religionists, new-agers and those who identify with and seem trapped by ‘heavy culture’. Podcasts such as The Skeptics’ Guide to the Universe, Skeptoid and Australia’s The Skeptic Zone, as well as various science-based blogs like Why Evolution is True and Skeptical Science are fighting a seemingly never-ending fight against the misinformation churned out by passionate supporters of fixed non-evidence-based positions. But spending too much time arguing with such types does your head in, and I prefer trying to accentuate the positive than trying to eliminate the negative.

And on that positive side, exciting things are always happening, whether it’s battery technology, cancer research, exoplanetary discoveries, robotics or brain implants, more developments are occurring than any one person can keep abreast of.

So I’ll end with some positive and reassuring remarks about science. It’s not some esoteric activity to be suspicious of, but neither is it something easily definable. It’s not a search for the truth, it’s more a search for the best, most comprehensive, most consistent and productive explanation for phenomena. I don’t believe there’s such a thing as the scientific method – the methods of Einstein can’t easily be compared with those of Darwin. Methods necessarily differ with the often vast differences between the phenomena under investigation. Conspiracy theories such as the moon landings ‘hoax’ or the climate science ‘fraud’ would require that scientists and their ancillaries are incredibly disciplined, virtually robotic collaborators in sinister plots, rather than normal, questing, competitive, collaborative, inspired and inspiring individuals, struggling desperately to make sense and make breakthroughs. In the field of human health, scientists are faced with explaining the most complex organism we know of – the human body with its often perverse human mind. It’s not at all surprising that pseudo-science and quackery is so common in this field, in which everyone wants to live and thrive as long as possible. But we need to be aware that with such complexity we will encounter many false hopes and only partial solutions. The overall story, though, is positive – we’re living longer and healthier, in statistical terms, than ever before. The past, for the most part, is another country which we might like to briefly visit, but we wouldn’t want to live there. And science is largely to be thanked for that. So, why not science? The alternatives do nothing for me.

The SGU team – science nerds fighting the good fight

Written by stewart henderson

October 7, 2017 at 6:18 am

stand-alone solar: an off-grid solution for Australia’s remote regions (plus a bit of a rant)

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According to this article, Australia is leading the world in per capita uptake of rooftop solar, though currently South Australia is lagging behind, in spite of a lot of clean energy action from our government. The Clean Energy Regulator has recently released figures showing that 23% of Australians have installed rooftop solar in the last ten years, and this take-up is set to continue in spite of the notable lack of encouragement from the feds. South Australia is still making plenty of waves re clean energy, though, as it is continually lowering its record for minimum grid demand, through the use of solar PV. The record set a couple of days ago, interestingly on Sunday afternoon rather than in the middle of the night, was 587MW, almost 200MW less than the previous record set only a week or so before. Clearly this trend is set to continue.

It’s hard for me to get my head around what’s happening re disruptive technologies, microgrids, stand-alone solar, EVs, battery research and the like, not to mention the horribly complex economics around these developments, but the sense of excitement brought about by comprehensive change makes me ever-willing to try. Only this morning I heard a story of six farming households described as being ‘on the fringe of Western Australia’s power network’ who’ve successfully trialled stand-alone solar panels (powered by lithium-ion batteries) on their properties, after years of outages and ‘voltage spikes’*. The panels – and this is the fascinating part – were offered free by Western Power (WA’s government-owned energy utility), who were looking for a cheaper alternative to the cost of replacing ageing infrastructure. The high costs of connecting remote farms to the grid make off-grid power systems a viable alternative, which raises issues about that viability elsewhere given the decreasing costs of solar PV, which can maintain electricity during power outages, as one Ravensthorpe family, part of the trial, discovered in January this year. The region, 500 kilometres south of Perth, experienced heavy rain and flooding which caused power failures, but the solar systems were unaffected. All in all, the trial has ‘exceeded expectations’, according to this ABC report.

All this has exciting implications for the future, but there are immediate problems. Though Western Power would like to sign off on the trial as an overwhelming success, and to apply this solution to other communities in the area (3,000 potential sites have been pinpointed), current regulation prevents this, as it only allows Western Power to distribute energy, not to generate it, as its solar installations are judged as doing. Another instance of regulations not keeping up with changing circumstances and solutions. Western Power has no alternative but to extend the trial period until the legislation catches up (assuming it does). But it would surely be a mistake not to change the law asap:

“You’d be talking about a saving of about $300 million in terms of current cost of investment and cost of ongoing maintenance of distribution line against the cost of the stand-alone power system,” Mr Chalkley [Western Power CEO] said.

Just as a side issue, it’s interesting that our PM Malcolm Turnbull, whose government seems on the whole to be avoiding any mention of clean energy these days, has had solar panels on his harbourside mansion in Point Piper, Sydney, for years. He now has an upgraded 14 kW rooftop solar array and a 14kWh battery storage system installed there, and, according to a recent interview he did on radio 3AW, he doesn’t draw any electricity from the grid, in spite of using a lot of electricity for security as Prime Minister. Solar PV plus battery, I’m learning, equals a distributed solar system. The chief of AEMO (the Australian Energy Market Operator), Audrey Zibelman, recently stated that distributed rooftop solar is on its way to making up 30 to 40% of our energy generation mix, and that it could be used as a resource to replace baseload, as currently provided by coal and gas stations (I shall write about baseload power issues, for my own instruction, in the near future).

Of course Turnbull isn’t exactly spruiking the benefits of renewable energy, having struck a Faustian bargain with his conservative colleagues in order to maintain his prestigious position as PM. We can only hope for a change of government to have any hope of a national approach to the inevitable energy transition, and even then it’ll be a hard road to hoe. Meanwhile, Tony Abbott, Turnbull’s arch-conservative bête noir, continues to represent the dark side. How did this imbecilic creature ever get to be our Prime Minister? Has he ever shown any signs of scientific literacy? Again I would urge extreme vetting of all candidates for political office, here and elsewhere, based on a stringent scientific literacy test. Imagine the political shite that would be flushed down the drain with that one. Abbott, you’ll notice, always talks of climate change and renewable energy in religious terms, as a modern religion. That’s because religion is his principal obsession. He can’t talk about it in scientific terms, because he doesn’t know any. Unfortunately, these politicians are rarely challenged by journalists, and are often free to choose friendly journalists who never challenge their laughable remarks. It’s a bit of a fucked-up system.

Meanwhile the ‘green religionists’, such as the Chinese and Indian governments, and the German and Scandinavian governments, and Elon Musk and those who invest in his companies, and the researchers and scientists who continue to improve solar PV, wind turbine and battery technology, including flow batteries, supercapacitors and so much more, are improving their developments and disrupting traditional ways of providing energy, and will continue to do so, in spite of name-calling from the fringes (to whom they’re largely deaf, due to the huge level of support from their supporters). It really is an exciting time not to be a dinosaur.

 

Written by stewart henderson

September 20, 2017 at 9:32 pm