Friday, April 19, 2013

The Next Electric Cars

We've had over a century of development on fossil-fuel powered vehicles.  It was a time when the requirements of motorists and the romance and passion of motorsport combined to produce improvements in cars that were about sensible things such as economy and ride quality; but also the things that get petrol heads out of their seats like top speed performance, handling and acceleration.  It was a time when cars went from being expensive, dangerous and noisy rattle-trap playthings for the rich, to being fast and practical transport for the many.
The 1915 Detroit Electric

During that time sadly virtually no progress was made on a automotive propulsion batteries or electric vehicle motive power.  The Electric Vehicle arrived on the scene around the same time as the Internal Combustion power car, and while the EV was supreme in the cities, through accidents of history and industrial conspiracy which you can read about in Edwin Black's "Internal Combustion" the EV passed into the annals of history.

Electric Citicar - Southward Auto Museum, New Zealand

Technologists and even motor companies dabbled in electric vehicles during that 100 years, but saw them as toys and quirky golf-cart size "personal transports", like this "Electric Citicar" made between 1972 & 1978 by Sebring-Vanguard.  Really these sorts of vehicles were new bodies on the old technologies no better than the lead-acid batteries of the Detroit Electric 60 years previous.  They were light-weight experiments instead of real full-blown motor cars.  So called electric "neighbourhood cars" still produced today are still evidence of this lack of progress.

Until now.

Photo of the Porsche 918 from GizMag
The 2013 Porsche 918R Hybrid 770bhp 3s 0-60 (
Now with crises in air quality in our big cities, the effects of global warming and pollution in general on our planet, and the need for energy security we are seeing a resurgence in electric vehicle technology, and electric vehicles on the production lines of many of the world auto makers.

We are also seeing high-performance vehicles powered by electric motors on our race tracks.  Vehicles like the incredible Porsche 918 Hybrid.  While it does have a petrol power-plant on board as well, the 918 can run on pure battery power, and with advances in batteries (see below) Porsches technology will no doubt be seen in future all electric vehicles.  The point is that the electric power train is already seen by high-performance motor engineers as the way forward.

I drive a Nissan Leaf: a practical all electric passenger sedan with a range of 175km and performance equal to or better than similar sized fossil-fuel powered cars.  The Leaf has no exhaust pipe and produces zero emissions, so as I drive past schools and sidewalk cafes I can be sure I'm not ruining the air quality for my fellow city dwellers.  I don't have to make a regular pilgrimage to buy fuel at gas stations, and any time I go down to the car in my garage its there ready to go, charged up for free courtesy of the solar panels on my roof.  Its a clean machine.

But electric vehicle development is not stopping there, and its interesting to wonder how far behind we are after our 100 year sleep, and how quickly we can catch up.  Look at the speed of the cellphone revolution for examples of the speed of innovation we can expect.

There are a couple of things to be said about this catchup process - first is that electric cars while already good, they are only going to get better.

Motor-sports aficionados already recognise the applicability of the new technologies in EV and hybrid power, so we are seeing a new age where the petrol-head becomes the electron-head, as speed and handling come from improvements in electronic and electric drive technology.

One example is the active steering and suspension on the Porsche which has many new freedoms for designers of high-performance cars due to the flexibility electric drive gives you.  The old CV joint and half-shaft, or conventional differential and driveshaft setup of petrol powered vehicles meant many restrictions on what can be achieved.  Porsche engineers are breaking out of these paradigms with the 918 and setting new performance benchmarks as they do so.

exploded image of in wheel motor and tyre
Protean in wheel motor (

In wheel motors promise huge advances in this area, effectively giving 3 degrees of freedom for suspension geometry design and active (computer controlled electronic) suspension and drive systems.  Protean claim also much improved regenerative braking energy recovery.  While in-wheel motors have a challenge with unsprung weight that is outweighed many times over by the prospects for fully active suspension, steering and drive that comes from an in wheel motor.

graphic interpretation of the micro battery architecture with tiny interleaved cells
University of Illinois interdigitated battery architecture (BBC)

This new battery technology unveiled just days before I write this article comes from the University of Illinois and promises power outputs 10s or 100s of times better than current battery technology.

Update: (thanks Russell!) it was pointed out that the U of Illinois battery is more about power output than watts per size (energy density, or capacity).  Other projects are promising big improvements in EV range from higher battery capacity, such as the 3 x lithium-air chemistry and 10 x aluminium-air projects, like the one from Phinergy (although the latter one is currently not rechargeable).

With that sort of energy density my Nissan Leaf would have over 1000km of range on a battery half the size of the one it currently has.  Countries that want to improve air quality in their cities while keeping up with the bleeding edge of technology in transportation are investing heavily in the R&D of battery technologies.

Fossil-fuel powered cars will still be around for a long time, but their golden age has past now.  No matter how good you make internal combustion engines, they rely on foreign oil and produce pollution.  Yes, there are ethanol and other bio-fuels now, but in practice you have to buy E10 or other mixes with petrol.  In theory diesels and flex-fuels can use 100% bio-fuels, but its not available now and production in quantity appears to be neither economically viable or environmentally sustainable.

Advances in internal combustion powered vehicles show fewer and fewer returns for R&D dollars spent, compared to electric.  There's no flux capacitor or magic catalyst that is going to improve petrol 10s or 100s of times over.  ICE cars are about as good as they can ever be and no promised fuel technologies are coming to change that.

I'm driving my 100% emissions free sun-powered electric vehicle today.  Right now.  No theories, no corn subsidies, all real.

Now the point of all this is that the way ahead for Electric Vehicles is expanding and full of promise.  Every new advance brings large improvements in practical areas like range, and carrying capacity.  When EV's are powered by clean sources like my solar panels the entire personal transport experience is of low impact to our environment.

How far can the Electric Vehicle go?  I'm excited to find out.

Saturday, July 21, 2012

Post-normal Science?

Recently the Liberal-National Party came out again in favour of teaching Climate Denialism in schools, and I wrote in Google plus about how this policy came directly from the Heartland Institute - a USA neocon policy institute.  LNP declared that climate science is "post-normal science" and thus should not be counted as real science.

Huh?  There's a new science?  What does "post normal" even mean?

This bogus tag of "post-normal" has been constructed from incoherent ramblings in the name of philosophy of science by writers including Jerome Ravetz, whose writing can be seen on notorious climate denialist blog "Watts Up With That".  According to Watts, vociferous climate denier, author of the blog, and recipient of funding from the Heartland Institutes coffers, Ravetz is an honoured guest.  Wonder what I mean by incoherent?  See if you can make any sense out of the gibberish at the post normal science blog referred to in the Watts article.  It reads like the worst excesses of post-modernist philosophy, or like something from computer generated post-modernist satire the Da-Da engine.  (hint: if you go to that link, refresh the page and each time you'll get a nonsensical pile of computer generated post-modern drivel).  Here's a sample of post-modern as generated by the dada engine:

1. Stone and conceptual socialism
“Society is dead,” says Sartre; however, according to Brophy[1] , it is not so much society that is dead, but rather the meaninglessness, and some would say the rubicon, of society. Several narratives concerning precapitalist theory exist. The characteristic theme of Cameron’s[2] analysis of dialectic narrative is a posttextual whole. Therefore, Sontag uses the term ‘postsemiotic Marxism’ to denote the difference between class and sexual identity. The main theme of the works of Stone is the role of the observer as writer. If one examines precapitalist theory, one is faced with a choice: either accept Batailleist `powerful communication’ or conclude that language may be used to exploit minorities, given that the premise of dialectic precultural theory is invalid. Thus, the subject is contextualised into a conceptualist theory that includes truth as a totality. Baudrillard uses the term ‘precapitalist theory’ to denote the fatal flaw, and therefore the absurdity, of subdialectic culture.
Just to make it crystal clear - that quoted paragraph was not written by a human - it was generated by a computer algorithm programmed to produce crazy.  And here is Ravetz explaining post-normal science:

1. Introduction
Post-Normal Science (PNS) is a new conception of the management of complex science-related issues.  It focuses on aspects of problem solving that tend to be neglected in traditional accounts of scientific practice: uncertainty, value loading, and a plurality of legitimate perspectives.  PNS considers these elements as integral to science. By their inclusion in the framing of complex issues, PNS is able to provide a  coherent framework for an extended participation in decision-making, based on the new tasks of quality assurance.  The shift to a post-normal mode is a critical change. The approach used by normal science to manage complex social and biophysical systems as if the were simple scientific exercises has  brought us to our present mixture of intellectual triumph and socio-ecological peril.
Notice a similarity?  :-)

I'm being a bit tongue-in-cheek here, but the sort of stuff that Ravetz is on about is exactly what the programmers who built the dada engine were satirising.

So what is Ravetz on about then?

Its origins are in the media storm about emails published from the Climate Research Unit in East Anglia, England.  There's not room to go into it here, but a massive archive of emails and other material were published by a journalist, and items cherry-picked from it purported to show ill-intent and unethical conduct on the part of climate scientists there.  In the event there was no smoking gun, no-one owned up to stealing the emails from CRU, and  the CRU scientists were shown to be innocent of the claims.

However during the fracas the likes of Ravetz turned up claiming (in his almost inaccessible prose) that the CRU emails meant that scientists must all open up everything they do, and in particular that unqualified people should be able to get in on the peer review process - Hulme, the co-author is a climate scientist at CRU, and author of the book Why We Disagree About Climate Science.  It reached a huge audience when published in a much referenced article by the BBC.  So how is that the denialists are fete-ing Ravetz as a champion of their cause, when he was launched to fame at the side of a prominent climate scientist?

When the issue with climate change became urgent enough for governments to see that action was needed they called on a dream-team of their best scientists in the field to report on what could be done about it.  Not hearing the danger music of the trap that was waiting for them the scientists did their job, produced the facts and summed it up in the IPCC reports.

The problem is that scientists are no good at politics, and they are not PR experts.  Hulme saw that the opponents of action on pollution and climate change would do anything - including stealing and cherry-picking their private email communications - to impugn the reputation of the scientists, and try to undermine their work.  Maybe Hulme thought that democratizing science would mean that less heat would come on scientists themselves for unpopular conclusions.

This confusing blog article discusses the idea further in classic post-normal science prose, so difficult to follow that its not easy to determine whose viewpoint it supports, who its author is, or what claims it is actually making.  In my view the idea of post-normal science is ridiculous and I can't imagine anyone in their right mind seriously promoting it as a way to better obtain scientific knowledge.

Regardless of what these proponents of PNT are actually saying, the way you actually obtain scientific knowledge is for scientists in research centers and laboratories to do work, collect data, analyse it and present their findings in peer-reviewed journals of high-standing.  Those scientists share their data with their peers, and discuss their methods to allow verification and replication of their results.

Allowing in amateurs, commentators and provocateurs is not democracry.  You don't vote for the truth.  Science is not a committee decision.  Also it allows for the likes of Stephen McIntyre on of who demands scientific data from researchers so that he can go hunting for anything that supports his denialist agenda.  Note that word "audit" - a key idea from the post-normal manifesto.

So is post-normal science good or bad then?

That is like asking are vampires or witches good or bad.  Post-normal science is a fiction.  There are no post-normal scientists.  There are only commentators and philosophers wishing they were post-normal "scientists" - like Stephanie Meyers vampire wannabes; and actors like McIntyre dressing up like it.

On the one hand, it's a name-calling tool of the denialist industry, trying to make out that the IPCC scientists are part of some socialist conspiracy.  On the other hand its a way for people like McIntyre to legitimise his amateur science work.  McIntyre is a retired mining executive and coal-industry consultant who is on the payroll of the Heartland Institute, and is desperate to be taken seriously by the scientific community.

So sleep easy LNP - you don't have to worry about post-normal science taking over.  Its just a piece of bad supernatural fiction.

Wednesday, July 4, 2012

Diesel Fumes and Cancer. Buy EV instead!

The World Health Organisation has concluded in a recent panel ruling, as reported by the Guardian that fumes from diesel engines cause cancer, at about the same rate as standing in a cigarette smoke-filled room, or copping too much sunburn.

This is interesting to me, because diesel cars are something I hear put forward as environmentally sound motoring choices.  [edit] In 2009 according to Wired's Autopia car site, Green Car Journal named a diesel as its Green Car of the Year.  I say interesting because that was 2009, now we have electric vehicles (EV's) and I struggle to see how those diesels are green by comparison.  Another article says forget about "black plumes of smoke, noisy engines" because diesels are clean and green now.  Maybe when they are brand new - but I see plenty of 5-10 year old "modern diesels" on the road producing black smoke.  It doesn't matter how old an EV is it is never going to produce smoky fumes.

Also, when I talk to people about Electric Vehicles I still get this recycled FUD about the long tailpipe, which is basically this idea that EV's "emit pollution" from the power stations that they draw electricity from.

The WHO panel ruling shows how bogus this is - what the actual vehicle itself is emitting is important. If you are on the footpath going for a cappuccino, and you find yourself next to several lanes of traffic in the city then each vehicle that is emitting pollution from its tailpipe is damaging you.  For children playing in the schoolyard next to a busy major road then they are being exposed to carcinogens from diesel exhausts of vehicles on that road.

EV's have no tailpipe, and no exhaust fumes.  Even if they were charged the previous evening from the most fiendishly polluting power source, when they drive on the road no pollution is being emitted from those EV's into the busy urban and suburban environments that we live in, work in, and send our kids to school in.

Getting back to the diesel thing, when I drove a Prius, before getting the Nissan Leaf, I would also hear quite often an argument that diesel cars were a good environmental alternative because they did a better mileage than the Prius in some cases.

If you look at popular diesel hatchbacks like the Ford Focus, or Peugot 308 they are in the same league as the Prius for consumption figures:

CarEmissions gm/kmConsumption ltrs/100km
Prius 1.8 Hybrid T3 2009923.3
Peugot 3081194.0
Ford Focus TDci diesel1574.8

Now the first thing to notice is that emissions is not consumption.  The Peugot for example does pretty well on consumption, using 1.2 times as much fuel per distance as the Prius.  However its emissions are 1.3 times that of the Prius.  For the Ford Focus the fuel usage is 1.45 times that of the Prius, but its emissions are 1.7 times worse!

How can this be?  Isn't the petrol here the source of the emissions?  Surely if you burn 1 litre of fuel, you create some fixed amount of pollution?  A moments thought shows that this is wrong, because engines ain't engines: some are more emissions efficient, not just mileage efficient.  The Prius has an Atkinson cycle engine, which can take advantage of its electric hybrid transmission to operate in an optimum range, meaning that it produces less emissions for a given amount of fuel burnt.  The Prius engine is very mileage efficient, but that is almost just a side effect of the engineering put into making it very very emissions efficient.

So, getting back to the argument above - diesels are good environmentally because they do better mileage - you can see that this is just plain wrong.  Better mileage does not equal better emissions.

And now we know from the WHO study that those diesel emissions are carcinogenic, as well as being a greenhouse gas pollutant.

The thing with electric vehicles, is that not only do they produce no tailpipe pollution emissions at all - they can also use clean, greenhouse-gas free electricity from sources like solar and wind.  You could cover Australia in solar panels and the diesel and petrol cars on the road are still going to be producing just as much pollution as they always did.  In fact it doesn't matter how far science advances, in cleaning up our local Australian-grown energy production, if you stick to fossil-fuel powered cars none of those advances can help our pollution problems at all.

Electric Vehicles can take advantage of home-grown energy solutions, instead of costing us in expensive oil imports in many cases from countries that none of us want to be beholden to.  Diesel cars, no matter how mileage efficient still get their fuel from foreign oil.  Think about it: where do you want your motoring dollar going to; the Middle East or to buying Australian?

Now I hear some people say that they have to drive to Sydney or, as we say in Australia when talking about long distances "to the back of Bourke".  Because of these long trip requirements they just can't buy an Electric Vehicle.  Really?

There's lots of things that people expect of their vehicles - it must be able to take me fishing on the beach at Stradbroke Island, or I must be able to load the surfboards, wetsuits and a Esky full of beer into the back.  Or it has to be able to do zero-to-sixty in 4.2 seconds.  Now add to that list of expectations this idea that a car has to be able to drive interstate on a tank of gas.

Realistically I think for 95% of us, those requirements are just not logical criteria to use for choosing the car you drive every day.  For many cars are an emotional thing.  We want a ute or pickup; or we want an SUV or 4WD, or a sports car.  A big full tank of gas equals freedom and self-determination.  But think about it, the 100th time you're trying to back that thing into a parking spot in the supermarket, or navigate city traffic, or stretching to afford the best part of $100 to fill the tank up to full.  Was that really the best decision you made on a vehicle?

For some of us, those emotional things; they're deal-breakers - OK.  If for some reason you have to drive to Sydney, or your commute is hundreds of miles then go and buy a Prius.  The Prius is a great car, with loads of room in the back, and it goes places that any other road car can, and further besides.

But if, like me you can take advantage of an Electric Vehicle for emissions free motoring, never ever having to buy gas, just go ahead and do it.

Your lungs will thank you.

Monday, July 2, 2012

T-Shirt Underworld

Some time ago I made a little joke, and I so amused myself with it that I decided to draw a picture to go with it.  Well, I still thought I was funny - so I posted it on G+ and Twitter - and guess what, my sense of humour is kind of perverse and the result was more of your "groan..." than LOL.

Thing is, this is the internet, and no matter how perverse, there's going to be someone out there that thinks this is hilarious.  So you know what - I'm going to put it on a T-Shirt (thanks to Zazzle) and see if my true brilliance is recognised.

Or if they still stay away in droves then - well - OK, I was only funny to myself. That much gritty self-analysis I can handle.  Ahh, the struggle of the artist.  No-one knows my pain.

Either that or Kate Beckinsale fan-boys and movie studio moguls will band together to sue me.

Maybe, if that doesn't happen, this was kind of fun, so I might make some more T-Shirts.  Let's see!

Wednesday, June 13, 2012

Leaf: the car evolves

Since 2007 I have been researching, writing about and advocating for electric cars.

These cars produce no emissions.  Since they do not need fossil fuels like oil or petrol, they are cheap and efficient to run, and provide energy security.

Now for me, finally, electric cars are real.  In Australia, this forgotten corner of the world where we are still digging coal out of the ground and shipping and burning it at a crazy rate, EV's are not just a dream.

Can you remember when mobile phones were just something that rich people in limousines used?  When they were a prop for Wall Street types, looking stylish while they flipped out their Motorola StarTac phones?

Back then we said things like "Oh, do you have a normal phone number?  I don't want to make an expensive mobile call!"

Now the idea of having to go anywhere, let alone a phone booth, to make a call is ridiculous.  Want to make a call?  You just pull your phone out right there, and call anyone.  All your friends numbers are stored right there in your phone.  Looking up a phone number in a book?  Weird!!

Cell phones.  It's the way phones should be.  Ask any teenager.  Try to explain to them how phones used to be and they'll look at you like you're a freak.

In 20 years time that's how it will be with cars powered by fossil fuels.  The teenagers of 2032 will tell you that the only people who use petrol cars are old people, cranks and freaks.

You had to drive your car to some special place - what's it called?  A gas station?  And they had these pumps where you had to queue up and pump fuel actually into your car?  No way - that's medieval.  Like lamp oil and stuff.

It's true!  And you know what?  When electric cars first came out people said they'd never catch on because you can't drive half-way across the state on one battery charge.  There was a name for it - they called it "range anxiety".

Why would anyone ever want to drive for hours and hours!  That's nuts.  If you're going to another city just catch a train or a plane and micro-rent when you get there.  You old people are hilarious.

But those old cars where you put petrol in them, they had big tanks, and so it turns out that they could go for 500 miles on one fill of gas.  People felt that gave them independence.

Independence, when you're chained to getting this gas stuff from some shop you have to find on the side of the road?  That's as weird as those phone booth things you were telling me about!!

But you know what, most of the time what it actually meant is that you were always worrying about when your gas would run out.  Because in fact you never really went for 500 mile road trips.  What you really always did was drive to work, and on the day when you absolutely did not want to be late, you'd jump in your car only to find you didn't have enough gas to get to work.  And you'd have to go to a gas station, instead.

You know what I think?  This range anxiety?  That is where its really from, right there.  I never worry about how far my car can go because its always charged up and ready to go.  Yeah - I love you old people and your funny stories.

Well I'm happy to be one of the first dinosaurs to evolve.  Why don't you join me?

Friday, January 27, 2012

Scientific embarrassment

I'm listening to a Ted talk by a chap who says we don't always know what we think we know. To prove it he says, he asks 4 questions of science educators, producers of science TV shows and even of 7 year old children.

I've stopped the video of his talk at 1:55m where the 4 questions are displayed and I'm going to try my hand at answering them. I'm not going to refer to Google, or the internet in anyway - I'm going to draw purely on what I already know (or think I know).

If you want to follow along - stop reading here, click the link above and prepare your own answers to the "Science Pop Quiz" and see how you do.

Don't scroll down if you are following along!



So here goes:

1. A little seed weighs next to nothing but a tree weighs a lot. From where does the tree get the stuff that makes up a wooden desk?

My answer: from the air. Specifically the tree-stuff is mostly cellulose and that is a complex molecule which the tree gets by binding carbon from CO2 in the atmosphere using photosynthesis. The tree knows how to do this due to the genetic codes stored in the seed.

2. Can you light a little torch-bulb with a battery, a bulb and one piece of wire?

My answer: you can. You touch one pole of the battery to the terminal on the base of the bulb, and use the wire to connect the other pole of the battery to the conductive housing of the bulb. This question seems to talk about 2 bulbs - if that is not a mistake, then you might be able to connect them in series by touching the terminal to the housing.

3. Why is it hotter in summer than in winter?

My answer: Because the axis of rotation of the earth is tilted with respect to the plane of its orbit around the sun. In the height of the southern hemisphere summer, the south pole is partly pointed toward the sun by this tilt, exposing a lot more of the earths southern aspect to the sun for longer.

4. Could you scribble a plan diagram of the solar system showing the shape of the planet's orbits?

My answer: Hmm tough one. I drew elliptical orbits with the planets around the sun, starting from Mercury (closest), then Mars, Venus, Earth, Jupiter, Saturn, Uranus, Neptune and Pluto (furthest away). I don't think the elliptical orbits all lie in the same plane.

How sure am I about my answers?

I'm most unsure about the planets one, but I think I probably got it about 80% right.

Ok. Now to click "Publish" and embarrass myself, by playing the rest of the video and seeing how I did.

Friday, December 23, 2011

Self-esteem at Christmas time. - Dark matter ring in galaxy cluster Cl 0024+17
An interesting article appears here from Alister McGrath, Professor of Theology at Kings College of London. It's part of the ABC's "Religion and Ethics" series, and appears on the ABC's website just before Christmas.

He talks about meaning, science and dark matter (like that pictured left). In particular McGrath talks about finding meaning in life through Christianity. Let me discuss how I disagree with him.

Before I get to general business regarding meaning, there are some irritating clarifications to get out of the way.

I thought the general quality of the responses to his article on the ABC website was a lot better than you see on some of these sorts of posts. First up I would say there are many good points in this article, and I agree with some of them wholeheartedly. I recommend reading it. But his conclusion is wrong.

Firstly I take issue with his generalisations about atheists. I don't label myself as one, because some I have had contact with who would describe themselves that way are those who once were religious, but have been betrayed by religion and are now filled with venom and spleen as a result. I understand their anger, but cannot personally relate to it and find it difficult to be around. Other self-described atheists have at times adopted positions which I don't think are defensible. So generally I reject that label for practical reasons. But I feel the need to defend atheists against claims like some of the ones McGrath makes.

Regarding the labels "atheist" or "agnostic" I find these terms unhelpful and misleading. For myself I don't see why we need a special word to say that I do not accept supernatural accounts of anything - not meaning, and not things in the world. My position is that if someone wants me to accept a supernatural explanation, then they need to provide supporting evidence. Evidence is some observation that cannot be better explained by simpler, non-supernatural means.

If they cannot provide such evidence then I am likely to say that its an intriguing conjecture - get back to me when you have some thing more. I'm not going to demand proof, and I am not going to say that they are definitely wrong. I'm just not going to spend any energy entertaining the claim at all, until there is something to support it.

If not only can they not provide any supporting evidence, but the claim is such that nothing could ever count as evidence then I say it is empty of meaning in that case.

Religion has not really harmed me much, and most Christians I know are excellent people so I am lukewarm on the matter of atheism. As I've said I don't like the word. But I feel I must stand up when these sorts of claims are made because there is disingenuous reasoning here on McGrath's part, or an intent to mislead - and that must be spoken against.

"Some atheist scientists ridicule Christians for believing in a God whose existence cannot be proved."

I'm not sure that any published atheist scientists say that. I would like to see him produce a reference for this.

It's very different to say that a claim cannot be tested, than to say it can't be proven.

For example, the dark matter he mentions if it exists might have certain effects in the universe, on visible stars for example. If the theory about dark matter predicts those effects, but they are not observed to be the case, then your theory is wrong and either dark matter does not exist or it does not exist as described in the theory.

However observing those effects is consistent with dark matter, and makes the dark matter theory more compelling. It gives it more explanatory power. But it does not prove it. This is the perfectly valid point that the author makes and here I agree with him 100%. "Where the naive demand proof the wise realise that this is limited to logic and mathematics". Well, limited to analytic closed systems - but yes, spot on.

And I think most scientists would agree with him here.

Which is why I find troubling that he has not named any of these "atheist scientists" whom he says are requiring proof from Christians in this way.

He actually has many many good points in his article, but as I mentioned I disagree with his conclusions.

His argument is essentially the same as Stephen Jay Gould's non-overlapping magisteria, or NOMA argument. Science explains and religion gives meaning, he says.

However the phrases "what is the meaning of my life" and "what is the meaning of this sentence" are not using meaning in the same way.

Science, or at least reason and empiricism does give the second kind of meaning by asking "What would count as this claim being true?". What is a test for it? If you make a claim about the real world and there is no way to make a test for it then it is meaningless.

That is a very important kind of meaning, and one that we all need to ask for constantly. If we allow our faith to blind us to that requirement we will be duped and sapped by every impostor, colour therapy merchant and fraudster that enters our orbit. This is the vital life skill of being questioning, of critical thinking, and its essential that we all do that as often as possible.

So science, or at least its essential fellows reason and empiricism, does provide that kind of meaning, and not just explanation.

Where the non-overlapping magisteria argument really falls down is that various religions do indeed make claims about matters of fact. Religious catechisms and preachers of Christian faith for example do not stop at saying "here is a fictional homily about Jesus miraculously healing someone which illustrates a point about how we should behave".

They actually claim that God exists, gave Jesus miraculous powers, and that the supernatural healing event described actually happened. Claims about supernatural things actually happening in the real world are firmly about explanations of phenomena, and thus are in the magisteria awarded to science by this NOMA argument.

In fact if you do not make enough supernatural claims as a church apparently you lose your tax-exempt status (see 11.14 & 11.23). So in so far as meaning in the first usage where it relates to empiricism, religion crosses over into sciences side of this artificial distinction McGrath makes all the time.

Now if it does not, and its all accepted as being a fictional homily - then I have no problem with it. But that - as far as I know it - is not the case at all. And the link I posted above was just from a brief Google search - these stories are claimed to be historical facts. McGrath's article states at the foot that God entered our history - this is a claim about facts in the world. So we are no longer talking about some abstract type of meaning, and are firmly on the turf of the empirical.

However, let's move to the second kind of meaning. The "meaning of life" kind of meaning.

This other kind of meaning is personal.

If someone can truly find that in religious faith, well more power to them. I mean that. If religious faith can be truly really fulfilling then great news.

I do not accept at present that it is possible. Its like taking a pharmaceutical substance that makes you feel happy. That is not real happiness. If a sense of meaning in life is externally induced, then its not real. If you don't accept this think about whether you believe taking a pharmaceutical that causes you to see pink elephants actually makes you see real pink elephants, or illusory ones. You really do see them, so the visual event in your brain might be real. But the elephants are not. Moreover they vanish when the substance is taken away. Similarly you might feel you have meaning in life if induced by some agent in this way, but its not in actuality real and certainly not sustainable.

Please don't think I'm saying religion is the opiate of the masses. That is not my point here at all. What I am saying is that mental states - such as visual images, happiness, or self-esteem - induced by an external agent are not true or sustainable instances of those states. They are illusory and ephemeral facsimiles, which further do little or nothing for the individuals ability to reach those states by true or sustainable means.

It's a case of trying to get self-esteem from someone else. There's a reason its called "self-esteem" - it has to come from you, not from some external source. You can coach someone, and they can find inspiration from your deeds and words, but ultimately it has to come from themselves.

I understand its difficult to find that self-belief. I think that when people say they are having a conversation with God about weighty things in life, it is actually a way of lending credence and substance to messages from within themselves, that are fraught with self-doubt.

For those who suffer from poor self-esteem and personally struggle with believing in their own importance as people, it may seem that one's own belief in what is valued and worthwhile is not enough, hence those thoughts must be recast as coming from one's deity.

The way I see it is that meaning in the personal sense either comes from within yourself, or from external sources - inspiring books, deeds, experiences and people. To the extent that it comes from within yourself, it has the quality of true hard-won self-esteem - no-one can ever take that away from you. This is the sustainable, long-lasting self-esteem. To the extent that it comes from somewhere outside yourself, it is potentially out-of-date, irrelevant, incorrect or even fraudulent. To determine that it is not any of those bad things, you yourself must do the work to determine that it is not - and thus full-circle we are back to relying on ourselves again.

Experiences of being on a mountain-top, or near death in a war, or any other life changing moments, however transcendent, come through the filter of ourselves. We must understand them, and interpret the meaning of them for ourselves. Same with books and deeds of others, and same with the advice from those who would preach to us.

Even Descarte found himself before he went on to find anything else (including God).

To the extent that we go in the other direction, and look to surrender our selves to the external self-proclaimed experts in meaning, then the more the meanings of our lives are placed in the hands of the fallible, corruptible and at best out-of-date. If we are unlucky we find out that the minister who has been preaching chastity and abstinence has been up to no good with the choir boy, or the pastor has been spending the ministries money on his mistress.

I think that even for the very best of religious institutions it is just a matter of time before bad comes of it. Even if that is a very very long time, how would anyone know if their local church was becoming the Westboro Baptists or the Branch Davidians, unless they look to their own values first?

Also if we accept that we must be the first authority for our own meaning in life, but resort to the the books and the catechism for unsullied meaning, then where is the chapter on stem-cells and the internet? What about out-dated exhortations about how what to do when your oxen gores someone's daughter? If we interpret the books to find that meaning then we are back to relying on ourselves again.

I think that it is great that this man who wrote the article is encouraging people of faith to think, and to find ways to understand and defend their beliefs.

I would have loved to respond to the article but comments on it are closed, and them "mail" link is only a thing to share it with others.

Finally can I say that written at Christmas time as it is, this is a bad time to be filling people with the guilt and self-loathing that comes from so much of religious dogma. Original sin, the debt we supposedly owe God for giving his son: all of this is weight that no-one needs on top of the pressure of modern life, as we try to make sense of it all. I personally have never had to suffer any of that but have had several close friends who have.

My advice if you want it, is to look inside yourself, and work to know well what you can do to make a unique and valuable contribution to the world. What is it about you that is special, and what can you do that is worthwhile? Help and inspire others to do the same, where possible, but most of all believe in yourself, and your value as a person.

This is the true source of self-esteem.