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Archive for April, 2009

I suppose I’ve never really written about this before, because it seems like too obvious a point to need addressing. But people do keep making these same tired old arguments, displaying a very tedious lack of imagination or intellectual curiosity.

To paraphrase the general theme of the argument: Why do atheists bother arguing against something that doesn’t exist? If there is no God, why are they so fixated on the idea? Why would they spend so much time trying to disprove something that they supposedly don’t even believe is there?

… Dude. We’re not in an argument with God. Our main concern doesn’t actually focus on something that doesn’t exist. God’s just made up; he’s not a threat to me.

You people are the goddammn threat.

People are preventing children from getting an effective science education. People are hindering the progress of life-saving medical technologies involving stem cells. People are inflicting social ostracism, discrimination, and physical abuse on each other because of minor, irrelevant differences, such as sexual orientation. People are killing their children in attempted exorcisms. People are, occasionally, blowing each other up by the thousands.

Because of irrational religious belief. This is what atheists have a problem with. God is as fictional as Captain Hook, and about as scary – but people can be fucking terrifying.

You really shouldn’t need to keep asking “What’s the harm?” in other people’s beliefs. That’s an ample list of answers right there.

The rest of this site has so many pages of inanity, I could probably occupy myself there for the rest of my life and never need to look elsewhere to find another misconception or fallacy to blog about again. But even sticking to this one page, there’s plenty of fun. I particularly like the irony of:

After all, if God did not exist, He and His followers would be no enemy to the atheist. We’d just be deluded people.

It’s argued on the same page that, because we all know deep down that obviously God is real, atheists don’t exist. So why do religious people spend so much time trying to prove this? Surely we’re no enemy to them. We’re just deluded people. (Unsurprisingly, this much self-awareness is entirely absent.)

Then there’s all the usual yadda yadda about what the fool hath said in his heart, which provides a very handy excuse for claiming that anyone who disagrees with you already knows they’re wrong, and saves you the trouble of actually making any kind of a case. And for a stunning conclusion:

An atheist once wrote and said, “2+2 is not necessarily 4”.

I have absolutely no idea what the point is of bringing this up. Is it meant to be representative of the philosophy of atheists in general? Because… it’s really not. Disbelief in the existence of gods absolutely doesn’t rely on doubting whether 2+2=4. Seriously. A lot of people I know without any imaginary friends can still do all the maths they learnt when they were five.

(Technically the atheist who supposedly wrote this is correct, but I can forgive the author his/her ignorance of modular arithmetic. A very minor failing, all things considered.)

So in summary: theists, please try and understand that I, and many other atheists, aren’t simply in denial about the obvious truth of an unknowable deity who really doesn’t appreciate being denied. We’re part of the debate because we have as much right to speak out about our beliefs as anyone, and because actions inspired by belief can have real effects, even if the God behind them is a fantasy. (If you’re not a Muslim, ask yourself whether Islamic extremist suicide bombers pose “no threat” just because you don’t believe in Allah.) I don’t believe in your god, because I just don’t buy it. But the harm that people can do on his account – nobody’s denying that.

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The world’s been around for a while. And although there’s no shortage of cool stuff in it for us to look at, some people aren’t content with being limited to everything that’s around now. They reckon that some of the stuff that happened “before now”, in a period of time experts refer to as “the past”, might also be quite interesting. To learn things about the past, and what exactly went on there, we’ll have to have some way of extracting this information, from things we can look at in the present.

Sometimes this is simple. If you want to know what was on the mind of any given emo poet in the last few years, there’s LiveJournal. This and many other equally vital pieces of information are stored, regularly and reliably, and provide an easily accessed insight into yesterday, yestermonth, and beyond. There are also news archives, parish records, and diaries kept by rather more notable historical figures than the emo poets of the 21st century, to give us a more rounded view. Sometimes these can be unreliable sources, riddled with political and personal bias (that Adrian Mole clearly can’t be trusted, for one), but they at least provide some insight into what the past was generally about, even if we can never totally avoid the danger of inadvertently buying into someone’s own line of bullshit.

But sometimes we want to know about things that nobody wrote anything about, or passed down any credible verbal stories about, or filmed on their camera-phones. One important part of this is finding out how old something is, for those times when you don’t also manage to dig up the diary of the guy who put it there. Dating historical artefacts is a massive and complicated area of science, embracing many fields of study, in none of which I am qualified to claim even rudimentary competence, let alone expertise. This, then, will be a brief description of radiometric dating, a broad and shallow summary of how it works, without too much detail just yet as to how we know it works as well as we do. There’ll be a few other articles branching off from this one soon, looking at some of the common complaints and objections raised to it, to the extent that my poor monkey-brain can cope with the intellectual rigour of it all.

So.

Up and atom

Before we can get into the meat of this topic, we’ll need to cover some basic particle physics. But you guys like reading lengthy essays on the internet about particle physics, right? I mean, porn can only hold your attention for so long before you start lusting for some hard science action, am I right? Well, if not, you can skip down to the next heading in bold, but I’ve written this bit now so I guess I’ll leave it here.

Good. So, physics. Broadly speaking, all the stuff that everything’s made of is itself made of three types of basic particles: protons, neutrons, and electrons. (Don’t worry about the dozens of others. It’s fine to simplify for now. There won’t be a quiz.) In an atom of any particular type of stuff, some protons and neutrons will be clustered together in a big dense ball (the nucleus of the atom), and some number of electrons will be floating way out around them (relatively very far, but still well under a billionth of a meter away).

Let’s pick one particular type of stuff as an example. Look at a pencil. The stuff in the middle that you write with is graphite, which is a form of carbon. Each atom of carbon is made up of those particles as described above: specifically, six protons and six neutrons bundled together in a ball in the centre, and six electrons circling around them1. That arrangement is what makes it carbon.

If, instead, you have just two protons and two neutrons in the middle, with two electrons orbiting, you get helium, the gas responsible for one of the most univerally hilarious phenomena known to science: making people’s voices go squeaky.

The numbers of particles don’t always have to match up exactly, like they do in those two examples. Sometimes there are more neutrons than protons, or very occasionally vice versa – but you can’t just throw any old mess of protons and neutrons into a nucleus and expect to make an atom. There are forces pushing them apart and pulling them together, kinda like gravity or magnetism pull at things sometimes, and so only some arrangements are stable.

For instance, the carbon I described up there has six of each type of particle. But that’s not actually the only way to make carbon. The number of protons is what defines what element a molecule is, so anything with six protons is carbon. You couldn’t have a nucleus with only those six protons, though, and no neutrons, because then there’d be a strong magnetic force pushing them away from each other (the same kind of magnetic force which makes your fridge magnets not want to get too close to each other), so it’d all fall apart. But if you put six neutrons in there as well, they provide a sort of binding force (I hope it’s clear that I’m still greatly over-simplifying all this) and hold the whole lot together. Because this particular type of carbon (one of carbon’s isotopes) has twelve particles in the nucleus (six protons, six neutrons), this is called Carbon-12. Carbon-12 is stable – the nucleus bit in the middle won’t ever just fall apart on its own – and around 99% of the carbon you’ll ever see will be like this.

Carbon has one more stable isotope, Carbon-13, which has seven neutrons instead of six in the nucleus. There’s still six protons (otherwise it wouldn’t be carbon), and six electrons (otherwise it would be ionised, which isn’t worth worrying about just now). This makes up almost all the rest of the carbon, the stuff which isn’t Carbon-12.

And then there’s one more type, Carbon-14, which has – anybody? Bueller? – eight neutrons. There’s very little of this stuff around on Earth – about one in a trillion carbon atoms are of this type – and unlike the other two, Carbon-14 is radioactive. It won’t just sit still being carbon, like its isotopes tend to do (and for which your DNA should be grateful), but over time it decays into different types of matter, because all the stuff in the nucleus can’t quite hold itself together indefinitely. In this case, Carbon-14 will undergo what’s called beta decay.

All the people atoms, so many people atoms2

Beta decay means that, every so often, one of the neutrons in an atom of Carbon-14 will suddenly transmogrify into a proton, and emit an electron (which would make your Geiger counter click, if you happened to be waving one around)3. Because of this extra proton, it’s now an atom of Nitrogen-14, and not carbon any more. This could happen at any moment, depending partly on the stability of the atom in question. Some radioactive stuff will tend to linger for years; other elements will decay into something else much more quickly. How long the radioactive stuff stays around is determined by its half-life.

The half-life of a radioactive element is the amount of time in which you would expect half of a sample of it to have decayed – or, the time after which the odds are 50/50 of any particular atom decaying. The reason I use words like “expect” is that it’s still random, so you can never be certain exactly when your Geiger counter will click, but it’s guided by a measurable process.

Time for a dubiously appropriate real-world mathematical analogy. Imagine you’ve got a thousand coins laid out on a table, all currently turned to heads. You flip them all once, and get rid of the ones that come up tails. You’d expect about half of them to go – maybe not exactly 500 out of 1000, but pretty close, because that’s the average you’d expect when the odds are 50/50 either way. Radioactive decay is like that: after a certain time (one half-life, or one round of coin-flips), you expect half your atoms to have decayed, on average. Flip the remaining 500-ish again, and about half will go again, one further half-life later, and so on.

Now, if I know that this is what you’re doing, I can figure out how many times you’ve been through this process of flipping all the coins and removing the tails. If I know you started with 1000, and now there’s around 125, I can be almost certain that you’ve done it three times (because when you take 1000 and halve it three times, 125 is what you’d expect to end up with). In a similar way, if scientists know how fast some radioactive stuff is decaying, then by looking at how much of it there was and how much there is now, they can tell how long it’s been decaying for, and thus how old it is.

The half-lives of radioactive stuff range from tiny fractions of a second, to billions of years. So, onto some specifics of how we can use this to actually work stuff out.

All we hear is, radiocarbon

To a lot of people, any way of finding out how old some really old stuff is, is basically “carbon-dating”. And by “a lot of people”, I mean me until a few paragraphs ago. It’s actually only one of many ways we can use radioactive decay to measure how old something is, but it’s a useful one, so let’s focus on that first.

Most carbon is Carbon-12, as you may remember from that bit you probably skipped over. A very small proportion is Carbon-14, which has a half-life of around 5,730 years.

We’ve found this out to a reasonable level of accuracy (the error bars usually given are about 40 years either way), basically by just taking a sample of C-14 atoms, and watching how fast they decay. Fortunately we don’t need to wait an entire half-life to get a useful answer, because unlike the individual coin-tosses in the example earlier, radioactive decay is a continuous process – so, if half of a sample will have decayed after 5,730 years, a much smaller (but mathematically calculable) sample will have decayed after a much shorter, more easily measurable time.

It might sound like only a really, really tiny amount would decay in a short enough time to measure, if it takes millennia for half of the stuff to go, and that it could therefore never be measured with any useful accuracy. But atoms are really, really, really small, and a tiny fraction of a gram can contain billions of them, easily enough to get a meaningful measurement of how fast the stuff is decaying. So, we know Carbon-14’s half-life, to within a low (and also well known) level of certainty.

So now that we know the rate of C-14 decay, we just need to know how much of it something started with, and measure how much is left now, to tell how old it is.

Plants take in carbon dioxide from the air in photosynthesis, some of which will be C-14. Other living things that don’t photosynthesise (such as “animals”, in technical biology jargon) tend to eat these plants (or other animals, with plants somewhere further down the chain). So every living thing is continually taking in and excreting some C-14, mixed in with all the rest of the carbon in their diet. The overall level of C-14 in their bodies stays fairly constant, depending on how much of it is in the air they’re breathing, and the stuff they’re eating.

Once they’re dead, though, this cycle comes to an abrupt halt, and the C-14 inside them is left to just radioactively decay. Because it’s only after the moment of death – when they stop breathing and eating other things with carbon in – that the amount of C-14 begins to drop off rather than being continually topped up, we can estimate how long ago the poor sod whose carbon content we’re poking around in died.

That’s basically carbon dating. It’s useful, but obviously limited. It’s not generally used on samples older than 60,000 years, since after more than ten half-lives or so, there’s such a small proportion of the original C-14 left undecayed that it’s impossible to tell with much accuracy how long it’s been decaying. Also, not everything even has any carbon in it to measure. But potassium-argon dating can be useful with rocks upwards of 100,000 years old, and uranium-lead dating is what you want if you’ve got some zircon that’s been lying around for billions of years, and there are many other similar techniques. The basic priciples of radioactive decay are the same in each case.

I wish to register a complaint

Unsurprisingly, not everyone’s happy with of this. Many people disagree with the conclusions of radiometric dating. Just as unsurprisingly, a lot of the complaints stem from a misunderstanding of how science works. In particular, the detractors of radiometric dating methods tend to approach it with an all-or-nothing mindset, and assume that a single result that seems unreliable, or any sign that it doesn’t work perfectly in all circumstances, must nullify every aspect of the discipline.

This drastically oversimplifies things; obviously we should be on the lookout for faulty results and anything which calls these methods into question, but it’s not implausible to suggest that we might be able to understand its particular shortcomings, and come up with a more limited (but still useful) system in which the results we get are still valid, and can be shown to be consistent, replicable, and entirely scientific. The pen I’m currently holding in my hand isn’t plummeting straight down into the Earth’s gravity well, but that just means we need to understand Newton’s laws in context, and be sure of how they can or can’t be applied, if we want to avoid being reckless and leaping to ridiculous conclusions. The scientists who developed these methods have had plenty of time to figure out their shortcomings.

The people who have a fundamental problem with the entire field of radiometric dating, though, often seem less than clear on what errors led to the supposedly faulty conclusions. For many of them, I suspect their doubts didn’t originate with a flaw they uncovered in the scientific methodology being used – but strict Biblical doctrine implies that the world is no more than 10,000 years old, so if that godless, immutable behemoth of Science somehow says that some things have been around for millions of years, then it’s obviously gone wrong somewhere. The details of where these mistakes have been made is rarely given quite so much thought – it’s only obvious that they must have been made somewhere, because the results disagree with the inviolate axiom of Biblical infallibility and Jesusy goodness, on which their world turns.

When fundamentalists are trying to protect their dogma from an onslaught of pesky facts, the most useful pseudoscience tends to concern theories at a slight remove from what’s commonly understood and accepted by laypeople. Nobody wastes any time denying that elements consist of a nucleus of protons and neutrons, and surrounding electrons, just as there’s no real dispute these days that genetic information is passed from living organisms to their offspring by DNA – these are things we all kind of understand, and they don’t threaten anyone’s ideology, so it’s universally settled that we’ve got these things more or less nailed. (This is always subject to change if new data arises, of course, but we’ve observed enough by now that we can be pretty confident we’re on the right track.)

But the controversy comes when the science gets a bit trickier, the concepts less easily grasped by anyone who hasn’t spent time studying them, and the implications less comfortably reconciled with the dogmatic claims of belief systems. Because of this, fields of study which are equally well established and supported by evidence start getting labelled as “controversial”, and it can easily seem like some scientific theories are much weaker than in fact they are. You won’t find many evolutionary biologists who think that the basic idea of evolution (that life on Earth evolved through a process of Darwinian natural selection) is any less likely to be true than the fact that our genes carry our genetic information, but it’s a much simpler task to spin one as a “controversy” than the other. The evidence supporting it is overwhelming, but a lot of it is harder to understand, so it may be less intuitive to accept “Because it’s obviously true” as a reason why the scientific community seems to be so unanimously behind it.

Of course, simply labelling anyone who disagrees with the majority view as an ideologue who doesn’t understand the subject matter, and ignoring their arguments, would be a colossal logical fallacy. If these “scientific” objections are as out of touch with real science as all that, then even I should be able to explain the flaws behind some of them. But it’s taken far too long already to put this together, so I’ll cut this off early, and talk about some of those problems in separate articles soon. In the meantime, you might find enlightenment at the Radiometric Dating Resource List, or these articles by Dave Matson, or the ever-invaluable TalkOrigins, or any of the other articles linked to further above.

1Though, they don’t really circle in that traditional pattern, like planets orbiting the Sun. Physicists, don’t send me emails about electron clouds.
2Half-life. Like Parklife. It’s a pun. Don’t worry about it.
3I know, I’m still simplifying a great deal here. Physicists, don’t send me emails about neutrinos.

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I started writing a response to Andrew Sandstrom’s comment here to my article about Kent Hovind, and it turned into a bit of a rant. You’ll need to read what he says to get the context, I’m not going to quote him here in full.

“The Big Bang doesn’t support evolution… But there’s an interpretation on how the big bang happened by many prominent Darwinists.” – Well, you’re right that there’s a lot of crossover between acceptance of evolution and of Big Bang theory, and certainly most Darwinists more or less accept the current model of the origins of the Universe, as do most scientists of any kind, even if it’s not their area of study. But it’s not that there’s absolutely no connection between the different ideas.

The approximate age of the Universe has been calculated entirely independently of anyone else’s forming hypotheses about the origins of life on Earth, but the two fields produce results which seem to support each other. Cosmology and astronomy indicate that the Universe began around 13.7 billion years ago, expanded rapidly, matter coalesced into stars and planets, and Earth’s own history stretches back around 4.5 billion years – and evolutionary theory describes the history of developing life on this planet, on an independently formulated timescale which lines up nicely with our cosmological ideas.

This wasn’t always true – some doubt was cast on Darwin’s theory when he first proposed it, because the Earth wasn’t thought to be old enough to allow for such levels of development as evolution required. But doubt was also cast on Lord Kelvin’s estimates of the age of the Earth (initially said to be 20-400 million years), more observations were made, new methods were devised, and we’re much closer now to a more consistent and accurate understanding, backed up by many different fields of study.

“A group of fossils deep in the earth’s crust…” – Could be interpreted (or interpretated, if you prefer) in either of the ways you mention, as long as you’re not actually doing any science, and aren’t going to examine anything in any more detail than to notice that there’s “a group of fossils deep in the earth’s crust”. At that level of precision, maybe they’re creatures living a long long time ago, maybe they’re animals who were too stupid or slow to find high ground before the flood, or maybe they’re remnants of a jigsaw puzzle that some Martians got bored with and left scattered around the planet before humans got here.

Thing is, millions of pages of research and data have been published, in journals of geology and such, so we actually know quite a lot more detail about the fossil record of the Earth than just that it’s “a group of fossils deep in the earth’s crust”, and the two latter explanations on that list have been largely dismissed, because they fail to fit any significant amount of the evidence.

“When all of the dating methods are very inaccurate…” – Um, no. I lack the inclination, the capacity, the background knowledge, and the time to conclusively demonstrate the validity of scientific dating methods in a single post, but this is another area of science in which numerous results converge from different directions to produce a convincing level of certainty, and in which new results are predicted successfully time and again. There are obviously limitations, which need to be understood if the results of using these methods are to be valid, but these have generally been found and highlighted by other scientists, refining the tools of research, rejecting and falsifying anything which can be undermined by the facts. My next Skeptictionary post will be about the basics of radiometric dating, and I should make a few follow-ups at some point to address some of the common criticisms.

“Evolution is a speculation and interpretation of the evidence.” – This is clearly meant to imply that any other interpretations might make just as good a fit, but that’s not really how evidence works. Evolution has, for a long time, explained the vast majority of the known data, and been able to make testable predictions of future discoveries and measurements, better than any other model.

The history of science is a history of contradictory evidence being brought forth, examined, tested, poked, prodded, and eventually either being discarded as misleading or invalid, being accepted and assimilated into a modified and improved understanding, or occasionally gathering enough momentum – through repeated experiments constantly confirming it, and by withstanding all efforts to knock it down – and overturning a previous way of thinking. This is just as true of the science of measuring the age of the Earth; it’s developed fascinatingly over time, as new theories have trumped old simply by better fitting the observed facts, and in recent years a concensus has grown regarding the broad truth that the Earth is around 4.5 billion years old. As much as you might like there to be, there’s no kind of conspiracy keeping young-Earth ideas out of science. There doesn’t need to be; people are just following the actual weight of the evidence.

I’m not at all sure what your point is in linking to that NASA story. It’s one of many, many, many examples of scientists discovering something they don’t currently have an obvious explanation for, and beginning to wonder how it will affect their theories, and whether it means they’ve been wrong about something. The people who made this observation, and understood what it implies, were astronomers – not Creationists, not advocates of some minority position trying to bring down any current consensus, but scientists working within the field whose theories are being shaken up.

They say that this observation is “not what the models predict”, and once some more information is gathered, they’re going to have to start adapting their theory to make sense of it. (Since the story’s over five years old, maybe I should try and find out if they’ve done that by now, and in what ways.) This is just how science works. Nothing about the discovery of a string of galaxies 300 million light years long does anything to support any kind of Creationism, or to undermine evolution, or to confirm or deny any predictions made by any outside-the-box thinking “scientist” like Kent Hovind.

“[Evolution] really can’t go past the theory stage…” – Please to be learning what a theory is. Evolution is as much of a fact as gravity.

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Fred Phelps is a hate-group leader, and a loathsome fucktard. The Westboro Baptist Church, which he founded, regularly pickets military funerals, and seems to take great pleasure in loudly telling pretty much everyone that God hates them, from gays to Catholics (with equally liberal use of the epithet “fags” in either case).

He also regularly beat his thirteen children, and seemed to relish the pain he caused them almost as much as the thought of almost everybody on the planet burning in Hell for eternity. This is according to one of his children, Nate Phelps, who has spent some time attempting to distance himself from the physical abuse, and mentally abusive religious indoctrination, of his childhood, and who has recently begun speaking publicly about his upbringing in the Phelps household. Read about him from someone who saw him speak. I’m going to have to try and hear more from him. It’s a close to unique perspective he’s got.

Oh, and as Ben Goldacre points out: the Daily Mail is campaigning both for and against the cervical cancer jab, at the same time, depending on whether you’re reading the British or Irish edition of their paper. This seems to be the most demonstrably disingenuous, dishonest, irresponsible, cynical approach to journalism it’s possible to imagine. Any kind of consideration of facts, knowledge, or any other basics of journalistic reporting appear to have gone entirely out the window. It’s all just about selling a story, and it’s rather depressing.

I’m sure there was one more thing… but I can’t find it. So have a Jenny McCarthy body count widget instead. 152 dead so far, watch it keep on ticking!

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Wow. Go go, Roger Ebert. Even though he’s gotta be on one of those “Men who look like old lesbians” lists somewhere, the guy can write a pretty awesome smackdown.

It’s worrying how many people still apparently watch Bill O’Reilly’s show with absolutely no irony. Does a photo of him exist that doesn’t look identical to the one at the top of that page?

Anyway. I’m aiming to finish redrafting something for the Skeptictionary tomorrow. It won’t be earth-shattering, but it’ll at least let me shift my focus onto something new.

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I think it was the 8 Lessons and Carols for Godless People show in December that finally persuaded me to read Ben Goldacre‘s book Bad Science. You should unequivocally read it yourself too, by the way, whoever and wherever you are. It will teach you many useful ways to watch out for complete bullshit in the media, and to evaluate the usefulness and validity of scientific studies for yourself. The only thing that bugged me just a little was that, after I’d bought my copy, I heard that the next edition (to be released in the new year) would include a new chapter, which he’d spoken about at the Godless People show, but which he couldn’t officially write until he’d finished being sued by the guy it was about. It ceased to bug me once I actually started reading the book, though, and I decided I might just pick up a copy of the new edition when it was available, and pass the old one on to someone who might appreciate it.

Well, the new edition of the book is here. And the new chapter is in it – but it’s also been reprinted, in its entirety, for free, on Ben’s blog. It’s released under a Creative Commons license, which means that distributing copies to everyone you know is wholeheartedly encouraged. It’s a brilliantly told and profoundly unsettling story about nutritionism in South Africa, and the effects that a few campaigners for “multi-vitamins” are having on the HIV epidemic there, and on the efforts made by health workers trying to get useful medication to millions of dying people. The Jenny McCarthy body count ain’t got nothin’ on these guys.

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Dr David Gorski just keeps getting more and more awesome. His latest WIN is a blow-by-blow takedown of the whole Jenny McCarthy and Jim Carrey interview on Larry King. Man, I can’t even blog a quarter of that much in a whole week, half as intelligently, and I’m not even curing cancer for most of the day.

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