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Saturday, February 6, 2010

Radiometric dating

Many creationists spout lists of pieces of evidence that support a young earth, they all share one or two problems. They either are completely erroneous or have already been refuted, without exception.

In particular Young-earth creationists have 3 main criticisms they frequently cite about radiometric dating, these are as follows.
They claim that scientists ignorantly assume that:
  1. The initial conditions of the rock sample are accurately known.
  2. The amount of parent or daughter elements in a sample has not been altered by processes other than radioactive decay.
  3. The decay rate (or half-life) of the parent isotope has remained constant since the rock was formed.
From Answers in Genesis.

These assumptions are known by geologists, and are taken into account, and I'll go through the refutations to each of these criticisms.

Isochron dating methods do not assume that the initial conditions are known. This assumption is only made in very simple radiometric dating, the kind that you'd use only if you did know the initial ratio of the parent/daughter minerals, such as with radiocarbon dating. To explain Isochron Dating I'm going to give you a paragraph from TalkOrigins that explains it very well. Though understanding this concept requires a basic understanding of statistics and also of radioactive decay.

With isochron dating, we also measure a different isotope of the same element as the daughter (call it D2), and we take measurements of several different minerals that formed at the same time from the same pool of materials. Instead of assuming a known amount of daughter isotope, we only assume that D/D2 is initially the same in all of the samples. Plotting P/D2 on the x axis and D/D2 on the y axis for several different samples gives a line that is initially horizontal. Over time, as P decays to D, the line remains straight, but its slope increases. The age of the sample can be calculated from the slope, and the initial concentration of the daughter element D is given by where the line meets the y axis. If D/D2 is not initially the same in all samples, the data points tend to scatter on the isochron diagram, rather than falling on a straight line.
 Other types of radiometric dating do make assumptions about the initial levels of parent/daughter minerals but these assumptions are justified. For example C-14 dating assumes we know the level of C-14 in the atmosphere when the organism died, and this does vary quite substantially. Lucky for us, for dating samples within the range of C-14 dating, we can use other methods to calibrate the accuracy of it, for example ice-core samples and tree-ring dating (dendrochronology).

The second criticism that scientists assume that a rock is a closed system is almost laughable. Absolutely closed systems do not exist even in ideal conditions, but many types of igneous rock come about as close to a closed system as you can possibly imagine. As was mentioned in the paragraph from TalkOrigins, multiple samples are taken in any dating procedure, and the fact that they consistently produce results within one percent of each other is testament to the closed nature of most igneous rocks. Even if a particular lava flow was contaminated, the chance that all samples were contaminated equally, so as to give results within 1 and 3% of each other is extremely low.

Not only are most rocks barely capable of being contaminated, even if they were, isochron dating methods are capable of detecting contamination and even correcting for it. Geochronologists are well aware of potential rock contamination and take precautions to avoid samples that may have been contaminated, for example they will not use a sample that has been weathered.

The third criticism is just stupid. All scientific research that has been done on this idea has conclusively come to show that radioactive decay is a very consistent process, and does not fluctuate under different conditions. Some creationists claim that cosmic rays or neutrinos would affect the half-lives of minerals, but there has been no evidence to show this is the case. This is simply a bald assertion from the Creationists, showing once again that they are not interested in doing real science, but only to propagate falsehoods and lies.

6 comments:

  1. I'm sorry but whats the point of this blog?

    I've skim read most of your articles (because they all seem to mostly be made up of inane babbling about why creationism is wrong, which I get) and I don't understand who your target audience is.

    I get that you don't beleive in creationism from the million wikipedia articles you post but I don't see any evidence for atheism?

    I don't understand how you can derive an atheistic way of life purely based on hatred of your own teenage stupidity, if anything it would make me want to find out the answers to my own spirituality more, rather than blindly follow another book (a biology book) and have my entire outlook based on that. Thinking people are stupid and retarded just because they don't beleive the same things as you or they use incorrect grammer is fucking stupid.

    You need to get off your computer chair and go outside and experience the real world before you become too "smart" for your own good.

    ReplyDelete
  2. Well most of them aren't in fact about creationism, less than half of my posts have been about creationism. I don't have a "target audience".

    Million wikipedia articles? Really? I doubt that I've linked to wikipedia more than 10 times out of 75 posts.

    "Evidence for atheism" is an oxymoron if you didn't realise.
    I don't see how I could derive an atheistic way of life simply by hating how I was led ignorantly into creationism either. If you had actually read some of my earlier posts about my deconversion you would have seen me write that my deconversion wasn't overnight, and in the process I did some soul-searching, finding there was really nothing there. I, nor anyone I know do not read science books the same way a devout christian reads the bible. To say that I 'blindly follow' a biology book is strange.

    People aren't stupid because they believe different things to me, not at all. They may simply be ignorant (which isn't an offensive term) of the evidence. They only become stupid (or deceitful) when they see the evidence, ignore it, and continue to spread lies.

    You seem quite hostile towards me and I'm not really sure why. Unless you're Wendy Wright or Kent Hovind I've never personally attacked you, so take a chill pill.

    ReplyDelete
  3. Projection...?
    I can't speak for kj, but personally, my atheism has nothing to do with hatred, it has to do with my preference to believe what is true. I don't follow anything blindly, evidence is what matters. The biology books (and science books) i have read, are, based on evidence and scientific research. It's fairly amusing that you accuse us of 'following biology books blindly' just because you blindly follow the bible, a book full of misinformation, evil deeds, and supernatural gibberish.
    I don't think anyone i don't agree with is stupid, what i do think is that they are wrong.
    Experiencing the real world, interacting with others, marvelling at reality, is all fine and good. But you seem to have a problem with KJ educating himself, you seem to have a problem with the enthusiasm KJ has for the subjects he posts about. You seem to have a problem with the sheer frustration KJ has in regards to pseudoscience. This is wrong and, to me, absolutely retarded. There's no such thing as 'being too smart', so please shut the fuck up.

    ReplyDelete
  4. I just had a brief look over all my posts and I have only linked to wikipedia 7 times out of 75 posts. 4 of those links were in only 2 articles, and only 5 of them were after I "came out" as an atheist. Dramatic hyperbole's might be exciting, but it seems like you're trying too hard to make me look like a wikipedia junkie who doesn't research anything properly. Nice try.

    ReplyDelete
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