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Comment by ajju | Hacker News Reader

Cue creationists jumping on this to challenge evolution (by challenging carbon dating) in 4...3..2..

Creationists? Everyone should jump on challenging carbon dating. If we can measure variance inside of 33 days, and that's extrapolated over a few millions of years, that could skew the numbers a bit.

But I bet the ballpark of neutrino's the sun has put out and will put out stays relatively constant inside of some rotational variance. The output behaving like a sin wave doesn't change things much, but if it's on an incline or decline, that has a huge impact on carbon dating.

It seems exciting that we have an observable cause and effect and we don't understand why. That seems like it could be a good treasure chest of knowledge right there!

Yeah, true, but I still predict the creationists will be all over it.

But you could add much wider error bars to carbon dating and it still wouldn't support creationism.

Maybe something 20 million years old is just 7 million. Fine. It's not six thousand.

I completely agree. I just find it funny that new science appears and everyone's moaning about the impact of the creationists argument!

It's more like: maybe something estimated to be 20.0 million years old (with an error bar of 0.5 million years) should have been estimated to be 19.99 million years old, with the same error bar and hence the same precision, which is still 20.0 million years. And that only makes sense if we weren't talking about carbon dating, which isn't used for those timescales.

Whatever variation may exist, carbon dating has been independently verified via other dating means such as coral ring formations and dendrochronology. Unless whatever is having an effect on carbon dating also affects these other, unrelated, forms of dating in the exact same way we can expect the variation to be small and not significant enough to upend everything we know. The evidence that our dating mechanisms work is undeniable - tectonic movement, linguistic evidence of language dispersion, physiological changes in species and their geographical distribution, etc etc all happen at predictable rates and all match up with what we know about our dating methods.

Really, creationists should be better suited applying their ultra-skepticism at the much larger gaps in evidence and analysis found in their own ideas. The thing about people who value science is that whenever data presents a challenge we have to account for it, unlike the idiot creationists who only embrace data when it agrees with their already pre-conceived ideas.

  If we can measure variance inside of 33 days, and that's extrapolated over
  a few millions of years, that could skew the numbers a bit.
  [..]
  that has a huge impact on carbon dating.

No, the effect is very extremely small and this has no impact at all. Lets suppose that:

* we measure differences of 1/1000th in decay rates (this is reasonable given the differences the article is based on)

* the average variation is 1/1000th, otherwise it would have been detected earlier.

* the halflife of C14 is 5000 years (to make calculations easy)

* we are determining the age of something 20000 years old (carbon dating is only used for ages in that order of magnitude).

* the decay formula is y = x(1/2)^(t/tau), where y is the amount of C14 you will measure after t years, tau is the halflife in years and x is the initial amount of C14 we obtained via other means.

We measure an amount of C14 that's 2^4 times smaller than current amounts and conclude that the amount of C14 was halved 4 times. If the decay rate was actually 1/1000th larger on average, then we should have conclude that 2^(-4) = 1/2^(t/5005) or t = 20020 years. In other words: the error is as large as the relative seasonal variation, which is quite small already and probably falls well within the regular error bars.

But that means you're expecting the C14 rates to be the same now as when the subject died. A reasonable assumption but as far as I understand C14 hasn't reached any kind of equilibrium for some reason. Aren't there different amounts in the air than say, 50 years ago?

Carbon dating always requires an estimate of the initial amount of C14 in the object whose age is being determined. That is an issue separate from the one being considered in this thread, but one whose error bar is probably more important. I cursorily touched upon that with:

  *x* is the initial amount of C14 we obtained via other means.

These 'other means' are thoroughly explained in various places on the web, due to the amount of creationist attacks on carbon dating.

I think the paper itself is a challenge to carbon dating. The question is whether the resultant inaccuracies in carbon dating would invalidate the theory of evolution. Whether or not they do (and it seems obvious to me that they don't), creationists will claim they do.

Even if the rate of radioactive decay does vary periodically (with a known period), you just do a different calculation when figuring out some dead thing's age from carbon-14 measurements.

Since this effect sounds like it's a small perturbation on top of the main model (a constant decay rate), I'd expect the final answer (the calculated age) to be about the same.

Actually C-14 levels have varied over history, so we already need to calibrate C-14 readings with other measuring sticks, such as tree rings.

That calibration would catch any possible variation.

Incidentally did you know that C-14 dating no longer works? The reason is that we've released a lot of carbon from fossil fuels that is very low in C-14. As a result fresh organic matter today has lower C-14 levels than organic matter from 100 years ago. Odd, but true. (And don't think that the Creationists haven't been all over that fact.)

My general point was that one can make a mathematical model that takes into account the historical value of the ambient C-14 to C-12 ratio, plus the historical value of the C-14 decay rate.

C-14 dating isn't used for dating recently-dead things, but not for the reason you suggest. The real reason is that the half-life of C-14 is about 5730 years. Not much decay happens in 200 years, and the little that does happen is difficult to sort out from measurement errors.

Other techniques are used for dating things that died recently. Watch CSI for some clues :D

Been there, done that. The Institute for Creation Research started the RATE project in 1997. http://www.icr.org/rate/

Sure, but it appears this is new evidence to support those claims? Or is this an old discovery that just 'went mainstream'?

The creationist pseudoscience tries to demonstrate that radioactive decay is variable here on Earth.

This seems to be another case where our standard laws of physics break down at massively high temperatures and pressures.

And of course, radioactive dating is one tool among many. The distribution of soil and rock on the Earth is almost certainly the result of billions of years of erosion, earth shifts, and climate changes.

Also: say that radioactive dating turns out to be worthless (which is not the case, even if the results in the linked article are true), that still wouldn’t tell you anything about the age of the earth. You can’t then just privilege the hypothesis that the earth is 6,000 years old.

It’s quite funny actually, if we didn’t have radioactive dating it would make a lot of sense to say that evolution itself is one of the best pieces of evidence for an old earth. It is supported by so much evidence independent of any dating methods that any discovery which changes how much we believe we can trust radioactive dating is practically meaningless. (The obvious exception are results which would indicate that earth is orders of magnitude younger than radioactive dating makes it seem to be. But, no surprise, this is not that.)

This seasonal discovery is new, but it's exactly the sort of thing RATE has been talking about. The main point of the RATE project is to discredit the radioisotope dating methods. Sometimes they just send samples from the same rock formation to different labs and get different results. But they also spend a lot of time finding reasons that radioisotope decay rates might change over time.

This is all from what I remember from a conversation I had with someone involved with the project about 10 years ago. They got a lot of funding and a lot of interest back in the late 90's when they were just starting. I thought some of their research was interesting, but there was so much propaganda mixed in that it turned my stomach, so I stopped following it.

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