Posted on 09/02/2008 8:14:57 PM PDT by B-Chan
Here’s an interesting conundrum involving nuclear decay rates.
We think that the decay rates of elements are constant regardless of the ambient conditions (except in a few special cases where beta decay can be influenced by powerful electric fields).
So that makes it hard to explain the curious periodic variations in the decay rates of silicon-32 and radium-226 observed by groups at the Brookhaven National Labs in the US and at the Physikalisch-Technische Bundesandstalt in Germany in the 1980s.
Today, the story gets even more puzzling. Jere Jenkins and pals at Purdue University in Indiana have re-analysed the raw data from these experiments and say that the modulations are synchronised with each other and with Earth’s distance from the sun. (Both groups, in acts of selfless dedication, measured the decay rates of silicon-32 and radium-226 over a period of many years.)
In other words, there appears to be an annual variation in the decay rates of these elements.
Jenkins and co put forward two theories to explain why this might be happening.
First, they say a theory developed by John Barrow at the University of Cambridge in the UK and Douglas Shaw at the University of London, suggests that the sun produces a field that changes the value of the fine structure constant on Earth as its distance from the sun varies during each orbit. Such an effect would certainly cause the kind of an annual variation in decay rates that Jenkins and co highlight.
The big question with decay-rate dating is the question of whether ANY heavy metals which we find near the Earth’s surface are native to our planet or arrived via impact events. Given the standard idea of our planet having formed from swirling masses of solar material, you’d expect all the heavy metals to be at the center and nowhere near the surface.
Did my best to give you and out … ;-)
It’s good for the scientists, who do know so much, to be occasionally reminded how much they don’t know.
I wonder if this changes the age of stars. I don’t know if it’s a factor. But it seems like this might have consequences for things where the difference from Earth gravity is much more than the difference we have from spring to summer.
Nothing on this thread is difficult to learn, a home-schooler with a little sense would get it after a little study.
Physics is easy. Somebody suggests something, folks figure out a way to measure it. That's the way it goes.
But it's not above your pay-grade. You can do physics. You DO physics, whether you realize it or not.
Own the geekage!
/johnny
I, too, first thought of solar neutrino flux.
With the normal rotation of the earth in it's orbit, you *are* moving closer and farther away from the sun. The earth's orbit is not a circle, it's an ellipse, with one foci essentially at the center of the sun.
Okay all you FR physicists, help me out here, s'il vous plaît
I'm really only seeing one theory. Do they run together somehow? Was the second theory just modulated out of existence, perhaps from being engulfed by a scalar field?
But neutrinos pass through matter without hardly ever interacting with it.
Not my generation.
/johnny
Even with them, this would be a generally very boring project. Boring is hard work, especially for the likes of most physicists.
True. The Earth is actually about 3 million miles closer to the Sun during northern hemisphere *winter*.
*groan*
But if it's caused by something to do with the Sun, then there's no reason to believe that any fundamental properties of the universe are changing.
And besides, I'm just a cook..... That can program on bare metal.
/johnny
We’ve already been discussing this article for a few days.
Do nuclear decay rates depend on our distance from the sun?
the physics arXiv blog ^ | 8/29/08
Posted on Friday, August 29, 2008 9:29:09 AM by LibWhacker
http://www.freerepublic.com/focus/f-chat/2070597/posts
“But I’m not moving closer to the Sun, if that’s what you’re suggesting.
And I’m not moving farther away, either. “
You do know the Earth’s orbit is not a perfect circle, don’t you?
“I, too, first thought of solar neutrino flux.”
Me too. I heard they have a new album out.
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