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To a modern physicist, perhaps the most interesting thing about the Oklo reactor is that it gives us one of the biggest levers on the question "Have the laws of
by ISL 13y ago
To a modern physicist, perhaps the most interesting thing about the Oklo reactor is that it gives us one of the biggest levers on the question "Have the laws of physics changed over time?"
So far as anyone can tell, nuclear physics was the same back then as it is today.
- minikites 13y agoI didn't know this was in doubt, do you have any additional information on this debate? It sounds interesting.
- maaku 13y agoIt's not ind doubt so much as there is little intrinsic reason to support either side, and scant evidence. Maybe the laws of physics worked differently in the early universe -- how would you know? The answer of course is astronomical observations -- it's the only window into the past that we have, other than a few historical events like the OP, as the GP points out. But how do you interpret astronomical observations? By using the currently understood laws of physics, of course, so it becomes a bit of a circular argument. If you assume that certain constants change over time, that does help explain away current mysteries like inflation & dark energy, under some models. However too much deviation would contradict other observable evidence.
- jsweojtj 13y ago> But how do you interpret astronomical observations? By using the currently understood laws of physics, of course, so it becomes a bit of a circular argument. One of the best ways to measure this is to use quasar absorption spectroscopy to probe the precise energy level spacing of atoms (like iron, magnesium, and so on) from billions of years ago with the energy level spacings found in the same atoms of today. If the fine-structure constant (for example) were different by some amount in the distant past, its effect is calculable -- and the spectroscopic signature of a different fine-structure constant is distinct from any other physical effect (redshift of the spectrum, etc.). There are some intriguing results that have come out over the past decade or so, with new information coming in all the time.
- NoMoreNicksLeft 13y agoSo all the stories I've read about how it implies the fine structure constant has changed, those are bullshit?
- ars 13y agoYou misread them, those stories are talking about checking IF the constant has changed. They are not saying that it has. None have shown any change.
- dragonwriter 13y ago> To a modern physicist, perhaps the most interesting thing about the Oklo reactor is that it gives us one of the biggest levers on the question "Have the laws of physics changed over time?" I don't think it really does, because our interpretation of the causes that produced the effects that we can see now as something which supports the conclusion that the laws of physics were the same then itself rests on the assumption that the laws of physics were the same then.
- maaku 13y agoIt provides one more data point that constrains just how different the laws of physics could have been in the past -- no matter how different the laws of physics were, it must have still enabled an event which created the isotopic concentrations we see today. Yes, that is a much looser constraint than the GP described, but it is still a significant data point.
- jsweojtj 13y ago> laws of physics were the same then itself rests on the assumption that the laws of physics were the same then No, that's definitely not true. Here's a good (somewhat technical) overview of these kinds of scientific investigations: http://relativity.livingreviews.org/Articles/lrr-2011-2/ http://relativity.livingreviews.org/Articles/lrr-2011-2/ The pdf should be free to download and there's an entire section on the Oklo reactor.