Underground Experiment Confirms Fusion Powers the Sun 141
sciencehabit writes: Scientists have long believed that the power of the sun comes largely from the fusion of protons into helium, but now they can finally prove it (abstract). An international team of researchers using a detector buried deep below the mountains of central Italy has detected neutrinos—ghostly particles that interact only very reluctantly with matter—streaming from the heart of the sun. Other solar neutrinos have been detected before, but these particular ones come from the key proton-proton fusion reaction that is the first part of a chain of reactions that provides 99% of the sun's power.
That's not how science works (Score:5, Interesting)
Nothing has been proven. Scientists have long had a theory about how the Sun powers itself. That theory can be used to make predictions, such as the type of neutrinos that we should expect to see emanating from the Sun. An experiment was devised to test such a prediction, the hypothesis being that this type of neutrinos is being produced and thus will be detected. Having performed the experiment, we see that the results match what we expected, validating the hypothesis. This is important and significant, and it provides further evidence suggesting the widely accepted theory is accurate, but it does not -- nor can it -- constitute a proof.
The other interesting result would be if the expected neutrino type was not detected by this experiment, invalidating the hypothesis. This would raise further questions such as: is there some other mechanism powering the Sun? Is there something deficient in our understanding of neutrinos that prevented us from detecting them despite them being there? Was there an error in the test setup (i.e. is it repeatable by other parties)?
Re:Thought that was obvious... ? (Score:5, Interesting)
Another surprising fact about fusion in the Sun is that the fusion power generated is about 1.5 watts per ton of core. Even in conditions in the core of the sun, fusion is hard, and the particular reaction process just confirmed was at the end of a long chain of reasoning explaining what we do see. So I think this actually give evidence that a bunch of stuff in Wikipedia about processes in the Sun is also true. (If a different fusion process was found, then we'd likely be wrong about how much power is generated, and thus about the rate and manner that that power eventually makes it to the surface and gets radiated).
Re: That's not how science works (Score:4, Interesting)
"Science never disproves anything any more than it proves anything."
Except for "global warming" and evolution of course.
It's interesting that you use those two examples. There are a variety of scientific (and unscientific) theories regarding "global warming" or "global climate change" which have attained varying levels of acceptance. There is also a widely accepted scientific theory of biological evolution on the Earth.
There is also ample evidence of global warming, as well as ample evidence of biological evolution. The evidence is just that. Collected observations of objective reality.
The number, variety and independent verification of those observations of "global warming" and "biological evolution" make it abundantly clear that they do, in fact, exist. However, the quality and predictive power of the above scientific *theories* might be a topic of some debate.
Collecting those observations and using them to create and improve scientific theories which describe those observations and the processes that cause them is called "science."
Get it now? Oh, and you're welcome.
Comment removed (Score:5, Interesting)