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Underground Experiment Confirms Fusion Powers the Sun

Soulskill posted about 3 months ago | from the if-you-lost-a-bet,-go-pay-up dept.

Science 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.

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Thought that was obvious... ? (2)

davethomask (3685523) | about 3 months ago | (#47769847)

Well, interesting read anyhow...

Re:Thought that was obvious... ? (4, Insightful)

wallsg (58203) | about 3 months ago | (#47769885)

Obvious is different from proven.

Re:Thought that was obvious... ? (2)

Noah Haders (3621429) | about 3 months ago | (#47769935)

it caught me by surprise as well. but thinking about it more it's mind blowing to think that there are a lot of things we take as fact when they may just be assertions. like fusion powering the sun, for example. I call this the Wikipedia phallacy.

Re:Thought that was obvious... ? (1)

wallsg (58203) | about 3 months ago | (#47770137)

I think (hope) you mean "fallacy"...

Re:Thought that was obvious... ? (5, Funny)

Anonymous Coward | about 3 months ago | (#47770201)

it caught me by surprise as well. but thinking about it more it's mind blowing to think that there are a lot of things we take as fact when they may just be assertions. like fusion powering the sun, for example. I call this the Wikipedia phallacy.

I think (hope) you mean "fallacy"...

No, he has it right. By analogy with "democracy", "oligarchy", "anarchy", and so forth, naturally Wikipedia is a "phallacy" since it's quite well established that many of the editors there who run the place are pricks.

Re:Thought that was obvious... ? (1)

Applehu Akbar (2968043) | about 3 months ago | (#47771893)

An example of a phallacy is: "You can tell by looking at his shoe size."

Re:Thought that was obvious... ? (1)

Neil Boekend (1854906) | about 3 months ago | (#47772449)

Clowns must be really well endowed.

Re:Thought that was obvious... ? (0)

Anonymous Coward | about 3 months ago | (#47772617)

Why do you think they never stop smiling? :o)

Re:Thought that was obvious... ? (1)

TheEmpyrean (788742) | about 3 months ago | (#47773303)

Then why aren't there more of them in porn?

Re:Thought that was obvious... ? (1)

davethomask (3685523) | about 3 months ago | (#47769965)

sure.. you're right

Re:Thought that was obvious... ? (1)

Anonymous Coward | about 3 months ago | (#47769969)

They can't "prove" it. There could be other theories that predict the same result. For example something else could be powering the proton-proton fusion that is creating these neutrinos.

Re:Thought that was obvious... ? (0)

Anonymous Coward | about 3 months ago | (#47770413)

This at least proves fusion is occurring? Did anybody doubt that? I know the electric/plasma cosmology enthusiasts did not doubt it.

Re:Thought that was obvious... ? (0)

Anonymous Coward | about 3 months ago | (#47772075)

I've bumped into a few and received cold contacts from a few others that insisted that no fusion happened within the sun, that it was powered by a combination of external currents or fission. They were all unaware of some combination of the previous detection of neutrinos from other fusion reactions within the sun, the creation of fusion reactions within labs for studying detailed properties of the reaction, or the extent of work on neutrino oscillations.

Re:Thought that was obvious... ? (2)

Bondolon (1000444) | about 3 months ago | (#47770531)

Yeah, but we didn't need to detect proton-proton neutrinos to know that fusion powers the sun, because we have myriad other indicators (spectrum, energy output, solar wind) that agree with the current theory. The fact that we have now seen proton-proton neutrinos is cool as hell, but this will never be "proven" significantly more than it currently is, unless science changes drastically to allow for deductive facts. Science allows for an inductive form of "proof" (something being so probable it will likely never be demonstrated wrong) that's less rigorous than the logical kind, and fusion in the Sun has long been under that label. For analogy, we didn't have to wait until Sputnik had orbited Earth to know that Earth was round (since that was known to academics 2000 years earlier), but it certainly made people feel more confident in that fact when it happened.

Re:Thought that was obvious... ? (3, Informative)

dnavid (2842431) | about 3 months ago | (#47771761)

Yeah, but we didn't need to detect proton-proton neutrinos to know that fusion powers the sun, because we have myriad other indicators (spectrum, energy output, solar wind) that agree with the current theory. The fact that we have now seen proton-proton neutrinos is cool as hell, but this will never be "proven" significantly more than it currently is, unless science changes drastically to allow for deductive facts. Science allows for an inductive form of "proof" (something being so probable it will likely never be demonstrated wrong) that's less rigorous than the logical kind, and fusion in the Sun has long been under that label. For analogy, we didn't have to wait until Sputnik had orbited Earth to know that Earth was round (since that was known to academics 2000 years earlier), but it certainly made people feel more confident in that fact when it happened.

Science allows for deductive facts to carry scientific weight. I have no idea why you would think it does not.

Science uses both deduction and induction, because while induction is not as absolutely rigorous as deduction, its not possible to deduce the entire cosmos from first principles. One of the axioms of Science is that the universe is not completely random and operates on the basis of rules that govern its behavior, and those rules can be discovered through observation. Universal gravitation is an induction, because there's no way to deduce that gravity operates in the same way everywhere. The presumption is that its highly unlikely that gravity operates the same way in every place we directly measure it, and also operates in a consistent way in every place we can indirectly measure it, but somehow operates differently in every place we just happened to not directly or indirectly observe it.

All logical deduction must start with fixed axioms, and depending on what physical scientific laws you consider strong enough to be axiomatic, you can deduce a lot which is considered scientifically rigorous. For example, when we observe photons striking a detector, we *deduce* they were emitted from somewhere along the path the photon struck the detector. You could argue that's just an induction; that we're only guessing because that's how we've observed photons to behave in the past, but at some point that's sophistry, because it rejects the notion that Scientific reasoning can contain any axioms. Without some reasonable starting point - like being able to trust observations at all - you can't do Science at all.

Also, I doubt there exists any significant number of people who were suddenly more confident the Earth is an oblate spheroid after the launch of Sputnik than before. Nor am I sure how the launch of Sputnik demonstrates the Earth is approximately spherical better than all other demonstrations of that fact prior to Sputnik. Sputnik did not itself observe the Earth, and observers of Sputnik did not get significantly more information from Sputnik in a scientific sense that other observations of Earth's curvature prior to that point.

Re:Thought that was obvious... ? (1)

Bondolon (1000444) | about 3 months ago | (#47771847)

Of course deductions carry scientific weight, but they don't serve as meaningful evidence and instead as the basis of a hypothesis. The very nature of an axiom in science is that of a logically-unproven premise that, itself, can't be used to scientifically "prove" a concept. Therefore, it's necessary that induction be used to justify a deduction, but any logician will assert/concede/stand-completely-baffled-at-any-counter-assertion that inductive evidence could ever be used to logically prove a deduction. Therefore, the level of "proof" for science, which is to say the level at which it becomes warranted to treat a theory as an axiom, is much less rigorous than the level at which it becomes warranted to treat a deduction as a premise. The assertion that you have to meaningfully "trust" evidence runs counter to the foundations of science is a bit of a misnomer, therefore, as one need not assume that a theory is indefatigably true to build off of it, but to assume that the theory has logical conclusions that can be tested.

I'm certainly not pretending that people were suddenly convinced because of Sputnik that the Earth was round. There were myriad reliable indicators to show us that the Earth is round (horizons, sailing in a straight line around it, high-atmosphere observable curvature, shadows on the moon, etc.), but throwing something into space and watching it circle around several times is something like the final nail in a coffin that had been comfortably nailed shut for some time. This, therefore, is why I chose the analogy of Sputnik to illustrate that stronger support for an already completely uncontentious theory is not the "proof" the article is asserting it is, it's just more strong evidence that agrees with the already-existing strong evidence.

Re:Thought that was obvious... ? (1)

Bondolon (1000444) | about 3 months ago | (#47771865)

any logician will assert/concede/stand-completely-baffled-at-any-counter-assertion that inductive evidence could ever be used to logically prove a deduction

Also, I clearly meant but completely mistyped that logicians assert, etc. that inductions can "never" be used as logical proof of deductions.

Re:Thought that was obvious... ? (1)

bobbied (2522392) | about 3 months ago | (#47770613)

Obvious != proven

Proven != Obvious

You are correct, they are totally different.

Re:Thought that was obvious... ? (4, Interesting)

lgw (121541) | about 3 months ago | (#47770843)

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:Thought that was obvious... ? (4, Interesting)

mark_osmd (812581) | about 3 months ago | (#47771029)

Another surprising fact, the Sun's core is so dense (150 g/cc) that a metric ton of core only needs the volume of a cube 19cm per side to occupy.

Re:Thought that was obvious... ? (1)

CheeseyDJ (800272) | about 3 months ago | (#47773257)

Here's another good one - if you could heat a pinhead here on Earth to the same temperature as the Sun's core (about 15 million Kelvin), it would incinerate everything within a 100km (60 mile) radius.

Re:Thought that was obvious... ? (1)

K. S. Kyosuke (729550) | about 3 months ago | (#47772573)

Uh, nope. Given that the core weighs about a third of Sun's total mass, the ~3.8e26 or so watts generated in the ~7e26 tons of core mean that about half a watt is produced per each ton.

Re:Thought that was obvious... ? (0)

Anonymous Coward | about 3 months ago | (#47772941)

Given that the density varies by a factor 10 across the core, and the temperature varies by about 50% (the fusion reaction rate at those temperatures scales roughly with temperature to the fourth power and with density square), the power per volume varies by a couple orders of magnitude within the core, while the power per unit mass varies by over an order of magnitude. You can't just take the total mass of the core and average it out across the core and get something comparable to the peak, or even comparable to the inner 50% of the core's volume which produces 9 times as much power as the outer half of the core's volume.

Re:Thought that was obvious... ? (1)

Applehu Akbar (2968043) | about 3 months ago | (#47771887)

Neutrino detectors have been around for some time, including a large one at the South Pole. Others are located at Tsukuba, Japan and Lead, SD. What has prevented those detectors from finding solar neutrinos?

Re:Thought that was obvious... ? (0)

Anonymous Coward | about 3 months ago | (#47772019)

The energy of the neutrinos being detected here is below the threshold of the older detectors. Putting together a detector that is sensitive to the neutrinos from the proton-proton reaction was much harder than it was for the older ones, which weren't easy either.

Re:Thought that was obvious... ? (0)

Anonymous Coward | about 3 months ago | (#47772091)

Solar neutrinos have been detected for decades now, but so far all of them have been from side reactions that produce much higher energy neutrinos. This detector can detect the lower energy ones associated with the main reaction within the sun. Previous work though closely agreed with the energy spectrum expected from various different impurity and side reactions that can happen.

Re:Thought that was obvious... ? (2)

davester666 (731373) | about 3 months ago | (#47771913)

Can't actually "prove" it, this just makes it much more likely.

Phone back when they actually go to the sun and check inside.

Learn something new every day... (0)

Anonymous Coward | about 3 months ago | (#47769867)

I thought we already knew this? It was just a theory now confirmed? Huh. I've learned my one new thing for the day, that the sun IS actually powered by fusion.

Re:Learn something new every day... (0)

Anonymous Coward | about 3 months ago | (#47770549)

Thankfully we'll still have the solipsists to keep us intertained.

Re:Learn something new every day... (2)

Artifakt (700173) | about 3 months ago | (#47770881)

A theory is something that has strong supporting evidence, and if you agree with Popper and Kuhn and various" Historians or Philosophers of Science", something that skilled people have tried to come up with alternatives, tested them, and the theory has survived where they didn't. Ideas that have been proposed, and maybe have a little supporting evidence, but are considered not tested enough, and not studied rigorously to see if they can be falsified, or if some other idea better fits Occam's razor, are called hypothesi (or often just interesting ideas until they get at least a little support). Yes, just who qualifies as skilled, which idea is actually simpler by the razor, how much testing is enough, and 'how much better at predicting what than the competing ideas are' are all somewhat subjective, and individual scientists are not exceptionally flawless at making those judgement calls. But that's true of just about everything. Science works because the method tends to correct for those subjective aspects, not make them more powerful as in so many other areas of human activity.

By this era, the theory that the sun was powered by Fusion of Hydrogen into Helium had a lot of evidence supporting it, such as the abundance of various elements in it and other stars, as determined spectrally. Try a web search for Hans Bethe if you want to know about the first evidence that helped raise this hypothesis to the status of theory, in 1930, although he didn't get the Nobel for his work until 1967. It's interesting to me that people are debating just what counts as a theory, and for this particular case, there's an exact date when a particular paper was published, and widespread agreement that this date and event is when the hypothesis got enough support to start calling it a theory. This is additional evidence that adds more support, and by the Philosophers of Science, ought to mean anyone who thinks they have a better idea will have to gather even more evidence and work even harder if they want their alternative to be taken seriously.
 

In doubt? (1)

BobandMax (95054) | about 3 months ago | (#47769877)

I'm with the other two posters who also thought this was considered fact.

Powered?! (1)

MrL0G1C (867445) | about 3 months ago | (#47769883)

I hope no-one finds the off switch.

Re:Powered?! (1)

bobbied (2522392) | about 3 months ago | (#47770631)

No need of one... Eventually the Sun will run short of fuel... Then you will see some SERIOUS global warming as the Earth will be within the burning part of the Sun...

Re: Powered?! (1)

Anonymous Coward | about 3 months ago | (#47772395)

Don't worry, life on Earth will be extinct well before that, and the human race way earlier. Oh, we may have some time yet, a lot on our scale, but eventually we'll be gone. Think of it! The conquests of millennia, the art, the philosophy, the knowledge of generations, all those wars, struggles, endeavours... All for nothing. Lost forever. Left to decay and erosion, and all traces of it lost into the ocean of magma that will be this once living planet. No more Blue Marble. No more anything!

That's not how science works (5, Interesting)

AikonMGB (1013995) | about 3 months ago | (#47769905)

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:That's not how science works (1)

AikonMGB (1013995) | about 3 months ago | (#47769915)

s/this type of neutrinos/this type of neutrino/

And there is the matter of (0)

justthinkit (954982) | about 3 months ago | (#47769985)

And there is the matter of neutrino oscillation [wikipedia.org] , which could in itself nullify these results.

Re:And there is the matter of (1)

dnavid (2842431) | about 3 months ago | (#47771851)

And there is the matter of neutrino oscillation [wikipedia.org] , which could in itself nullify these results.

Unlikely, because research has both confirmed the process of neutrino oscillation and allowed observers to account for the oscillation in neutrino measurements. Also, neutrino oscillation can only reduce the number of neutrinos you observe (relative to the amount you think you should), so neutrino oscillation cannot in any way erase a signal, it can only make a signal harder to detect. The problem with the neutrinos observed in the article in question is that they are the p-p neutrinos which have relatively low energy; about half as much as the next strongest neutrino type thought to come from solar fusion processes and significantly weaker than the neutrinos we were first observing when the solar neutrino deficit now attributable to neutrino oscillation was first discovered. That's what made them difficult to detect until recently.

But, again, neutrino oscillation can't nullify these results, because oscillation only makes neutrinos harder to detect (by changing their "flavor"). It doesn't create neutrino signals where none originally existed (at least not in this sense).

Re:And there is the matter of (1)

Ungrounded Lightning (62228) | about 3 months ago | (#47771985)

But, again, neutrino oscillation can't nullify these results, because oscillation only makes neutrinos harder to detect (by changing their "flavor"). It doesn't create neutrino signals where none originally existed (at least not in this sense).

Sure it can: By "oscillating" other flavors of neutrino into the type they're looking for, when they weren't there in the first place (or not in sufficient number).

They'll need to look at the ratio of the various types and back-calculate to eliminate other possible signals, or combinations of them, to see if there is a way for other (possibly unexpected) reactions to produce a signal that looks like the ones expected and/or observed.

Re:And there is the matter of (0)

Anonymous Coward | about 3 months ago | (#47772855)

Newer detectors can detect all three known flavors and at the distances and energies involved for the sun, there are equal amounts of the three flavors. At worst, with a detector that only picks up on flavor, you get one third of your expected signal. It is pretty clear which detectors are sensitive to which types, and some can even distinguish the types and/or direction of source. The precision achievable in distinguishing different reactions within the sun is far beyond just "something is there" to quantitatively matching different reaction branching ratios.

Re:That's not how science works (2)

radtea (464814) | about 3 months ago | (#47770111)

Nothing has been proven.

Correct.

Science is the discipline of publicly testing ideas by systematic observation, controlled experiment and Bayesian inference. As such, proof is simply not relevant to what it does, which is produce knowledge. Knowledge--unlike faith--is inherently uncertain.

It'll take a few hundred years for the popular science press to catch up to this. What is being presented here is evidence that the idea p-p fusion powers the sun is correct, so the posterior pluasibility of that idea goes up, although not to 1 (which would be a certainty, and therefore an error: an idea that was immune to additional evidence.)

If neutrinos had not been detected, the plausibility would have gone down, although not to 0 because that would be the same error. Science never disproves anything any more than it proves anything. Proof and certainty are like the philosopher's stone sought by alchemists: a fundamentally mistaken goal.

Philosophers are the alchemists of epistemology, discovering all kinds of cool things while on a hiding to no-where.

Re:That's not how science works (0)

Anonymous Coward | about 3 months ago | (#47770195)

"Science never disproves anything any more than it proves anything."

This seems incorrect, do you have a source for this? For example:
Guy: All swans are white.
Girl: Look over there! A black swan!

Perhaps crappy theories that only predict vague things cannot be disproved, but good ones with precise predictions surely can be.

Re:That's not how science works (2)

tysonedwards (969693) | about 3 months ago | (#47770765)

Science is intended more to adapt an actual "theory" over time to better suit the evidence that it is presented with until it increasingly encompasses all edge cases that relate to the topic in question. That "adaption" can be considered disproving with an immediate re-creation of an alternate theory moments later to encompass the changing circumstances. In that narrow world view, than yes, disproving of a scientific theory can happen quite regularly, simply because there's a LOT of science going on.

On the flip side, actually "proving" something is exceptionally hard work. It is saying that at no point, ever, under any circumstances in this or any conceivable universe, with any natural or unnatural influence could this situation *EVER* take place for *ANY* reason. These are the rules, these are how things behave, and this is how things will always, and forever behave; EXACTLY like this and there's not a damn thing that anyone including the hand of God himself could do to change that.

Now think about that for a second and the level of difficulty involved in actually "proving" something and considering it "proved", solved forever and ever, and letting us as a species move on to bigger and better things. And that's ultimately the problem. Saying that something is "proved" means that there is nothing more that could ever be known about that topic, and that nothing could ever impact that field, be it further advances anywhere else, supernatural influence, extra dimensional characteristics, weird things that we haven't even considered possible... In most cases a theory remains "good enough". Gravity is one such theory. We know that it exists, we know how it works, we know how to calculate it, we know how to utilize it's traits for all kinds of things. But "proving" that water goes downhill ... It's something that we take for granted and require to base civilization as a whole on, through irrigation and plumbing. Something doesn't need to be "proved" to be immeasurably useful in the daily lives of incalculable people over countless generations. You may think that this is getting pedantic, and it is, but at the same point, it is the difference in Science between "Proving" a theory and not.

Referring to a simple and previously untested idea as what you've described in your swan scenario as a "theory" is what is ultimately damaging the credibility of the term in public perception.

Re:That's not how science works (2)

NotSanguine (1917456) | about 3 months ago | (#47770949)

Somewhat tangentially, in order for a scientific theory [wikipedia.org] (such as proton-proton fusion in the core of the sun) to be considered valid, it must be falsifiable [wikipedia.org] .

Note that a scientific theory [wikipedia.org] is not the same thing as is meant when referring to theory [wikipedia.org] more generally.

Many people make the mistake of equating one to the other, often causing confusion.

Re:That's not how science works (0)

Anonymous Coward | about 3 months ago | (#47771037)

Science is intended more to adapt an actual "theory" over time to better suit the evidence that it is presented with until it increasingly encompasses all edge cases that relate to the topic in question. That "adaption" can be considered disproving with an immediate re-creation of an alternate theory moments later to encompass the changing circumstances. In that narrow world view, than yes, disproving of a scientific theory can happen quite regularly, simply because there's a LOT of science going on....[the rest talks about proving rather than disproving]"

I don't see what narrow worldviews have to do with anything. If a theory predicts a certain value for a parameter, or that something does not exist, then it can be disproved. That would not mean the theory is worthless or has no "verisimilitude", but it is quite literally wrong and requires modification.

Re:That's not how science works (1)

Anonymous Coward | about 3 months ago | (#47771337)

"Referring to a simple and previously untested idea as what you've described in your swan scenario as a "theory" is what is ultimately damaging the credibility of the term in public perception."

The thing damaging the credibility of science is scientists making overblown claims. Just because evidence is consistent with a theory does not prove it or confirm it. This appears to be less of a problem here (although I am no expert) since the theory predicted a specific distribution of neutrino energies, but often in the life sciences the theory can only predict a measurement will be higher/lower which is so vague it is easy to accidentally get "confirming" results.

Also, the reason a theory cannot be "disproved" is that no theory can be tested alone. There are always auxiliary assumptions present, these can be as mundane as "the equipment was functioning correctly". If we get results inconsistent with a theory all we can say is: "Theory is not true or the equipment was malfunctioning (or both)". Of course usually there are quite a few more auxiliary assumptions that just that.

For:
T=Theory
A= Assumptions
O= Observation
~=Not
->=Entails

(T and A) -> O
~O -> (~ T or ~A)

Re:That's not how science works (1)

drinkypoo (153816) | about 3 months ago | (#47770803)

This seems incorrect, do you have a source for this? For example:
Guy: All swans are white.
Girl: Look over there! A black swan!

That's not science. That's simple observation. There's no hypothesis involved, for one thing, just a statement which happens in this example to be false.

Re:That's not how science works (0)

Anonymous Coward | about 3 months ago | (#47770981)

It's the same thing:

Theory:
Nothing can travel faster than c
Observation:
This particle traveled faster than c.

Re:That's not how science works (1)

amaurea (2900163) | about 3 months ago | (#47772411)

That would be an example of strong evidence against the hypothesis that all swans are white. But it wouldn't make us 100% sure that the hypothesis is false. After all, it is possible that the boy lied, or saw something else than a swan, or that we misunderstood him, or somebody had painted a swan black, etc. etc.. There are always unlikely alternative explanations. That's why 0% or 100% should never be used when speaking of certainty. In a sense, it is too bad that our way of representing probability makes these extremes so easy to express. In a different representation, these extremes would be "minus infinitely certain" and "infinitely certain", which makes it more obvious how ridiculous it is to claim to be that certain.

Re:That's not how science works (0)

Anonymous Coward | about 3 months ago | (#47772647)

Yes, it is because you can never disprove a theory isolated from various auxiliary assumptions. You would be a fan of Paul Meehl:
(1997) The problem is epistemology, not statistics: Replace significance tests by confidence intervals and quantify accuracy of risky numerical predictions. In L. L. Harlow, S. A. Mulaik, & J.H. Steiger (Eds.), What if there were no significance tests? (pp. 393-425). Mahwah, NJ: Erlbaum
http://www.tc.umn.edu/~pemeehl/169ProblemIsEpistemology.pdf

Re: That's not how science works (0)

Anonymous Coward | about 3 months ago | (#47770709)

"Science never disproves anything any more than it proves anything."

Except for "global warming" and evolution of course.

Re: That's not how science works (3, Interesting)

NotSanguine (1917456) | about 3 months ago | (#47770983)

"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.

Re:That's not how science works (1)

gtall (79522) | about 3 months ago | (#47772857)

"Science is the discipline of publicly testing ideas by systematic observation, controlled experiment and Bayesian inference. As such, proof is simply not relevant to what it does"

No it isn't. Physics is built using mathematics, indeed, it is the language of physics. Mathematical proof is central to much of physics otherwise there would be few predictions. Physics as we know it would be impossible without mathematics.

Science in general uses the language of and reasoning of mathematics, even biology. Even paleo-anthropology uses mathematics via dating methods, estimating volume of bone, etc.

What you think of as a neutrino is really just some mathematics that we kind of feel represents an object with neutrino's properties. We test for the properties and then proclaim one of these is one of them.

Re:That's not how science works (0)

Anonymous Coward | about 3 months ago | (#47770283)

I'd say the "other interesting result" would be better described as the "interesting result" as it is when our experiments do not produce the results we expect, that we find out new things about how the universe works.

Scientists almost always want their experiments to not go as expected. Expected is boring.

Re:That's not how science works (1)

bobbied (2522392) | about 3 months ago | (#47770681)

You got that right. That physics lab was a real snooze...

Actually, I kind of enjoyed the physics and chemistry labs, where we got to put all the fancy math they'd been teaching us to use in predicting stuff and measuring things like the speed of light. Even though the experiments had been done for centuries, the matching of the math to the physical world still seems a wonder to me and made me greatly respect the thinkers of old who figured all this stuff out, then invented the math to prove they where right..

Re:That's not how science works (5, Insightful)

khallow (566160) | about 3 months ago | (#47770357)

Or we could just realize that "proof" in empirical science means something different than it does in pure mathematics.

Re:That's not how science works (3, Insightful)

AthanasiusKircher (1333179) | about 3 months ago | (#47770507)

Or we could just realize that "proof" in empirical science means something different than it does in pure mathematics.

THIS. By GP's standard, >99% of the uses of the word "proof" in the English language are invalid. Almost all uses of the word "proof" in thousands of legal statutes around the world are bogus and meaningless.

And, empirically, from looking at actual scientific methods as practiced, it's clear that scientists clearly do NOT treat all scientific theories as equally "falsifiable." Some are treated as "proven," if not in a strict mathematical-philosophical sense. It would take a LOT more to overturn a basic established law of physics than some off-the-cuff guess ("hypothesis") in a new experiment. So what exactly is it that we are doing when we verify and reverify and reverify a basic well-established tenet of basic science over centuries if not, in essence, proving "proof" of it (in any reasonable sense of the English word outside of the strange world of pure math and logic puzzles).

Re:That's not how science works (1)

Skarjak (3492305) | about 3 months ago | (#47771703)

This comment is severely underrated. The GP is a pedantic explanation of the scientific process. The use of the word "proven" is quite adequate here considering how rock solid our evidence for the sun's fusion processes are.

Re:That's not how science works (1)

Pfhorrest (545131) | about 3 months ago | (#47772161)

Etymologically, to prove means to test. Hence phrases like "proving grounds" and, more tellingly, "the exception that proves the rule" -- an apparent exception, an anomaly, which puts the rule to the test.

So a well-tested theory is "proven" in an etymologically sound way, just a way that doesn't mean "demonstrated to be true with absolute certainty".

Re:That's not how science works (0)

Anonymous Coward | about 3 months ago | (#47772451)

Or we could just realize that "proof" in empirical science means something different than it does in pure mathematics.

It doesn't even have that meaning in mathematics. (Although a lot of mathematicians think it does.)

Re:That's not how science works (1)

dnavid (2842431) | about 3 months ago | (#47771817)

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.

Science is not about proof in the mathematical sense. Science is about amassing confirmation. To say something doesn't prove a theory in Science is like saying something doesn't prove a poem. Scientific proof is about sufficient confirmation of a theory as to make it the most useful and reasonable explanation for a set of observations.

In the case of solar fusion, the basic *idea* that the Sun is powered by fusion processes is sufficiently well demonstrated that its essentially a scientific fact: its "proven" as far as Science is concerned. But the precise mechanisms for that fusion and the precise way those processes generate energy is not yet perfectly understood. Without some means of direct observation of the core, it would be difficult to be certain that of all the possible fusion paths the current best candidate is actually happening would be difficult to determine in indirect ways. Solar neutrino observations give a way to perform direct observations of processes happening in the core, and that direct observation can significantly strengthen our confidence in the specific processes that are thought to happen in the core.

Science is always refining what we know, and not just expanding what we know. We can know, to within the limits of scientific certainty, that fusion generates the heat at the Sun's core without knowing for certain the precise particle interactions that occur as part of that process. Its also important to note that fusion is just the parent process believed to function in the core, and there are several different kinds of fusion (different interactions) that can and probably do generate heat in the core, and other processes also contribute that are secondary to fusion. Its a complex process. For example, the standard proton-proton cycle contains steps that generate gamma rays from fusing hydrogen and deuterium, gamma rays from annihilating electrons and positrons, decomposition (fission) of beryllium into lithium, fusion of beryllium into boron, and lots of other secondary reactions. So observations that can confirm both the individual reactions and their rough relative frequency can confirm the specifics of the theory while no on seriously thinks they would challenge the overall theory of nuclear fusion powering the Sun.

That almost happened a while back. (2)

Ungrounded Lightning (62228) | about 3 months ago | (#47772063)

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?

That almost happened, in the early days of neutrino dectection - before things like old mines full of purified water and 3-D arrays of photodetectors running for months at a time, and you could count the number of detected neutrinos on two hands (in bi-quinary so you could go a bit higher than ten). This was when the detectors could only detect the type of neutrino directly generated by fusion reactions, and before the discovery of neutrino oscillation, when it wasn't yet clear whether neutrinos had no, or very very little, rest mass.

Early numbers, and their error bounds, made it clear that there weren't enough neutrinos being detected. (This was known for years as the "missing neutrino problem".) But the earliest ones WERE about right for a situation where all the stars EXCEPT the sun were running by fusion and the sun was out.

That may sound odd. But there was a very cute explanation that made it plausible:

The gradual gravitatonal collapse of the sun, as heat is radiated away, could power it for millenia. It's nowhere near enough to power it long enough to explain the fossil record, but it IS enough to have kept it running for historic time. Meanwhile, if a fusion reaction were to start up near the center of such a ball of collapsing gas, it would also take many years for the heat to make it to the surface. Neutrinos (which go through the sun like marbles through a light mist) are about the only signature of what's going on in there NOW.

But suppose, instead of fusing continuously, stars were reciprocating engines. They might run without fusion for centuries, or millenia, until they were compressed enough to "light up" at the center. Then the fusion heat and reaction products might make the reaction ramp up. They'd burn for a little while (which would heat them up and expand them mabye a few inches), until the decreased density and/or reduction in fuel and/or accumulation of reaction products "put the fire out" again. Repeat for the life of the star.

In this scenario, if our sun happened to be between "putts (and the very nearest stars didn't happen to have an unusual distribution of where they were in their cycles), you'd see the same neutrio flux from the rest of the sky as if all the rest of the stars were running continuous fusion. That's because it's the average of stars that are "on" and "off", and comes out to the same amount of total fusion and neutrinos.

Of course later data, both larger samples and detectors that could "see" the other neutrino types, put the kibosh on that model. A big part of it was the discovery of neutrino oscillations, allowing a stream of neutrinos that started out as one type in the sun to arrive as a mix of the three types. (This means that neutrinos have a non-zero rest mass, fly slightly slower than light, and thus experience time and are ABLE to change from one type to another.)

A pitty, thugh. By the time this was discovered I had done an outline for a five-volume fiction cycle, working through at least four genres, based on the sun going "putt" from time to time. B-b

underground (1)

Noah Haders (3621429) | about 3 months ago | (#47769925)

at first I thought the underground experiment was conducted by anonymous on 4chan or something. but no, it's in fact an underground bunker lair for detecting invisible particles from the sun. that's astounding. now that the experiment is done can I lease the facility for my evil lair? why? no reason.

Re:underground (0)

Anonymous Coward | about 3 months ago | (#47770065)

at first I thought the underground experiment was conducted by anonymous on 4chan or something. but no, it's in fact an underground bunker lair for detecting invisible particles from the sun. that's astounding. now that the experiment is done can I lease the facility for my evil lair? why? no reason.

Yes, but you must bring your own lava and sharks.

Re:underground (0)

Anonymous Coward | about 3 months ago | (#47770783)

Welcome to my Secret, Underground Icelandic Moon Base!

Re:underground (0)

Anonymous Coward | about 3 months ago | (#47771005)

Yes, but you must bring your own lava and sharks with frickin' lasers.

There. FTFY

Somewhere, in a dusty academic office . . . (2)

StefanJ (88986) | about 3 months ago | (#47769949)

. . . the last professor in the once-prestigious Solar Combustion Sciences department clutches his chest, winces, and slumps face-down on his desk.

Re:Somewhere, in a dusty academic office . . . (0)

Anonymous Coward | about 3 months ago | (#47770189)

So does the last internet conspiracy enthusiast believing that the Sun is powered by electrical flames, a celestial dynamo of sorts. Then he raises his head and continues trolling message boards.

Re:Somewhere, in a dusty academic office . . . (1)

confused one (671304) | about 3 months ago | (#47770901)

The sun is made of burning coal.

Re:Somewhere, in a dusty academic office . . . (1)

BarefootClown (267581) | about 3 months ago | (#47771707)

The sun is made of burning coal.

No, it won't start burning carbon until after it's done burning helium...by which time the globe will have "warmed" into a cinder as the sun enveloped it.

Re:Somewhere, in a dusty academic office . . . (0)

Anonymous Coward | about 3 months ago | (#47771741)

The sun is like all stars in the sky just a hole in the earth-orbiting sky panel, making the holy light of the one true god shine through.

Linked article is in Italiano... (1)

Type44Q (1233630) | about 3 months ago | (#47770039)

using a detector buried deep below the mountains of central Italy

The linked article is in Italiano; unfortunately, my grasp of the language is limited to "ciao" and "vaffanculo."

It's all a matter of energy (5, Informative)

mbone (558574) | about 3 months ago | (#47770059)

It has been known since the 1960's that the Sun produces energy from fusion, but the actual neutrino's observed then (and until now) were high energy electron neutrinos that actually came from relatively unimportant fusion chains (from the standpoint of energy production), not the proton-proton chain though to produce most of the Sun's energy. Since there was a "neutrino problem" (the Sun appeared to produce only 1/3 of the neutrinos predicted by theory), some people did think that for whatever reason the main energy source - the proton–proton chain reaction - was for some reason mostly shut down, presumably as part of some long period oscillation in the Sun's deep interior (although Arthur C Clarke wrote a novel, "The Songs of Distant Earth," in which it was a permanent shutdown of the Sun's fusion, and a prelude to our Sun going supernova). At that time, the inability to directly see the pp chain seemed like a big deal, but since the discovery of neutrino oscillations (which nicely explain the factor of 1/3), and also with solar interior modeling from helioseismology, there has been a pretty solid consensus that the pp chain was running the Sun, even if there was no direct observation of it.

Now it has been proved. In 1990 that would have been a big deal, but now it is more a matter of just being satisfyingly complete in our observations of the Sun.

Re:It's all a matter of energy (0)

ScentCone (795499) | about 3 months ago | (#47770159)

but the actual neutrino's observed then (and until now) were high energy electron neutrinos

I don't know why these observations are being thought of as a big deal. Why go to all the trouble of building some big underground Italian detector when we can see, right here, that passing neutrinos hit the /. servers and cause apostrophes to appear randomly (but due to a quirk of quantum behavior, almost always right in front of the letter 's').

Re:It's all a matter of energy (1)

slew (2918) | about 3 months ago | (#47770475)

Buuuttttt think about the Electric Universe Theorists? ;^)

It's all a matter of energy (1)

Anonymous Coward | about 3 months ago | (#47770505)

the pp chain was running the Sun, even if there was no direct observation of it.

*gigglesnort*

1960s??!! You are so funny (1)

rubycodez (864176) | about 3 months ago | (#47771309)

Good god man, Hans Bethe worked out the fusion processes in the Sun in the late 1930s.

http://en.wikipedia.org/wiki/B... [wikipedia.org]

The other 1% (1)

approachingZero (1365381) | about 3 months ago | (#47770063)

'chain of reactions that provides 99% of the sun's power'

What is the other 1% that powers the sun?

Re:The other 1% (3, Informative)

clonan (64380) | about 3 months ago | (#47770145)

secondary reactions based around contaminants (as in non-H or He atoms).

One is the CNO cycle which is about 0.4% of the total solar energy.

Re:The other 1% (1)

approachingZero (1365381) | about 3 months ago | (#47772523)

Okay, thanks for responding.

Re:The other 1% (1)

ScentCone (795499) | about 3 months ago | (#47770167)

What is the other 1% that powers the sun?

Rich people.

Damn (0)

Anonymous Coward | about 3 months ago | (#47770147)

Looks like I'm going to have to pay off a bet. I bet on hordes of gnomes on treadmills.

Re:Damn (1)

clonan (64380) | about 3 months ago | (#47770165)

Maybe the gnomes also release low energy neutrinos...

Underground? (4, Funny)

Anonymous Coward | about 3 months ago | (#47770181)

But how the hell did they manage to coax the Sun underground, in order to conduct this experiment?

One of these days, I'm going to RTFA.

Re:Underground? (1)

rubycodez (864176) | about 3 months ago | (#47771325)

It's easy to do, at night when the Sun is dark

Re:Underground? (1)

Convector (897502) | about 3 months ago | (#47771517)

It goes down every day on its own. They just went way out west and built the lab in the spot where the Sun sets.

Underground Eureeka! (4, Funny)

Tablizer (95088) | about 3 months ago | (#47770333)

Making huge discoveries about the universe without leaving mom's basement? Nerdgasm!

Re:Underground Eureeka! (0)

Anonymous Coward | about 3 months ago | (#47771215)

Oh they left the basement alright.
Then they turned and made themselves a new basement to rule all basements.

Argument by Assertion (-1)

Anonymous Coward | about 3 months ago | (#47770463)

If our Sun produces energy through the process of thermonuclear fusion, it does so in direct violation of the Second Law of Thermodynamics. Various ad hoc hypotheses, such as the nonsensical idea of "magnetic reconnection" have failed to reconcile the theory with physical law.

Re:Argument by Assertion (0)

Anonymous Coward | about 3 months ago | (#47770717)

If you are serious, you are a nut.

If you are trying to be funny, it didn't work

Re:Argument by Assertion (0)

Anonymous Coward | about 3 months ago | (#47770869)

You appear to be unaware that magnetic reconnection was proposed specifically to address the 2nd Law problem. Name calling serves no purpose.

Re:Argument by Assertion (0)

Anonymous Coward | about 3 months ago | (#47772145)

If you think the idea of heating via induced currents from changing magnetic fields violates the second law of thermodynamics, then maybe you should take issue with more terrestrial examples, like electric motors and eddy currents creating heat far from power plants without hot temperatures in between the plant and motor.

Re:Argument by Assertion (2)

Pfhorrest (545131) | about 3 months ago | (#47770885)

To be completely accurate, the sun doesn't produce any energy, it converts energy from one form (rest mass) to another form (electromagnetic radiation), increasing entropy in the process in keeping with the second law. That conversion process itself requires an input of energy (though one less than the energy output by said process) to initialize and sustain, and that energy is in turn supplied, in the form of kinetic energy, by conversion from yet another form (gravitational potential energy) spontaneously, precisely because of the second law of thermodynamics.

At one time in the history of science, it was thought that all of the energy of the sun was converted more or less directly from gravitational potential energy: a cloud of hydrogen collapses under gravity, converting its potential energy into kinetic energy, rendered macroscopically as temperature, causing the ball of collapsing gas to glow incandescently. The problem was that that process can't last for very long, so the sun (and consequently the whole solar system) would have to be pretty young, relatively (still massively old on a human scale) if that's what's making the sun glow. When we discovered that the Earth itself, and space rocks, are much older than the sun would have to be according to that theory, it required that something else be powering the sun on a longer scale. The introduction of nuclear fusion to the model solved that problem, and nowadays almost nobody even remembers that we once thought the sun was just, in effect, gravity-powered.

electric universe put to rest? (0)

Anonymous Coward | about 3 months ago | (#47770897)

Wheres the electric universe guys when you need them?

Re:electric universe put to rest? (1)

Robear (68955) | about 3 months ago | (#47771085)

I imagine they are still shocked, electrified even, by this result.

Re:electric universe put to rest? (0)

Anonymous Coward | about 3 months ago | (#47772109)

Wheres the electric universe guys when you need them?

Patting the nuclear sun theorists patiently on their little heads while politely refraining from rolling their eyes and/or sighing heavily.

https://www.youtube.com/watch?... [youtube.com]

99% (1)

luckymutt (996573) | about 3 months ago | (#47771501)

This may be a daft question, but if "the key proton-proton fusion reaction that is the first part of a chain of reactions that provides 99% of the sun's power." then what is the other 1% of the sun's power if not the chain of reactions?

Re:99% (1)

BarefootClown (267581) | about 3 months ago | (#47771735)

The C-N-O fusion reaction, for some of it.

99% (0)

Anonymous Coward | about 3 months ago | (#47772455)

Fusion of all atoms lighter than iron will produce energy.

"Proof" and "to prove" (0)

Anonymous Coward | about 3 months ago | (#47772423)

A lot of the people who are very pedantic on what "science" is and isn't, will always use the mathematical definition of proof. When in fact the vast majority of the world's population do not use the word in that way. In normal usage one might say "Tom stole my phone and I can prove it!", in the samme manner you could say "the sun is mostly powered by proton-proton fusion and I can prove it!"

How can such a statement possibly be wrong?

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