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Physicists Produce Antineutrino Map of the World
KentuckyFC (1144503) writes "The origin of the heat generated inside the Earth is one of the great mysteries of geophysics. Researchers know that almost all this heat is generated by the decay of radioactive elements such as potassium-40, thorium-232 and uranium-238. But what they don't know is how these elements are distributed inside the planet and how much heat each contributes. In the next few years, they hope to get some answers thanks to the emerging science of antineutrino geophysics. Since radioactive decay produces antineutrinos, an experiment that measures these particles coming out of the Earth should provide a detailed picture of the distribution of the elements within it.
But there's a problem. Nuclear reactors also produce copious numbers of antineutrinos and these can swamp the signal from inside the Earth. What's needed is a map showing the distribution of reactor antineutrinos so that geophysicists can choose the best places to put their experiments. Just such a map is exactly what a team of nuclear physicists has now produced. The map shows that planned experiments in Hawaii and Curacao, off the coast of Venezuela, are in excellent locations and that Japan has recently become a much better site thanks to the shut down of the country's nuclear industry following the 2011 Tohoku earthquake. But a European experiment currently being planned in south-east France doesn't come off so well."
But there's a problem. Nuclear reactors also produce copious numbers of antineutrinos and these can swamp the signal from inside the Earth. What's needed is a map showing the distribution of reactor antineutrinos so that geophysicists can choose the best places to put their experiments. Just such a map is exactly what a team of nuclear physicists has now produced. The map shows that planned experiments in Hawaii and Curacao, off the coast of Venezuela, are in excellent locations and that Japan has recently become a much better site thanks to the shut down of the country's nuclear industry following the 2011 Tohoku earthquake. But a European experiment currently being planned in south-east France doesn't come off so well."
So, would this map let them locate any 'sneaky'/unreported reactors?
I should think that some people would like to be able to say "gee, I see something in country x which shouldn't be there, we should have a closer look."
Lost at C:>. Found at C.
Shouldn't we send a manned exploration team to the center of the Earth? After all, if sending people into a deadly vacuum is important, it must also be important to visit the center of the Earth. You know, to inspire new generations and the spinoffs? Stuff like that?
Researchers know that almost all this heat is generated by the decay of radioactive elements such as potassium-40, thorium-232 and uranium-238
Half-life of (K40, U238, Th232) is (1.2, 4.5, 14.0) x 10^9 years. Age of Earth is 4.5 x 10^9 years. That explains why we still have such elements...
Slashdot, fix the reply notifications... You won't get away with it...
I just watched the movie "The Core", and if it reflects the current state of science, it seems our understanding of what is inside the Earth is flawed on a more basic level...
If Pandora's box is destined to be opened, *I* want to be the one to open it.
Faced with a choice between clean, safe power for people (France's nuclear power plants) and physicists having it a bit easier to discover the answer to a question that 99.9999999999999% of the world's population could care less about, I'd opt for the former. I'm pro-science, but I'm for a science that respects people first and foremost. Not one with an exaggerated sense of its own importance (i.e. Carl Sagan) or one that's in league with those intent in carrying out H. G. Wells' nasty agenda of having a select few run the lives of the rest of humanity. And I'm for a science with enough backbone to take up moral causes, such as opposition to legalized abortion.
I don't think anyone is saying, in this case, that it's an either/or situation. They are just looking to make sure that their experiments are not affected by man-made nuclear reactors. So they made a map to show the likely spots that would and would not be problematic for them.
I browse on +1 so AC's need not respond, I won't see it.
Saying that, I imagine various navies and intelligence agencies will be paying a great deal of attention to this research, if they're not already doing so.
that looks like a map of Civilization!
yeah, you can take that as a slam against Alaska, Arizona, see if I care.
the preceding comment is my own and in no way reflects the opinion of the Joint Chiefs of Staff
We don't have any direct evidence of nuclear fusion in the sun's core either (maybe the neutrino detectors count for that lately), but we pretty much 'know' it is happening. Lack of 'direct evidence' != 'lack of evidence good enough to say with almost certainty'. 'Scientists know' can be shorthand for 'the established scientific consensus allows us have a very high degree of confidence'.
Sure we do. We haven't yet seen neutrinos from each step of the process (still need to confirm the small fraction of CNO process), but all the other ones have been found. The sun works as advertised (to something a bit less than the 10% error level).
Researchers don't "know" squat. They have lots of theories, none of which have supporting data. That's what makes the heat of the Earth's core a mystery. By all rights it should not be this hot. It should be dead cold like the moon.
How about "scientists have a pretty good idea". Here's a recent review article on geoneutrinos, which does compare direct neutrino observations and the overall heat budget.
Don't know everything, but the more tools you can turn on the problem, the more clear things become. Adds up to something a bit more than "squat".
You are right and I mentioned the neutrinos, but up until a few years ago when the neutrino physicists accepted neutrino oscillations, the neutrinos detected from the sun did not at all agree with theory, that situation lasted for at least a couple of decades. And nuclear fusion in the sun was well accepted before any of the neutrino results came in. Maybe not the greatest example on my part.
They keep erupting. They won't do this forever, eventually the core will cool down enough that it will stop.
But not soon enough.
Yellowstone is overdue. Soon, it will blow, and when it does, we will all die. All. Your underground bunker will keep you alive for what...a year? Then you will emerge into the global winter and freeze to death, assuming the air is not still so saturated with ash that you can even breathe.
All human ambition will be covered in ash.
wtf slashdot, you have an agenda?
But you can't say "scientists have a pretty good idea" about planetary formation.
I wasn't saying that: just that we've got a reasonable window into the thermal budget of the Earth at the present time. Looking back in the thread, that's what you opened up being worried about.
Why wouldn't friction be the source of heat? The very center of the earth has a balanced gravity pull outwards in every direction, creating a gradient that should condense the heavier atoms around the mantle. The internal core is spinning at a different rate that the crust creating a velocity gradient between the core, crust, and mantle. Regardless if there was no nuclear energy in the core, the friction alone should be substantial. And we know solid particles make up the core. Ancient Earth had some rather nasty experiences with meteors. That solid core settles to the center, but basic common sense would suggest massive meteor strikes would bounce that baby around like a rattle, fracturing the crust and mantle from the inside out not much different than how a baseball to the head can cause the brain to strike the opposite side of the head and create a skull fracture. The core being off center for any length of time has to ratchet up the internal friction.
It's "couldn't" care less about, numbnuts.
Pearl Harbor is a base for a classified number of nuclear submarines. I don't think this map reflects that.
No. The map was made using existing data on known nuclear reactors and their power output and extrapolating what their antineutrino signature should look like. However, if geophysicists install detectors that show strong signatures that do not match up with the map given here, then that might be evidence for clandestine nuclear activity.
Yes. I see from the map that it's missing a number of known nuclear stations, for which the IAEA is unable to obtain data, and it's missing a number of "natural reactors" such as Oklu in Gabon, as well as a significant number of former Soviet reactors that are known to still be in use. It's also missing data for several Middle East reactors, known sites in South America, and a number of U.S. Military sites.
Assuming they get their experiment detectors running at all, they should be able to detect unreported nuclear reactor activity, but they'll have a hard time distinguishing it from the non-reactor related events they are seeking with the detectors.
no, very well known it should NOT be "dead cold like the moon", the latent heat of formation is expected to be roughly half the heat. But the surprising thing is how hot the core is, much more than expected, so we'll give you partial credit.
What tripe. "We don't know" is what drives science.
You're spouting the same shit over semantics that creationists do over the "theory" of evolution. The only things we can know for certain are mathematical proofs.
Outside pure mathematics, all we can do is form models that make predictions which most accurately match our observations.
There are holes in most of our scientifically accepted theories. That doesn't mean you need to throw the baby out with the bathwater, just that modifications need to be made to the models (exactly as was done with Einstein's Relativity).
We don't "know" with a 100% certainty that gravity exists, but our models match our observations well enough that we can say it's "pretty fucking likely".
AGW most definitely is falsifiable, however neither camp currently has enough data to prove either way.
Before the neutrino results came in, the correct phrase would be "scientists believe...".
Now, it's "scientists know..."
"I do not agree with what you say, but I will defend to the death your right to say it"
...they always say AGW can result in any conceivable data, including an ice age.
Citation:
http://curiosity.discovery.com...
... retards claim these "geophysics" are uneducated sheepeople and all savvy intelligent people obviously support a nuclear reactor on every street corner because it's science-y.
Why is the earth so much hotter internally than the moon? It's a fair question that has no obvious answer.
Stratification of the Earth before such a collision causes a difference in composition between the two bodies. In some sense this is directly observable in the difference in their densities. Geologists have studied isotopic ratios in great detail though to work out a timeline of the stratification and when stuff could have been knocked off in a collision to produce the difference in density, and it does result in a rather big lack of radioactive material, heavier elements, and iron-bonding material associated with the Earth's core more so than its surface.
Simple calculations demonstrate that radioactive decay is not adequate for the current age of the earth.
If the calculations are so simple, why not show them then? An estimate of the amount of decay needed can be done with high school math and shows up an intro geology course at university, but it comes up quite adequate.
... In the 1800s, famed physicist Lord Kelvin (for whom the absolute Kelvin temperature scale is named) was the first to calculate that even if the earth was born in an incandescent molten state (and there is no evidence for this), it would have cooled to its current temperature billions of years sooner than the 4.6 billion years accepted today. Even using generous assumptions about the thermal energy produced by radioactive decay (which also have no direct evidence), the earth would still cool to its current temperature much sooner than 4.6 billion years...
No, this is not what Lord Kelvin calculated. What he calculated was that if the Earth cooled by conduction alone it would only take 20 to 400 million years (he later settled on 20 to 40 million) for the surface to cool to the present temperature, but that the core would still be quite molten. In other words he calculated how long it would take an (effectively solid) body to achieve a surface temperature profile (how quickly it gets hot as you descend into the Earth) such that the surface temperature profile matches what we see today. The core would still be extremely hot.
His chief error had nothing to do with not knowing about radioactive decay (not discovered until his last years). It was that he did not take account of the possibility of convection within the Earth that keeps bringing hot material up close to the surface, permanently maintaining a steep temperature profile in the crust. This is something he could and should have taken into account. Primordial heat (left over from Earth's formation) - the heat Kelvin was arguing about - is still roughly half of the heat coming from the interior of the Earth -- enough that it alone could still power the temperature profile even after 4. 6 billion years.
Starships were meant to fly, Hands up and touch the sky - Nicky Minaj
To falsify it? How about thirty years of falling temperatures while CO2 levels stay the same or rise?
"When you have eliminated the unacceptable, whatever is left, however improbable, must be the truthiness" - Holmes
mainstream science:
http://en.wikipedia.org/wiki/E...
and even moon had recent cooling:
http://www.nasa.gov/mission_pa...
its smaller diameter means it loses heat faster anyway, even if it were stone cold in interior would not be valid point to make
The conclusion that primordial heat is half the heat coming from the interior is pure speculation, since we don't have any workable models of planetary genesis. And no planetary scientist I talk to believes there is any way to account for the current heat of the core -- it's widely accepted that the current status contradicts the age of the earth. Hence the mystery.
Amazingly, no AGW proponent considers that a falsifying data set!
I'm not sure what planetary scientists you've been talking to, as none I've talked to or seen talks from had any issue with that, and have shown pretty good agreement between estimates of heating come from radioactive decay. Part of the problem is not it being difficult to account for the heating, but the exact opposite, that it is too easy and figuring out what portion comes from which isotope is difficult because a wide range of combinations fit current data. Stuff like this isn't bleeding edge, but has been covered in magazines like Physics Today a couple years ago.
Ummm... hasn't anyone told these scientists that Hawaii is the Pacific headquarters of the US Navy, including such things as nuclear powered aircraft carriers and nuclear powered submarines? I would think this is a horrible place to run an experiment given the fact that you would never know if the results were due to a submarine entering, leaving, or patrolling....
We were all warned a long time ago that MS products sucked, remember the Magic 8 Ball said, "Outlook not so good"
...And no planetary scientist I talk to believes there is any way to account for the current heat of the core
The only way I can credit this assertion is in the sense of it being vacuously true, that you have never spoken to a planetary scientist.
To the extent that a problem ever existed, it was the reverse of what you say - finding ways to cool the Earth down to the level that we see today. Kelvin's model predicted an extremely hot Earth's core. Look at "A Decade of Progress in Earth's Internal Properties and Processes", Science, Vol. 213, 3 July 1981, pp. 76-77. The problem they were grappling with then was getting heat transport efficient enough in their models to get rid of just the primordial heat even without radiogenic heating (improved convection models solved this problem).
The fact that you have something so basic as Lord Kelvin's analysis completely backwards demolishes any credibility you might want to claim, coupled with your failure to back up any of your assertions with a link, citation, or one of the "simple calculations" you allude to.
Perusing recent actual scientific articles about studies of the Earth's thermal structure (see for example "A Thermal Balancing Act", Science, Vol. 283, 12 March 1999, pp. 1652-1653 and "Mantle Flow Drives the Subsidence of Plates", Science, Vol. 328, 2 April 2010, pp. 83-85) I see that the gross anomaly you assert does not exist, and that current models are dealing with the fine structure of heat flow inside the Earth.
it's widely accepted that the current status contradicts the age of the earth. Hence the mystery.
Widely accepted? Then post a credible link.
Starships were meant to fly, Hands up and touch the sky - Nicky Minaj
Faced with a choice between clean, safe power for people (France's nuclear power plants)
That is true, but there is one problem: France has no Uranium Uranium supply in its own territory. What I do not know is how much reserve is available, in case of a supply problem (because of a war in supplier country, for instance)
That's not AGW, that's just "GW".
Anthropomorphic Global Warming suggests *we* are a major cause of rapid global warming. With enough data, that can be disproved - you can compare current records with past & future records to see if man made CO2 (& other gases) has made any difference to global trends.
I personally prefer the term "Climate Change", as "Global Warming" only describes one part of the trend. That the global climate goes through cycles & changes is not under debate in the scientific community, we have overwhelming evidence that the world goes through glacial & interglacial periods. What's under debate is whether human activity is the cause behind the most recent changes.
For what it's worth, current models do predict brief periods of cooling between increasing warmer periods.
Regardless, anyone who claims to "know" the exact whats & whys of our climate is a numpty & clearly taking liberties.
For what it's worth, current models do predict brief periods of cooling between increasing warmer periods.
My biochemist son has a phrase that I think fits here: "The absence of data is not data." Models are not data, and none of the models have done an even remotely viable job of predicting climate. But even if they had, simulation is not empirical science. Just because a model occasionally agrees with experiment in no way means the model is correct. There is plenty of mathematical research indicating that climate simulation is an intractable problem, due primarily to chaos.
You might want to shift gears and change the name of the game to "climate change", but the public policy debate is specifically over global warming caused my humans, hence AGW. And when you say "With enough data, that can be disproved", you beg the question. Neither the IPCC nor any scientist proponents of AGW will admit to any data that would falsify their theory. They won't even entertain the possibility. That's not science. That's religion, fanatical.
here is plenty of mathematical research indicating that climate simulation is an intractable problem, due primarily to chaos.
You seem to be conflating things. localized weather was a famous example because of how Lorenz stumbled into chaos from working on weather. While weather prediction is near impossible to get much beyond two weeks in advance, regardless of practical accuracy of measurements, that is distinct from climate. You can't argue because of that prediction we can't say if winter will be colder than the summer in the north. Much like how you can take a chaotic system and derive things like thermodynamics that look at longer trends, or things like the virial theorem even if the underlying components are individually intractable to predict.
Keep out of Venezuela if you want to keep your precious neutrino sensors. They basically confiscated the brazilian gas plant there and the government is turning into a de-facto dictatorship much like the Cuba of old or worse
sign(c14n(envelop(this)), x509)