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Physicists Produce Antineutrino Map of the World

Unknown Lamer posted about 7 months ago | from the neon-green-antineutrinos dept.

Science 75

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."

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Hmmmm ... (5, Insightful)

gstoddart (321705) | about 7 months ago | (#46584033)

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."

Re:Hmmmm ... (0)

Anonymous Coward | about 7 months ago | (#46584081)

Yes, I had a flashback to the Skyrim quest with the Synod guy and his map.

"It would take to long to explain, but every deposit of radiothermal energy keeping the core warm should show up on this map. However, all we're seeing is the expected glow from the Fukashima residue and a brilliant light in North Korea."
(paraphrased and mangled from the NPC's ranting)

Re:Hmmmm ... (1)

JoshuaZ (1134087) | about 7 months ago | (#46588057)

Fukushima won't show up more than any other nuclear reactor, if anything since there's no longer an active reactor, it will produce fewer neutrinos. A nuclear meltdown does not in general involve the production of more radiation than a running reactor, the primary problem is that all the radioactive waste can get exposed.

Re:Hmmmm ... (1)

bberens (965711) | about 7 months ago | (#46584099)

Is it safe to assume that even nuclear weapons will emit a considerable amount of anti-neutrinos? Because that'd be.. Oh wait, there's a knock at the door.

Re:Hmmmm ... (4, Interesting)

Anonymous Coward | about 7 months ago | (#46584263)

What about nuclear submarines ? Will navy provide their locations at any given time? Can a foreign military pinpoint submarines location by their anti-neutrino emissions ?

Submarines Move (2)

Catmeat (20653) | about 7 months ago | (#46584803)

Nuclear submarines move. So if the experiment is run for long enough, then the skew caused by having one pass by in the nearest stretch of ocean won't be a worry.

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.

Re:Submarines Move (4, Interesting)

habig (12787) | about 7 months ago | (#46585137)

When the Borexino experiment was being built (under the Appenines in Italy), they calculated that if a nuclear sub parked for more than a couple weeks in the same spot in the Adriatic, they'd be able to see it using neutrinos.

Not sure if anyone's redone that calculation now that the experiment works, but the preliminary one attracted some interest from the defense side of things.

There is a reasonably well thought out set of specs for "if DoD wants to use neutrino detectors to monitor nuke activity in, say North Korea, what would they have to build". Done from the perspective of the particle physics guys saying "if we can get DoD to spend some of its semi-infinite pile of cash on some neutrino detectors we're interested in, how would we do it?". The answer turns out to be almost feasible, actually. Here's only the most recent paper [arxiv.org] I bumped across, there are many others.

Re:Submarines Move (1)

DarkOx (621550) | about 7 months ago | (#46585311)

Another question can you use this technology to effectively defeat the stealth of the nuclear subs?

Re:Submarines Move (1)

chihowa (366380) | about 7 months ago | (#46587005)

If they move, but travel along consistent paths, those will become apparent after enough data is collected. Similarly, given enough time you could tell where the never travel or where they tend to dwell longer.

Re:Hmmmm ... (3, Informative)

Eunuchswear (210685) | about 7 months ago | (#46584285)

Is it safe to assume that even nuclear weapons will emit a considerable amount of anti-neutrinos?

Doubt it.

Nukes are not doing very much when they're not going bang.

See, for example, Japan going dark as the reactors are taken off line.

Re:Hmmmm ... (1)

r1348 (2567295) | about 7 months ago | (#46588289)

I think he meant the antineutrino signatures of the nuclear reactors that power nuclear submarines.

Re:Hmmmm ... (4, Insightful)

quenda (644621) | about 7 months ago | (#46584469)

Is it safe to assume that even nuclear weapons will emit a considerable amount of anti-neutrinos?

Yes, but only very briefly, and only once.

Re:Hmmmm ... (1)

Eunuchswear (210685) | about 7 months ago | (#46584787)

Heh, same as I said, but in a snappier and funnier way.

+1

Unlike Supervolcanoes (0)

Anonymous Coward | about 7 months ago | (#46585401)

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.

Re:Hmmmm ... (2)

Rising Ape (1620461) | about 7 months ago | (#46586535)

Probably not, actually. Neutrinos come from beta decay, which isn't what produces the energy in a fission chain reaction. Even the fusion reaction in a hydrogen bomb isn't itself neutrino producing. The fission products left over would produce neutrinos as they decay, but that would occur steadily over time and over a wide area, as they'd have been dispersed by the explosion.

Re:Hmmmm ... (5, Informative)

SeeSchloss (886510) | about 7 months ago | (#46584113)

The map is actually produced from IAEA data, not from measurements, so no it won't help. On the contrary, the idea is that these measurements are so difficult/expensive to make that it's better to choose a place far from nuclear plants which would skew them. We can't just measure antineutrinos worldwide (at least for now).

the secret is to bang the rocks together (1)

Thud457 (234763) | about 7 months ago | (#46584807)

that looks like a map of Civilization [medium.com] !

yeah, you can take that as a slam against Alaska, Arizona, see if I care.

Re:Hmmmm ... (5, Informative)

Anonymous Coward | about 7 months ago | (#46584129)

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. It should be possible to determine the origin of the antineutrinos from their energy signature--i.e., whether they come from natural or artificial sources. Which actually sounds like a pretty straightforward way to get a project like this funded.

Re:Hmmmm ... (2)

delt0r (999393) | about 7 months ago | (#46584587)

The current nuclear detection network is struggling to keep its funding. So no this angle will probably not help with funding.

Correct. (3, Interesting)

tlambert (566799) | about 7 months ago | (#46586231)

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.

Re:Hmmmm ... (1)

Anonymous Coward | about 7 months ago | (#46584183)

unfortunately this map is calculated and not measured. You can see that even with the assumptions of 100% efficiency you still get very few counts. Since the scale on the map is linear it is hard to tell what background count rates are, but even near reactors it is only in the lower hundred TNUs (1 TNU= 1 event/yr/10^32 detectors) which means you would have to count for a long time or have massive amounts of detectors.

Re:Hmmmm ... (0)

Anonymous Coward | about 7 months ago | (#46584243)

Is it possible to view Submarine and Nuclear Wessles... I mean Vessels with this satellite imagery?

Re:Hmmmm ... (0)

Anonymous Coward | about 7 months ago | (#46584497)

Possibly -- it looks like there is a tiny yellow splotch in the region where Iran would be... and then we look at Korea and... holy crap

Re:Hmmmm ... (0)

Anonymous Coward | about 7 months ago | (#46584513)

Well, if this were real-time views from satellite, yeah, I suppose it would. It would also allow us to pinpoint nuclear powered battleships and submarines. I suspect it's not real-time though.

Re:Hmmmm ... (1)

Charliemopps (1157495) | about 7 months ago | (#46586693)

I'd kind of like to have them point this "UP"

Just how many reactors do you think we have in orbit now? I bet you it's more than a few.

Here's your HOPE and CHAINS you dorks (-1)

Anonymous Coward | about 7 months ago | (#46584077)

Hey super dorks, what has your socialist betters done for you lately? Is this another media cover up or not? Sons of Obama doing the jobs Americans won't do, is that about it?

Does anyone think that the rule of law, equally applied is what makes for a civilization? If we do not maintain our civilization then in the end things are going to be very nasty indeed. Wouldn't it be nice for laws to be adhered to by all our neighbors, and those in charge also?

Oh well...

http://therightscoop.com/200-teens-riot-in-louisville-sat-night-robbing-assaulting-people-man-claims-victim-of-attack-the-night-before/

"Riots broke out in Louisville, Kentucky on Saturday night, according to WDRB News, when 200 teens began robbing and assaulting people, including a 13-year-old girl and a man trying to help her. A woman who was parked in her car with two children in the back seat said she was also assaulted by a group of teens. She told police they repeatedly punched her and threw trash cans at her car.

WDRB News also reports that a large group of teens robbed a convenience store, assaulting the clerk as he tried to shut the doors on them. They actually have surveillance video of this attack and all the teens shown appeared to be black.

Police say there were another three victims of assaults in three separate attacks that night and they all had to be taken to the hospital. The mayor is now calling for calm in the city."

Ummm (0)

Anonymous Coward | about 7 months ago | (#46584267)

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?

Re:Ummm (0)

Anonymous Coward | about 7 months ago | (#46584443)

space is easy. We can generate enough heat to counteract the lack heat in space almost without trying. Similarly its not hard to engineer a craft that is "holds in" 1 atmosphere worth of pressure. Compare that to going into the earth and you have to safeguard against insane amount of pressure and heat.

Re:Ummm (-1)

Anonymous Coward | about 7 months ago | (#46584567)

Low Earth Orbit is easy. Space is infinitely huge, barren, hostile, inimical, deadly and empty. Yet we worship every test pilot that went up in rubber underwear. Yet only three people ever went to the bottom of the Mariana Trench and no one ever talks about them? Why? Is it because you geeks worship the "easy", even though Kennedy's speech was about how "hard" it was?

Weird. So going to the center of the Earth is hard? Boo hoo. I thought with 3D printers and better computers we'd be colonizing the mantle by now?

Half-life (4, Insightful)

hcs_$reboot (1536101) | about 7 months ago | (#46584363)

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...

Re:Half-life (1)

Gothmolly (148874) | about 7 months ago | (#46584399)

In other news, water is wet. If their half-lives didn't exceed the age of the planet, we wouldn't be having the discussion.

How did that post get marked up?

Re:Half-life (0)

Anonymous Coward | about 7 months ago | (#46584543)

Besides any other reasons informative posts could get marked up, decaying nuclei don't just blink out of existence, they turn into another nuclei. This is how we get radon after all, for example, so what you say is patently incorrect.

Re:Half-life (3, Funny)

Smiffa2001 (823436) | about 7 months ago | (#46584697)

Half-life (Score:3)

Half-Life 3, Confirmed.
[Of course this only works if folks mod so that score remains at three...]

Science v. People (-1)

Anonymous Coward | about 7 months ago | (#46584459)

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.

Re:Science v. People (1)

EvilSS (557649) | about 7 months ago | (#46584585)

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.

Re:Science v. People (0)

Anonymous Coward | about 7 months ago | (#46586011)

It's "couldn't" care less about, numbnuts.

Re:Science v. People (1)

manu0601 (2221348) | about 7 months ago | (#46589885)

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)

The Core (1)

StripedCow (776465) | about 7 months ago | (#46584545)

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...

Re:The Core (1)

Immerman (2627577) | about 7 months ago | (#46584763)

Well, it came out of Hollywood, so it's probably safe to assume that its relationship to actual scientific understanding is somewhere between "slim" and "none"

Re:The Core (1)

daem0n1x (748565) | about 7 months ago | (#46585223)

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...

No, it reflects the current state of movie making, which is pretty dire.

Scientists "know"? (-1)

mbeckman (645148) | about 7 months ago | (#46584619)

"The origin of the heat generated inside the Earth is one of the great mysteries of geophysics. Researchers know..."

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.

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.

A related mystery is how planets form at all. The conventional theory [hubblesite.org] is that they "clump up" from smaller particles, eventually achieving enough critical mass form an accretion disk that gains heat from compression, gradually acquiring a gravitationally-optimal spheroid shape. But that model has been shown to be inadequate: [ciw.edu] "Growth beyond meter size via pairwise sticking is problematic, especially in a turbulent disk. Turbulence also prevents the direct formation of planetesimals in a gravitationally unstable dust layer."

So when someone says "scientists know", they are often flat out wrong, as is this story's author.

The three little words so many scientists are deathly afraid to say: "We don't know."

Re:Scientists "know"? (2)

thrich81 (1357561) | about 7 months ago | (#46584835)

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'.

Re:Scientists "know"? (2)

habig (12787) | about 7 months ago | (#46584935)

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).

Re:Scientists "know"? (1)

thrich81 (1357561) | about 7 months ago | (#46585061)

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.

Re:Scientists "know"? (2)

CrimsonAvenger (580665) | about 7 months ago | (#46586491)

And nuclear fusion in the sun was well accepted before any of the neutrino results came in.

Before the neutrino results came in, the correct phrase would be "scientists believe...".

Now, it's "scientists know..."

Re:Scientists "know"? (-1, Troll)

mbeckman (645148) | about 7 months ago | (#46585157)

Bad example on your part. We can directly observe the Sun, and as you note, directly measure neutrinos. Still, solar fusion is just a theory, just one with no controverting data.

However, the planetary accretion processes cannot be directly observed. Yet the models do have controverting data, which I cited, in the form of reproducible calculations.

It's simply unreasonable to ever say we "know" a theory to be true when someone can demonstrate the impossibility or improbability of the theory, as has been done with all planetary evolution models to date.

"Scientists know' can be shorthand for 'the established scientific consensus allows us have a very high degree of confidence."
See, you're doing it right now! You don't want to say "We don't know." It sticks in your craw. Are you a scientist? ;)

Other euphemisms scientists often use for "We don't know":

"It isn't clear..."
"The best evidence indicates..."
"The consensus is..."

One thing no true scientist can forget: science is not a consensus enterprise. If one million scientists hold to a theory, and one scientists -- or even a non-scientist -- can provide reproducible calculations or experiment contradicting the theory, then the theory as posited must be discarded.

Moreover, to even qualify as a scientific theory, the theory must be falsifiable. Planetary accretion theories are falsifiable, as I've cited, but many other so-called scientific theories are not. Such as anthropogenic global warming (AGW) .

Re:Scientists "know"? (1)

Anonymice (1400397) | about 7 months ago | (#46586365)

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.

Re:Scientists "know"? (-1, Flamebait)

mbeckman (645148) | about 7 months ago | (#46586795)

Anon,
If AGW is falsifiable, please provide an example of data that you would consider falsifies it. I've discussed AGW with many of it's scientist proponents, and they always say AGW can result in any conceivable data, including an ice age.

Re:Scientists "know"? (0)

mbeckman (645148) | about 7 months ago | (#46586833)

...they always say AGW can result in any conceivable data, including an ice age.

Citation:
http://curiosity.discovery.com... [discovery.com]

Re:Scientists "know"? (1)

Anonymice (1400397) | about 7 months ago | (#46590235)

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.

Re:Scientists "know"? (1)

mbeckman (645148) | about 7 months ago | (#46590509)

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.

Re:Scientists "know"? (0)

Anonymous Coward | about 7 months ago | (#46590549)

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.

Re:Scientists "know"? (1)

david_thornley (598059) | about 7 months ago | (#46588485)

To falsify it? How about thirty years of falling temperatures while CO2 levels stay the same or rise?

Re:Scientists "know"? (1)

mbeckman (645148) | about 7 months ago | (#46588889)

Amazingly, no AGW proponent considers that a falsifying data set!

Re:Scientists "know"? (2)

habig (12787) | about 7 months ago | (#46585009)

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 [arxiv.org] 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".

Re:Scientists "know"? (-1, Troll)

mbeckman (645148) | about 7 months ago | (#46585337)

When even scientists call it a mystery, that is pretty definitive that they don't know. Nobody calls solar fusion a mystery, because we can directly observe the process and there is no controverting data. It's a theory, to be sure, but valid until dis-proven.

But you can't say "scientists have a pretty good idea" about planetary formation. They have ideas. None has been shown to be even remotely "pretty good". In fact, they're all pretty bad, because they can be countered with mere calculation. A true scientist does due diligence on his own theories before publishing, but that process has gone by the wayside in recent years. Planetary accretion doesn't work because the kinetic energy of collisions is many times too great to permit particle coalescence as a function of gravitational attraction. That's undergraduate astronomy mathematics.

On the other hand, I could posit that planets are made on the Magrathea Factory Floor [pikdit.com] , and have as much evidence going for me as any other theory.

Re:Scientists "know"? (1)

habig (12787) | about 7 months ago | (#46585617)

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.

Re:Scientists "know"? (-1, Troll)

mbeckman (645148) | about 7 months ago | (#46586095)

But we don't have a reasonable window. We literally have no data supporting the radioactive sustenance of the Earth's core temperature. Simple calculations demonstrate that radioactive decay is not adequate for the current age of the earth. Something has to give in a major way: either the earth is far less than even a million years old, or there is some other engine heating the Earth's core. Hell, for example ;)

Re:Scientists "know"? (0)

Anonymous Coward | about 7 months ago | (#46587793)

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.

Source of heat inside the earth (0)

MadRat (774297) | about 7 months ago | (#46585647)

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.

Re:Source of heat inside the earth (1, Insightful)

mbeckman (645148) | about 7 months ago | (#46586205)

When you survey the literature on geothermal heating, you find that friction is indeed _the_ major component of core heat. Especially tidal friction due to lunar gravity, which is far more significant that even meteor strikes, because it's a continuously varying force. But the physics of friction are well understood, and basic calculations show that friction is still not nearly a large enough source for measured temperatures and theoretical time spans.

In fact, radioactive heating was originally postulated as a source to make up for the inadequacies of frictional heating. But the magnitude of radioactive heating is orders of magnitude less than even frictional. As mathematicians would say, it may be "necessary, but not sufficient."

Re:Source of heat inside the earth (2, Interesting)

Anonymous Coward | about 7 months ago | (#46587425)

In fact, radioactive heating was originally postulated as a source to make up for the inadequacies of frictional heating. But the magnitude of radioactive heating is orders of magnitude less than even frictional. As mathematicians would say, it may be "necessary, but not sufficient."

I'm not sure where you are getting your numbers from, but they don't seem to make any sense. Considering the heat released by the Earth is on the order of 40 TW, and frictional energy loss by the moon on the order of 3 TW (tidal heating from the sun much less) most of which is near the surface, this becomes a rather insignificant contribution to the heating of Earth.

You also keep claiming that the math just doesn't work for radioactive decay. If you assumed it was all from U-238, you would need about 4e18 kg of it to produce the required heating. If it was only located in the inner core, that amounts to only 40 ppm, which is a factor of 20 larger than the crustal abundance. If this was evenly spread out among the inner and outer core, you're talking about 2 ppm, which is not much higher than the crustal abundance.

There are a lot of questions about the specific details of the heat from which decay and exactly where in the Earth's structure. But that is wholly different than saying we have no idea and acting like the math is no where near the realm of possibility.

Re:Scientists "know"? (1)

iggymanz (596061) | about 7 months ago | (#46586291)

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.

Re:Scientists "know"? (-1)

mbeckman (645148) | about 7 months ago | (#46586741)

By dead cold I mean that no lunar-thermal heat reaches the surface. Mere compression brings the moon's core to 2,000F or so, but that's much lower than the Earth's peak of about 10,000F. The lunar surface is dead cold at -300F in darkness.

Care to cite a source for your claim of "half the heat"? I have an observable example in the moon for my position, with many measurements, which is presumed younger than the earth if you accept the collision theory of the moon's formation. Why is the earth so much hotter internally than the moon? It's a fair question that has no obvious answer.

Re:Scientists "know"? (0)

Anonymous Coward | about 7 months ago | (#46587489)

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.

Re:Scientists "know"? (1)

iggymanz (596061) | about 7 months ago | (#46588509)

mainstream science:
http://en.wikipedia.org/wiki/E... [wikipedia.org]

and even moon had recent cooling:
http://www.nasa.gov/mission_pa... [nasa.gov]

its smaller diameter means it loses heat faster anyway, even if it were stone cold in interior would not be valid point to make

Re:Scientists "know"? (1)

careysub (976506) | about 7 months ago | (#46588319)

... 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.

Re:Scientists "know"? (1)

mbeckman (645148) | about 7 months ago | (#46588869)

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.

Re:Scientists "know"? (0)

Anonymous Coward | about 7 months ago | (#46589037)

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.

Re:Scientists "know"? (1)

careysub (976506) | about 7 months ago | (#46589565)

...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 [wikipedia.org] , 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.

Another shut down the nukes story (0)

Anonymous Coward | about 7 months ago | (#46585423)

wtf slashdot, you have an agenda?

Hawaii Has Nuclear Subs (1)

Boycott BMG (1147385) | about 7 months ago | (#46586187)

Pearl Harbor is a base for a classified number of nuclear submarines. I don't think this map reflects that.

So how long until (0)

Anonymous Coward | about 7 months ago | (#46587003)

... 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.

Hawaii? (1)

Fallen Kell (165468) | about 7 months ago | (#46589423)

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....

Venezuela (1)

McLoud (92118) | about 7 months ago | (#46592751)

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

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