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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."
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) .
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, and have as much evidence going for me as any other theory.
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 ;)