Spectacular force: A georeactor deep in the ancient Earth's D''-layer (dark orange layer near core) goes supercritical - suddenly increasing temperatures to 13,000ºC. This turns rock into vapour, creating a rising bubble which pushes mantle, crust and atmosphere into space in a giant eruption.
Credit: Theo Barten
Melosh maintains that the impact theory is still rock-solid. "This problem with the isotope ratio is to be regarded as a small puzzle within the solid framework of the impact hypothesis," he says. "There is no need at all to ditch the impact hypothesis and put ill-conceived ideas about exploding georeactors in its place."
Van Westrenen and de Meijer, however, have other data to nurture their theory. This evidence comes from thousands of kilometres beneath our feet.
In a major breakthrough reported in the U.S. journal Science in 2005, Earth scientists Maud Boyet and Richard Carlson of the Carnegie Institution in Washington DC, concluded that both a partition between the Earth's mantle and core, and another within the mantle, formed within 30 million years of the planet being born.
This internal partition isolated the lower mantle, the D''-layer, from the rest of the mantle. Boyet and Carlson arrived at their conclusion by investigating the rare earth elements samarium (Sm) and neodymium (Nd). Samarium-146 is a radioactive element that decays relatively speedily, with a half-life of 103 million years, to neodymium-142.
At present hardly any samarium-146 is left on Earth. Theoretically, terrestrial rock should contain just as much neodymium as the primordial material from which the Earth was formed – samples of which sometimes still reach the Earth in meteorites.
But the researchers discovered something odd. Rock from the Earth's mantle contains more neodymium than these meteorites. The only conceivable explanation is that samarium was distributed unevenly throughout the planet, because the overall concentration should be equal to that in meteorites.
But where can this neodymium-poor rock be? Not in the Earth's core, because neither samarium nor neodymium can bond chemically to iron. That only leaves the D''-layer. This chunky boundary layer between core and mantle must be low in neodymium.
Boyet and Carlson discovered that the Moon has a peculiarity too: rocks that are just as rich in neodymium as the Earth's mantle. This makes the impact hypothesis very improbable indeed, according to van Westrenen.
"Considering that at this giant impact 4.5 billion years ago the Earth's core and Theia's core fused, it is most improbable that isolated layers deep within the planet survived the impact. Yet this is what the data from Carlson and Boyet suggest."
Carlson was candid about this over the telephone: "Our data show a strong similarity between terrestrial and lunar rock, but there is no good explanation for that at all."
How the impact with Theia took place, and how the D''-layer survived this impact while the Earth's core fused with the core of the impactor, is beyond Carlson's comprehension as well.
Research into the mysterious D''-layer, some 2,900 km down, is now very popular. "It's the most dynamic region within the Earth," says van Westrenen. "It is a very hot layer that is one of the causes for the outer core, which generates the Earth's magnetic field, staying molten."
The D''-layer is puzzling because it exchanges heat with the surroundings, but hardly any material. It also varies in thickness from a few tens to hundreds of kilometres. Carlson compares the layer to a landscape of icebergs, floating on the outer core.
Birth of the Moon: a runaway nuclear reaction?
I read a rather instersting article about how writers approach stories regarding new scientific theories. And reading this article it struck me just how true there was in that article.
Once again, the guy with the new theory, in this case Rob de Meijer and his coleague, is being painted as mavericks. He is trying to attain legitimate consideration for his "radical" new theory. He has an uphill battle against the well established theories of his peers and they will do everything they can to debunk him and his ridiculous theory.
Well for one thing, why don't you let your readers decide for themselves whether a theory is outlandish.
Also, debunking theories, new or old is how science works. Theories are supposed to be able to stand up to scrutiny. Eventually, the evidence will either lend credence to or disprove the theory.
Not A 'Maverick' story in my world
From my read of the article, we have a scientist who has an interesting new idea about the moons formation that, if it proves to be viable, might explain some anomalies in the system, relative to the other popular explanations.
I don't see any "people are trying to suppress me" whining. I just see someone with a fledgling theory that seems properly (dis)provable and he's trying to put together an experiment that would properly put his theory to a test.
If he manages to build his anti-neutrino detector, I'd like to see what results it generates. Among other things, I'm curious about it detecting antineutrinos that are unrelated to either georeactors or human-built reactors -- and what that might expose about the universe around us.
THE MOON
IT SEEMS TO ME THAT THE MOON WAS CREATED IN A COLLISION. IT MAY NOT BE TRUTH. THE MOON WAS CREATED AT THE SAME TIME AS THE EARTH. IT NEED TO BE SUPER HOT TO FORM THE CIRCLE. IS LIKE A DROP OF WATER WHEN IT FALLS IT MAKES A PERFECT CIRCLE, BECAUSED OF THE GRAVITY. SO IF A COLLISION OCCURED THE MOON WOULD NOT BE IN A PERFECT SHAPE THAT IS NOW. IT WILL BE LIKE THE ASTEROIDS WITH NO FIGURE IN SHAPE. MAGMA ONCE IS COLD WILL DO DIFRENT SHAPES. BUT WHEN IS HOT AND CONTINUES TO BE HOT WILL FORM A PERFECT CIRCLE ONCE YOU DROP IT IN THE AIR. WILL FORM A PERFECT CIRCLE. AS THE MOON NEED TO SUPER HOT TO BE IN THE SHAPE THAT IS NOW.
Energy calculation
"....a one gigawatt nuclear reactor generates just 1017 joules a year.."
I guess this is probably meant to read "3 x 10^16 joules a year"
Calculations
Similarly " ...so you'd need the annual energy production of 1013 of these reactors to get the same amount."
I guess this should read "10^13".
Error in typography
On p5 of this article, surely the phrase "a one gigawatt nuclear reactor generates just 1017 joules a year," should read "a one gigawatt nuclear reactor generates just 10^17 joules a year,"
Errors fixed
Thank you, dear readers. Sometimes superscripting drops off in translations to the web, unless we keep out an eagle eye. All fixed now!
Wilson da Silva
Editor-in-Chief
page 5 (& printable) still broken.
page 5 (& printable) still broken.
The superscript tag isn't closed, so some text is missing and everything after it is in superscript.
You have (using the wrong brackets so they don't get exec'd):
[sup] 13[/su
where you need
[sup]13[/sup]
page 5 (& printable) still broken.
page 5 (& printable) still broken.
The superscript tag isn't closed, so some text is missing and everything after it is in superscript.
You have (using the wrong brackets so they don't get exec'd):
[sup] 13[/su
where you need
[sup]13[/sup]
I agree with the other visitor
Yes! Please fix your html so we don't need to view source to see the end of a sentence.
Also, and I ask so many media outlets to do this, put an e-mail address on your contact page specifically for typos, wrong information, etc, so we don't just post comments you're likely to not read often!