The Nuclear Heart of the Earth
"... in the heart of the earth.(Matthew 12:40)
What would we find if we were to dig a hole all the way down to the centre of the Earth? According to high school science books we would discover a liquid iron alloy core and a smaller solid inner core at the center. For ten years, geophysicist J. Marvin Herndon has presented increasingly persuasive evidence that at the very centre of the Earth, within the inner core, there exists a five mile in diameter sphere of uranium which acts as a natural nuclear reactor.
Dr. Herndon likes to term this beast the "georeactor".
Think of the early Earth as having been like a spherical steel hearth. A hot ball of liquid elements freshly formed out of the primordial disc surrounding our sun. The densest metals sinking down by force of gravity while lighter materials "floated" outwards. Uranium is very dense. At about 19 grams per cubic centimeter, it is 1.6 times more dense than lead at the Earth's surface. But deep within our planet density depends only on atomic number and atomic mass. Uranium, having the greatest atomic number and atomic mass, would be the most dense substance in our planet and will ultimately end up at the center of the Earth. The implications of this relatively new georeactor hypothesis are far reaching indeed. Not only does it threaten to change the way we view our own Earth and planetary formation in general but the very origin of the stars might need to be rewritten.
Recently returned from the red carpet World Premiere Screening of "The Core", I caught up with Dr. Marvin Herndon for an interview.
Wayne: Dr. Herndon, I have read that you believe Mars to have a dead georeactor as evidenced by its not possessing any electromagnetic field. Can you speculate on other planets in the solar system including the Gas Giants?
Dr. Herndon: I first came upon the idea of planetary-scale nuclear fission reactors by considering the Gas Giants. When I went to school, I was taught that planets don't produce energy; they just receive energy from the sun and re-radiate it. But in the late 1960's astronomers found that Jupiter radiates about twice as much energy into space as it receives from the sun. Later, Saturn and Neptune were also found to radiate prodigious amounts of internally generated energy. For twenty years planetary scientists, believing that they had considered and eliminated all possible planetary-scale energy sources, pronounced that the extra energy being radiated was from the original gravitational collapse some 4.5 billion years ago. When I started thinking about the problem around 1990, that explanation did not make sense to me. Jupiter is 98% hydrogen and helium; both of these gases are extremely efficient heat transfer media. Then I realized that each of the Gas Giants had all of the necessary ingredients for a planetary-scale nuclear reactor, an energy source that had not been previously considered. Jupiter, Saturn and Neptune each radiate prodigious amounts of internally generated energy and have very turbulent atmospheres; Uranus radiates little if any extra energy and its atmosphere appears featureless.
[Speculation: Has Uranus' nuclear reactor shut down or died?]
After the paper on the Gas Giants was published in Naturwissenschaften, I realized that hydrogen was not necessary for slowing neutrons; that bit of insight lead me to begin developing the concept of a nuclear fission reactor at the center of the Earth, which I first published in 1993. We have no direct evidence (yet) that Mars has or had a nuclear reactor. However, Mars has the largest volcano in the solar system, Mons Olympus. There was at one time a source of energy needed to form that volcano. Now it appears that the interior of Mars may not be frozen. Interesting. Jupiter's moon, Io, has volcanic activity. I have read recent reports suggesting that tidal interaction with Jupiter may not supply enough energy. One might SPECULATE on the possibility of a nuclear reactor being involved, but at present it would only be a speculation. There was a recent report suggesting that the interior of our own moon may not be entirely frozen. There is paleomagnetic evidence to support the idea that the moon had its own magnetic field during its first 500 million years of life. What is needed is hard evidence.
Wayne: This aspect will I know interest the readers. Could a georeactor possibly "blow up" destroying its surrounding planet?
Dr. Herndon: No. For an explosion one needs very pure "weapons grade" uranium or plutonium. The impurities in natural uranium, including U-238, would rule this out. (Too bad for reader interest.) There is some nonsense on the web about global warming causing the georeactor to explode. Nonsense. Pseudoscience.
Wayne: Except for a georeactor winding down, are there any other dangers posed to life?
Dr. Herndon: The only elements that can escape from the core are very light elements. Light element fission products are low in abundance and, if radioactive, typically have short half-lives.
Unlike other potential planetary-scale energy sources which can change only very gradually in one direction over time, a nuclear reactor is capable of variable energy production, as I pointed out in my 1994 Proceedings of the Royal Society of London paper.
Questions that scientists should begin thinking about are whether such variable energy output for the earth can be detected and how might it affect the surface regions of our planet. Is the El Nino, for example, affected by such variability??? Ice ages??? I am not suggesting that they are, but one should keep an open mind. For example, in models of global warming, the heat flux from the interior is ASSUMED to be constant.
Is it? These are questions that scientists should address.
Wayne: What would control this energy output variability if it does exist?
Dr. Herndon: In a nuclear fission reactor, the nuclei of uranium and other actinide elements are caused to fission in a chain reaction, splitting typically into two pieces.
These fission products absorb neutrons and, if left in place, will slow the neutron chain reaction and, ultimately, will shut down the reactor. But the fission products have roughly half the atomic number of the uranium fuel and half the atomic mass. At the pressures that prevail in the deep interiors of planets, density is a function of atomic number and atomic mass. The fission products will therefore be less dense than the uranium fuel and will tend by gravity to migrate radially outward while the uranium fuel re-concentrates inward. One might imagine in the ideal case something of an equilibrium being established. But if, for example, the rate of production of fission products exceeds their rate of removal, the output power of the reactor might be reduced until the fission products have a chance to migrate by gravity away from the reactor zone. Then the power will increase.
Wayne: I was thinking about how this georeactor planetary theory if proven must apply to most if not all planetary bodies throughout the universe. I'm certain you are familiar with Drakes equation for trying to guesstimate the number of intelligent civilizations which might exist in the universe. Much revered by SETI. Wouldn't a new value have to be added representing the expected lifetime of a georeactor at any Earthlike world?
Dr. Herndon: I think that people would very much like to find evidence of life elsewhere in the universe. But the fact remains that Earth is the only planet where life has been found. I do not think that one can assign a probability to an event that has only been observed once. I am not in any way against efforts to find evidence of life, but I think that people need to be objective in that pursuit.
Wayne: Do you envision any strange examples of natural fission? Physicists have theorized about all manner of peculiar things such as miniature and even doughnut shaped black holes for instance. Could an unusual type of natural fission reactor exist somewhere in the universe?
Dr. Herndon: I try to build science step by step, one insight leading to another. I have had no reason to expect unusual types of reactors to exist in the universe. On the other hand, I think there is much that we still do not know about "ordinary" planetary-scale nuclear reactors. And who knows what we may ultimately learn?
Wayne: I hope you had fun in Hollywood rubbing shoulders with the stars.
Dr. Herndon: I found to my surprise that, not only did I get to rub shoulders with the stars, I was treated as a star and paraded along the red carpet at the World Premiere of THE CORE. That's quite a boost for science.
Wayne: Dr. Herndon thank you for taking time out from your hectic life to speak to us.
Dr. Herndon: It has been my pleasure. I find that people want very much to learn about their world. I am glad to have the opportunity to make this knowledge available. Thank you.
On June 2 1972 a French analyst named Bougzigues discovered spent uranium in an ore sample later found to have originated from the Oklo deposits of Gabon in South West Africa. A number of ancient natural reactors were consequently discovered in the middle of this ore deposit. Scientists investigating the site confirmed that fission had taken place there approximately 2 billion years ago. U-235, the fissionable isotope of uranium, was more abundant in natural deposits of that era than at present. So ancient ores were in fact quite similar to enriched uranium and could fission under the right circumstances. With water acting as a moderator on particularly porous ores a sustained reaction became possible. The existence of natural reactors such as these had been theoretically predicted by P. K. Kuroda in 1956; Oklo was the first actual evidence of them to have been found.
Inside the Earth.
What we do know about the deepest regions of the Earth is largely deduced from meteorites and rock samples.
Lava and basalt contain small amounts of helium-3 not predicted by traditional planetary theory. There was no known natural production method to account for this isotope being present in such high quantities so scientists could only conclude that it originated from the Earths formation around 4.5 billion years ago. Rather incredible to believe but with no other obvious explanation available other than cosmic dust it has remained the generally accepted theory for over 30 years. To make it fit the evidence roughly 10 times as much helium-4 from radioactive decay had to have been mixed with the helium-3 and in a fashion enabling very narrow ranges of composition.
Results of the first numerical simulation of a deep-Earth reactor were published in 2001 by Marvin Herndon and Daniel Hollenbach. Confirming everything Herndon had published in the eight years prior to it, the calculations showed for the very first time how a deep-Earth nuclear reactor would produce both helium-3 and helium-4 in similar ratios to what is actually found in volcanic lavas and basalts. This is extremely strong evidence for a deep earth reactor. Recently, nuclear engineers and scientists at Oak Ridge National Laboratory made further numerical simulations which refine and extend the original findings of Herndon and Hollenbach. A 4.5 billion year old planetary scale georeactor with a heat output of approximately four terawatts looks increasingly likely as more evidence keeps mounting. The variable energy output expected with such a natural reactor has some supportive evidence also. Earth's geomagnetic field has over the course of history weakened, increased, reversed and even temporarily shutdown. Activity which makes very little sense if you ascribe to the traditional assumed heat generation from an assumed cooling and growing nickel iron inner core.
A five-mile-wide spherical reactor of mixed uranium 235, uranium 238 and self made plutonium is what nuclear engineers would call a fast-neutron breeder reactor. The nuclear fission produced heat warms the nickel silicide inner core and supplies energy to the mechanism that produces the geomagnetic field. Many people think that the heat from the inner core then heats the fluid core causing convection motions which act like a dynamo to produce the geomagnetic field, although the true mechanism is not yet known with any certainty.
One argument raised by other geophysicists is to ask how all of that uranium could have reached the center.
Many people think that uranium combines with oxygen and becomes part of the silicate mantle. Herndon's answer to this thorny question came to him from space. From stony meteorites to be exact. Chondrites are rubble left over from the creation of the solar system. "Most of today's geophysics is based on the idea that Earth is like ordinary chondrites, which were formed under relatively oxygen-rich conditions," says Herndon.
Enstatite chondrites which were created in conditions of low oxygen show much closer similarity to Earth's composition and do contain uranium. "These are like the inner planets, the oxygen isotopes in enstatite chondrites are identical to what we find inside Earth.
When there is plenty of oxygen, all of the elements that like to combine with oxygen would go with the silicates. But when there is limited oxygen, elements such as uranium and magnesium would in part go to the Earth's core," he explains.
Dark Matter and Stars.
If natural fission is commonly found at the hearts of planets then it might also be found in metal rich protostars. This might then be the actual trigger mechanism for fusion. Thus rewriting the theory of how stars ignite and challenging the traditionalists among astrophysicists 'and' geophysicists. The popular explanation has long been gravitational collapse heat as being the trigger for a fusion reaction. Such a reaction requires temperatures of about one million degrees celsius. Herndon's idea of fission providing the trigger is experimentally proven by the detonation of hydrogen bombs. No experimental proof on the other hand exists for gravity being capable of achieving the same result. In fact, calculations indicate that it may not be possible to attain a million degrees by gravitational collapse because energy is radiated away as a function of the fourth power of temperature.
Using step by step logical reasoning we can therefore assume that stars not containing a critical mass of fissionables can't ignite. Astronomers seem to be slowly coming to the same conclusion, having observed that dark matter appears especially plentiful near stars with low amounts of metal. No significant level of fissionable metals means no fission and therefore no fusion. So the bulk of that missing 90% of the universe labelled 'Dark Matter' which astronomers have been scratching their heads over for decades, might simply be accounted for by non-ignited stars.
The end of the georeactor's lifetime is approaching.
Nuclear georeactor numerical simulation results reveal increasingly higher ratios of helium-3 to helium-4 fission products occurring as the world ages. A sign of uranium fuel depletion at the core. This trend combined with the high helium ratios observed today in fresh lavas from Hawaii and Iceland indicates the end of the georeactor's lifetime to be rapidly approaching(geologically speaking). Dr. Herndon is now working to narrow down a more specific date for this event currently estimated to happen anytime from the next century to a billion years in the future. Beryllium-9 and beryllium-10 samples from the core, if locatable, might contain vital information to help with predictions. When combined with other data it could provide us with an answer to 'when'.
After the georeactor does die, the Earths magnetic field will follow, having no source of energy to power it. This collapse will have an adverse global effect on animal and plant life, from birds getting lost to solar radiation stripping off our atmosphere. It's questionable if life could in fact survive at all. We do know that the sterile looking surface of Mars presently has no geomagnetic field.
This theory undoubtedly deserves serious scrutiny from the scientific community. Like so many other 'earthshaking' new ideas in science it has sadly been largely ignored to date. Plate tectonics suffered the same 'pariah' status for fully half a century with experts refusing even to consider it. Radical new ideas in science frequently face hostility because scientists themselves are only human. Geophysicists who have spent the better part of their lives writing papers on the dynamics of Earth's inner structure do not want to hear about how they might have been wasting their lives chasing the wrong theory. Building up a reputation as being an authority on a subject is extremely difficult. It requires enormous dedication and long years of study with little pay and perhaps mounting debts. Many of us imagine the scientific community to be extremely logical and fair-minded in assessing new ideas. We see these people in their spotless white frocks taking exceedingly precise measurements of the universe and its easy to think they must administer themselves in the same way.
Following the demandingly stringent doctrines laid down by the scientific method to judge any new theory on its merits alone. This would be the action of a robot. In truth, science is just another belief system that can be corrupted by ambition, jealousy and fear.
Dr. Herndon discovered this the hard way and has paid for much of the research done so far out of his own pocket. However, as evidence builds in favour of his "georeactor sub-core", the walls of opposition are now finally starting to crumble. People everywhere are beginning to realise that it makes sense. The Earth is not yet a dying planet, but a World that is alive with a nuclear reactor heart.