I saw Herndon give a seminar on this topic a few years ago. It is a plausible theory, but not an established fact, and not accepted by most in the field. As I recall, we don't understand the earth's core well enough to know if enough uranium could have collected at the center for a reactor to happen. One way of testing the idea is to look at the flux of anti-neutrinos coming from the earth. If the number is greater than can be explained by beta decay of the thorium-chain elements, it would point toward a geo-reactor. I seem to recall that some proposed neutrino detectors have a chance of measuring this. They have to be able to discriminate against the large flux of neutrinos coming from the sun. An interesting part of the theory is that the geo-reactor proposed by Herndon will run out of fuel relatively soon, so if it exists the earth will lose and important source of internal heat and begin cooling much sooner than if all the heat comes from radioactive decay.

My wife and I drive old cars so we can afford to send our kids to private school. It is worth it. The oldest is now a in his second year at one of the hardest colleges in the country, studying physics, and doing well. He was very well prepared by his high school.

RTGs http://en.wikipedia.org/wiki/Radioisotope_thermoelectric_generator use Pu-238 http://en.wikipedia.org/wiki/Plutonium-238, not Pu-239 http://en.wikipedia.org/wiki/Plutonium-239

In an era where all space science is done by unmanned probes and robots, I think it says a lot that we are willing to preserve our heritage in manned space flight. These selfless men and women in their period costumes, devote their careers to re-enacting history, so that we can enjoy the spectacle. Very much like the royal family in the UK. I'm so happy that the US taxpayers are willing to spend billions of dollars each year to keep this history alive. It is almost as good as civil war re-enactments!

You must be new

87.3% of them to be exact.

You'll get no argument from me than religion is one of the greatest evils.

Yes, you could be right. It is hard to separate cause and effect. It could be the losers I knew in HS who smoked pot would have been losers anyway. In any case, we both agree marijuana should be legalized.

Good point.

We should be honest about this. Legalized pot will result in more people using, more people abusing, and all the problems that implies. We all remember smart kids from high school that wasted their lives on pot. But, this is still far better than incarcerating people for only harming themselves and the huge amount of money and abuse of freedom that we currently have. In addition, we will be taking away a guaranteed source of income from drug gangs, some of the nastiest people on earth. It is not a panacea, but it is a large net gain.

The wonderful thing about standards is there are so many to choose from.

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OK, I'll try to say this slowly. The radius of the event horizon is linearly proportional to the mass. The radius of a spherical mass at constant density is proportional to the cube root of the mass. This means the average density required to create an event horizon is inversely proportional to the square root of the mass, Therefore, as the mass gets bigger, the average density to create an event horizon goes down. At a mass of 270 million solar masses, the density required to form an event horizon is the same as ordinary water. It is possible for enough ordinary matter to form an event horizon. As I originally said, no singularity is required. Of course, most black holes we imagine are much smaller, and require huge densities. A solar mass black hole requires an average density almost 400 times nuclear density. At these densities, we know of no force that can prevent complete collapse so we assume a singularity forms. Certainly there are alternate theories that apply in this case. I'm know stepping off your lawn, old man.

You are arguing with nature, not me. A large enough mass in a small enough space will have an event horizon, but will never form a singularity because nuclear repulsion is enough to prevent complete collapse. No alternative theories required. Now whether such a large black hole actually exists is another question, but the laws of physics don't prevent it. BTW, you seem to not know, but a singularity has a zero radius by definition. You completely missed my argument.