If you claim it’s something natural, the burden of proof is on them to prove it’s not natural. This way you can claim it’s anything.
The above comment was meant to defend the belief in UFO's by "woohoos."
So let's discuss the burden of proof for the benefit of Norval and Gale. Generally the burden of proof is accepted to lie on the shoulders of the person making a claim that disagrees with what's generally accepted. Einstein had the burden of proof for relativity (he did so mathematically, extrapolating from other things that had been done experimentally. Others proved relativity experimentally later). Galileo had the burden of proof of showing the earth revolved around the sun (he showed discrepancies between the geo-centric model and actual observations were not under the helio-centric model. Precise measurements eventually showed the earth did revolve around the sun). Shoemaker had the burden of showing that an extra-terrestrial impact caused Barringer Crater (he found shocked quartz, which forms only under extremely high pressures not attributable to volcanic activity. This was similar to nuclear blast craters). In all these cases, the burden of proof rested on those proposing a change from the "null hypothesis."
Now Shoemaker's case is a doubly good one for this discussion because it relates to the formation of craters, but also because there are some assumptions involved. Basically, he reasoned Barringer was formed from an asteroid impact because it was the only known event that could provide enough energy to displace that much earth fast enough to form shocked quartz. It was not remotely logical to think it was a man-made nuclear bomb because there is no evidence at all that any man possessed a nuclear bomb however many thousands of years ago. In fact, the biggest bombs we've ever built could not dig a crater that big.
Other geologists and astronomers were reluctant to believe it was possible because they'd never observed such an event, but gradually came to accept the change from the idea that it was a volcanic feature
1.) Because Shoemaker had presented evidence to the contrary
2.) He had identified an alternate theory
3.) There were observations to support his alternate theory
Specifically regarding the observations, we have observed many, many meteors. We have also observed impacts on the earth, the moon and Jupiter. We have found meteorites on the earth and on Mars (thanks to the Mars rovers). We have identified asteroids and comets in orbits that bring them into proximity with every place we have observed craters, with kinetic energies sufficient to form all but the biggest (which likely occurred in the chaotic early solar system). We have identified a mode of destruction of the impactors.
Destruction of the impactors is actually testable. You can build a really expensive rail gun to shoot little rocks at big rocks at high speeds and see what happens under various conditions. Also, the impactor from the Deep Impact mission struck the comet Temple 1 with a velocity of something like 40,000 miles per hour. The impactor is believed to have disintegrated. You could go there and search the crater for signs of impactor. You can test the overall theory as a whole if you happen to be fortunate (or unfortunate as the case may be) enough to observe a major impact.
Now, regarding the theory proposed by Craterchains:
The theory as it stands is that something else caused the craters. That by itself is fine. Many other people have asked themselves if it is possible, but have not found 1, 2 or 3 above. Craterchains believes he has 1 - evidence that contradicts the theory (just as Shoemaker's shocked quartz contradicted the volcanic origin theory). The links also claim 2 exists, an alternate theory (UFO's), but he has avoided associating himself with that theory here.
Namely, his contradiction is that no one can find impactor remains in major craters. More to the point, he's contradicting the mode of destruction that is a part of Shoemaker's alternate theory. Also, in this thread, he is contradicting the theory regarding the formation of multi-ringed craters, which is closely related as it too deals with stresses in rocks. A lot of modelling has been done showing that impactor destruction is not only feasible, but expected in a high velocity impact. I don't have any links and am not quite sure where to look, but I suspect some experimental support might exist, too.
So, have I summarized things correctly? If so, in order to convice me some change in theory is needed, I need as equivalent evidence to that which convinced me of the current theory in the first place. If you can show via either experiment or approximate calculations that a rock at moving 60,000 mph (or even half that) hitting an object of equivalent strength and density can reasonably be expected to survive, I will apologize and give your theory more dedicated consideration and research. Others have done very detailed calculations. I bet I can do some rough numbers on paper based on acceleration, mass, and stress that would support their calculations.
"Any man whose errors take ten years to correct is quite a man." ~J. Robert Oppenheimer (speaking about Albert Einstein)