Posted on 05/02/2008 8:53:50 AM PDT by blam
Sun's Movement Through Milky Way Regularly Sends Comets Hurtling, Coinciding With Mass Life Extinctions
A large body of scientific evidence now exists that support the hypothesis that a major asteroid or comet impact occurred in the Caribbean region at the boundary of the Cretaceous and Tertiary periods in Earth's geologic history. Such an impact is suspected to be responsible for the mass extinction of many floral and faunal species, including the large dinosaurs, that marked the end of the Cretaceous period. (Credit: Art by Don Davis / Courtesy of NASA)
ScienceDaily (May 2, 2008) — The sun's movement through the Milky Way regularly sends comets hurtling into the inner solar system -- coinciding with mass life extinctions on earth, a new study claims. The study suggests a link between comet bombardment and the movement through the galaxy.
Scientists at the Cardiff Centre for Astrobiology built a computer model of our solar system's movement and found that it "bounces" up and down through the plane of the galaxy. As we pass through the densest part of the plane, gravitational forces from the surrounding giant gas and dust clouds dislodge comets from their paths. The comets plunge into the solar system, some of them colliding with the earth.
The Cardiff team found that we pass through the galactic plane every 35 to 40 million years, increasing the chances of a comet collision tenfold. Evidence from craters on Earth also suggests we suffer more collisions approximately 36 million years. Professor William Napier, of the Cardiff Centre for Astrobiology, said: "It's a beautiful match between what we see on the ground and what is expected from the galactic record."
The periods of comet bombardment also coincide with mass extinctions, such as that of the dinosaurs 65 million years ago. Our present position in the galaxy suggests we are now very close to another such period.
While the "bounce" effect may have been bad news for dinosaurs, it may also have helped life to spread. The scientists suggest the impact may have thrown debris containing micro-organisms out into space and across the universe.
Centre director Professor Chandra Wickramasinghe said: "This is a seminal paper which places the comet-life interaction on a firm basis, and shows a mechanism by which life can be dispersed on a galactic scale."
The paper, by Professor Napier and Dr Janaki Wickramasinghe, is to be published in the Monthly Notices of the Royal Astronomical Society.
Adapted from materials provided by Cardiff University, via EurekAlert!, a service of AAAS.
No, you assume that it rotates because you assume that the universe does not.
The point being that the guy basing his rotating earth argument on Occam's Razor now has more assumptions in his model and therefore can't use Occam's Razor as an argument.
Off topic. The article was not about global warming or atheistic scientism.
Scientism is, by definition, atheistic.
“Days of Future Passed”. It still sounds pretty good after all these years!
Agreed, the modifier was probably unnecessary. However the article was science, (in terms of research, analysis and a theory) not scientism.
You're the one who correctly but inadvertently invoked scientism.
Not me.
Thanks for the ping
“OK, so how is assuming that there is no difference between the earth and rotating bodies we observe less an assumption than assuming that there is a difference between the earth and the rotating bodies we observe and therefore an argument for Occam’s Razor?”
It wasn’t “less of an assumption”, however it was a simplifying assumption.
BTW, one of the basic precepts of all science is that there are no “special” places in the Universe where things work differently than elsewhere. It would take a lot of good evidence to overturn that one. Occams Razor also applies there.
“What about objects that aren’t observed to rotate, like the moon. You assume they do rotate even though they appear not to? Where is Occam’s Razor now?”
What do objects that don’t rotate have to do with those that do? (Another poster made the point about the Moon rotating so I’ll leave that alone.)
I made no “assumption” about non-rotating bodies rotating... I was simply speaking of the numerous rotating bodies we do observe.
“I don’t think that is correct. The moon does not rotate.”
Yes it does, as any basic astronomy text would tell you.
“If it did, we would see the other side of the moon regularly.”
No, if it DID NOT rotate we’d see the other side as it orbited the Earth. The Moon is tidally locked and rotates once per orbit, always keeping the same side facing the Earth.
I hope that cleared things up for you. If not:
http://en.wikipedia.org/wiki/Moon#Two_sides_of_the_Moon
LOL
Not so. Math is real, that is, not a matter of opinion..
Ockham never actually enunciated the Principle of Parsimony and it wouldn't apply to the empirical anyway.
This may be where you are having the problem. You think that there are fewer assumptions in a rotating earth model than in a rotating universe model. There are not and Occam's Razor does not apply.
You assume that the moon rotates because you assume that the universe does not. I observe that the universe rotates and observe that the moon does not.
There are fewer assumptions in a rotating universe model and Occam's Razor cannot be used as an argument in favor of a rotating earth.
How many other moons are “tidally locked” with their parent bodies? What are the chances that a captured body would have the precise trajectory and rotation to become captured and tidally locked? Why is the Earth and all other planets not tidally locked with the sun?
Well, that's the whole of the argument. What standard of fixity will be used, the earth or the universe? That the universe does not rotate is an assumption that the astronomers make, not an observation.
The result of this assumption is the conclusion that the moon rotates once per orbit. If the universe is rotating, then the moon does not, as you note.
Imagine your head is Earth and semi-circle your hand from one side to the other. If it wasn’t rotating you’d see each side with 1/4 rotation.
Sorry for the confusion.
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