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101 Ways To Kill The Dinosaurs
blank writes "Everyone knows there are many impact craters on Earth; around 170 in fact. This article from the Seattle PI points out that more than one of those impacts could have caused the extinction of the Dinosaurs. In Ukraine, scientists found that a well-known crater had been inaccurately dated - the correct date puts the impact sometime around when the Dinosaurs disappeared..."
Remember the Far Side cartoon entitled what really killed the dinosaurs? They were all smoking. That is on of the all time classics. I'd post a link if I knew of one.
How ya like dat?
Politics killed them, that and lawsuits over patents, copyrights, and anti-trust. I wonder if we could work the DMCA into it some where. Or we could just ask Strom Thurmond.
Sorry about the writing. Robot fingers, you know? Cliff Steele in DOOM PATROL #23
You would think they would just realize the it might have been more than one. Look at last 1/2 dozen that smaked into Jupiter.
Nothing like a one two punch to really put a cloud in the sky and cool things down.
Neck_of_the_Woods
#/usr/local/surf/glassy/overhead
1) Asteroids, meteorites and comets tend (okay, massive generalisation here, but whatever) to travel in packs (a la Leonides and Perseides).
2) I don't kow about you, but I have trouble believing that a single impact could wipe out "all" life without destroying the planet, ripping off the atmosphere, etc...
I am alone, yet I also surf the universal backwash of undifferentiated Being, which is LOVE.
Does anyone with a better knowledge of radioactive dating than me know what kind of effect these impacts have on radioactive dating methods? Would there be any, and if so on what scale? Furthermore how localized would the effects be, and finally how could/are they compensated for? The part of the article about how few craters have been accurately dated got me wondering about what kind of complications they presented for dating methods in the area around them.
I wouldn't be surprised if the dinosaurs died off as a result of a multiple-impact object, instead of a single crater. Something similar to what
Shoemaker-Levy 9 did to Jupiter. Are there any known examples of related impact sites on earth? I imagine that'd be hard to prove, but it would be a neat piece of trivia.
Since Carbon-14 has a half-life of 5.73 x 10^3 years, I really doubt that your mountain was dated using it. Craters (and other geological formations, such as you mountain) are not dated using it as it's half-life is only about 5 or 6 thousand years, meaning it's only useful to date back approximately 70 thousand years, as any specimens from before that would have to be made entirely out of C-14 for any of it to survive to modern times. It's interesting to note that we are screwing over archeologists of the future thanks to the industrial revolution - there is more C-14 present in the atmosphere now due to pollutants (Nitrogen + neutron = Carbon-14). Potassium-40 and Uranium-238 are the isotopes used to date old rocks, as their half-lives are 1.26 x 10^9 years and 4.5 x 10^9 years respectfully. It is most likely that the crater in question in the above article was inaccurately dated due to an abundance of the isotope used to date it being present in the meteor that caused it.
I don't need to be made to look evil. I can do that on my own. - Christopher Walken
I went back in time and infected them with the flu. They all died.
Eat at Joe's.
re:
<RantMode>
Why do people (the 'media' in particular) always miss out the error margins when quoting scientific results? The first thing you should learn when doing any form of quantitative science is error analysis: without this all the results are meaningless as you have no idea of the certainty or significance of them.
For example, with these results you quote, if the measured result were actually 2.8 Million years +/- 2 million years, then that would not give any cause for concern, or 350 thousand years +/- 10 million years would be as good as spot on. OTOH if the results were 2.8 Million +/- 1 year then we should definitely be questioning the accuracy of such measurements.
<RantMode>Let's not forget that many species of dinosaurs were in decline well before the k-t event that is generally accepted as the point (65mya) when dinosaurs went extinct. Although the idea of a big rock killing all the dinosaurs is popular with geologists and catastrophists, many paleontologists still don't buy this explanation. Some even point to birds as the direct descendents of theropods and insist that dinosaurs never really went extinct in the first place.
As others have no doubt pointed out, you misunderstand what radiometric dating is, and more importantly, you seem to be missing something about the nature of radio-carbon, such as where it comes from, its half-life, and its application in archaeological and paleontological dating.
First C-14 is the only readioactive form of carbon used for radiometric dating. No physical collision at any speed that occurs in the earth's vicinity could produce it. The isotope is produced by the interaction of cosmic rays and N-14 (that is a nitrogen isotope). The C-14 later decays reverting to N-14 and emitting a neutrino. The produciton of C-14 takes place within the earth's atmosphere. The atmosphere alone contains enough gas in any form to act as a significant source to donate radiocarbon into the biosphere. No significant amount of carbon arrives from space and no C-12 coming from space could have any significance to the production of C-14; they are not related, and C-12 plays no roll in the existence of C-14.
Second, who ever told you about the "small mountain" had a serious case of rectal-cranial inversion. Additional radiocarbon would cause an organic mass to appear younger, not older, though many thoroughly confused and consistently ignorant creationists persist in thinking the opposite.
Last and most important, radiocarbon has a half-life of about 50,000 years and a useabilility range for dating purposes of about 100,000 years at best, if accelerated mass spectroscopy dating methods are employed. Since dinosaurs disappeared from the planet about 70,000,000 years ago, radiocarbon is useless, because about 1400 half-lives of radio carbon have passed. For practical purposes that means that there is no C-14 left in any sample you look at.
------ The only greater hazard to your liberty than n politicians is n+1 politicians.
You are correct. The 50,000 was the result of me hurrying. I added an extra zero there when I entered what was intended as a rounded figure in the calculator, then stupidly repeated it when I (accurately) transcribed my mistake, and carefully punctuated it. The two common half-life figures I am familiar with are the Libby half-life of 5568 +/- 30 years and the Cambridge figure of 5730 +/- 40 years which you mention. This of course puts the Cretaceous about 14,000 radiocarbon half-lifes away, not the mere 1,400 I had came up with there.
Thanks for the correction. It is why there is peer review in science.
------ The only greater hazard to your liberty than n politicians is n+1 politicians.