Sorry to be taking so long to get back to this. I really want to respond to the links in your first post and this is my first answer. The rest of the thread is going to have to wait.
It did? Really? Let us find out:
(AP)Researchers studying rocks from Antarctica have found chemical evidence that a huge meteorite smashed the Earth 251 million years ago and caused the greatest extinction event in the planet's history, killing about 90 percent of all life.
The extinction, which scientists call the Permian-Triassic event, came some 185 million years before a similar meteorite collision with the planet killed off the dinosaurs.
So far what we have here is just one possible fact, "chemical evidence" in "rocks from Antarctica" and a lot of hypotheticals. So, may I expect from the rest of this article to discover information that this "chemical evidence" is indeed commensurate with the hypothetical event suggested? Let us see.
By the way, before I proceed further: A photo accompanies this story that shows a huge splash of water in the ocean which is obviously supposed to suggest the impact of a meteorite. But I seriously doubt this is in fact a photo of an actual meteorite hit. Probably an undersea nuclear test? Or what? Is this kosher science not to identify the actual photo but let it suggest something it no doubt doesn't in fact represent?
And according to much on the rest of this thread, such a gigantic meteorite hit as is supposed to have happened wouldn't just look like a splash in the ocean but would create intense heat. If you're going to illustrate the idea, do it right I say.
But let us continue.
"It appears to us that the two largest mass extinctions in Earth history ... were both caused by catastrophic collisions" with meteoroids, the researchers say in their study appearing this week in the journal Science.
Asish R. Basu, a professor of Earth sciences at the University of Rochester, said proof of a massive impact 251 million years ago is in the chemistry found in rocky fragments recovered on Graphite Peak in Antarctica. He said the fragments were found at a geological horizon, or layer, that was laid down at the start of the Permian-Triassic extinction. Analysis shows the fragments have chemical ratios that are unique to meteorites.
A fact: Aha! Now we find that this "chemical evidence" of this catastrophic event so many aeons ago is found in "rocky fragments" in a layer of the "geo column" known as the Permian-Triassic period. Since I'm allergic to describing natural phenomena such as a layer of dirt in interpretative terms that imply whole scenarios about the distant past, I must reduce this to the simpler factual statement that this chemical find in rocky fragments was found at the juxtaposition of two discrete layers of distinctly different kinds of compacted dirt. Which kinds of dirt/sediments are not described. I guess they don't consider it important. Only the unique chemistry of these fragments is of interest. OK, except for the need for the more strictly descriptive and therefore more empirical -- as opposed to tendentious and interpretive -- renaming of the phenomena involved I'm open to hearing about this.
Another fact: "Analysis shows that the fragments have chemical ratios that are unique to meteorites." OK. I have no reason to argue with this. I can assume they know about chemical ratios in meteorites. HOW they know it I can't be sure but I assume whatever it is, it's different from what normally occurs on Earth. OK? So far so good. But -- maybe something like it occurs deep in the earth? Just a thought.
"The only place you would find the chemical composition that we found in these fragments is in very primitive, 4.6-billion-year-old meteorites, as old as our Earth," said Basu, the first author of the study.
Hokey dokey. He SAYS it's the only place, so OK, no problem, I'll accept that, why not? But I do have a problem with his interpretative labeling again, which assumes an age and a condition called "primitive" which implies oodles of interpretive hooha, but I'll just put this on the shelf for the moment too.
That supports the theory that space rock the size of a mountain streaked in from outer space and smashed into the Earth.
Well I can go with the conclusion that *a* meteorite had to hit us in order to deposit this as-yet-unnamed "chemical" anywhere on our planet, but nothing has said been yet that suggests anything about the SIZE of this baby. A few fragments of this stuff found on a mountain in Antarctica doesn't exactly add up to this streaking mountain.
And get the dramatic language. "STREAKED in from outer space and SMASHED into the Earth." Not that I would normally object to such language but I've become a bit cynical about the elaborate imaginative scenarios that pass for science in the whole arena of evolutionistic and geo time frame speculations. So
little fact, so
much drama.
The violence of the impact would have caused a huge fireball and sent billions of tons of dust into the atmosphere, enough to darken the sun for months. It also would have laid down a layer of dust bearing the same chemical composition as the meteorite.
Uh, where's the evidence that this this thing is ANY particular size, let alone this monster size? NOTHING so far has been said to show SIZE. Come ON, shouldn't science types muster their information in a bit more orderly way?
Scientists believe the six-mile-wide asteroid that killed the dinosaurs left a thin layer of a metal called iridium all over the globe. Basu said that element was not found in the fragments recovered from the Antarctica, suggesting the earlier space rock had a different composition than the dinosaur-killer rock.
Well, I never read up on this one when it was a big thing. I wonder if much info will be given in this article. What exactly is the evidence for this six mile wide asteroid? So huge it left iridium ALL OVER THE GLOBE. A very thin layer, but really, ALL over the globe? Exactly where? How many places? Anyway so this one is different, different chemical evidence. Earlier. How do they know it's earlier? OH YEA. Where they found it. Sigh. Where they found this chemical evidence. Which layer in the geo column. Sigh.
Basu said specimens recovered from Permian-Triassic rocks formations in China, however, have a chemistry that matches that of the meteorite fragments found in Antarctica, a discovery that supports the impact theory. Also, shocked quartz, a telltale sign of an asteroid impact, has been found at both sites, he said.
OK, so far "all over the globe means Antarctica and China. Wonder what this "chemistry" is. Not that it matters awfully, but it seems a little odd not to have mentioned it by now. Shocked quartz is a sign of an asteroid impact -- as opposed to any other kind of "space rock?" Or a sign of ALL such impacts? But I don't doubt this is all evidence of a "space rock" impact. Just so far they haven't said anything to show its size or when it hit, merely keep talking about it as if they know it to be a certain fact.
At the time of the Permian-Triassic event, Africa, South America, India, Australia and Antarctica were joined in a giant continent called Pangea. Just where the asteroid hit in that land mass is uncertain, Basu said.
Well, can't you tell from where its crater is NOW???? I mean Pangaea split up in a pretty well known pattern. Oh, no crater, right?
"The impact had to have been in the southern continents someplace," he said. "We think it is near what is now western Australia."
Gee it would be interesting to know why they think it hit in that location. They think this but they aren't interested in giving us their reasoning. Is this because this is just a puff piece for the ignorant average person or something?
Life on Earth at the time was far different from what it is now and what it was when dinosaurs lived.
Oy. Now we're getting strung WAAAAY out. Haven't had an actual fact mentioned in quite a few sentences here.
"There were no large animals then, but there were lots of species living on the land and in the sea, and there were plants," said Basu. The most dominant plant, which is found commonly in fossil beds from the Permian-Triassic, was a giant fern called glossopteris. In the geological layers following the impact, that fern is absent from the fossil record.
Translation into empirical terms: Which means in the geological layers ABOVE the layer the chemical evidence was found in, or at least the layers that are ASSUMED to be above it, as sometimes all the layers aren't actually present and they aren't telling us in this case as usual.
Empirical = based on what is experienced or seen rather than on theory. So why is it in reports of this kind of thing that all we ever hear is theory and never ever what is experienced or seen?
What is it these layers in Antarctica and China in actual fact have in common? How many layers are present, what is their composition at these locations? Are they in fact identical in composition and arrangement or are we just being given the accepted interpretation about this too, treated as fact? Mabye it doesn't matter as far as this chemical evidence's being a sign of a "space rock" impact, which I've accepted it is, but it would go a long way to giving some sense of reality to what remains a mere imaginative construction otherwise.
"That was the last blooming of that plant," said Basu. "After that, it was gone forever from the planet."
Theory again, that the order of the layers is an ordering of great spans of time. But he's right of course, it WAS the last blooming of that plant, whatever the occasion of its demise was.
Around the same time of both the Permian-Triassic and the dinosaur extinctions, there also were massive outflows of a lava called flood basalt. It continued for thousands of years and thickly covered hundreds of miles. Basu said it is possible that asteroid impacts triggered both eruptions of lava, but the connection has yet to be proven.
What a non-story this is. I can't believe I read through this whole thing and it's a big nothing.
Some experts are skeptical that Basu and his co-authors have found 251-million-year-old meteorite metals, although nobody questions that the material did come from outer space. The surprise is that the specimens survived the weathering on Earth for so long.
Well, now that's very interesting. Until this point this entire article hasn't said one thing about the chemical composition of this chemical evidence the whole story is about. This is even the first time it's called "metals." And just as we find it out we also find out a major objection to the very idea itself, that whatever these metals are, they would be vulnerable to weathering in 250 million years. Interesting.
"It's astonishing, it's incredible, it's unbelievable," Jeffrey Grossman of the U.S. Geological Survey said in Science.
Birger Schmitz of the University of Goteborg in Sweden said in Science that it "would really be remarkable" to find unaltered meteoritic fragments such as those claimed by Basu and his colleagues.
"I get a gut feeling it's wrong," he said.
Basu, however, said, "nobody in the world can question our chemical findings."
The question, he said, is what were the unique circumstances that allowed the material to survive virtually unchanged chemically for 251 million years.
"We have to work that out," said Basu.
So what does this story tell us? All of one fact I believe, just one. This chemical stuff, which remains unnamed throughout the article, finally identified as "metals," which are known to be found in these proportions only in meteorites, has been discovered in "rocky fragments" in Antarctica. The same stuff has been found in China, supposedly in the same "time period" although we have to take their word for this as they never tell us what the actual strata look like and how they know. Over how broad an area this stuff has been found can't be told from this evidence, just that some was found in Antarctica and some was found in China. A whole scenario is concocted about a GIGANTIC meteorite hit in that "time period" based on what? The find of this stuff in two places only. Then along comes somebody and raises a reasonable question: How did it survive weathering patterns over such a long period of time? And poof, away goes this gigantic "space rock" that supposedly wiped everything out 251 million years ago.
I wonder if possibly it might suggest a smaller meteorite hit or even a bunch of them in a shorter time period a lot more recently? Just a thought. I mean if this stuff really is found only in meteorites I see no reason to doubt that origin of it -- that anybody's mentioned so far anyway. But there's no evidence whatever of a gigantic hit, no crater, nothing.
Anyay, what an absolute NON-story, but you used it as evidence that there have been many such events that would make all life on earth extinct.
I'm SO not impressed.
More to come.
This message has been edited by Faith, 05-26-2005 03:50 AM
This message has been edited by Faith, 05-26-2005 03:52 AM
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