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Dinosaurs Died Within Hours of Asteroid Impact, says New Study
colonist writes "SPACE.com reports that most dinosaurs were incinerated within hours by the 'heat pulse' of an asteroid impact 65 million years ago. The study 'Survival in the first hours of the Cenozoic' presents a scenario where the only survivors were underground or were underwater in swamps or oceans. All unprotected creatures were 'baked by the equivalent of a global oven set on broil.'"
An appropriate post for the Memorial Day weekend. Imagine the world's largest barbeque.
the major advances in civilization are processes which all but wreck the societies in which they occur - A.N. White
I'd like to RTFA, I really would !
it's too bad their all-star oil drilling team didn't quite make it in time...
The real reason dinosaurs became extinct!
Actually it's well accepted as by far the most likely candidate for what happened. By the way, other theories include the theory of gravity, relativity theory etc... all pretty much proven, ask Hiroshima about E=mc^2 if you don't believe that one :P
"Studies have shown that people who eat peanuts live longer than those who do not eat."
Alright, so what do I need to survive the next major asteroid impact of this magnatude? It sounds like most buildings won't be sufficient protection.
Do I need a cave to hide in? Should I go to a large body of water?
"Hey, Lou, what the F is " *SPLAT*
Everything in science is a theory. The "asteroid impact" idea has a lot to back it up however since there are some realy big craters on this ball of mud we call home. Check out the 170 km one at the Yucatan Peninsula.
"Have you ever thought about just turning off the TV, sitting down with your kids, and hitting them?"
the consensus is: The asteroid that killed off the dinosaurs is the one that hit in the Yucatan Penninsula The asteroid that killed off 99.9% of life before the dinosaurs existed was the one that hit near austrailia
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Of course I didn't read the article, as I don't subscribe and am lazy, but wouldn't the heat kill all the plants too? And I thought there were "many" survivors. Mostly small animals, besides plants and lower life forms. And how could 1 impact effect the entire planet with such a high amount of heat? Wouldn't that metemorph rocks as well? Or even react the atmosphere?
Why don't you guys have friends or journals?
The majority of the dinosaurs were instantly fried, like in a nuke blast that wrapped around the globe. I haven't seen a movie lately, that had those kind of cool FX. How about you?
Think about to all the meteor's crashing into earth movies there are, now think about all the FX. Nothing as impressive as ALL THE DINOSAURS getting fried as a heat wave travelled around the globe.
Why can't Hollywood just pay attention to history and science. It's way cooler than the drek they come up with.
But seriously folks, just think of all the Brontoburgers. I bet Fred and Barney boiled off the surface still salivating at the endless plains of dino ribs.
Arrogance is Confidence which lacks integrity. -- me
So many things survived from that time other than the Dinosaurs. Large trees, many forms of reptiles and mammals that are virtually the same (based on fossil records) to this day.
Not too mention that the fossil records for Dinosaurs don't stop on 1 day.
It seems that the Doomsday theory gets more headlines than other theories suggesting, disease and climate change (a much slower, more boring process) were the cause. Even though the damage of a meteor strike would have been far more devastating and left the planet set back near square one as far as life.
If the earth was baked and then the sun was blocked by smoke and ash, how come so much survived?
*Note IANAS (I Am Not A Scientist), just wondering.
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"Alvarez Hypothesis" is the term used to describe the idea that dinosaurs died as a result of a catastrophic asteroid impact. I do not believe that the hypothesis has attained the status of theory, however. The main evidence for such a hypothesis seems to come from the observation of geologist Walter Alvarez of a significant layer of Iridium on the Cretaceous-Tertiary boundary (KT boundary), due to the fact that Iridium is a very rare element on Earth but found in abundance in asteroids and meteorites. This link has some more information along with Wikipedia.
I think you're talking about two different mass die-offs. The Yucatan crater theoretically caused the Late Cretaceous die-off (approx. 65 million years ago) that made the dinosaurs go extincet. The Australian crater has been linked to the Late Permian die-off, which happened about 250 million years ago.
So, Racer X, the scientific community would appear to have two consensuses (consenses? WTF?), one on each of the two issues.
Mass extinctions are a fairly regular event in the Earth's geologic history. There are at least two more, besides the Permian and Cretaceous catastrophes, with which I'm familiar. Most people only get taught about the Cretaceous one in high school, though, so they never hear about the others.
Kind of like the Ice Age. Up until I was 16, I only thought there was one. Turns out there were a shitload of them.
All unprotected creatures were 'baked by the equivalent of a global oven set on broil.'"
Thanks for the metaphor. This "heated air" concept is difficult to get across to the layperson.
There is a theory that the earth was lighter back then, which let heavier animals thrive. It's an interesting theory - it also says that the Pangea continent covered the whole earth (not just one side) since the earth was ~40% of it's current size, and that it grew by collecting space debris over time. Someone should do the math concerning muscle efficiency and this ancient mass of the earth and see if it works out.
-- This sentence is false.
So now we have prior art for animal crackers.
I read the article
Another wild hypothesis without a shred of verifyable evidence.
I couldn't read it THIS time (because the server is slashdotted). But I did read it - or another describing the same theory - when it first became newsworthy some years ago.
There's plenty of evidence for it.
First off, the prediction comes straight out of physical modeling of what happens when a big asteroid hits:
- A bunch of rocks are kicked every which way.
- If the asteroid is big enough a LOT of them go into space.
- A fraction of them have enough energy to get above the atmosphere but not achieve escape velocity.
Once you realize those three things, it's straightforward for a physicist to calculate, for various size impacts on various sites (land, shallow ocean, deep ocean), how MUCH mass goes up, how MUCH of it comes back down, WHERE it comes down, HOW FAST it comes down, and what the results are.
So they calculated that. And came to the conclusion that for impacts of a certain range of sizes the result would be several hours of a rain of sand, all over the Earth, at speeds of up to several miles per second (plus rains of rocks of varying density at different distances from the crater and its antipode). The sky becomes essentially solid meteor trails for hours.
And those are HOT! Hot enough to dry out most of the plants and set them afire. Hot enough to kill any animal life on the surface that can't get underground or under water right away and then stay there for hours.
So if the sky turned into a broiler oven over the whole Earth for several hours all at once, what does this predict? One hemisphere is day and the burrowing nocturnals survive, the other is night and the burrowing diurnals survive. (And in particular regions it got REALLY hot, or REALLY shocked by the primary impact or the secondary rain of rocks, and NOTHING survived).
So they looked at the fossil record and that's what they found. Prediction confirmed - very good evidence for the model. Further, they could now tell WHAT TIME OF DAY the impact occurred and roughly where.
Then they looked in the area where this model predicted the impact should have been and FOUND A CRATER of the correct size (along with plenty of other evidence that this PARTICULAR crater's impact coincided with the extinction event).
Looks solid to me. Unless something new comes up I consider the puzzle of the extinction events solved.
The only question I have is: Why is this news NOW?
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
And just how much stronger could dino muscles have been than modern mammalian muscle? 140% stronger, 170%? That's really stretching it, and it still isn't nearly enough.
When doing comparisons be careful to avoid human muscle. Humans are cursorial hunters (jogging after their prey until it collapses from heat exhaustion.) Most of their muscles are set up to only use a few percent of their fibers at a time - and switch to another batch when the first run out.
That's why hysterical strength is so much greater: Under great stress you CAN use your whole muscle power for a few contractions - like a mother lifting a car off her kid (a rather common event, actually). But it comes at a cost: The bones, pads between them, and muscle attachments are NOT built to the necessary strength for this. Use of hysterical strength normally means some serious, often permanent, injury.
Most other animals (including even our close relatives the chimps) use a much higher fraction of their muscles all the time - or under only moderate provocation - and have the structure to support this use. (That's why they're so dangerous to people who handle them without having armor on and weapons handy.)
Land animals probably can't be much bigger than an elephant.
Not if they're going to be chased around by lion prides, packs of canids, and humans. (The square-cube law also applys to dumping heat.) You can build a workable animal MUCH bigger than an elephant. But now that there are warmbloods specializing in running things to collapse and eating them you can't keep a population of things that large viable in the wild.
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
But really, all this fancy language is another way of explaining the ovbious:
The dinosaurs got 0wned. Real bad.
Obviously, the dinosaurs were ignorant of the "Duck And Cover" method for surviving an incinerating holocaust. Or is that only for nukes?