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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.'"

11 of 862 comments (clear)

  1. Re:Correct me if I'm wrong. by another_henry · · Score: 5, Insightful

    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

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  2. kill all the plants too by slothman32 · · Score: 5, Insightful

    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?

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    1. Re:kill all the plants too by DragonMagic · · Score: 4, Insightful

      Plus, if it were that powerful to bake animals, would not the water temperature rise, and the air bake the animals which did survive, and destroy the birds as they're not too good about going underwater, and melt the ice at the caps, and...

      Sorry, but this theory doesn't even sound plausible. What could they base it on? (Sorry, article /.'ed)

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    2. Re:kill all the plants too by ultramk · · Score: 5, Insightful

      Plus, if it were that powerful to bake animals, would not the water temperature rise, and the air bake the animals which did survive, and destroy the birds as they're not too good about going underwater, and melt the ice at the caps, and...

      To kill most large animals, the air doesn't need to be hot enough to bake the whole animal, just ruin its lungs.

      Plants are easy. Many (most?) plants have evolved mechanisms to allow them to survive forest fires, brush fires and the like. The root stock would survive, and the seeds are mixed with soil/blown into protected places etc. Remember, they don't all have to survive, just enough to repopulate the species. There would be myriad places where plants or animals would be sheltered by the shape of a canyon/cave or whatever.

      There are quite a few bird species that live in burrows/caves/hollow logs etc which would have survived. There are a lot of bird species that respond to any danger by diving into the water, and diving deep. Grebes, cormorants, and the like. There are lots of diving birds.

      As far as raising the temperature of the water, you're vastly underestimating the amount of energy it would take to raise the temperature of all of the earth's oceans. It takes a lot more energy to raise the temperature of a volume of water than it takes to raise the same volume of air the same amount. (any physicists/chemists/engineers want to run the numbers?) The surface temperature of the oceans would probably rise a bit, then most of that energy would be shed back into the atmosphere by evaporation. The overall temp of the oceans would remain pretty constant, certainly not enough to melt the ice caps. For the superheated air directly above the glaciers, there would probably be a little bit of surface melting, which would immediately refreeze, leaving a glazed surface.

      m-

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  3. Detroy the world fallacy by __aanonl8035 · · Score: 4, Insightful

    1. Do the Americans really have enough nukes to destroy the world ten times over?

    This one I hear a lot. First of all, despite what you may have heard, really the majority of the energy of a nuclear explosion turns into heat and blast immediately, NOT radiation. The only exception to this is the so-called Neutron bomb, designed specifically with radiation (more specifically fast neutrons and gamma rays) in mind. But realistically, although the Americans have built approximately 70,000 warheads of almost 70 different types, they now possess a stockpile of around 9600 warheads. Surprising as it may sound, this is NOT enough to 'destroy' the world. Even hitting every city in the world with everything in every country's arsenal would not be able to 'destroy' the world. The world is still a
    BIG place. Keep in mind the Russians have around the same numbers of warheads.

  4. Re:You know, thats really not funny. [NT] by Daniel+Dvorkin · · Score: 4, Insightful

    Funny, no. But sometimes that kind of dramatic analogy is necessary to get the point across to people who don't understand what the word "theory" means in a scientific context.

    I tend to personalize it a bit: "If you believe that ___* is 'just a theory,' be aware that gravity is 'just a theory' as well. I invite you to try jumping off a skyscraper because, surely, nothing that is 'just a theory' can hurt you."

    *___ is almost always evolution, of course, though sometimes it's relativity.

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  5. Why isnt this article SPAM by robogun · · Score: 4, Insightful

    Someone post the article so we can make intelligent comments on it.
    To be honest, I have no idea why an article like this is not considered spam, if we have to pay to read it.

  6. Re:The important question... by jebell · · Score: 4, Insightful
    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.

    I think you're underestimating how strong many animals really are. Our close relatives, the chimpanzees, are considerably stronger, pound-for-pound, than we are. Reptiles are also noted for being very muscular, even if they don't have much stamina.

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  7. Re:Correct me if I'm wrong. by vaccum+pony · · Score: 4, Insightful
    "Actually it's well accepted as by far the most likely candidate for what happened."
    In the general public's mind perhaps, but not elsewhere. There is a LOT of fossil evidence showing that Chicxulub did NOT wipe out the dinos. There is also fossil evidence that dinos were already in decline BEFORE Chicxulub hit.

    Before and after Chicxulub Earth was experiencing a lot of volcanic activity. So much in fact, that the compositiom of the atmosphere was changing. As I recall the oxygen content was reducing from 30% down to 24% (I'm sure these are not the exact numbers, but they are close). Less oxygen meant that animals had to work harder in take in the same amount of oxygen. The dinos may have have suffocated.

    Of course, a large impact would not have helped them out...
  8. Re:You know, thats really not funny. [NT] by Daniel+Dvorkin · · Score: 4, Insightful

    Nope, the fact that you fall if you jump off a skyscraper is that fact that you fall if you jump off a skyscraper. Gravity is the theory that says you fall because the Earth, being rather large, exerts a powerful attractive force on your soon-to-be corpse. You could just as easily explain the falling by using the Aristotelian (IIRC) "things fall because it is their nature to fall" -- but that theory proved to be incompatible with the evidence, and thus was discarded; modern gravitational theory is the best we've got, so far.

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    The correlation between ignorance of statistics and using "correlation is not causation" as an argument is close to 1.
  9. So, we've given up on real science then? by alien_blueprint · · Score: 4, Insightful

    The new study reviewed existing geologic evidence for the known impact and considered interesting patterns in species survival. How did some birds, mammals, crocodiles, snakes and other animals endure the calamity that wiped out larger species?

    That's a good question. But it's got a bug in it - the phrase "wiped out larger spieces". Better to say - selectively wiped out one branch of animals that came in all shapes and sizes, and lived in all kinds of environments right alongside animals that *didn't* die out.

    That asteroid sure was amazing!

    The survivors burrowed underground or were protected from the firestorm by swamps or oceans, says study leader Doug Robertson of the University of Colorado at Boulder. The details were published in the May-June issue of the Bulletin of the Geological Society of America.

    That's so plainly idiotic that it beggars belief. Dinosaurs came in a wide variety of sizes, some smaller than chickens. And there were many aquatic animals that also became extinct, that supposedly would have been safe according to this "study leader".

    Another win for the hypothesis that makes for a good special effect, then. And published by the Geological Society - well colour me not suprised.