Dinosaurs Died Within Hours of Asteroid Impact, says New Study 862
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.'"
Dino-burgers (Score:5, Funny)
Re:Dino-burgers (Score:5, Funny)
Mmmmm. Ribs big enough to tip over your car at the drive-in.
Re:Dino-burgers (Score:5, Funny)
20-30 million dinosaurs (various species)
Iridium seasoning
Garlic salt
Chili powder
Directions
Place the dinosaurs in an oven-safe planet. Shake the seasonings until all the dinosaurs are evenly covered with a light layer of iridium. On top of that, shake on a little bit of garlic spice (not too much since it is salt). On top of that, add a few hearty shakes of chili powder to cover the animals lightly. Place the planet in the oven on the broil setting. It's important to place the planet in the middle of the oven so that it is not too close to the top broilers or it will burn. Let the dinosaurs cook for about 15 minutes on one side or until they start to get a little bit crisp. Flip the dinosaurs over in the planet and spice the back side like you spiced the front. Toss them back in the oven for another 10 minutes or until slightly crisp. Pull the planet out of the oven and flip the dinosaurs over a few times in the juice.
Feeds 2-3 billion.
Re:Dino-burgers (Score:3, Funny)
Broil? (Score:5, Funny)
Re:Broil? (Score:3, Informative)
Re:Broil? (Score:5, Funny)
The dinosaurs got 0wned. Real bad.
Re:Broil? (Score:3, Interesting)
"'Twas brillig, and the slithy toves
Did gyre and gimbol in the wabe."
British [jabberwocky.com]? Broil is what you do at 4 o'clock in the afternoon [eosdev.com].
Re:Broil? (Score:3, Interesting)
Broiling is what the English call grilling.
Of course a grill over here is one of those outdoor things with charcoal (or gas).
Re:2 Marks from.... (Score:5, Informative)
Gas Mark is a Fahrenheit scale.
From this chart [godecookery.com] it is possible to infer that Gas Mark 0 is 250 Fahrenheit, and each increment of 1 Gas Mark is equal to 25 Fahrenheit degrees.
So at what Gas Mark setting did they bake/flambe the dinosaurs?
As an exercise for the interested reader, using spectroscopic data, estimate the surface temperature of Zubenelgenubi in Gas Mark.
Re:2 Marks from.... (Score:5, Funny)
Re:Broil? (Score:3, Interesting)
Gas Mark 9 for example was extremely hot, around 250 degrees C or more. Gas Mark 1 would be "warm up some buns" or something.
Re:Broil? (Score:4, Funny)
right then. Imagine a cooker that went up to 11.
Re:Broil? (Score:3, Funny)
I'll bet the average American would pay about twice as much for a "convection" oven than they would for a fan oven. I know I would!
Re:Broil? (Score:4, Informative)
Hmm, considering there's a dish called "London Broil", it just makes me wonder if that's not actually British, but yet another American bastardization...
Re:*YOU* don't know?!?!? (Score:4, Informative)
What you call broiling we call grilling. What you call grilling we call frying. What you call frying we call deep frying.
RTFA (Score:5, Funny)
Why isnt this article SPAM (Score:5, Insightful)
To be honest, I have no idea why an article like this is not considered spam, if we have to pay to read it.
too bad for the dinosaurs (Score:5, Funny)
Pot Smokers Rejoice! (Score:5, Funny)
Gary Larson Lied! (Score:5, Funny)
Survival (Score:5, Funny)
Do I need a cave to hide in? Should I go to a large body of water?
Re:Survival (Score:3, Interesting)
The article stated that ground-level temperatures were only ~10K higher than just prior to the event. That's no big deal, save maybe during summer in parts of the world.
Any building that didn't itself burn due to the IR radiation would shield it's occupants quite well. Concrete/Brick's transmission of IR radiation wouldn't be much more than that of
Re:Survival (Score:5, Interesting)
Unless you are on the wrong side of the planet (in which case you are f*cked anyway), your building should be the least of your worries.
Global food production will probably take a very deep dive as large areas get drenched/ baked and exposed to a bunch of other nastiness. Maybe the sky will go dark for some days or years also.
We humans being what we are (animals with a strong urge to survive) one can probably expect violence and war for remaining food, and lots of refugees as some parts suck worse than others.
Maybe you should look for a place far inland, a descent house, keep some water and purification equipment, plenty of food, and I'm sad to say, weapons.
Tor
wrong side of the planet (Score:4, Insightful)
This is easy to visualize if you imagine a strike at the North Pole and the debris traveling along the lines of longitude to the South Pole.
Duck and cover (Score:3, Funny)
Or get one of the 1950's vintage A-Bomb-proof school desks.
Chip H.
Mmmm, Broiled Dino (Score:4, Funny)
I'd say some died instantly (Score:5, Funny)
Article title (Score:4, Informative)
According to the article, the dinos were cooked by super-heated air. That would mean they were broiled, not fried
Facts? (Score:4, Insightful)
"There's no question over whether an asteroid hit. The roughly 6-mile-wide (10-kilometer) space rock carved out the Chicxulub crater off Mexico's Yucatan Penninsula."
But fairly recently there was another article posted on slashdot, about the alleged impact having occurred in (what is now) Australia. (check, e.g., here http://www.msnbc.msn.com/id/4969840/ for a similar story.)
so what is the consensus *really*, in the scientific community? or is there just none?
Re:Facts? (Score:5, Informative)
Re:Facts? (Score:5, Informative)
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.
Re:Facts? (Score:4, Informative)
kill all the plants too (Score:5, Insightful)
Re:kill all the plants too (Score:5, Insightful)
Sorry, but this theory doesn't even sound plausible. What could they base it on? (Sorry, article
Re:kill all the plants too (Score:5, Interesting)
I don't know about the birds, but this is hardly a fatal objection. Small animals can find many hiding places unavailable to larger ones. I don't think we need be too surprised if a number of smaller dinosaur species survived.
There were no polar ice caps during the Mesozoic.
I'd be shocked to discover that space.com's servers were ever overloaded by /. If you don't want to read the article, then say so. (If you're referring to the original paper, you can only get the abstract without a paid subscription anyway.)
Re:kill all the plants too (Score:5, Insightful)
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-
Re:kill all the plants too (Score:5, Informative)
This doesn't at all take into the account the fact that the starting temperature of the air is higher than that of the water. The average temperature of water in the oceans is just a bit above freezing in the pole areas and is about 17C(62F) on average (max 36C). The average temperature of air is much higher due to being over landmasses. Thus heating all of the air is MUCH easier than water.
Re:kill all the plants too (Score:5, Informative)
Re:kill all the plants too (Score:4, Informative)
The Truth is so much cooler than Fiction (Score:5, Interesting)
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.
But so much survived (Score:5, Interesting)
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.
Re:But so much survived (Score:3, Insightful)
Exactly! Evolution put a lot of effort (so to speak) into evolving seeds that refuse to germinate unless the conditions are just right. Germinating only when conditions are right maximises the chance of survival for the plant.
I had a packet of cactus seeds with instructions to soak them in very hot water for one minute, plant them immediately afterwards in moist sandy soil and leave them in the dark for a week or so. Even so, mine didn't germinate until three weeks later. Fussy little bug
The important question... (Score:4, Interesting)
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.
Land animals probably can't be much bigger than an elephant.
And no, I'm not a christian scientist. I don't think it's a conspiract, the bones are there, and they show how big the things must have been. I'd just like answers (prefereably those that don't have anything to do with superstitious bible crap).
Re:The important question... (Score:4, Insightful)
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.
Re:The important question... (Score:5, Funny)
Re:The important question... (Score:4, Interesting)
There is quite a bit of research going on in this area that relates to dinosaurs. I don't have any specific refs, but if you check out the recent literature, you should be able to find a number of current articles.
Re:The important question... (Score:5, Interesting)
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.
Re:The important question... (Score:3, Interesting)
I'm still confused on why *all* the Dinosaurs died 65 million years ago, yet the rest of land animals (amphibians, reptiles, mammals, and birds) survived.
Dinosaurs weren't all big dumb lumbering brutes -- some were as small as our present-day reptiles and amphibians, and had mostly the same environment. Ne'ermind that at least one of the reptiles had a brain/body mass ratio better than a wolf.
So why did every dinosaur die but reptiles survived? Why did every dinosaur die but birds survived?
Quest
Re:The important question... (Score:3, Funny)
You've obviously never tried to pill a cat...
Thank God (Score:4, Funny)
And in other news (Score:3, Funny)
PETA boycotts all asteroids in protest of the senseless murder of the dinosaurs.
They are throwing red paint on meteorites, and showing up nude at natural history museums everywhere.
Oven set on broil. (Score:5, Funny)
Thanks for the metaphor. This "heated air" concept is difficult to get across to the layperson.
conflicting theories (Score:5, Interesting)
Personally, I'd like for these theories to go through a bit more critical review before they're broadcast to the public. This smacks as sensationalism more than science.
Great... (Score:5, Funny)
Nonsense (Score:3, Funny)
Read the Bible!
Re:Nonsense (Score:4, Funny)
Neither did Noah!!
COLD!!! not HOT (Score:3, Interesting)
Some points from the Journal article (Score:5, Informative)
Unfortunately the linked article is available in the Online Journal which you can either subscribe to or go to you neareast Uni Library and check it out.
A Thermal heat pulse and the ejecta from the impact could travel around the world because of gravity dragging the ejecta back towards the earth. Upon reentry, the ejecta emitted IR radiation, brightening the sky globally. This means no night and no shadows (as the heat sources were distributed across the sky compared with the single-source solar IR radiation). This means there was nowhere to hide unless you were underground. Even rock crevices were no shelter. Subsequent fires igniting simultaenously [the suggest that there are isotopically uniform charcoal deposits at the boundary] would have added to the carnage. These fires were not significant compared to the intensity of the IR radiation. Normal solar flux ~1.4kW.m^-2, this event was calucated by Melosh in a previous paoer in 1990 to product ~10kW.m^-2. Note that ambient air temerature would have only rise ~10 K.
As for survivors, those burrowers > 10cm below the soil surface would survive. Sheltering and semi-aquatic birds are posited to be survivors.
The important thing is that this paper presents no specific fossil evidence. It does offer some phylogenetic evidence to support the bird survival hypothesis. It presents one model that can be further refined and/or refuted with evidence. It is not necessarily true or false but it can be falsified. They suggest checking Gondwanan sites for evidence of spherules (proof of ejecta reentering) and their distribution. That is the nature of science which the majority of posters thus far need to grasp. Think of science in terms of mathematical functions that approach a limit/converge as evidence and models accumulate.
So, we've given up on real science then? (Score:5, Insightful)
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.
And the chicken-sized dinosaurs still exist... (Score:3, Insightful)
The extinction event killed off all species larger than about 20kg. That wouldn't have included any mammals. Mammals 65 million years ago were tiny (mice sized) and most likely nocturnal.
One species could survive the impact (Score:3, Funny)
World-wide fire? (Score:4, Interesting)
Duck And Cover (Score:5, Funny)
Re:Correct me if I'm wrong. (Score:5, Insightful)
Re:Correct me if I'm wrong. (Score:4, Insightful)
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...
Re:Correct me if I'm wrong. (Score:4, Funny)
Wow, how old ARE you?
Re:You know, thats really not funny. [NT] (Score:5, Insightful)
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.
Re:You know, thats really not funny. [NT] (Score:5, Insightful)
Re:You know, thats really not funny. [NT] (Score:3, Insightful)
Actually, the fact that you fall if you jump off a skyscraper is the fact of gravity.
You are assuming that you know what will happen in some unobserved (hypothetical) event. Either you are Psychic, or you are using some theory that seems to have been useful in the past to predict what will happen in the situation you propose.
Whaddayaknow? You were using the theory of gravity. (the fact of gravity that you speak of is strictly for chumps)
Re:You know, thats really not funny. [NT] (Score:3, Insightful)
Oh, and just so you know, the theory of gravity hasn't been proven,
Re:thats really not funny. /I'll bite [T] (Score:3, Informative)
Domestication is a form of evolution. By man learning and practicing husbandry of animals and selecting desirable traits he (he in the generic sense) exerted specific pressures on large based familial lines. Thus was eventually born our concept of breeds. The blue heeler was bred for herding ability, the greyhound for running, the poodle as a dare (?). nearly every trait that a modern dog has is genetica
Re:thats really not funny. /I'll bite [T] (Score:3, Insightful)
Back in a time before you can imagine (Score:3, Informative)
Viruses mediate the exchange of genetic material.
The development pathway that unites all animals includes a stage in which a viable (usually fertilised) egg cell (zygote) divides a number of times to form a ball of cells (morula, blastula) gradually differentiating because of (dorsal/ventral etc.) gradients in (HOX) gene expression.
Sponges (porifera) are a likely candidate for the oldest surviving animal lineage, potentially dating from the recently annointed Ediacaran [slashdot.org]
Re:Correct me if I'm wrong. (Score:5, Interesting)
Unlike in some circles, well accepted means no has yet found evidence against it in science. Not, we all beleive it to be true. When someone has evidence against it, it becoem a disproved theory is the evidence is strong enough. However the theory of evolution has had no credible evidence against it, neither has gravity, or thermodynamics. Only small addendums.
I have faith in Christ. I need not refute scientific evidence to support my faith. God is wonderfull, sometime msyterious, and I needn't beleive in fairies ot beleive in God. Why should I beleive in creationist theories when the evolution theory fits my faith just fine.
Re:Correct me if I'm wrong. (Score:3, Insightful)
Cool. An anonymous coward knows more than the Pope about religion. Arrogant, aren't we?
The Pope stated sometime in the 1980s that christianity and evolution don't contradict, and that one can easily believe in
Re:Correct me if I'm wrong. (Score:4, Insightful)
The AC says:
The AC, is in fact, quite mistaken. What he quoted here is not the core tenet of Christianity; this is just a nice way to live with God thrown in for good measure. What Christianity is is this:
God and mankind had a good releationship, but this relationship was broken because people choose to live without acknowledging God. People are incapable of reconciling this relationship, so God, because He loves people, sent His son Jesus Christ to die on the cross and suffer horribly as a reconciliation so we can have a restored relationship with God. The restored relationship with God is what allows people to actually succeed in loving others and God...
That is the core of Christianity; not the Pope, not communion, not hymns, not going to church every week, not even the Bible. You can verify this for yourself, it's not some "theory" about Christianity - you should be quite able to go pick up a Bible and read it and you should see this is the case, and if you are so inclined, I'd recommend it.
As a man who has decided to commit himself to Christ, I kind of am distressed and saddened by the fact that people do not really understand my faith and lump it in with "you narrow-minded American Christian!". Especially since I am a scientist, love physics, and don't see a conflict between evolution and a universe created by God (if God is all powerful, why can't He use evolution?)
Anyway, at least I hope that you have an understanding now that the common perceptions of "Christianity" might not be universally accurate. Another instance of "don't believe everything you see on TV! (or read on /.!)"
Re:Correct me if I'm wrong. (Score:3, Interesting)
Because the burden of proof was on them to prove that it fits the observed Universe. If it's a theory, it's already done that.
I mean, if we're going to play that game, then I have a theory that you're an idiot.
That's not a theory. It's a hypothesis. The next step would be to devise experiments to prove or disprove the hypothesis. If t
Re:Correct me if I'm wrong. (Score:3, Insightful)
Re:Correct me if I'm wrong. (Score:3, Insightful)
No offence, but my wife was declaired dead for almost two minutes about 5 years ago. What did she see? Nothin'. She thought she had simply fallen asleep. The one thing she does remember is that her chest hurt like hell from the electrodes though.
Granted, she's only one data point, and I'm sure you will discount her experience. But I thought I'd share it anyway.
Re:Correct me if I'm wrong. (Score:3, Informative)
Re:Correct me if I'm wrong. (Score:5, Interesting)
Re:Correct me if I'm wrong. (Score:3, Insightful)
Now we can go looking for X and if we find it and the prediction was somewhat unexpected before the theory was proposed it is a strong indication of its validity.
Case in points Einsteins prediction of light being bend by high gravity object that was indeed confi
Re:Correct me if I'm wrong. (Score:5, Interesting)
Taken from: Wikipedia article on theory [wikipedia.org]:
So, proven for 99.9999% theory of gravity is still a theory.
Re:Correct me if I'm wrong. (Score:3, Informative)
It is widely accepted that an asteroid fell down around 65 million years ago and that this approximately coincided with the end of the dinosaurs (except for birds). You will not find a single serious scientist who disagrees with this.
What is more controversial is how quickly they died off and if it was only because of the asteroid or if other factors were involved as well. This latest cla
"Alvarez Hypothesis" (Score:5, Informative)
Re:substantial with a lot of holes (Score:3, Insightful)
Now true, tuataras are burrowing animals, but they have to leave their burrows to feed on the insects they love so much.
Don't even get me started on birds. This theory has so many holes in it. If the Earth was grilled as the report suggest, then where's the geological evidence? A thin layer of carbon circa 65 million years ago representing all the burnt land flora?
Even the author admits it does
Detroy the world fallacy (Score:5, Insightful)
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.
Re:Detroy the world fallacy (Score:5, Interesting)
You're assuming that 9600 warheads detonated together would 'only' amount to 9600 times the results of one warhead detonation. This is by no means a widely accpeted view. It's much more likely that there is a "tipping point" where the damage from a nuclear exchange cascades into a catastrophe for the species (us).
In any event, I prefer not to prove it conclusively, Dr. Strangelove.
Re:Detroy the world fallacy (Score:3, Interesting)
The whole problem is that people are vague about what they mean when they say 'destroy the world.' A full-scale nuclear war would definitely
It m
Re:Detroy the world fallacy (Score:3, Funny)
I'd counter their argument with the possibility that there are other worlds for us to destroy too and planning for only ONE is lazy. Heh, silly short-sighted anti-nuke people!
Why is that sad? (Score:4, Insightful)
The fact that man has the power to potentially do something shouldn't make you sad. It should actually make you proud. Now, if man would actually do it, that would be sad.
Man can kill man, but until they do, there is nothing to be sad about.
Re:Why is that sad? (Score:3, Insightful)
- "Hey, we managed to coexist for 40 years without incinerating 500 million people, this calls for a celebration and a congratulatory pat on the back. Attaboy!"
??
Re:Why is that sad? (Score:4, Funny)
OH NO!!
we could kill them all 12 more times
Phew! Thank goodness we have had the foresight to protect ourselves from the inevitable wave of zombies.
Re:Obligatory Jurassic Park Quote (Score:4, Interesting)
What good would it of done, if they couldn't do anything about it? If we found a dinosaur-killer heading our way, could we stop it?
Obligatory Jurassic Park Quote is Luddite Crap (Score:3, Insightful)
So you only "earn" the "right" to make a product if you personally developed every single scientific t
Not really. (Score:3, Informative)
But as t
Plenty of evidence for this one. (Score:5, Interesting)
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?
Re:Plenty of evidence for this one. (Score:5, Interesting)
I presume you mean "extinction event", not "events". There have been a few mass extinctions, not all caused by impacts.
Anyway, there's a lot of evidence to indicate that something probably hit the Earth, yes. The puzzle that remains is why it only affected the dinosaurs.
Remember, they were all sizes and lived in all kinds of environments, so saying things like "the smaller animals did such-and-such" also includes the smaller dinosaurs. We don't have any small dinosaurs running around today (or even large ones - assuming that they would have kept their capacity for diversifiation and speciation if even some had survived) so there was obviously more to it than "something big hit the Earth".
That is the remaining puzzle - and nobody has been able to even come close to solving it that I've heard. I'd be interested to hear of anyone who has, though!
Re:The Cock Roach (Score:3, Interesting)
Don't laugh. You know what a wood louse or sow bug is?
Well, they have larger underwater cousins [noaa.gov], which are sometimes called "sea roaches".
You can see them live at the New England Aquarium [neaq.org].