2845: Extinction Mechanisms

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Extinction Mechanisms
The Late Heavy Bombardment was followed a few billion years later by the Comparatively Light but Oddly Specific Bombardment.
Title text: The Late Heavy Bombardment was followed a few billion years later by the Comparatively Light but Oddly Specific Bombardment.

Explanation

Around 66 million years ago there was a mass extinction event responsible for the extinction of all non-avian dinosaurs. This is why there are no more dinosaurs (except for birds! [1]) There have been a number of explanations for this, but most currently accepted explanations center on the Chicxulub impact, in which a large asteroid (the comic suggests it was a comet) hit the Earth. The exact mechanism for the extinction caused by this event, however, is not clear. The comic suggests three possibilities: impact winter caused by dust released from the impact, firestorms along with ocean acidification from acids generated by the impact, and the enhanced eruption of volcano(es) in the Deccan Traps region in India. Here all three possibilities have been crossed out and a fourth one, "the rocks hit the dinosaurs," is circled as the correct answer.

The argument is that the comet had a volume of 500 km3 (10 km diameter), or 5×1014 L. Earth has a surface area of around 500 million km2, or 5×1014 m2. The idea is that the comet broke up into liter-sized rocks, so that there were sufficient of these to fall, on average, one on every square meter of surface. Somehow, these rocks managed to fall in a distribution such that they directly hit each of the dinosaurs, but presumably did not hit the other forms of life that did not go extinct. It is unclear how such a breakup or scattering might have occurred – a body that passes within Earth's Roche limit will eventually break up into a ring, but this limit is generally a single-digit multiple of the planet's radius, so an object on an inbound collision course would only experience high tidal forces for a matter of minutes before impact.

The title text refers to a hypothetical event early in Earth's history, ironically known as the Late Heavy Bombardment, in which a number of asteroids struck the Earth and other terrestrial planets around 4 billion years ago. The mass extinction event of 66 million years ago is then referred to as the "Comparatively Light but Oddly Specific Bombardment", presumably because it isn't as heavy as the LHB, but oddly specific in its targets.

Transcript

Ambox notice.png This transcript is incomplete. Please help editing it! Thanks.
[A drawing of the Chicxulub meteor]
Marking to the right: ≈ 500 km3 (5 × 1014 L)
[Five arrows show individual small rocks coming from the meteor and spreading across the Earth. A sixth arrow provides more elaboration.]
Marking of the separate rock: 1 liter rocks
[The rock is shown entering a square marked "1 m2", which has another arrow to a larger grid of squares, before an arrow back to the Earth.]
Marking near example square meter: >1 rock per m2
[Four dinosaurs are drawn, including a theropod, what may be a velociraptor, a sauropod, and a triceratops. Each has a small rock falling directly toward it.]
[List header, underlined:] Comet Extinction Mechanism Ideas
[The first three list items are crossed out]
Dust caused impact winter
Firestorms and ocean acidification
Triggered Deccan Traps magma
[The fourth suggestion is circled rather than struck through:]
The rocks hit the dinosaurs
[Caption below the panel:]
Paleontologists are missing the obvious answer.


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Discussion

-Hello, I'm a Christian that has done research to be intellectually fulfiled, and I would just want to say that I did not know that paleontologists were having trouble with this problem. A general Christian solution is that Noah's Flood, combined with the aftermath being much cooler, was the cause of the dinosaur extinction. Also, before you hate on me, I'm not trying to correct anyone, or be offensive. I just thought I'd share my thoughts on this and add another theory to the mix. This is my second time posting a comment, so sorry if I did something wrong or something. Also, I know there's a comic that "debunks" this, but there seems to have been more evidence and research done since then. Also, the biggest help to me has been The Case for A Creator by Lee Strobel. Azerty99 (talk) 15:17, 23 October 2023 (UTC)

Reading a book (or even many books) is not research. Science means you're never absolutely sure about anything. You're only relatively certain until contradictory proof of the currently theory (or theories) exists. This is not a weakness, but exactly the strength of the scientific method. If you have significant and non-controvertible proof that men and dinosaurs existed at the same time, I'll tentatively accept your ideas. Until then, it's all just bunk. 162.158.197.151 15:32, 23 October 2023 (UTC)
Paleontologists are not having an issue with this. It is merely the premise for the comic. The available evidence vastly points to the extinction of the non avian dinosaurs ~66 million years ago. Of course the scientific community always welcomes new evidence to evaluate and see if it leads to a different conclusion or modification of the current consensus.
It's a troll folks, treat it with the contempt it deserves. 172.69.43.240 19:09, 23 October 2023 (UTC)

-We should change "Earth and other terrestrial planets" to Earth and its allies.Danger Kitty (talk)

One obvious type of hole was not discussed. The Acme Portable Hole™ is an entirely different class of holes as extensively demonstrated in (this)[2] documentation.

-Ok, thanks for the comments in return! And thanks for not being extremely rude! Here's one article that shows several bio-organic materials that should have decayed if in the situations they were in for -66 million years. https://genesisapologetics.com/faqs/dinosaurs-lived-recently-and-died-in-noahs-flood/ Also, can I see the evidence shown in the second comic? I would like to see all this evidence. Also, I wasn't aware that scientific ideas shown in xkcd that were heavily implied to be true were false. That sounds a bit rude, but usually xkcd gives funny interpretations of actual problems, like all the ones about COVID, or the Heartbleed Bug. Also, I'm not a troll. I'm willing to debate as long as people aren't saying things like "Science says" and equivocal stuff, and shows evidence instead of just giving vague statements. Thanks! Azerty99 (talk) 22:25, 23 October 2023 (UTC)

There's little disagreement that an asteroid striking the Yucatan around 66 mya caused or was a significant contributor to the extinction of the dinosaurs, but there are multiple (not necessarily mutually exclusive) hypotheses about what exact mechanisms had the biggest effects.
It's like finding a body with nineteen bullet wounds. The detectives will have to piece together the evidence and come to tentative conclusions about what kind of gun was used, from how far away, whether the body was moved after the shooting, whether the victim died immediately or after some time, etc. But until someone finds something major that suggests otherwise, "death by shooting" is going to have to remain the working theory. 172.69.247.41 23:09, 23 October 2023 (UTC)

-That analogy makes almost perfect sense, except there's a pretty big difference between finding 19 bullet holes in a man and concluding "death by shooting" and thinking that a meteor caused extinction because fossils were found in rocks that could be from the time that the meteor struck. Also, assuming that the mechanisms shown in the comic that are crossed out have been shown to not be possible, then what evidence is there that the meteor was the cause at all besides the correlation of the meteor impact and the extinction time? Does the correlation imply causation? Also, the theory of the meteor assumes the time of the extinction of the dinosaurs, which, while excepted by the majority of scientists, has been called into question.

Ah, you figured it out. The extinction of the dinosaurs must have caused the meteor impact. The crossed-out mechanisms have not been ruled out; they're the leading hypotheses. That's the whole joke. Whoosh! There's plenty of evidence to conclude that the meteor was the cause of the mass extinctions. I don't see the need to provide you with them - they can be easily found. But you're not really interested in learning about evidence that could falsify your beliefs; you're fighting tooth and nail against anything that contradicts your preconceived conclusion. --172.69.34.140 07:25, 24 October 2023 (UTC)
well dinosaur fossils are found below the cretaceous-paleogene boundary and not found above, so the major groups (excluding birds) most likely died out around that exact period; it contains a large amount of iridium, which is common in asteroids and there would be a low chance that there would be any other method to deposit iridium worldwide. its age can also be estimated using radiometric dating which puts it at around 66 mya (66.043 ± 0.011 mya to be exact) 172.69.134.181 00:47, 24 October 2023 (UTC)
XKCD is a webcomic that often derives humor from science. However, it is not a reliable source of information.[citation needed] Consider the various "phone ideas" comics that present phones with "features" that are absurd or impossible. The "crossing out" of the hypotheses in the comic should not be taken as an indication that these hypotheses have been discredited. The comic presents the hypothesis that a meteor broke into pieces, all of equal volume, that struck each square meter of the Earth's surface, and hit each dinosaur individually. I'm reasonably confident that that is physically impossible, but the comic lists this hypothesis together with some of the current leading hypotheses and shows those leading hypotheses crossed-out and describing this alternative hypothesis as "obvious." There idea that this alternative hypothesis is in any way comparable to the others listed, or has any legitimacy, is absurd to the point of being laughable, and thus funny. Regarding the apparently preserved tissue found in some fossils, I found this interesting link: Researchers identify mechanisms of blood vessel preservation in a T. rex dinosaur--172.69.22.210 10:30, 24 October 2023 (UTC)

-While Noah's Flood was likely an actual event, it would not have been worldwide. Christianity originated in ancient Rome, which is near the Mediterranean Sea, and it is likely that after the last Ice Age, the sea levels rose, and the Atlantic Ocean flooded through what is now the Strait of Gibraltar, creating the Mediterranean Sea. Although this was not a worldwide flood, to the people living in the affected area, it would have seemed as such. Unknown User (talk) 01:00, 24 October 2023 (UTC)Unknown User

(What's with the non-standard indenting? Anyway...) The biblical Flood wasn't initially recorded/conceived of in Rome (thus the Mediterranean), but in earlier Abrahamic/pre-Abrahamic sources. It could well be a mesopotanian-area event (or events), or the Black Sea or elsewhere (or a mix of several possible aural histories/tales, merged together by the time they entered the Old Testament's first official compilation process).
And to people living on wide and fertile riverine plains, they're going to encounter the occasional flood every few generations (too often and the original settlers wouldn't stay settled in a flood-endengared way for long, either invent a word for "floodplane" and moce away or just accept/expect the cycles and explicitly build their civilisation around it like Egypt did). But once-a-century catastrophes probably happened somewhere amongst most prebiblical peoples, and depending on whose imaginations were left (to wonder how and what happened) they could have come up with what could have been any kind of ur-legend. (If not an actual legend about Ur!) 172.69.195.104 00:47, 25 October 2023 (UTC)


- Issues with Noah’s flood. 1. If it was worldwide and lasted 40 days, all the salty ocean water would have contaminated all fresh water on earth. This would have killed all fresh water fish within minutes or hours. Yet we have fresh water fish. Maybe in the millennia since fish have evolved the ability to survive in fresh water again? 2. The math shows that it would take 3-4 times the current amount of water to cover the earth worldwide. Where did all that water go? It’s not on earth now. We would be aware of that. The math ain’t mathing.

-Okay, to answer the comment directly above mine, if God can create the universe, I doubt he had a problem with seperating salt and fresh water for 40 days. Next comment: While early Christianity was started in Ancient Rome, Noah's Flood is in the first five books of the bible, which were written by Moses, about people that were about 30 generations his ancestors, passed down through traditions combined with the guidance of God. So they probably weren't near the Metiterranean during the flood. Next comment: I understand now that it's a joke, while I understood that the non-crossed out one was obviously a joke the whole time. Also, I'll be honest, I can't open that link, but I'll assume it was true, in which case that's a great discovery for them. I'm assuming that that link is to a good website, is true, and does not exagerate. Next comment up: The iridium thing is true, and I'm not going to make an argument from ignorance and say "we just haven't found the source yet". That's a valid point, but the rock layers could have been moved or solidified earlier, and just formed at that time. We have no concieved notion of how long the days were when God was making the earth, so each on could of been like 5 million years. But that's a valid point! Next comment up: Yes, I know. Also, "But you're not really interested in learning about evidence that could falsify your beliefs; you're fighting tooth and nail against anything that contradicts your preconceived conclusion." I'm honestly trying my best, but you're right that it's hard to accept evidence that goes aqainst you. But, please make sure you don't fall into that category as well. I'm just some random guy on the internet, and I'm going to go through my day feeling a strange mixture of hopeful and grim, not because of what you've shown me, but how you've shown me it. If you're really interested in tearing down my religion, go after the Bible itself. Making some random dude feel like crap because some of you were rude won't do anything. To those of you who actually brought up valid points, thanks. I hope that you put thought into what I'm saying, instead of just refusing to go against your preconceived judgements. To those of you that just said, "there's so much evidence" know that you need to do better if you're arguing. Be polite. You never know how bad a day the person you're talking to just had. Thanks. I probably won't post here anymore. This is a nitpicky thing inside of a nitpicky thing and you're saying that my religion is false because I have a different opinion than you. I hope you don't go away feeling smug and self-satisfied, but instead think about the ripple affect of everything you say. Bye! Azerty99 (talk) 11:07, 24 October 2023 (UTC)

If God can create the universe, I doubt he has problems with just making everything He does look like a perfectly explainable phenomena. A God which has to tinker too much with his Creation, just to deal with an unforseen(??) necessary adjustment to it, isn't really worh Their own pillar-of-salt.
The actual omnipotent/omniscient/omnipresent deity wouldn't have to do anything, really, after the Letting There Be Light moment (give or take a good proportion of the following week). Perhaps They can reliably rely upon the imaginations of the humans to come up with the stories They value more as stories (centuries/millenia after the 'fact') than actual effort to adjust matters that They didn't realise They would not like to have happen.
Though I tend to think that the God Of Logic actually made the universe to look logical and (through proper study) explainable, and doesn't even appreciate all the different Holy Books everyone keeps thinking is some particular form of Truth.
Even better, the GOL could have created everything last Thursday, complete with seemingly arbitrary memories embedded in all the billions of people created, and everything else historic (books, dust on undusted mantlepieces, strata/seximents, light from distant stars, etc) installed in the ultimate Young Earth joke. But such that everyone reads the intended scientifically-observable 'previous' and comes to the conclusion that it all happened just like everyone is supposed to conclude. Those who reject that (and GOL surely knows who those will be, of course) and actually believe in some of the 'trap' materials (Bible, Koran, Torah, the Daozang, all those Sutras, all those Vedras, ..., the Mission Earth Dekalogy) are those who will be sent to whatever GOL's idea actually is of damnation. ((Some might suggest we already have been. Others might suggest that we're not actually at Creation yet, what we're experiencing is the God's 'dry run' and mental check of how Creation will turn out, but of course the mere ponderings of such a god are so powerful that include details such as whether those so imagined are ever going to philosophise about whether they are even real or not.))
The whole point of a 'capital-G' God (i.e. not confounded by fellow pantheon members with a similar magnitude of control over things and variously different motives of their own) is that they are just so all-powerful and perfect. And it's clear that the biblical God is lacking in various ways (as with all the others in all other comparable holy scriptures, with their own adherents and supporters) that can be explained away by "having granted free will" but without helping the reputation of said deity to allow (the appearance of) Free Will and yet be annoyed by what inevitably happens inevitably happening... 172.69.195.104 00:47, 25 October 2023 (UTC)

What the meteor does, looks like a cluster bomb. BTW does one like to do the math for the meteor falling apart into pieces of 1l and those being randomly distributed. What is the expected value of dinosaurs of various area sizes being hit? Sebastian --162.158.94.219 07:59, 24 October 2023 (UTC)

You get one point for each brontosaur, twenty points for a velociraptor, thirty for a zhongjianosaurus and fifty for compsognathus. Double that for hitting their young (even harder to hit); double up again, per additional rock, if you can show that you hit every egg in a nest with a different fragment. 172.69.194.155 11:22, 24 October 2023 (UTC)

The title text missed a great opportunity to call it the Comparably Light Bombardment But Oddly Restricted just for the acronym. Phil Srobeighn (talk) 11:18, 24 October 2023 (UTC)

- Reconciling religion and science is always going to be a bit challenging (gross understatement), but for what it's worth--I think the goal of each is substantially different, but can be complimentary. There are elements of the Bible that are clearly figurative / allegorical / metaphorical / designed to teach a principle but is not necessarily literal. The Bible's intent is to teach us about our relationship to God and each other, and how to become more like God. It's content is intended to be understood by a general audience, without requiring e.g. a degree in Physics. Science, on the other hand, is an inductive search to understand the reality we live in. This is an oversimplification, but you could see science as answering the "what" or "how" of existence, and religion, the "why". My personal approach is to accept scientific evidence, and consider how the current models--even things like evolution--may fit in to God's overall purpose. 172.68.35.75 14:33, 24 October 2023 (UTC)

That's not how I think about it, but that's a great way too! Azerty99 (talk) 18:35, 24 October 2023 (UTC)

I think that, although this discussion/argument over the philosophy of religion and science is interesting, I do not think that this talk page is the best location for this. I also think that it may be be helpful to sort the original post from Azerty99 and all of the responses into a separate section to make reading sorting out the other comments easier.Claire Kholin (talk) 15:55, 21 March 2024 (UTC)