

Finally confirmed: An asteroid wiped out the dinosaurs - lispython
http://www.extremetech.com/extreme/147978-finally-confirmed-an-asteroid-wiped-out-the-dinosaurs

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gatlin
No, you became more certain that an asteroid hit a certain place to within a
11,000 year range. Title is false. From the actual paper's abstract:

> The Chicxulub impact likely triggered a state shift of ecosystems already
> under near-critical stress.

So this confirms that one thing (likely) happened while other things were
happening. I can think of other things that were happening that would put the
ecosystem into near-critical stress:

\- For one thing, the Deccan traps were spewing crazy huge volumes of noxious
material into the atmosphere for about 30,000 years.

\- For another, the supercontinent cycle was in a period of orogeny and likely
caused an icehouse climate. There would be lower diversity in "bottom rung"
niches, which combined with the hazardous effect of global volcanic eruptions
for 30,000 years could very likely destabilize the food chain. This bodes
poorly for large megafauna which reproduce relatively infrequently and require
large amounts of specific foods to meet their nutrition requirements.[1]

There was a large confluence of factors and it makes intuitive sense that,
just as the abstract says, a large impact could be the proverbial straw on the
proverbial camel's back. I have no doubt the asteroid was important.

But this Roland Emmerich disaster movie interpretation of geology isn't nearly
the whole picture. My best guess as to why we latch onto this hypothesis,
aside from how admittedly awesome it sounds, is because it's hard for us to
accept that this kind of change is gradual and can sneak up on us. It takes
the matter out of our hands and alleviates us from certain responsibilities.
Clearly something sudden must happen because otherwise we totally have this
under control, right? But that sort of waxing is not terribly useful.

[1] (Update). Note how avian dinosaurs survived, but plesiosaurs did not. The
air was apparently survivable enough, but the near-shore ecosystem - which
would be adversely affected by the reduction in coastlines from a
supercontinent aggregation - lost its large lumbering members sitting atop the
precarious food chain. None of this constitutes evidence, but I think my wild-
ass guess is at least as valid as any other wild-ass guess, consensus or not.

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tokenadult
See a current submission to HN

<http://news.ycombinator.com/item?id=5187709>

for a more nuanced discussion that is not a rehashed press release, but an
edited long-form article by an experienced writer on the topic.

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xijuan
When I read the title, I was also shocked by the word 'confirmed.' Any kind of
explanation about dinosaurs explanation should be a theory. We can say 'the
new evidence provided support for a theory' but cannot say 'the new evidence
confirmed that the theory is the truth.'

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xijuan
I made a spelling mistake for that post but can no longer edit it. It should
be 'Any kind of explanation about dinosaurs extinction'

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peeters
I was hoping for some more evidence of causation. The new research is still
circumstantial, in that before it was the assumptive cause because the impact
was dated to within ~1 million years of the extinction event, and now it's
even more assumed to be the cause because it has been dated to within ~11,000
years of the extinction event.

Where was the line drawn for it to be "confirmed"? Is circumstantial evidence
the best we can do?

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raverbashing
There's also the issue the extinction event is not instantaneous, but took a
long time

As per wikipedia: "The fossil record shows that the tempo of the K-Pg
extinction was extremely rapid, occurring on a scale of thousands of years or
less"

But it is "confirmed" in the absence of better opposing evidence. Better
results probably only with a time machine, or a better explanation

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italophil
Perhaps science changed in the last decade, but when I worked on my PhD words
like "confirmed" and "definitely" were frowned upon.

~~~
qntmfred
we've learned how to science a lot harder these days

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codex
Frequent asteroid impacts lend credence to the Doomsday Argument [1], which,
simply put, argues that it is unlikely that the human race will be long lived,
simply because it is growing so fast. According to the DA, there is a 95%
chance of extinction within 9,120 years.

[1] <http://en.wikipedia.org/wiki/Doomsday_argument>

~~~
rkuykendall-com
While we might all be disappointed that man has not left earth for the last 40
years, I am reasonably confident we will be able to get our act together
within the next 9,119.

Reasonably.

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bluedevil2k
I have a tough time believing the word "confirmed" when the scientists behind
the study use the words "likely triggered".

~~~
bodegajed
As a programmer who have to replicate bugs everyday just to tag something as
confirmed, I have high respect for the word. Scientists do not, apparently.

~~~
incision
>As a programmer who have to replicate bugs everyday just to tag something as
confirmed, I have high respect for the word. Scientists do not, apparently.

If only scientists had the option to check all their theories by spinning up
snapshots of Cretaceous–Paleogene Earth in a test universe.

Unfortunately, they have to make due with an fractional set of undocumented
logs in form of geology.

