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Effect of a giant meteorite impact on Paleoarchean environment and life

chemistryworld.com

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Re: Effect of a giant meteorite impact on Paleoarchean environment and life

#21

Post by andrewflnr »

EGreg wrote: post #12
dan353hehe wrote: post #3

Earlier quoted context omitted.

> Drabon and her colleagues went in search of evidence of ancient major impacts in a remote area south of Kruger National Park in South Africa. There they sought out rocky outcrops containing a layer of spherules – molten droplets formed following a major meteorite impact that rained down over huge swathes of the planet. There are eight such spherule bands in this area, each preserving an ancient impact event. > Whil…

[flagged]

> Yeah, but it's just a theory that tries to fit this data. Doesn't mean it is correct.

Yes. What else do you expect from science, or really from any human attempt to find truth? Are you just upset they don't include the caveat "subject to potential future evidence or better theories" on literally every single piece of science journalism? Are you upset that people do their best to make sense of weird situations and then tell people about their work, even if it's not absolute truth? What do you want to happen here?

Re: Effect of a giant meteorite impact on Paleoarchean environment and life

#22

Post by drdaeman »

EGreg wrote: post #12
dan353hehe wrote: post #3

Earlier quoted context omitted.

> Drabon and her colleagues went in search of evidence of ancient major impacts in a remote area south of Kruger National Park in South Africa. There they sought out rocky outcrops containing a layer of spherules – molten droplets formed following a major meteorite impact that rained down over huge swathes of the planet. There are eight such spherule bands in this area, each preserving an ancient impact event. > Whil…

[flagged]

I hope that your reaction is because the headline is way more sensational (to the extent of probably being incorrect) than the actual paper's abstract (https://www.pnas.org/doi/10.1073/pnas.2408721121)

Here's what the actual paper says:

> [...] Thus, the S2 impact likely had regional, if not global, positive and negative effects on life. The tsunami, atmospheric heating, and darkness would likely have decimated phototrophic microbes in the shallow water column. However, the biosphere likely recovered rapidly, and, in the medium term, the increase in nutrients and iron likely facilitated microbial blooms, especially of iron-cycling microbes.

Which sounds and - if I understand it correctly - means something kinda different than how "reset early life" is ordinarily understood, huh.

Re: Effect of a giant meteorite impact on Paleoarchean environment and life

#23

Post by _moof »

iambateman wrote: post #15
EGreg wrote: post #2

[flagged]

The downvotes are misplaced. This is a good question. The value of HN is when people-who-know help curious folks understand the validity of a story. Surely someone here is more capable of assessing this story and I agree that skepticism is in order at first.

The downvotes are because people are reading the question as rhetorical rather than being asked out of genuine curiosity. It's only a good question if the person asking it is doing so with an open mind.

(That and the article answers the question.)

Re: Effect of a giant meteorite impact on Paleoarchean environment and life

#24

Post by _moof »

EGreg wrote: post #12
dan353hehe wrote: post #3

Earlier quoted context omitted.

> Drabon and her colleagues went in search of evidence of ancient major impacts in a remote area south of Kruger National Park in South Africa. There they sought out rocky outcrops containing a layer of spherules – molten droplets formed following a major meteorite impact that rained down over huge swathes of the planet. There are eight such spherule bands in this area, each preserving an ancient impact event. > Whil…

[flagged]

Have you got a better theory that fits all available data and has predictive power?

Re: Effect of a giant meteorite impact on Paleoarchean environment and life

#25

Post by dataflow »

patrickthebold wrote: post #19
hehehheh wrote: post #16

When is the next one coming? Or what is the probability distributuon like?

It's a poisson distribution.

Have the data actually been fit a Poisson distribution? Or is this is just a guess assuming constant rate and independence?

Re: Effect of a giant meteorite impact on Paleoarchean environment and life

#26

Post by nverno »

patrickthebold wrote: post #19
hehehheh wrote: post #16

When is the next one coming? Or what is the probability distributuon like?

It's a poisson distribution.

I imagine it is more of an exponential decay mixed with poisson since strikes were far more common back in the day. Also, I'd guess an exponential decay in the expected size of impactors over time as they've been smashing themselves into pieces.

Re: Effect of a giant meteorite impact on Paleoarchean environment and life

#27

Post by bulatb »

iambateman wrote: post #15
EGreg wrote: post #2

[flagged]

The downvotes are misplaced. This is a good question. The value of HN is when people-who-know help curious folks understand the validity of a story. Surely someone here is more capable of assessing this story and I agree that skepticism is in order at first.

Skepticism should begin with the skeptic's own motives. A skeptic's second question (after "Really?" or "Why?") should be, "Why am I asking?"

Do they want to test the claim to learn something, or to dismiss it, just to dismiss it?

If they're asking questions which are literally answered as part of the claim, they need to start over, and start with themselves.

Re: Effect of a giant meteorite impact on Paleoarchean environment and life

#28

Post by glial »

dataflow wrote: post #25
patrickthebold wrote: post #19

Earlier quoted context omitted.

It's a poisson distribution.

Have the data actually been fit a Poisson distribution? Or is this is just a guess assuming constant rate and independence?

No natural phenomena ever exactly fits any probability distribution.

Re: Effect of a giant meteorite impact on Paleoarchean environment and life

#29

Post by iambateman »

bulatb wrote: post #27
iambateman wrote: post #15

Earlier quoted context omitted.

The downvotes are misplaced. This is a good question. The value of HN is when people-who-know help curious folks understand the validity of a story. Surely someone here is more capable of assessing this story and I agree that skepticism is in order at first.

Skepticism should begin with the skeptic's own motives. A skeptic's second question (after "Really?" or "Why?") should be, "Why am I asking?" Do they want to test the claim to learn something, or to dismiss it, just to dismiss it? If they're asking questions which are literally answered as part of the claim, they need to start over, and start with themselves.

The article claims that 363 billion tons of phosphorous were dropped on earth 3.26 billion years ago during a decade of darkness.

I’m completely incapable of making sense of that claim because it’s so far outside of my expertise.

But my fundamental problem is that I don’t trust the source’s incentives to deliver reliable information and I want someone independent to help me understand if this is a how strong or weak this science is.

And my starting point for that is “it’s very hard to know anything specific about the deep past. And I’m tired of scientific retractions.”

Re: Effect of a giant meteorite impact on Paleoarchean environment and life

#30

Post by dataflow »

glial wrote: post #28
dataflow wrote: post #25

Earlier quoted context omitted.

Have the data actually been fit a Poisson distribution? Or is this is just a guess assuming constant rate and independence?

No natural phenomena ever exactly fits any probability distribution.

Right but I'm saying do we have data showing it's even close? (Genuinely asking, I have no idea.)
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