[HN Gopher] Earth's blobs are remnants of an ancient planetary c...
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Earth's blobs are remnants of an ancient planetary collision
Author : okl
Score : 72 points
Date : 2023-11-02 15:15 UTC (7 hours ago)
(HTM) web link (news.asu.edu)
(TXT) w3m dump (news.asu.edu)
| swatcoder wrote:
| Trust in the scientific community (which is approaching crisis)
| gets eroded every time papers are overstated, like in the
| headline here. The researchers ran a simulation that seems to
| align with the scarce physical insights associated with the LLVP
| "blobs" and the hypothesized Theia body. It's cool research and
| invites more research attention being put in that direction.
| That's very exciting on its own.
|
| And thankfully, the article body exercises honest scientific
| humility in its presentation, or at least strives too:
|
| > _suggests_ , _proposes_ , _appears_ _that_ , _hypothesizes_ ,
| etc
|
| But the headline? Gotta get those clicks and shares! "We've done
| it! We've figured out what the blobs are and it was that
| cinematic ancient planetary collision that created the moon too!
| Eureka!"
|
| Of course, for a paper about geophysical and astronomical
| history, the consequences of this kind of overstatement are
| minor, but the editorial practice of doing so is a real problem
| that we should all probably pay some more attention to.
| not2b wrote:
| Authors of articles in publications rarely get to write the
| headlines. However, Hacker News people pay inordinate attention
| to headlines, so we see statements like this: "trust in the
| scientific community ... gets eroded" because of headlines. We
| don't need to pay more attention to the problem of clickbait
| headlines. We pay too much attention to that already. What
| matters is the substance and interested people can dive deeper,
| treating headlines and press releases with appropriate
| skepticism.
| swatcoder wrote:
| I mean, you're right that the personal adaptation everyone
| can start making today is to treat headlines and press
| releases with appropriate skepticism.
|
| But this isn't some fringe HN phenomenon where riled up nerds
| focus on spurious details and make big complaints about them.
| Headlines matter. Before social media, headlines are what
| people read as they walked by the newsstand, what they heard
| from the crier, what they saw on the overlay on the TV news
| station in the lobby and at the gym. And now, in the age of
| social media, headlines are an even louder currency of fact.
| Almost all social media sites operate as headline + votes +
| comments. There _are_ stories behind those headlines, a click
| (and maybe a paywall) away, and the minority of
| intellectually diligent communities like HN do a a good job
| of surfacing the details into the comments so that bad
| headlines are less toxic.
|
| But our behavior here is _already_ the exception and we _do_
| need to keep banging on _misrepresentative_ headlines. While
| also a form of clickbait, they are a different and far more
| irresponsible class of it than the than harmlessly,
| wastefully vague click-for-the-mystery headlines that you 're
| tired of hearing complaints about.
| deprecative wrote:
| It's not that HN folks pay inordinate attention to headlines
| in isolation. I don't think you meant it that way, but that's
| how it comes off. The issue is that people often don't read
| the articles that the headlines are for. We can see this on
| any social media app. For the purposes of this comment, maybe
| discussion?, I think that HN, Reddit, Twitter (X), Facebook,
| Instagram, etc., are all social media. Some folks might want
| to squabble over exacts but to make things simple to discuss
| I chose to define it as such.
|
| For science in particular, I think it gets a bad wrap
| generally because people don't like it when you tell them
| something might be true then say it isn't. The general
| population really doesn't seem to like it when the scientific
| community says "we may have the answer for x, y, and/or z but
| we don't know for certain." as that's too complex of a
| thought to keep. We, generally, love to be told simple truths
| for complex problems.
|
| We see this in politics broadly, as well. When discussing
| tickets as a SWE I know we tend to understand this by the
| time we're intermediate developers and adapt our language
| appropriately.
| hinkley wrote:
| HN policy is not to modify the headlines when posting
| things, which I think exacerbates the issue.
| vkou wrote:
| > However, Hacker News people pay inordinate attention to
| headlines, so we see statements like this: "trust in the
| scientific community ... gets eroded" because of headlines.
|
| Trust in HN's ability to think critically is eroded every
| time circumstances force you to remind everyone of this.
|
| It's always interesting to see which groups of people are
| held responsible for other people misrepresenting them, and
| which aren't.
| ahmedfromtunis wrote:
| This makes me sad. Now whenever some article with ambitious
| claims pops up into view, my first reaction is "what's the
| catch?"; i.e. what elemts of the research are overstated for
| the sake of virality.
|
| It's even more frustrating when done by what are considered
| "mature" if not "reputable" publications. "Who am I supposed to
| trust now?" is a question I never wanted to answer when it
| comes to scientific research.
| adolph wrote:
| > "Who am I supposed to trust now?" is a question I never
| wanted to answer when it comes to scientific research.
|
| _Nullius in verba (Latin for "no one's words" or "take
| nobody's word for it") is the motto of the Royal Society.
| John Evelyn and other fellows of the Royal Society chose the
| motto soon after the Society's founding in 1660._
|
| https://en.wikipedia.org/wiki/Nullius_in_verba
| xattt wrote:
| > But the headline?
|
| If you search for Theia right now, you get the same headline
| and story propagated across a number of publications who
| syndicate their science news.
|
| It appears that it takes one person placed in a position of
| power (writing headlines) to screw this all up.
| roywiggins wrote:
| The headline here is from a press release, so the culprit
| here is the university press office.
| ChainOfFools wrote:
| relevant as ever:
|
| The Science News Cycle
|
| https://phdcomics.com/comics/archive.php?comicid=1174
|
| Uni PR office at 2 o'clock
| jlas wrote:
| > The researchers ran a simulation that seems to align with the
| scarce physical insights
|
| Fwiw, we will probably never be able to directly observe the
| contents of the mantle. Computer simulation has been a godsend
| for geology research.
| Qem wrote:
| > Fwiw, we will probably never be able to directly observe
| the contents of the mantle.
|
| Unless this proposal goes forward someday:
| https://www.nature.com/articles/423239a
| runeofdoom wrote:
| Get real human beings to stop clicking on eyeball bait. Far
| easier said than done, when the bait is ultimately being
| generated not by other individual human beings, but
| corporations (effectively slow-AIs or Lovecraftian
| monstrosities) that can bring far more resources to bear on
| getting us to click.
| dmckeon wrote:
| Relevant not-xkcd "The Science News Cycle"
| https://tapas.io/episode/18523
| everybodyknows wrote:
| Some 20 seconds in, got a pop-up demanding I install an app.
| Dismissing the pop-up caused the page to close.
| ChainOfFools wrote:
| OP posted a link aggregator or something, try going to the
| original site:
|
| https://phdcomics.com/comics/archive.php?comicid=1174
| lostlogin wrote:
| > Trust in the scientific community (which is approaching
| crisis) gets eroded every time papers are overstated, like in
| the headline here.
|
| I mostly agree, but the headline caught my attention and I read
| the article and learned some things.
| nonameiguess wrote:
| This is tremendously unfair, though. The "scientific community"
| is not responsible for these university press releases and
| popular science journalism. The papers themselves almost never
| contain claims that aren't propertly quantified and modest,
| outside of grifter realms like psychologists selling self-help
| services.
|
| We're not going to stop the press, and the scientists
| themselves are usually already doing the right thing. The only
| real hope I see is for the public to somehow come to better
| understand the difference between science and the press. When
| you see this, absolutely point it out, but place the blame
| where it belongs, on newspapers, magazines, and university PR
| departments, not on the researchers.
| uoaei wrote:
| Is Earth's orbit stable enough not to be thrown away from the Sun
| after such a collision? Are there interactions between Earth and
| other large bodies which have a stabilizing effect? I know
| there's some interesting dynamics in the Earth-Venus interactions
| but I wonder if there's enough there that you could consider it
| stabilizing per se.
| ahmedfromtunis wrote:
| Not an expert but if the earth is in the orbit it has now, it's
| because that's indeed the most "stable" orbit it can assume.
|
| Even if the earth got pulverized, the remnants would be
| floating as a cloud around the sun, in the shape of its orbit.
|
| The Earth's orbit is a influenced not only by the sun's
| gravity, but by that of every component of the solar system (to
| varying degrees, of course).
|
| Also, I'm sure the orbit we have now is not the same as the one
| pre-collision.
| queuebert wrote:
| It depends entirely on the momentum of the impactor. If the
| impactor's momentum was much less than the Earth's then it
| would have little effect.
|
| We hypothesize that Thela was like the size of Mars. Since all
| orbits in the solar system are due to gravity (assuming no
| rocket powered alien space rocks), we can calculate the maximum
| velocity a planetesimal would have as if it were falling from
| infinity into the sun. I can't be asked to do this right now,
| but based on the Virial Theorem and Earth's orbital velocity of
| 30 km/s, I bet ~60 km/s is the theoretical maximum impact
| speed. Mars has 10% of Earth's mass, so at best Thela would
| have 20% of the Earth's momentum.
|
| And more likely the impact occurred in a grazing fashion in
| order to make the moon and with much less velocity, since it
| was probably already in an orbit around the sun. So back of the
| envelope, we wouldn't expect much to happen to Earth orbit
| other than a small disturbance that makes it more elliptical
| for a time. Then over the next few Gyr the solar tidal
| interactions circularize it.
| andrewflnr wrote:
| I think the key/tricky point is that orbits tend to
| circularize over time. I figured it was due to other
| perturbations, but is it mostly tides?
| uoaei wrote:
| Related question, how much do tidal forces inside the
| planet contribute vs tidal forces from the ocean?
| macintux wrote:
| Discussion yesterday:
| https://news.ycombinator.com/item?id=38107078
| AzzyHN wrote:
| I for one support a fully free and open-source earth, with no
| proprietary blobs
| while_true_ wrote:
| Isn't this finding to be expected? I thought all planets were
| formed by accretion.
| scotty79 wrote:
| Do you think humanity will seriously start to dig down at some
| point? For resources, energy and living space?
| adolph wrote:
| It already has: * Resources: lengthy tunnels,
| caverns, pipes and open pits are already bringing a wealth of
| subsurface minerals, salts, diamonds, hydrocarbons and other
| ores for the use of humans. * Energy: geothermal
| energy is used now and is often deployed in places where
| portions of superheated mantle are closer to the surface, like
| near volcanoes in Iceland and Costa Rica. * Living
| space: subsurface living space is less common due to human's
| aesthetic preference for "natural light." However even as long
| ago as the 1800s US West people built subsurface dwellings as
| depicted in author Laura Ingalls Wilder's book "The Banks of
| Plum Creek." [0]
|
| 0. https://sitesandstories.wordpress.com/tag/the-dugout-site/
| lostlogin wrote:
| > the seismic wave pattern is dominated by the signatures of two
| continent-sized structures near the Earth's core. They are
| interpreted as regions with unusually high iron content, whose
| increased density and temperature slow down seismic waves passing
| through
|
| I would have thought that increased density would cause
| propagation velocity to increase? With heat, density falls so
| that bit stacks up. What have I got wrong?
| whatshisface wrote:
| Increased density slows down propagation. It is easy to come up
| with false explanations of why, but here is one I think is
| probably true:
|
| If you imagine a bar that has been struck by an xylophone
| mallet, it makes sense that increasing its inertia would slow
| down the periods of its alternating motion. You can build
| traveling waves from sums of its modes of oscillation, and that
| carries the effect of higher density to wave speed.
| tabtab wrote:
| I thought the Earth is rather fluid inside such that stuff gets
| mixed around over time. That such blobs can stay intact for
| billions of years seems far-fetched.
| andrewflnr wrote:
| The mantle is officially "solid" (as proven, I believe, by
| propogating shear waves, which an actual liquid cannot do). It
| flows, but very slowly. Very very slowly. I'd say that big
| chunks of material staying intact over billions of years is, in
| fact, an illustration of just how slowly.
| purpleblue wrote:
| The idea that something collided with the Earth and created the
| Moon is an unscientific, absurd idea. There is a zero percent
| chance that a collision as described could result in the Moon
| maintaining an almost perfect orbit around the Earth, and the
| Earth maintaining a near perfect orbit around the Sun.
| s1artibartfast wrote:
| So all the planets popped into existence with their current
| Mass and Orbits?
|
| Of course not. Mass is summed as is momentum
| purpleblue wrote:
| Everything was formed by the spinning of gas clouds and
| consolidating into planets and such. That's why the planets
| haven't fallen into the Sun after 14 billion years.
| s1artibartfast wrote:
| indeed, and how is that proof that the moon didn't come
| from a collision with the earth?
| wolfendin wrote:
| > There is a zero percent chance that a collision as described
| could result in the Moon maintaining an almost perfect orbit
| around the Earth, and the Earth maintaining a near perfect
| orbit around the Sun.
|
| I'd love to see the math you did to come to that conclusion. Do
| you have it in a paper somewhere?
| matrix12 wrote:
| Velikovsky would be proud.
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