Has Earth’s inner core stopped its strange spin?
nature.com
nature.com
“I keep thinking we’re on the verge of figuring this out,” says John Vidale, a seismologist at the University of Southern California in Los Angeles. “But I’m not sure.”
Such as? Seems to me that good science does tell us stuff, and also admits when it doesn't know.
Which is to say, it suffers from the same fallacy as when people complain about Hacker News' collective opinion as though a collective anything with voluntary participation is going to be in anyway consistent.
It might not be consistent but even Ray Charles can tell you where the bell curve roughly centers for any given topic.
sometime later...
"Scientists say eating one or more eggs per day cures X, Y and Z"
sometime later...
"Scientists say people who eat one or more eggs per day are more likely to exhibit A, B or C"
What frequently occurs is one person or a group of people say or publish something, and then all the media broadcasts it like everyone is in complete agreement.
In real science, there is very little complete agreement. Even things most of us assume are 100% true, do not always have unanimous consensus within the scientific community.
Laymen might think that's a bad thing. But it's not... it's exactly how science is supposed to work. The problem is, people need to be told an absolute, but science can't do that for the most part.
What even is a scientist? Is it anyone that works for a lab? What about people who graduated with "Science" in their degree title? Does that mean Computer Scientists are the fabled "Scientists"? How do we know?
The word "Science" has become a sort of pseudo-religion these days. Nobody can disagree with "The Science". Which is quite an oxymoron in itself.
That is pure science - accept something until better data comes along and changes the way we think about the topic.
We lose people there though, unfortunately. People like to "know" something absolute, and the media does a horrible job of communicating disagreements or opposing data.
So, while we now know that Newtonian physics breaks down in some circumstances, where relativity and quantum mechanics are needed Newtonian is still good enough for most everyday and a lot of not so everyday applications (like sending probes to Mars).
It doesn't flip / flop like the "eating eggs was good yesterday and is now bad".
In general an element of both is present, but on one end tou have, say Newton, and on the other you have some study that says electromagnetic waves are bad for you because of some statistical health outcome but proposes no causal mechanism.
The problem seems to be that the further towards the latter part of the spectrum someone's research is, the more likely they are to be adamant that they're "doing science" and promote all the BS about consensus and peer review that gives a pretend version of how science happens.
Presumably due to insecurity. When your work rests on a foundation of p-hacking, you're more likely to be pounding "the science" as justification, vs if you're a physistics that's traced a result back to basic axioms of your field, your work speaks for itself and you don't need to yell how the science is settled
This way, we ensure that our meta-analysis firepower (whatever/whoever that actually is), can be directed at studies that actually have a potential to uncover some real knowledge.
“Science says” is a statement of belief in a knowledge mafia.
“Scientists asked this question and here’s what they discovered and here is what they think” is how science news should be reported. More like entertainment tonight and less like a Sunday school sermon.
The word "Scientist" has become a word without meaning. It's applied to anything we think we want to convince others of or use as argument of authority. When people say "Scientists", they often mean statisticians or other number/data crunching careers.
Instead, that statement could be rewritten as: "The Eggs-For-Health Institute, Department of Eggs-Every-Day asked this question and here’s what they discovered and here is what they think".
This rewritten statement now informs the reader of all the basics - who, what, where, when and why. It's unsurprising the Eggs-For-Health Institute (for a made up scenario) says eating eggs is a good thing.
Unfortunately it gets murkier when it's highly regarded institutions publishing ideas, such as the FDA, CDC, etc. These folks aren't any more certain of things as the rest of the community either. We saw variations of this during the pandemic - the CDC would release some preliminary aggregated data and suddenly headlines ran with "Scientists from the CDC say do X to stop Y" etc... which led to a lot of perceived flip-flopping along the way (because all of this was new territory at the time, ie. the scientific process was playing out in real time.
Scientists have my full support to stumble around in the dark and figure things out. But it's not the laymen who desperately need certainty. It's the scientists themselves when they deign to make policy demands based these half-baked theories de jour.
Truth is a probability and not a binary, but politics is still a casino pretending to be a church.
"When someone says ‘science teaches such and such’, he is using the word incorrectly. Science doesn’t teach it; experience teaches it." - Feynman
- Science
Almost every news article that uses Betteridge's law of headlines. Usually, it's not the scientists fault and the linked articles are very clear of their reach and limits.
If it were up to me popular science reporting always would include that disclaimer.
As for what would cause it to slow down or speed up with relationship to the speed of the planet's spin, they just say "magnetic and gravitational forces", whatever that means.
So far there's debate, but the data supports the core is spinning 0.1 degrees per year faster or slower. Other researchers think it's changes in the surface of the core (not the rotation). What we do know is that earthquakes show waves that travel slightly faster or slower than we'd expect if the core's rotational speed was constant with the rest of the planet.
But overall it's nearly in the noise compared to the other energies involved. The flows involved are turbulent and move like fluids, but at the pressures and viscosties involved they change rather slowly. Some models show it switching from slightly faster (0.1 degrees per year) to slightly slower ever 35 years or so.
The discussed difference is only 0.1 degrees per year, on the surface of the planet that's only 7 miles. So what's under the surface today might be 7 miles different in a year. The movement that deep is quite a bit less than 7 miles since the circumference at that depth is much less. Additionally it's not rock and dirt at that depth, but a liquid magma with an average speed of a foot a day is not too surprising.
Humans think of these things as constant, but the length of the day and the distance of the moon are changing because tides are transferring rotational energy of the earth into the moon. Said forces aren't directly impacting the spin of the core, so it might well be catching up and oscillating around the speed of the earth's rotation every 35 days.
But yes, there is an absolutely absurd amount of energy in this scenario. On the scale of "let's stop the moon spinning" big.
Even at the scale of slowing from one degree of rotation per year to zero degrees over a few decades, it's a lot of energy.
And that's not even counting all of the other energy drains in this system, like turbulence between the outer and inner cores from rotating at different rates, or the magnetic field of the inner core fighting the outer core.
The amount of energy involved is just absolutely bonkers.
I know magnetic north has been slowly shifting… but as I understand it, this currently involves changing the values on runways (the number on a runway is the degrees per magnetic north)… but that is pretty much it.
What happens if magnetic north becomes magnetic south?
Is there anything beyond the obvious (compasses and things that rely on compasses) that would be impacted?
Does this increase the susceptibility of the Earth to the effects of solar wind, such as increased radiation at sea level or atmospheric erosion (like on Mars)?
The magnetosphere protects the lower levels of the atmosphere from charged particles from the sun and further sources. This isn't just solar flares, but a constant bombardment of energy. Without it the rest of the atmosphere will began to degrade, with specific worry about our ozone layer. Some animals such as birds are shown to relay on the magnetosphere to help navigate. Aside from the changes to ecosystems and climate, the magnetosphere is also responsible for the aurora borealis, so we would miss out on that.
On the plus side, we'd finally have enough data to answer questions about what sort of radiation shielding generational spaceships would need, and exactly how much cancer prevention Earth's atmosphere is providing.
https://en.wikipedia.org/wiki/Laschamp_event
> This loss of the geomagnetic shield is claimed to have contributed to the extinction of Australian megafauna, the extinction of the Neanderthals and the appearance of cave art. However, the lack of corroborating evidence of a causal link between the Laschamp event and population bottlenecks of many megafauna species, and the relatively moderate radio-isotopic changes during the event, have cast significant doubt on the real impact of the Laschamp event on global environmental changes.
Caveat: Even with the atmosphere fully present, the magnetosphere does indeed stop many charged particles that a gas barrier does not, and this would definitely be an immediate problem to surface life to some extent (how much is debatable however). We'd also be much more susceptible to electronic and electrical grid damage caused by a much larger percentage of solar storms that would have previously been too weak to do much because of our giant magnetic shield..
It's not an humanity destroying event, but it is a big stressor on a world already going through a lot.
"Other sources estimate that the time that it takes for a reversal to complete is on average around 7,000 years for the four most recent reversals."
A range of 2k-12k is also in the introduction.
https://upload.wikimedia.org/wikipedia/commons/thumb/7/74/Ma...
I wonder if these two things are related.
It's unknown how migratory species that sense the magnetic field will be affected. Maybe they easily adjust, maybe there is a massive die-off due to large percentages getting lost.
Sigh.
With no magnetic field there will be more harsh radiation at the surface. Plus the solar wind may erode away the atmosphere as has on field-less Mars.
The article mentions switches between super- and subrotation have occurred within just the past 50 years. So, yeah seems to happen pretty frequently.
Note noting is talking about the cessation of rotation. The article is very clearly about the "strange spin" discrepancy between outer and inner core.
From what I have read, we have not had any probes too far into the earth.
I remember someone saying that we know more about space than we do about the earth.
I dont know if I should have listened to the guy.
I do understand that the article references distributed readings over long timespans of seismic data that allows scientists to establish the current view.
Seismic waves suffers from antenna limitation artifacts with the 70% ocean barely instrumented. A French group launches torpedo seismometers for months at a time to fill in gaps.
i recently (within a few weeks) watched this from beginning to end, and holy cow was i not impressed. to have so many actors of high report to end up such a horrible movie.
For me at least, a movie just isn't a spectacle the way it used to be. Going out to see Top Gun: Maverick, and seeing The Batman at a drive-in cinema is probably the closest I've been to that feeling since the original Avatar. Maybe I'm not giving enough credit to the Avengers movies.
You no doubt are thinking of his famous anecdote of questioning Michael Bay about training oil drillers to be astronauts, as opposed to the other way around.
Bay's film's approach is correct, though. NASA had by then been flying payload specialists on the shuttle for more than 15 years, because it really is easier to train specialists in some subject to fly in space, than train astronauts an entire specialty for one flight.
Deep Impact is not a great film, but does a surprisingly good job of telling its story in a moving way.
Its archrival Armageddon is also not a great film, but is arguably even more effective at its job (that being "fun summer popcorn thriller").
Unobtanium that gets stronger under pressure and can also generate power, and to tap that power you just need to weld conductors to the hull and plug that into the engine and it goes, just awesome nonsense.
Also it's great to watch Stanley Tucci be sniffy and pert nonstop.
But actually, I can rewatch that movie endlessly on repeat
If your going to ditch science, may as well go all in.
They should use it in public schools to teach earth science.
Dr. Josh Keyes: We can't.
General Thomas Percell: Not in my vocabulary.
(possibly the greatest burn in movie history)
Dr. Josh Keyes: Then you might want to get one of those word-a-day calendars, General, because it's impossible. The core is the size of Mars. You're talking about jump-starting a planet. This is a superheated hyper-fluid of molten iron and nickel at 9,000 degrees Fahrenheit. And the deepest we've ever been is... 7 miles, with a two-inch drill bit.
General Thomas Percell: If we can go into space, we certainly...
Dr. Josh Keyes: Space is easy. It's empty. We're talking about millions of pounds of pressure per square inch. Even if we somehow came up with a brilliant plan to fix the core, we just can't get there.
But it's not a great burn, because the general turns out to be right and the scientist is wrong!
Further, Percell is clearly being characterized as believing that raw effort—spend as much money,[1] throw as much resources at a problem as it needs—always wins out. And, again, he turns out to be right.
[1] Leading to the best single line of the film, far better than your choice
A warning however, it takes a sharp left turn towards horror at one point.
We may cause some extinctions and such, but overall, the Earth and life will go on with or without us.
Modern sensors might be sensitive enough that a nuke could provide sufficient stimulation?
(the article notes that they did use historical seismic data on nuclear tests to probe what the core was up to in the 60s)
We need to do better.
We really do not have a sense of scale to imagine the size of the earth.
Not sure where you got that. As far as I can see from most online sources, the Earth's atmosphere weighs about 5 x 10^18 kg, but the oceans weigh about 1.3 x 10^21 kg.
It makes sense that the atmosphere weighs less than the oceans if you think about it. The weight of air at sea level is about the same as 10 meters of water. The oceans cover most of the earth, and average a depth of a lot more than 10 meters.
So, reading the article, the answer is in fact "We don't know. Nor is there enough evidence right now to even guess" for that perfect time-wasting double whammy. Nice! What lovely click bait.