Unexpected Solidlike Fracture in Simple Liquids(quantamagazine.org)
quantamagazine.org
Unexpected Solidlike Fracture in Simple Liquids
https://www.quantamagazine.org/we-know-simple-fluids-can-flow-turns-out-some-can-fracture-20260710/
https://journals.aps.org/prl/abstract/10.1103/t2vy-32wr
49 コメント
> a project in collaboration with the oil and gas company Exxon Mobil
I find it a bit dark that, at a time people, crops, forests and biomes are dying due to extreme heat caused by the fossil fuel industry’s reckless behaviour the last 50 years, the said fossil fuel industry funds research on exotic rheology.
I find it a bit dark that, at a time people, crops, forests and biomes are dying due to extreme heat caused by the fossil fuel industry’s reckless behaviour the last 50 years, the said fossil fuel industry funds research on exotic rheology.
This is the same company whose research funding was among the first to produce forecasts of these affects. Yet that didn't stop them.
Can't get more "dark" than that.
https://en.wikipedia.org/wiki/ExxonMobil_climate_change_deni...
Can't get more "dark" than that.
https://en.wikipedia.org/wiki/ExxonMobil_climate_change_deni...
Oh yes, they had some of the best climate scientists back then.
It’s somewhat a scale up of what the tobacco industry did, same strategies, etc
It’s somewhat a scale up of what the tobacco industry did, same strategies, etc
of what the tobacco industry did
They care about rheology because that expertise enables fracking, and they're smart enough to understand that you have to fund basic science to get (valuable) applied science.
I have worked half of my life in both fundamental and applied science, I know how this work. In particular you can refuse jobs you deem unethical.
Why not funding energy transition research for instance. It’s know to science for half a century we’ll cook to death if we don’t phase out fossil fuel energy.
And by know, I mean there’s literally millions of papers on the topic.
Why not funding energy transition research for instance. It’s know to science for half a century we’ll cook to death if we don’t phase out fossil fuel energy.
And by know, I mean there’s literally millions of papers on the topic.
well unless you figure out how to replace plastic..
We could replace a large number of plastics right now and be just fine. Society flourished and thrived before we used plastic for everything in our lives. Some people would make less profit though, so of course it's impossible to make those kinds of changes, but we could.
Society flourished without lots of stuff we have today. It just flourished less.
And people aren’t failing to migrate away from plastic because “somebody would make less money”, they’re using plastic because everything else basically sucks in comparison. It’s tough, cheap, light, stable, easy to shape, doesn’t often break dangerously, can have all of its basic properties modified, and more. Nothing else is THAT good.
Edit: Not to mention, it’s not as simple as “don’t use plastic packaging anymore”. We pull oil into a machine and cook it off at various stages to produce various things. Turning cooking stage 8 of 12 into a worthless pile of garbage to be discarded doesn’t stop us from pulling in that oil for the other 11 uses.
And people aren’t failing to migrate away from plastic because “somebody would make less money”, they’re using plastic because everything else basically sucks in comparison. It’s tough, cheap, light, stable, easy to shape, doesn’t often break dangerously, can have all of its basic properties modified, and more. Nothing else is THAT good.
Edit: Not to mention, it’s not as simple as “don’t use plastic packaging anymore”. We pull oil into a machine and cook it off at various stages to produce various things. Turning cooking stage 8 of 12 into a worthless pile of garbage to be discarded doesn’t stop us from pulling in that oil for the other 11 uses.
All we need to do is to replace all plastics with bio degradable ones. But I guess that will take some time since we don’t have replacements for all petroleum based plastics yet.
Hopefully this will get us recycling friendly plastics for foods in the long run since those just get burned nowadays cause you can’t recycle those we have today for that job.
Hopefully this will get us recycling friendly plastics for foods in the long run since those just get burned nowadays cause you can’t recycle those we have today for that job.
Well, the mainstream adoption of plastics following World War II happens to coincide with an unprecedented period of relative global stability known as the “Long Peace.” So there’s at least some version of “thriving” that was, in fact, not previously achieved. Correlation does not imply causation but in this case it’s difficult to disentangle which innovations have lead to the relative global prosperity that has enabled this, and I think plastics are on the shortlist.
You are mistaking plastics for the MAD doctrine, and nuclear weapons.
This seems more of inertia, Newton's first law. "An object at rest stays at rest,...". What comes to mind say there is some threshold acceleration (e.g. or at extreme, accelerate to c within some short time, t), then essentially you have a body at rest and breaks at the weakest point. Interesting would be seeing this effect with varying viscosity.
Second comment for a semi-off-topic question: does the state of matter depend on the gravity?
Thought-experiment: take any solid, put it in an infinitely strong cup, and crank up gravity. At some point gravity overwhelms the forces holding the substance together and thus the substance ends up breaking apart and.. filling the cup just like a liquid, no?
Does everything become liquid-like at sufficiently high gravity? How does one distinguish what's a solid or a liquid when gravity seems to make them behave similarly?
Thought-experiment: take any solid, put it in an infinitely strong cup, and crank up gravity. At some point gravity overwhelms the forces holding the substance together and thus the substance ends up breaking apart and.. filling the cup just like a liquid, no?
Does everything become liquid-like at sufficiently high gravity? How does one distinguish what's a solid or a liquid when gravity seems to make them behave similarly?
https://i.pinimg.com/originals/a1/fb/66/a1fb663d7d2942c1988d...
If you put a cup of water in a strong enough gravity, lower part of the cup will have higher pressure, and that part will turn to unusual ice types. While top of the cup will remain liquid. Cranking up a gravity will only change the ratio. This is why people use pressure instead of gravity, pressure is what defines the state.
Your main point is something like "material becomes weak compared to gravity, conforms to the cup, as if liquid", or "cant have long range structure". But we already have solids that are like that - sand. Sand doesnt resist change to its shape, it just slides in a new position. And yet we still consider sand to be solid. Angle of a pile in particular.
Even a neutron star likely has surface level irregularities on a scale of centimiters. While a liquid can flow to submicron level smoothness even in a diy experiment.
Material gets stronger as pressure is increased. Unusual crystal structure becomes available. Superconductors and some other weird properties can exist only when crystal structure is compressed. And this tendency continues all the way to degenerate matter, as in neutron stars. Material from inside of a neutron star is likely the strongest a material can be in this universe.
So in the end, "solidness" continues to fight back, presenting enough properties to differentiate it from a true liquid, even if it could look somewhat similar, "shallow pile of material", all the way to degenerate matter of neutron stars.
If you put a cup of water in a strong enough gravity, lower part of the cup will have higher pressure, and that part will turn to unusual ice types. While top of the cup will remain liquid. Cranking up a gravity will only change the ratio. This is why people use pressure instead of gravity, pressure is what defines the state.
Your main point is something like "material becomes weak compared to gravity, conforms to the cup, as if liquid", or "cant have long range structure". But we already have solids that are like that - sand. Sand doesnt resist change to its shape, it just slides in a new position. And yet we still consider sand to be solid. Angle of a pile in particular.
Even a neutron star likely has surface level irregularities on a scale of centimiters. While a liquid can flow to submicron level smoothness even in a diy experiment.
Material gets stronger as pressure is increased. Unusual crystal structure becomes available. Superconductors and some other weird properties can exist only when crystal structure is compressed. And this tendency continues all the way to degenerate matter, as in neutron stars. Material from inside of a neutron star is likely the strongest a material can be in this universe.
So in the end, "solidness" continues to fight back, presenting enough properties to differentiate it from a true liquid, even if it could look somewhat similar, "shallow pile of material", all the way to degenerate matter of neutron stars.
It really depends on what’s in your cup at relatively low gs - some things will deform, others will brittle fracture, others yet will just stubbornly sit there, but if you keep on cranking that gravity dial you’ll get degenerate matter, which behaves quite a bit like a liquid.
I must be missing something.
If something is a fluid... or at least a liquid... that means it... flows, right?
Flow speed isn't infinite, so whenever you pull apart a liquid, you'll see some remnant of the pre-flow state. The thicker the liquid, the slower you need to pull it apart to see that.
Is this surprising? Why wouldn't every liquid do this? In what way is this somehow special to some liquids and not others?
If something is a fluid... or at least a liquid... that means it... flows, right?
Flow speed isn't infinite, so whenever you pull apart a liquid, you'll see some remnant of the pre-flow state. The thicker the liquid, the slower you need to pull it apart to see that.
Is this surprising? Why wouldn't every liquid do this? In what way is this somehow special to some liquids and not others?
Your intuition is correct, and what you’re describing is cavitation - which the article goes on to mumble about a little. Honestly, I am also struggling to see what the novel result here is. You can snap off a drip of pitch by pulling on it - if you shear it, it will probably just bend - yank on the droplet and it comes off with a satisfying snap.
But then again I suppose if you lead a cosseted life, never played with the contents of a shed, and had your first practical experience of actual hands on behaviour of viscous liquids in a lab… you might shout “Eureka”.
But then again I suppose if you lead a cosseted life, never played with the contents of a shed, and had your first practical experience of actual hands on behaviour of viscous liquids in a lab… you might shout “Eureka”.
Pitch is a viscoelastic polymer while simple fluids are non-elastic, that's the whole point.
Cavitation can be another “out” for that energy.
This looks like silly putty behavior.
Oobleck (corn starch and water) will do this too. But presumably they already knew that. The article describes it as being known to happen in “complex fluids,” but that it was news that it happens in “simple fluids.” Presumably silly putty and oobleck are “complex fluids?”
Specifically they're the subtype of non-Newtonian fluids, and it's also a colloid, and certainly is very elastic.
Turns out glass has been known to be a fluid and to fracture for quite some time.
[edit: but glass is not a simple fluid.]
[edit: but glass is not a simple fluid.]
I thought glass was a solid?
I lived in a house built around 1605 in the Netherlands, with some of the windows being hundreds of years old, based on expert opinion. The glass had started to droop downward in certain places, almost like the resin you see in trees. It made me realize that glass is not as rigid as I thought.
I think that glass flowing thing is a myth. The manufacturing method back then resulted in uneven panes and they were installed with the thicker side at the bottom.
It's an amorphous solid last time I dove into this.
The "well it's technically a liquid!" because it "flows" is really not telling the whole story. Like most science, it's just more complex than can be quickly summarized with one sentence, and doesn't quite map to just high school simplifications.
The "well it's technically a liquid!" because it "flows" is really not telling the whole story. Like most science, it's just more complex than can be quickly summarized with one sentence, and doesn't quite map to just high school simplifications.
Nope, lots of fluids that just flow over such a long period they appear solid.
Not sure why klustregrif got flagged - the answer was informative and correct.
What I said is true but not for glass. Pitch is a liquid even though it feels like a solid and shatters when smashed.
What I said is true but not for glass. Pitch is a liquid even though it feels like a solid and shatters when smashed.
That ‘long period’ can be many billions of years, glass is an amorphous solid.
That’s a misconception. Glass does not flow over time; it is a rigid, amorphous solid.
The uneven thickness seen in old cathedral windows is a result of historical manufacturing. Glass was spun into discs that naturally became thicker at the edges, and builders installed the heavier side at the bottom for stability. Physicists calculate that it would take longer than the age of the universe for room-temperature window glass to visibly deform under gravity.
Reference: Zanotto, E. D. (1998). "Do cathedral glasses flow?" American Journal of Physics, https://doi.org/10.1119/1.19026
> That’s a misconception. Glass does not flow over time;...Physicists calculate that it would take longer than the age of the universe for room-temperature window glass to visibly deform under gravity.
so then it does flow over time, just not on a scale where it matters to us.
so then it does flow over time, just not on a scale where it matters to us.
Should be called semi-rigid fluids. They have a structure, it’s just weak and breaks at weak points as you would expect.
Someone tell me the industries that are going to benefit the most from this in the short and long term and what I can expect to see in the next 30 years as a result of this discovery.
That sounds like a lot of work for someone to go do for a quanta article about something neat a researcher noticed.
I worry that this sort of request will become the norm in the age of AI where people forget that people aren’t there to serve them.
If it does I'm just going to start doing what AI does and make up bullshit like Calvin's dad. https://i.redd.it/egytd3v20qo81.jpg
Maybe it will not have any mmediate application. But guess what? It's still cool! And that can be its very own reward if you let it.
Oh, btw: electricity was a novelty toy for several long decades with no major practical applications. But that eventually changed because people kept researching it. And it changed the world.
Oh, btw: electricity was a novelty toy for several long decades with no major practical applications. But that eventually changed because people kept researching it. And it changed the world.
It’s a new, generalizable material-science property at STP. Those almost always find practical uses.
(Off the top of my head, a material that dissipates tension below a certain rate but fails when it is applied faster than that rate seems to resemble a mechanical breaker. As in not an electrical breaker that works mechanically. But one that decouples when you pull on it super hard. Being able to do that in fluids means one can potentially do that at very tiny scales.
More broadly, if simple fluids have a quasi-elastic mode, that has fundamental implications for hydrodynamics. I'd be super curious to know, for example, if anything similar to this occurs in air or water.)
(Off the top of my head, a material that dissipates tension below a certain rate but fails when it is applied faster than that rate seems to resemble a mechanical breaker. As in not an electrical breaker that works mechanically. But one that decouples when you pull on it super hard. Being able to do that in fluids means one can potentially do that at very tiny scales.
More broadly, if simple fluids have a quasi-elastic mode, that has fundamental implications for hydrodynamics. I'd be super curious to know, for example, if anything similar to this occurs in air or water.)
Maybe I'm wrong or too naive... but isn't it related to "cavitation"?
From reading the article, it does sound like that's a top hypothesis. Pulled fast enough, a bubble from cavitation can form and serve as the nucleation site of the crack