Submitted by stinkybuttttt t3_10obltn in explainlikeimfive
Comments
pierrekrahn t1_j6eaq9h wrote
A crowd of people or a speech can both be fluid, for instance.
scratch_post t1_j6eh4e7 wrote
Yup, any set of individual mass units can collectively flow. bucket of sand, people in the cities, cars in the streets. This is, afterall what is happening even with water.
Bonneville865 t1_j6g4rxi wrote
That’s fluid as an adjective. OP was asking about fluid as a noun.
tomalator t1_j6gkx3w wrote
All that's required is flow. A glacier is made out of ice, but it's still a fluid. Each individual in the crowd isn't a fluid, but the crowd itself is.
Macluawn t1_j6fj9hh wrote
Farts are fluids, not liquids
SleepWouldBeNice t1_j6gcpvg wrote
Specifically, fluids are substances that cannot resist a shear force, which are gasses and most liquids.
OkBottle8719 t1_j6gz9lp wrote
I'm a geologist and I'm delighted to tell you that solids are fluids too!
mildly_sexy t1_j6g4jf8 wrote
Stagnant liquid doesn’t flow
Plasdfgjs t1_j6dw4ew wrote
That's admittedly a common misconception, but glass is an amorphous solid.
Skusci t1_j6dwcqr wrote
Gas not glass.
EffectiveSecond7 t1_j6ed8yy wrote
Good thing glasses are made of glass then, you'll need some 😏
Unique_username1 t1_j6dnrmz wrote
A fluid describes something that can change shape to match the shape of its container, and can move.
A gas (like air) is actually a fluid, it can flow down a pipe just like liquids can.
The difference is gas expands to fill its container, while liquid only takes up a set amount of space. A glass half full of water will stay half full. If a glass was half full of air, the air would spread out to fill all of it with less-dense air.
Specific-Salad3888 t1_j6e7b2o wrote
Doesn't glass also change shape just really slowly like over 100s of years. I was told this when on Venice years ago.
Farnsworthson t1_j6ebhks wrote
Nope. Old fallacy based on old window glass usually being thicker at the bottom. But the way it was made at the time, it was always likely to be thicker at one end than the other* - and if your glass is like that (and expensive!) you're obviously going to put the heavier end at the bottom. Not least, there's less risk of it overtoppling and breaking while you're installing it. There's Roman glass around from over 2000 years ago; it's just the same shape as when it was made.
*(Basically, early window glass was made by spinning a blob of molten glass into a disc with centrifugal force. Which means that it gets thinner towards the edges. Then you'd cut the sheet up into panes. If you've ever seen old doors or windows with a rough, circular pattern of thickness on them - that's the cheapest bit, from the middle. Google "crown glass".)
XenosapianRain t1_j6h61yy wrote
Career glazier... Glass used to be put through rollers,at the edges of the sheet it was imprecise in thickness.. Old glass is thicker at the bottom by installers choice. Most pressure from gravity was on bottom, so you cut the glass so the skinny side is up to reduce breakage. Taught these details restoring an old train.
figmentPez t1_j6ec5fl wrote
Glass is not fluid enough to perceptively change shape in hundreds of years, if it's fluid at all. There may be some debate on if it would flow over the course of huge, cosmic scales of time, I'm not clear on that, but glass is a solid for all intents and purposes when it comes any earthly scale of time, even geological time.
Stained glass windows have glass panes with one side thicker than the other because of manufacturing defects, not because of fluid dynamics.
druppolo t1_j6e6smj wrote
Matter can be divided in Newtonian:
Solid: can’t flow, can’t be compressed*
Liquid: can flow, can’t be compressed*
Gas: can flow and be compressed.
Fluid is anything that can flow, eg gases and liquids
Non Newtonian materials are generally man made materials that “cheat” and behave in a way not strictly in one of these groups. The most common are for example padding for body protections, a sort of rubber like material that can flex with your body but stiffens when hit. Very handy as it feels like clothing but protects like a solid pad. Another example is wet sand or mud, as a whole, it does not behave like a classic solid or a classic liquid.
*compressed in the sense that if you give infinite room, the gas will take all the room, and if you change the space it is confined, it will evenly be squeezed in it. Non compressible means that if you try compress the material, it will change its volume by very very little and oppose a lot of resistance to it.
These categories are broad and used for broad description. There are applications in which you can force these categories of material to do weird things, in extreme circumstances. For example, air at supersonic speed is not compressible, or better, does not behave like a compressible fluid.
nmxt t1_j6dnmt2 wrote
Both liquids and gases are fluids. That is the difference. Gas is a fluid, but not a liquid. All liquids are fluids, but not all fluids are liquids.
WinBarr86 t1_j6dlk80 wrote
Liquid is a state of mater. Fluid is a state of movement. Not all fluids are liquid and not all liquids are fluid.
lemoinem t1_j6dmpby wrote
Now I'm curious. I know gases can be modelled as fluids but I'm curious about non-fluid liquids...
jmukes97 t1_j6dp2f1 wrote
All liquids are fluids
WinBarr86 t1_j6dq0fu wrote
Wrong.
A non-Newtonian fluid is a fluid that does not follow Newton's law of viscosity, i.e., constant viscosity independent of stress. In non-Newtonian fluids, viscosity can change when under force to either more liquid or more solid. Ketchup, for example, becomes runnier when shaken and is thus a non-Newtonian fluid.
ToxiClay t1_j6dqqsv wrote
But it's still a fluid, which was the contention.
WinBarr86 t1_j6dqxpg wrote
Ok let me use another example.
Glass. Glass is a non fluid liquid.
superbob201 t1_j6dsfmb wrote
Glass is not a liquid. It's either a solid using the grade-school definition, or in a separate state of matter that is almost, but not quite, solid.
WinBarr86 t1_j6duiyg wrote
amorphous solid is a liquid that does not flow: its atomic structure is disordered like that of a liquid but it is rigid and holds its shape like a solid.
superbob201 t1_j6duzze wrote
It is similar to both liquid and solid. If we were sticking to the big 4, it would reasonably be a solid. If we are allowing an expansion of the defined states, it would be a separate state that is neither liquid nor solid.
Edit: Note that in the article they keep switching between calling them 'solids that behave like liquids' and 'liquids that behave like solids'. Suggesting that neither category is really applicable.
WinBarr86 t1_j6dvuxm wrote
There are way more than 4 states of mater.
Schools teach the wrong shit to keep it super simple. There are 7 states of matter that I'm aware of.
I will die on this hill.
Not all fluids are liquid and not all liquids are fluid. You have non newtonian fluids that are not liquids and you have amorphous solids that have the make up of liquids but are not fluid.
superbob201 t1_j6dy1o4 wrote
Amorphous solids are not liquid. They are amorphous solid. They have properties of both solids and liquids, but they are neither.
There are far more than 7 states, and it is pretty likely that any list you or I or an expert in the field could come up with would be incomplete 20 years from now.
You are dying on the hill of 'There are more than four states of matter, but we must place everything in one of those states'
WinBarr86 t1_j6dy9cz wrote
Amorphous solids are solids that have an atomic makeup closer to a liquid.
phunkydroid t1_j6f8nq4 wrote
Your link is about solids that flow, not liquids that don't flow. Amorphous solids are solids. It's right there in the name.
LordEarArse t1_j6drmqa wrote
Keep digging.
WinBarr86 t1_j6dtv7l wrote
Amorphous solids like glass.
amorphous solid is a liquid that does not flow: its atomic structure is disordered like that of a liquid but it is rigid and holds its shape like a solid. Amorphous materials include silica glass and a multitude of other materials of different origins, such as soft glasses (like concentrated emulsions, mousses and colloidal glasses)
LordEarArse t1_j6hja1u wrote
A web page with 'science' in the URL that agrees with your misinformed opinion. Yeah; I'll take that as sufficient evidence to refute a universe of facts.
ToxiClay t1_j6drbt7 wrote
That's admittedly a common misconception, but glass is an amorphous solid. It's not a liquid in any sense of the term, even though the atomic structure resembles a super-cooled liquid.
WinBarr86 t1_j6dtdh3 wrote
Amorphous means it changes.
Definition.
An amorphous solid is a liquid that does not flow: its atomic structure is disordered like that of a liquid but it is rigid and holds its shape like a solid.Jul 7, 2008
ToxiClay t1_j6dtyue wrote
That's the same misconception.
"Amorphous solid" means that it lacks the long-range order characteristic of crystalline material. It resembles a liquid, but it is not a liquid.
WinBarr86 t1_j6du8sq wrote
W.e man. I litteraly linked the definition of amorphous solid.
ToxiClay t1_j6duppj wrote
You did, and you're still wrong.
An amorphous solid can be described like a liquid, but that doesn't mean it is one. An amorphous solid does not flow; it does not assume the shape of its container.
It is not a liquid.
WinBarr86 t1_j6dws6k wrote
An amorphous material has a liquid atomic structure but does not flow as a fluid.
That is the litteral definition of amorphous materials.
They are classified as a solid liquid or non fluid liquid.
ToxiClay t1_j6dx1mg wrote
They're solids. An amorphous solid is a solid.
WinBarr86 t1_j6dxwrs wrote
That has the atomic makeup of liquid structure. A non crystalline lattice.
ToxiClay t1_j6dyn7u wrote
But it's still a solid.
>In condensed matter physics and materials science, an amorphous solid (or non-crystalline solid) is a solid that lacks the long-range order that is characteristic of a crystal. The terms "glass" and "glassy solid" are sometimes used synonymously with amorphous solid; however, these terms refer specifically to amorphous materials that undergo a glass transition. Examples of amorphous solids include glasses, metallic glasses, and certain types of plastics and polymers.
>An amorphous metal (also known as metallic glass, glassy metal, or shiny metal) is a solid metallic material, usually an alloy, with disordered atomic-scale structure. Most metals are crystalline in their solid state, which means they have a highly ordered arrangement of atoms. Amorphous metals are non-crystalline, and have a glass-like structure.
WinBarr86 t1_j6dz1i3 wrote
Science named it amorphous solids.
In the most basic sense it's a solid liquid. But that's not conducive to the model so they named it amorphous solid.
It's a solid that is atomicly a liquid or should be according to the standard model of physics. But it's not. So it's an amorphous solid.
jmukes97 t1_j6dym8q wrote
Still a solid tho
Belzeturtle t1_j6ep8h7 wrote
Physicist here. Amorphous doesn't mean it changes. Amorphous means "it has no long-range order". As opposed to crystalline solids, where this longe-range translational symmetry is present.
Glass is an amorphous solid. It's not a liquid. It has a structure somewhat similar to a liquid, but calling it "a liquid which doesn't flow" is like calling a tank "an aeroplane that doesn't fly".
phunkydroid t1_j6f8v5e wrote
>Amorphous means it changes
No, it doesn't. It means it has non crystalline structure.
jmukes97 t1_j6dsrvy wrote
r/confidentlyincorrect
WinBarr86 t1_j6dudcp wrote
amorphous solid is a liquid that does not flow: its atomic structure is disordered like that of a liquid but it is rigid and holds its shape like a solid. Amorphous materials include silica glass and a multitude of other materials of different origins, such as soft glasses (like concentrated emulsions, mousses and colloidal glasses)
Shifter93 t1_j6dwn8d wrote
dude, you keep linking the same incorrect definition over and over again. whats more, its literally the only source i can find that calls amorphous solids liquids on the entire internet. every single other website correctly calls them solids and you chose to run with the single incorrect one.
WinBarr86 t1_j6dxd6l wrote
Yes a SOLID liquid.
amorphous solid, any noncrystalline solid in which the atoms and molecules are not organized in a definite lattice pattern.
Like a liquid.
Shifter93 t1_j6e27ve wrote
"like a liquid" does not equal a liquid. its a solid. not a "solid liquid", which isnt a thing, and its not a liquid.
all liquids flow. every single one of them. it is an intrinsic property of liquid. its literally impossible for a liquid not to flow because flowing is a requirement of being a liquid. if something does not flow, then it can not be called a liquid. the fact that amorphous solids do not flow is exactly what makes them not a liquid, because again, all liquids flow.
[deleted] t1_j6epcml wrote
[removed]
Otherwise-Way-1176 t1_j6hadh1 wrote
No, an amorphous solid is not a liquid.
A liquid is: “a nearly incompressible fluid that conforms to the shape of its container but retains a (nearly) constant volume independent of pressure” (from Wikipedia).
An amorphous solid does not flow to conform to the shape of it’s container. Thus, and amorphous solid is not a liquid.
Further, many solids are non crystalline. Wood for example. Also charcoal. Also paper.
Are you seriously planning to argue that paper is a liquid?
c4pta1n1 t1_j6dr7te wrote
What about that leads you to believe that not all liquids are fluids?
WinBarr86 t1_j6dsgv7 wrote
Bc non newtonian fluids.
ToxiClay t1_j6duh9b wrote
But a non-Newtonian fluid is still a fluid.
WinBarr86 t1_j6duo58 wrote
Ok. Amorphous solids
amorphous solid is a liquid that does not flow: its atomic structure is disordered like that of a liquid but it is rigid and holds its shape like a solid.
c4pta1n1 t1_j6dusc3 wrote
So are you saying that non-newtonian fluids aren't fluids?
WinBarr86 t1_j6dwfqt wrote
No they are not liquids.
Amorphous solids are liquid solids. Liquids that are not fluid.
amorphous solid is a liquid that does not flow: its atomic structure is disordered like that of a liquid but it is rigid and holds its shape like a solid.
c4pta1n1 t1_j6e9gg3 wrote
Ok, but nobody said that all fluids are liquids, they said all liquids are fluids. Regardless of whether you're correct about non-newtonian fluids not being liquids, you haven't shown a liquid that is not a fluid.
Amorphous solids may share some similarities with liquids, but are still amorphous solids, hence solids.
Specific-Salad3888 t1_j6e7js2 wrote
It's still liquid/fluid until a force is applied to it though so under normal conditions it's still a fluid right?
LibertarianAtheist_ t1_j6e2oxe wrote
Matter*
PD_31 t1_j6dz9gy wrote
A fluid is anything that can flow. A liquid is a type of fluid (another type is a gas, probably a plasma as well).
So liquid is a subgroup of the states of matter that are fluid.
series_hybrid t1_j6fpmb9 wrote
If you get a book on "fluid dynamics" it covers liquids and gasses, which follow many of the same engineering principles. The major exception is the compressibility of gasses.
tsme-esr t1_j6gzwfd wrote
Gases can be fluids. Gases are certainly not liquid (the difference is that a liquid has a given volume but the volume of a gas increases or decreases based on various factors.
StupidLemonEater t1_j6dnrc0 wrote
A "fluid" is something that flows.
All liquids are fluids, not all fluids are liquids. Gasses are fluids too.