Are there any substances that are a good opposite to custard?

[Mation]

Hello, science forum. I have remembered it exists ( )

So I was thinking today about custard. It's a 'non-Newtonian' fluid, meaning that how it behaves is dependent on how much force is applied to it.

Make it to an edibly runny consistency and it is good to go for pouring over crumble, etc, but smack the same solution hard enough and it will behave like it's a solid.

That got me to wondering about substances that might work the other way round. Are there substances that are initially solidish that become liquid with force applied?

Wikipedia tells me that ketchup is one such; shake it and it's thinner. But that just seems to me to be about mixing unmixed components, in a way that doesn't seem the opposite of hitting custard.

This is way outside my science field, so misinterpretations are likely, and corrections are welcome. What are the main, probably of many, things I'm missing?

Are there (potentially) rock solid inorganic substances that become liquid on impact?

Inorganic, I repeat.

 

[gentlegreen]

To be pedantic, custard is only non-Newtonian when you use far too much powder and before you cook it - at which point it becomes a gel ...

 

[gentlegreen]

Isn't window glass technically still a liquid ...

 

[High Voltage]

It's a super cooled liquid

 

[RubyToogood]

Isn't that basically what pyroclastic flow is? Solid rocks behaving as a liquid.

 

[platinumsage]

Gallium is a solid metal at room temperature but melts at 30C, basically if you give it a few slaps.

 

[Kevbad the Bad]

Maybe I'm just a bit weird, but I have never smacked custard hard. Ever.

 

[Mation]

To be pedantic, custard is only non-Newtonian when you use far too much powder and before you cook it - at which point it becomes a gel ...

What's a gel?

Isn't that basically what pyroclastic flow is? Solid rocks behaving as a liquid.

I will try to remember to look this up. (i wouldn't be able to take it in if I looked right now.)

Gallium is a solid metal at room temperature but melts at 30C, basically if you give it a few slaps.

Same.

Maybe I'm just a bit weird, but I have never smacked custard hard. Ever.

Totally you being weird

 

[Serene]

Rhubarb.

 

[gentlegreen]

What's a gel?

I'm not qualified to say

All I know is there's starch, gelatine, pectin and carageenan ... and the weird stuff they make handgel with ..

 

[Cid]

A slap is essentially just a form of pressure I think? In which case afaik many solids will become liquid under pressure. Water, metals etc.

 

[Fez909]

Are there substances that are initially solidish that become liquid with force applied?

Snails

 

[Cid]

Glass is an amorphous solid.

 

[Cid]

For highly viscous liquids you want the pitch drop.

 

[weltweit]

Rhubarb.

Crumble

 

[Mation]

For highly viscous liquids you want the pitch drop.

really deep voice How do you mean?

So, I don't know whether I should be expected to know this or not, as my education has been really patchy, but is the difference between liquid and solid a quantitative one of viscosity, or is it a qualitative one? Or both? (Christ: or neither )

 

[Mation]

Isn't that basically what pyroclastic flow is? Solid rocks behaving as a liquid.

Having now looked it up, I still firmly don't know Might be...

However, I did learn about the 1902 eruption of Mount Pelée, in Martinique, which I hadn't heard of before. An unimaginably hellish disaster that killed 30,000 people in under a minute, and left a handful of badly-burned survivors.

One of them was Ludger Sylbaris, who survived only because he'd been thrown in jail for the night, after some sort of drunken brawl. His cell was built partly underground, with an air vent that faced away from the volcano. With heroically quick thinking, he apparently pissed on his clothes, packed them over the vent, and avoided breathing in the 1000 degree heated air.

He later travelled with Barnum & Bailey Circus, in 'The Greatest Show on Earth', as a survivor of the event. He was the first black man in the company.

Ludger Sylbaris - Wikipedia

en.m.wikipedia.org

 

[Cid]

really deep voice How do you mean?

So, I don't know whether I should be expected to know this or not, as my education has been really patchy, but is the difference between liquid and solid a quantitative one of viscosity, or is it a qualitative one? Or both? (Christ: or neither )

My science is pretty crap. I do know that a liquid, strictly defined, is a state of matter. Solid, liquid, gas, plasma. So it does have quite specific characteristics... has to flow to fill containers, has to be near incompressible. I don't know what the dividing line is though... Like is mayonnaise a liquid? I know it's an emulsion of two liquids, but what is that. A colloid apparently. So there you go. I don't think liquefied sand is a liquid, just behaving like one.

This isn't very helpful, where did all the sciencey types go?

 

[Mation]

Haha, I'm supposed to be one of them, but clearly not this kind of science!

 

[DaveCinzano]

Gallium is a solid metal at room temperature but melts at 30C, basically if you give it a few slaps.

Does gallium often freak out at sea then?

 

[paul mckenna]

Isn't window glass technically still a liquid ...

that's a myth