Cornstarch & Water - Explained by Physicists - Heinrich Jaeger and Scott Waitukaitis

The process of impact-activated solidification that occurs when compressive forces are applied to fluid-grain suspensions. The two researchers conduct experiments with a mixture of cornstarch and water that is classified as a non-Newtonian liquid. This video examines the strange behavior of the cornstarch-water liquid, which instantly changes into a solid within the area of impact. The behavior of non-Newtonian liquids has puzzled scientists for decades, and Waitukaitis and Jaeger's report sheds new light on this longstanding problem in suspension science.

Heinrich Jaeger, William J. Friedman and Alicia Townsend Professor in Physics, and Scott Waitukaitis, a graduate student in the Physics department, have published a report in the July 12, 2012 issue of Nature.

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[johnb]

Based on the title, I was expecting to learn about the physics behind it, instead of hear a physicist say, "it's a liquid, but when you hit it really hard it turns into a sold".

Cool footage none the less.

[TrilobiteTerror]

I have a question. I have found that Swedish Fish (the gummy candy) can shatter when thrown or, in some cases, even just dropped on the ground. When it shatters or chips, it will break with a clean edge as if it was made of glass (or a hard candy, I guess). The candy doesn't need to be frozen or hard (from being stale), it can be soft and bendy but will still shatter when it hits a hard surface like concrete. There is a video on Youtube called "Shattering Swedish Fish" which shows this but besides this video and my experience of it (probably 8 or more years ago) I have not been able to find anything else on the subject. It seems like it may not work with every Swedish Fish, I've only ever see it happen to non-original flavor ones but I have no idea. Years ago when I first experienced it I was just eating some red and green Christmas edition Swedish fish which were left over from a holiday party and I dropped one. Its tail broke off cleanly with a sharp edge as if it had been a hard candy yet it was just a regular, gummy Swedish Fish. I was fascinated and experimented with all the rest I had and got similar results.

I have to wonder if it this is acting on a similar principle as cornstarch and water but have been disappointed in the utter lack of information on it. Interestingly, corn starch is listed as an ingredient in Swedish Fish but I'm aware this may just be a coincidence.

I was wondering if anyone knows anything about this or has experienced this before. Anything would be very much appreciated.

[AdamTaylorfootgiraffe]

Love this video but I would like to know how the molecules work, how do they react to each other to create a temporary solid?

[Fox-in-the-Storm]

This makes me wonder if something like it can be adapted into bullet-proof armor in the future.

[csbalachandran]

It would be nice to show / discuss what potential applications this fascinating research may have. Could you please publish a video on that also? Many thanks.

[Meathamski]

What happens if you hit it while someone finger is in it?

[swaitukaitis]

It depends on the speed! We're currently working on experiments to try to figure out how this speed/pressure dependence works!

[lallu]

I'm gonna buy cornstarch on the way home tonight!

[treeky]

I'm not a physicist but I can explain that I didn't expect that they explain what so obvious.

[helloflame]

How could this be put in car suspensions?

[manekineko]

What other materials can be used aside from corn starch? Corn starch will break down over time. Are there any minerals which, when put in suspension, also do this. This would make a terrific damper for seismic constrain. Free moving at low speed, and locked under impact.

[arthurhemming]

Interesting. So there may be a way to change between solid/liquid states by changing the pressure of the solution? I guess what I'm asking is would it be possible to create "structures" that can also be turned into a liquid or solid at will?

[TheClashOfCultures]

If scientists can replicate this principle for other surfaces (like clothes or plastic) and it is strong enough to stop bullets or will change (back to melee).... Or if they can give a liquid the properties to stop bullets or even rockets, we could maybe construct 'force shields' out of it.... Like creating a stable bubble of the liquid and surrounding a large object with it, could work even easier in outer space without the gravity (yes, surrounding spaceships with corn starch bubbles to have epic space battles)

[jabberman]

could you run on a pool filled with water and cornstarch?

[jigo]

It's the worst thing to drown into, besides lava, cement, sewer

[VicChiron]

does it have to be at a stable /non-moving status? what if you put it in kelvar, can it stop a bullet?

[arthurhemming]

The grains of cornstarch grouping together to form a "temporary column solid" seems fairly commonsense. Although I wonder, if pressure is continuously applied at the same speed, does the solution still remain solid?

[mrsemifixit]

Does the entire container harden with impact or just say the top layers?

[maurizioantoniocarluccizam]

Hello, I'm making a school project about this topic. Can I make you a few questions about the experiment?

[loopofconsciousness]

I went to search if cornstarch reduces the surface tension in water for my bath making and came across this coolness,