The science of cornstarch and water


[MUSIC PLAYING] When you mix cornstarch and
water, weird things happen. Swish it gently in a
bowl, and the mixture moves like a liquid. Squeeze it, and it starts
to feel like paste. Roll it between
your hands, and it solidifies into a
rubbery ball, until you try to hold that ball in
the palm of your hand, and it loses its structure
and dribbles away. To many who have played
with this material, perhaps as children, its
strange behavior is nothing new. But understanding
exactly how why and when this material will
act a certain way has always been
rather unpredictable. But now, a team of
MIT engineers have developed a mathematical
model that can accurately predict this material’s behavior
under various conditions. A single particle of cornstarch
is about 1 to 10 microns wide, and about 100 times smaller
than a grain of sand. It turns out that particles
at such a small scale experience effects that
larger particles do not. Because cornstarch
particles are so small, they can be influenced
by temperature and by electric
charges that build up between them, which causes
them to slightly repel against each other. So as long as you move
slowly, the grains will repel and slide past
each other like a fluid. But if you do anything too fast,
you’ll overcome that repulsion. The particles will touch,
there will be friction, and it will act as a solid. The researchers incorporated
equations into their model to describe the effects
of particle repulsion and the speed at which the
material is deformed to predict whether it would behave
as a solid or a liquid under various scenarios. The researchers
say the new model can be used to explore how
various ultra-fine particle solutions, such as
cornstarch and water, behave when put to
use as, for instance, fillings for potholes
or bulletproof vests.

29 Comments

  1. Sudipto Borun

    October 7, 2019 at 2:38 pm

    Link of the paper?

  2. Максим Чех

    October 7, 2019 at 8:38 pm

    B R U H

  3. MrYendor1968

    October 8, 2019 at 3:51 am

    ALSO if you mix it with olive oile it becomes electrically excited without physical movement ie it goes stiff the same as with water but  with electricity … and also why have I only ever seen one video that shows that affect ….. it would make the perfect break or clutch system

  4. Andrei Vingarzan

    October 8, 2019 at 1:54 pm

    This is cool

  5. Rajat Singh

    October 9, 2019 at 6:49 pm

    It is a non Newtonian fluid , but using it in pot holes. How can we overcome the disadvantage under gradually applied loads ?

  6. gengen One

    October 10, 2019 at 2:14 am

    Love this.

  7. Mu Effe

    October 10, 2019 at 5:33 am

    Didn't someone used this as speedbump? If you go slow, the bump stayed soft. If you drive fast, you become a flying car.

  8. Upasana Deka

    October 10, 2019 at 2:11 pm

    This is so great!

  9. jack fernandes

    October 10, 2019 at 2:24 pm

    Meanwhile me:

    4+4=44

  10. Akim Mustaqim

    October 11, 2019 at 1:33 am

    Shoot it with a gun

  11. SmolHeroine

    October 11, 2019 at 1:54 am

    29 years later and I'm still playing with it.

  12. Nathan

    October 11, 2019 at 4:48 am

    To think I cook with this stuff when I should be using it for a bullet proof vest.

  13. Philip P

    October 11, 2019 at 5:52 am

    I love how MIT mentions that it can be used for bulletproof vest…
    Meanwhile 6 years ago: https://www.youtube.com/watch?v=_ThtQkkXvdo
    5 years ago: https://www.youtube.com/watch?v=kK-Ob_dichQ
    4 years ago: https://www.youtube.com/watch?v=mYLIcOXG6Mw
    3 years ago: https://www.youtube.com/watch?v=Sl0BHueSjvA

    So yea….

  14. Kaushal Timilsina

    October 11, 2019 at 8:56 am

    This kind of resembles the goo used in sports helmets to absorb shocks.

  15. davidarf

    October 11, 2019 at 3:11 pm

    Potentially interesting but for the irritating unnecessary added noise. Do lecturers at MIT normally have this silly noise playing during lectures? I think not, which begs the question why it is added to this video report.

  16. Aajah Sampson

    October 11, 2019 at 5:21 pm

    People with cornstarch pica are shaking

  17. ToiR

    October 11, 2019 at 7:06 pm

    I remember we used to make this mix and pour it on subwoofers on school (idk how the hell the science teacher let us do that) and use different frequencies so the mix will wobble on the speaker.

    It was fun.

  18. Lawrence Cole

    October 11, 2019 at 7:39 pm

    SHOW THE THUMBNAIL! Downvote!

  19. Nikhilesh K

    October 12, 2019 at 12:15 pm

    I would like to see the testing of a bullet proof vest made of corn starch

  20. Blaze Walter

    October 12, 2019 at 2:08 pm

    i wonder if any scientist has tried to shoot a bowl of the stuff

  21. Hyoudou Issei

    October 13, 2019 at 9:52 am

    Really interesting

  22. Kim J

    October 13, 2019 at 11:46 am

    It also happens to tapioca starch. Not sure if all starches do this.

  23. Miraiana

    October 13, 2019 at 1:46 pm

    Wouldn't want to get stuck in this, is worse than quicksand… 😐

  24. Zeroy Voya

    October 13, 2019 at 8:27 pm

    1:19
    FBI open up

  25. John Dorosan

    October 13, 2019 at 9:38 pm

    Bulletproof vest made of cornstarch🤯

  26. Meh Tell

    October 14, 2019 at 12:07 am

    Cornstarch as filler in food No thanks.

  27. Mr. Z

    October 14, 2019 at 4:15 am

    One of my biggest pet peeves is wearing any kind of hand jewelry while working with dough or shit like this. Lol. Ah. Triggered.

  28. Yan Yan July

    October 14, 2019 at 5:43 am

    No you can't put cornstarch in the pothole as a fix. Bc what if the car goes slowly? What if the car stopped on top of that pothole? And what if it rains?

  29. Inside My Self

    October 14, 2019 at 3:17 pm

    Parang tamod

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