Ranch dressing is it a liquid? There’s a fifth state of matter. Imagine that you are eating your dinner. Imagine you’re eating dinner. You pour ranch on your plate so that your vegetables can be dipped in it. The container is turned upside-down, and nothing spills out. It looks like a solid. You shake up the dressing bottle and it falls out onto your plate. Seems like a liquid.
The dressing does not spread out all over your plate like it would with milk, or other liquids if they were spilled. It maintains a shape like your vegetables on the plate. It looks like solid. The shape of the dressing blob is slightly distorted every time the solid celery or carrot are dipped into it. This game allows you to spread and smear the dressing around. However, the celery’s shape or stiffness is not affected. Seems like a liquid. Is ranch dressing both a liquid or a solid
? Is it either neither?
As a professor in physics and biology, my research is focused on understanding materials with both solid and liquid properties. These materials are called soft matter by physicists. We investigate in my laboratory what makes biological material such as skin or snot soft, and we try to create materials inspired by these materials. Physics Mama is a channel on social media where I and my boys ask questions and get answers about everyday physics.
Basic states of Matter
In order to figure out why ranch dressing is different, it’s important that you understand the differences between each state of matter and how they are unique. The scientific term for “stuff,” is “Matter” and this is any mass-producing substance that’s made of microscopic building block called atoms. Subscribe to the latest discoveries in science straight to your mailbox. In school, you probably learned that matter exists in three different states: liquid, solid and gas. Imagine an ice cube or a water puddle. You may have also heard of a fourth, or plasma state. The interaction between the tiny molecules that make up matter defines the different states
. They are so tiny that they can’t be seen with the naked eye. Their invisible interactions are what determines the visible properties of materials. Molecules of a solid have a physical connection to one another that prevents them from moving. Solids are rigid because they can keep their shape.
On the other hand liquid molecules are not linked to one another. The molecules can slide by each other, move and even mix up. It is this freedom of motion that allows liquids to conform to the container they are in. Gas molecules are free to move without bumping against each other. Gases, like liquids, will conform to the container they are in. They have no set shape. Gases can change in size and volume, but unlike liquids or solids. Plasma is similar to gas, but it has much higher energy. The electrically-charged parts of molecules called electrons and protons are broken apart by this energy. Plasma is found in the Sun, stars and neon signs.
Solids aren’t completely rigid, but they do have some viscosity. Solids are elastic because the connections between molecules act like small springs. When you press on a solid it deforms, but will return to its original shape when you stop pressing, similar to your mattress after you bounce it on the bed. This happens on a molecular scale, and you cannot see this. Even though liquids are able to change form, the molecules of the liquid resist the change because they have friction. Viscosity is the term for this friction. Honey or syrup is viscous, and therefore harder to mix than milk or water. Imagine swimming in a pool of honey – delicious, but hard to do.
Soft matter is a 5th state. Ranch dressing actually belongs to this state. Materials scientists call it viscoelastic, a mixture of viscousness and elasticity. Soft matter can also include silly putty (snot), snot and slime. These substances, which are neither liquid nor solid but are a mixture of the two, are referred to as
. If you squeeze some shampoo from a bottle and then pull it apart with your hands, the liquid will spread between your fingertips. If you press on cookie dough, it will deform and not bounce back. Shear thinned viscoelastics are materials that become less viscous when they’re agitated. Shaking a bottle of ranch or ketchup will allow you to empty it, even though it had been too thick to do so before. When you quickly stir yogurt, it can become liquidy even though the consistency is quite solid.
Materials that are squishy can thicken by being squeezed. They become stiffer the more you deform them. Oobleck is a mixture of water and cornstarch that works in a similar way. It can be poured and submerged in water, just like other liquids, but it will solidify if it is squeezed or agitated.
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