# Viscosity with Metaballs Five metaball fluids race down glass ramps to show what viscosity is By PETE\! Topic: Physics & Chemistry [Open the interactive Jig](https://ask.jig.com/j/oNaCY3M2UPq6) ## Transcript ### 1. Thick and thin Some fluids splash, others ooze in a lazy ribbon\. That difference has a name: viscosity, which means how strongly a fluid resists flowing\. Five fluids are waiting at the top of five glass ramps\. People often call it thickness: honey is thick, water is thin\. ### 2. Blobs that melt together Each fluid here is drawn with metaballs: little balls that melt into one smooth surface when they come close\. A gentle stir is pushing every fluid the same way\. Water swirls freely, while honey barely turns\. Metaballs are a picture of a fluid, not real molecules\. Molecules are far too small to see\. ### 3. The great race Every ramp holds the same amount of fluid on the same slope\. Open the gates and watch which one reaches the bottom first\. The race is sped up for the slow fluids\. Real honey is about 10,000 times more viscous than water\. ### 4. Layers that slide A flowing fluid moves in layers that slide over each other\. The layer touching the ramp is held back, and each layer drags on the next\. In honey, sticky, crowded molecules make that sliding hard, so it creeps\. ### 5. Warm it up Heat gives molecules the energy to wriggle past their neighbours, so most liquids flow faster when warm\. Slide the heater to warm the honey and watch its ribbon speed up\. Warming honey from 20 °C to 40 °C makes it about five times runnier\. ### 6. Ketchup's trick Ketchup sat still during the race\. It needs a firm push before it flows, and once it is moving it gets runnier\. That is why shaking or tapping the bottle works\. Getting runnier when stirred or shaken is called shear thinning\. Blood and nail polish do it too\. ### 7. Thick is not heavy Viscosity is not the same as weight\. Thick motor oil floats on water because it is lighter, yet it can be about 200 times more viscous\. Viscosity is only about how hard a fluid finds it to flow\. ### 8. Viscosity all around Viscosity decides how honey drizzles, how paint spreads and how ketchup leaves the bottle\. Next time you pour something, look for it at work\. Rough viscosity at room temperature, in mPa·s: water 1, motor oil 200, glycerol 1,500, honey 10,000\.