Why do my Cheerios in milk act like magnets with different polarities causing them to repel or attract each other?



Why do my Cheerios in milk act like magnets with different polarities causing them to repel or attract each other?

In: Physics

They act like magnets because they are magnets.

Cheerios are fortified with iron. There is magnetic material baked into your Cheerios.

Because each individual Cheerios piece is meant to sink, but they can’t get through the milk’s surface *tension* (assuming it’s a dairy milk). Thus, the milk’s surface molecules direct pieces of Cheerios to “stick” to each other.

It’s fluid mechanics/physics at work.


Milk likes milk more than it likes air. When a cheerio floats on milk, it has milk in/on it, which attracts* the other milk molecules and pulls them up. You can see the surface of the milk curves up to meet the cheerio.

When you have 2 cheerios, the curved parts like each other more than they like air, so they behave like magnets.

* I’m not sure if “attraction” is the right word here, it’s more that the milk is taking the path of least resistance.


If you look closely at the side of the bowl, you can see that the milk clings to the side of the bowl and climbs up a small amount. The milk clings to the side of the Cheerios as well. Because Cheerios float, they want to be at the highest point of the milk, which happens to be along the edges of the bowl and near other Cheerios where the milk level is slightly higher due to it clinging and climbing.

[This short video](https://youtu.be/mbKAwk-OG_w) has some good visuals.

posts like these are too specific to be genuine =\. You probly watched that famous youtube video with vsauce or someshit where they talk about this phenomenon that you’d otherwise never heard of or notice. Then you come here asking this specific ass thing literally with the specific same cereal even used in the video to farm post karma for asking a ‘good question’

You know it, op, I know it. Everybody knows it

This is like me asking “how come when you throw life savers at the floor at high speed with the lights off it makes a blue shock visual”. SUREEEEE, you TOTALLYy didn’t just watch that. Everyone notices life savers making electricity when you smack them on the ground in the dark!

Isn’t this adhesion and cohesion at work. The same thing that helps water creep up soil and not stay at water level.

Water likes to stick to itself on a small scale. It has to do with the tension held by water droplets and it’s want to absorb into other materials.