My son asked a question this morning that I just can't answer!
He was eating a bowl of multi-grain hoops and wondered why they appeared to be attracted to each other in an almost magnetic way. Even when there were only a couple left in the bowl, they still seemed to be drawn together across the sea of milk!
Can anybody please help me explain to him why this happens?
Thanks.
2007-03-07 19:34:50 · 5 answers · asked by Daisy Artichoke 3 in Science & Mathematics ➔ Other - Science
Your son is very observant. Perhaps he will become a great scientist or engineer. Because milk is mostly water with a little fat, it has surface tension just like water. The hoops float on the liquid but some of the milk wets up the edges above the surface. This is like the meniscus when water rises in a glass tube. It also helps explain capillarity. Because the loops are floating in little indentations in the milk when they happen to near the surface tension draws them together within a single indentation. The pictures in the link should help see the indentations.
2007-03-08 02:38:21 · answer #1 · answered by Kes 7 · 0⤊ 0⤋
This is a matter of surface tension. It is energetically favourable for the liquid to minimize its surface area, that is, the amount of surface where it is in contact with something other than a liquid. This is because the attractive forces between water molecules and other water molecules are usually greater than the attractive forces between water molecules and other objects. A bunch of small objects floating in a bowl can reduce their total surface area in contact with the liquid, by clumping together to form, effectively, one big object, so that's what they do. (If they're touching each other, they're sharing surfaces with each other instead of with the liquid). you will notice that the multi-grain loops will also end up touching the sides of the bowl - for the same reason.
NB, this is not in fact a gravitational effect- gravity is actually an immensely weak force, and is completely dwarfed by surface tension.
2007-03-08 06:50:17 · answer #2 · answered by Ian I 4 · 0⤊ 0⤋
It happens with any cereal immersed in milk or liquid for that matter.
The only thing can think of is that the little pockets of air on the cereal's textured surface may suck the surrounding milk which creates a milk-boundry that, when a piece of cereal collides with another, makes the two boundries join. Since the two cereal pieces are so light with more air pockets, they move around as one piece.
2007-03-08 03:38:28 · answer #3 · answered by Anonymous · 0⤊ 0⤋
Gravity operates everywhere, all the time. Free to float, I would expect objects to go toward each other.
2007-03-08 05:57:07 · answer #4 · answered by Benji 5 · 0⤊ 0⤋
Surface tension.
2007-03-08 03:38:30 · answer #5 · answered by Anonymous · 0⤊ 0⤋