Is there a scientific reason for the following.

[Baitball Blogger]

I'm not sure if my observation was spot on, but I have noticed when working with water, that small particles that are floating at the top tend to cling to the sides of the container. If you watch, they speed up the closer they get to the edge. Almost like there is a magnetic pull.

Anyone else notice that?

[SticksnStones]

1. Viscosity?

[Baitball Blogger]

6. I read the definition, but can't see how it would apply here,

without further info.

[unblock]

2. gotta have something to do with the surface tension of water.

neighboring water molecules create hydrogen bonds with each other, which is why water tries to clump in drops rather than lay flat.

so i'd guess the surface is slightly raised in the middle of the container and lower at the ends, so things floating on the surface are just responding to gravity?

[Baitball Blogger]

4. I like the theory.

An example of water running uphill. Like wicking.

[CincyDem]

3. I think...

Surface tension of the water relative to the surface energy of the container. I'm not sure but I'll bet that if you use different containers, the phenomenon looks different. In some cases, it could go as far as being repellant, vs. the attraction you're seeing.

It is like magnetic pull but at the molecular level.

IMHO - that's what I get for reading popular science (I think).

[Baitball Blogger]

5. Thank you.

I wish there was a term for it.

[CincyDem]

7. Meniscus: I think the movement you're seeing in the particles is fluid being drawn into the meniscus

https://en.wikipedia.org/wiki/Meniscus_(liquid)

[VOX]

8. Capillary action, maybe? The H2O is "attracted" to the container...

https://water.usgs.gov/edu/capillaryaction.html
"Capillary action occurs because water is sticky, thanks to the forces of cohesion (water molecules like to stay close together) and adhesion (water molecules are attracted and stick to other substances). Adhesion of water to the walls of a vessel will cause an upward force on the liquid at the edges and result in a meniscus which turns upward. The surface tension acts to hold the surface intact. Capillary action occurs when the adhesion to the walls is stronger than the cohesive forces between the liquid molecules."

[Baitball Blogger]

10. Sounds like the meniscus explanation is getting traction.

[MGKrebs]

9. Perhaps you should consider a water filter.

[Baitball Blogger]

12. Good one.

[petronius]

11. It's part of what's called the 'Cheerio Effect'

Where the meniscus curves upward along the edge (the liquid molecules are attracted to the container more strongly than to each other), the buoyant particles will float to the highest point of the liquid, and thus cling to the edge. If the meniscus curves downward (the liquid molecules attracted to each other more than to the container) then the buoyant particles will float toward the higher liquid in the center. According to my google-fu, anyway...

[Baitball Blogger]

13. Since the term "miniscus" has come up a third time,

it is beginning to sink in.