Why Does Ink Move Rapidly on a Film When Refilling a Fountain Pen?

[mahela007]

In spite of the widespread ball point pen, I still use a fountain pen for calculations.. One day, I ran out of ink while writing (duh..) and opened the cap of my ink bottle to refill my pen. Now, as I opened the cap, a thin film of ink was formed around the mouth of the bottle.. in other words, it was like a partially formed bubble.. Now, because this was ink, I was able to see, rapid, random looking movements on this film/membrane of ink...Imagine the colors you get when oil mixes / floats on water.. now imagine those colors were all blue and imagine them constantly moving, turning, twisting etc..
what do you think caused these weird movements? I've read that the H bonds of water are in a constant state of flux and that the bonds keep forming and breaking... could this be the cause?

 

[Dadface]

An interesting observation and I suspect it was thin film interfernce,similar to the oil on water pattern you described.The movement could be due to the water draining and evaporating.

 

[mahela007]

thanks... I'll check that out.