Tuesday, 14 May 2013

Multi-scale Foam Computer Simulation and Why more Scientists Should Take Bubble Baths

Foams, Foams, Foams 

People like to blow bubbles.  This starts off when you are a child and blowing bubbles with soap.  It is fun.  I once won 500 euros (700 US dollars) in travel money because of blowing bubbles to show how they are related to other membranes.  Mathematician Thomas Young (and other scientists that predate him) studied bubbles in the 18th century to show how elastic.  The surface tension and elastic properties of the bubble and the surrounding environment cause it not to pop.  With a single bubble it is easier to understand.  With clustered bubbles physicists from Berkley recently figured out how they pop and why they produce a complex bunch of physical events.  Overall this effects the overall stability of all the bubbles.  (One for all and all for one in bubble bath terms I suppose).  After one bubbles pops the other bubbles can quickly rearrange to balance the overall cluster.  A cascade like a fission bomb occurs with a number of sequential pops.  

Mathematicians and scientists have pondered about this. What they did is slow down the time and divide it into steps...Scientists like to break things down into simple solvable problems.  These scientists from Berkley  broke the lifecycle into three phases that can be mathematically modelled:

1) rearrangement - the bubble reorient themselves after a pop
2) drainage - accounts for the effect of gravity and likely the water being drained
3) rupture - the moment when the bubble pops 

They say it in this eloquent yet nerdy statement:
'Liquid drains from the bubbles' thin walls until they rupture, after which the remaining bubbles rearrange, often destabilizing other bubbles, which subsequently pop. Note the sunset reflections. The research could help in modeling industrial processes in which liquids mix or in the formation of solid foams such as those used to cushion bicycle helmets.'  

These of course could help with other foams like bubble baths....

This is a scale-separated approach where important physics is done in each of the distinct scales.  The researchers at Berkley took the expressed equations within a computer simulation and for added realism (what is this a comic book) added the way the sunset would look on the reflected bubbles.  

Many of these problems could have been solved if more scientists took bubble baths like Archemedes.  These problems could help to make better solid foams for bike helmets, the safety foam in Judge Dredd or potentially liquid foams for uhhh well better bubbles baths.

See the whole article in Science

These steps can be seen in this video: