Reader Questions: Porosity Experiments

I received this curious picture from Khi. She was performing one of the popular hair porosity at home tests



The picture shows small bubbles gathered around her hair which was left in water for 2 hours.






So what could these bubbles be?



I don't really know but I have to say that it would be worth experimenting some more. My questions

1. Could the water bubble up on its own if left for 2 hours?

2. If there were other fibres, not specifically hair, would the bubbles travel up to these?


To answer these questions a new experiment is in order with 3 cups of water. One would hold just the water, the second with hair in the water and the third with another hair like fibre but not hair - for example a few strings that would float (polyester or nylon thread maybe).



All three cups need to made at the same time with the same temperature of water, placed at the same place and left alone for the same time. IF the bubbles still only appeared on the hair, then this would definitely merit some more investigation



My take on porosity



I love experimenting but I am not a fan of these porosity tests mainly because they really try to oversimplify the cuticle. The hair cuticle is really so tiny......tiny tiny tiny. It takes a really sensitive machine ( if you like geekery - it is known as an atomic force microscope or AFM) to be able to estimate its separation from the cortex. When I say sensitive, this thing measures in the range of a millionth of a millimeter - think about that number, seriously, pick up a ruler, look at the distance of one millimeter. Try and divide that distance a million times. Thankfully, there is a machine for that.



Now to be accurate, the cuticle is not that small, it is only two to three thousandths of a millimeter ( you can try and divide a millimeter by a thousand too........still tiny!.) However, my main point is, you cannot feel this distance without a machine.



If you want to read more of my porosity thoughts and scientific investigations, see these links

1. Hope versus hype : General article I wrote for super blog BGLH - here

2. Scientific research on porosity: Part 1 and Part 2