Those nano-geeks amongst you with long memories may remember that, back in 2009, I played around with a couple of visualizations of the relationship between particle number, surface area, and mass. Those of you with even longer memories may recall that the origins of these visualizations goes all the way back to 2002.
As I was digging through some old files this morning, I came across my original work here, and was caught off-guard by a wave of nostalgia.
Back in the early 2000’s I was working on ways of measuring the surface area of collections of nanoparticles, and giving an increasing number of talks about how particle surface area, number and mass are related.
The challenge was that, at the time, the standard way of assessing health impact from exposure to airborne particles was to measure the mass concentration of material depositing in the lungs. Yet research was beginning to show that, for fine particles, health impact was potentially associated with the surface area, or even the number, of inhaled particles.
This was a problem, as at the nanoscale, this would potentially lead to mass concentration measurements dangerously underestimating the risks of airborne nanomaterials.
At the time, I was using the platform Mathematica for a lot of my modeling work, and decided to play around with it to see if I could come up with a simple visualization of the relationship between particle number, surface area and mass.
Here, I should say that Mathematica — at least at the time — was a powerful but gnarly math platform that no sane person would use to create complex animations. But that didn’t stop me relishing the challenge, and so I started to play around.
The first iteration — from March 2002 according to my archives – was a video visualization of a cube being progressively split four times:
This was a good start, but it lacked any quantitative information. So the next iteration was to add information on the number, surface area and mass of the cubes: