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:
In this version, the original cube undergoes four splits into increasingly smaller cubes. The key points here were that, with each split, the diameter halves, the overall surface area doubles, and the number of particles increases by a factor of eight – showing that for a given mass of material, the number of particles increases geometrically with decreasing particle size.
What is striking here — and not always recognized — is that overall surface area doesn’t increase that fast, and is inversely proportional to particle diameter.
These videos found their way into many different keynotes over the next few years as I was invited to speak about nanoparticles and potential health impacts. But they didn’t change that much from the ones you see above.
Then in 2008, I began to play around with the visualization again.
At the time, I’d moved on from lab research and was the Chief Science Advisor to the Project on Emerging Nanotechnologies at the Woodrow Wilson International Center for Scholars — and was talking to more groups and organizations than ever about nanotechnology and the responsible and safe development of engineered nanomaterials.
Looking through my archive, I started to play around with the original Mathematica-generated visualization again in January 2008, creating a more sophisticated animation that included a fly-by perspective of the dividing cube and that also included a reversal of the divisions, ending up with a single cube:
From memory, this was developed as a way to demonstrate even more effectively how number, surface area and mass are connected.
This was a time when I was becoming increasingly interested in the fusion between art, science and performance in conveying ideas to increasingly broad audiences, and at some point I started to play around with adding a sound track to the animation.
I also suspect that I was missing the days when I’d immerse myself in mathematical modeling, and relished the challenge of developing the models in Mathematica that would enable increasingly complex simulations of a splitting, rotating cube!
The result was a version of the cube fly-by above set to a somewhat generic backing track (I was also playing around with Apple’s GarageBand at the time):
This was posted in January 2009 — suggesting that I was playing with the concept on an off for a year before getting here.
It’s also clear, looking back at the last cube visualization that I developed at this time (below), that I was either interested in further pushing the bounds of this animation, or I was desperate to show that I still had some skill with using Mathematica. The final cube video — also from January 2009 — is interesting from a technical perspective as I played around with mathematically-defined fly-ins as well as fly-bys – but is a bit of a jumble aesthetically:
Nevertheless, looking back, it’s intriguing to see how the idea of this visualization evolved from the first steps in 2002 when I was still a lab scientist increasingly getting involved in science communication, to 2009 when I was long-out of the lab, and becoming increasingly interested in the fusion between art, science and communication.
