Colloquium on granular matter in space

Published: 2019-01-27; Last edited: 2019-01-29

On December 21st 2019 I attended a colloquium on granular matter in space. DLR Oberpfaffenhofen invited to that event. The speaker was Professor Mattihas Sperl of the Institute of Materials Physics in Space of the DLR.

I did not take a lot of notes, so this post will be little shorter than the last time.

At the beginning of the talk Prof. Sperl dropped some words I could not relate to directly (especially the first two): Soft matter, dusty plasma and space conditions.

The knowledge of granulate matter is still limited and their fundamental physical properties are still not completely understood. Especially the interactions with the environment but also within the medium is researched on. That way the material behavior can be analyzed

He compared the vast knowledge in the aeronautics sector about aerodynamics with the possibilities to model and calculate the aerodynamic behavior of planes or airfoils. Also wind tunnels are a common tool for well over 100 years. This all is not the case with granulate matter.

Some problems that can be analyzed with more knowledge of granulate matter are the rings of Saturn, the formation of planets, the soil and process engineering.

Granulate matter can be divided into three categories with one common denominator: heterogeneous transmission of force. The three categories are: solid, liquid and gas. That means granular matter can behave, depending on its environment and the situation the matter is in, similar to a solid, a liquid or a gas.

The experiment that he presented (as a video) showed the non-intuitive behavior of granulates. Take 100 particles, place them in a partially partitioned box (50/50 on both sides), shake the box until the particles are spread out evenly and then slowly decrease the shaking. What is the distribution of the particles now? See this video. The effect is called Maxwell's demon.

At the end of the talk he showed, with the right amount of money, it's already possible to print a moon station out of the granular matter that can be found there, the regolith.

At the end of this post I'll list some more notes I took during the colloquium, unfortunately I do not remember enough to fill those point with more content.