https://hackerpaper.kaipfister.de/p/1402.7132/Collected HN comments and submissions linking this paper.enMon, 02 Nov 2026 11:16:22 GMThttps://news.ycombinator.com/item?id=19203235urn:hackerpapers:mention:1402.7132:19203235Tue, 19 Feb 2019 21:55:40 GMT<p>It makes more sense to call it a fractal rather than a pile. In the paper they reference, it is suggested that particles can form fractal like structures through a diffusion limited aggregation process[0]. One very important result in planetary science is the observation by the astronaut Donald Pettit of granular materials aggregating together in microgravity[1]* . In the experiment[2], it appears that some of the resulting structures resemble those formed in a diffusion limited aggregation process. *It is also worth noting that this experiment was entirely ad-hoc and came about from Don…</p><p><a href="https://hackerpaper.kaipfister.de/p/1402.7132/">Paper and discussion history</a>. A mention is not an endorsement.</p>astro-ph.SR