FOM research in the Scientific Block Calendar
Researcher Peter Schall helped to produce the Scientific Block Calendar 2010. For example, on Monday 16 August, tens of thousands of Dutch and Belgians read the following about the maximum packing degree of spheres.
Crystal clear
You will never manage to fill up a tub with marbles without any space remaining between the marbles in the tub. The degree of packing of the marbles in the tub can therefore never be 100%. What is the maximum packing density that you can achieve with spheres?
This question is important for scientists, as atoms can frequently be described as spheres. The interest in this problem is quite old and arises from the question as to how cannon balls can be stacked most efficiently on the deck of a ship. Back in 1611, Johannes Kepler proposed that the maximum density for spheres in an ordered packing, just like atoms in a crystal, is 74%.
However, this was not proven until 1998 when Thomas Hales used a computer program to generate all possible structures and to compare the densities of these. Hales’ work was checked by colleagues and they can state with 99% certainty that his proof is correct. Various mathematicians are still working on the production of a more elegant method that can prove Kepler’s supposition with 100% accuracy.
Source: Scientific Block Calendar 2010. Co-authors: Nick de Jong and Prof. Daniel Bonn, Van der Waals-Zeeman Laboratory, University of Amsterdam.
On 5 November 2010, Schall will hold a presentation on the block calendar together with two colleagues. This presentation was previously given on 8 February, 12 April, 13 and 15 May, and 26 June 2010.
Further information: Peter Schall, +31 (0)20 525 63 14.