17 Apr
2018
17 Apr
'18
5:37 p.m.
Did you hear the exciting news that Aubrey de Grey has increased the lower bound on the chromatic number of the plane from 4 to 5? https://cp4space.wordpress.com/2018/04/15/assorted-news-3/ The best upper bound is 7 (from colouring the cells of a hexagonal lattice of appropriate size). The previous lower bound of 4 is from the Moser's spindle. Best wishes, Adam P. Goucher