Philip Ball ; with a contribution by Dirk Helbing. E. D. Dorrell ; with a contribution by J. R. O. Collin. David A. Watt ; with a contribution by Muffy Thomas. Josef Novak ; with a contribution by Piet A. Leclercq. by Michael Liebman ; with a contribution by Rina Tadmor. ed. and with an introduction by Diana Trilling. Mary Lou Moore, with a contribution by Ora Strickland. Robert G. Sutter ; with a contribution by Larry Niksch.