Tweet TO MUCH fanfare, Italy celebrated 150 years since its unification two weeks ago. Less exuberantly, America is commemorating the 150th anniversary of the outbreak of the civil war, a failed attempt to undo its union. Amid this flurry of historical fissions and fusions it is easy to overlook another, arguably more significant unification set in motion in spring 1861. In March of that year James Clerk Maxwell, a Scottish physicist (pictured above), published the first piece of a four-part paper entitled "On physical lines of force". Sprinkled amid the prose in the Philosophical Magazine were equations which revealed...