The new partners cover a broad range of institutions, from Ivy League universities Columbia and Brown, which has lagged in offering free online courses, to Wesleyan, a small liberal arts college, to a top-ranked music school, Berklee College of Music, to state schools like University of Maryland at College Park, to foreign institutions like Hebrew University of Jerusalem and the University of Melbourne.

FORBES: Free Online Education Site Announces Big Expansion

Ken Rubin, professor of human development at the University of Maryland in College Park, says loneliness has developmental, but not necessarily genetic, origins.

CNN: Feeling lonely? Genes might be at fault

Another way of placing constraints on quantum gravity has been found by Ted Jacobson and his colleagues at the University of Maryland, College Park.

ECONOMIST: Planck-scale physics