In the 1960s, a small number of theorists plugged that gap by dreaming up Higgs, which provides a theoretical explanation for how some particles could attain mass.

WSJ: New Particle Found, Consistent With Higgs Boson

"When you have such a big mass in such a small space you have extremely high gravity, " said Charles Wang, a theoretical physicist at the University of Aberdeen, Scotland, who wasn't involved in the study.

WSJ: Einstein Proved Right on Gravity��Again

Since the 1930s, the mass of research evidence points to the existence of several factors common to all forms of therapy despite theoretical orientation (dynamic, cognitive, etc.), mode (individual, group, couples, family, etc.), dosage (frequency and number of sessions), or specialty (problem type, professional discipline, etc.).

FORBES: There Are No Silver-Bullets in Education Reform