““For many years, cosmologists have sought, with little success, some fundamental principle which would reveal why the cosmological constant mist be zero. The elementary-particle physicists have searched as well, but far from finding an answer to the problem they have merely compounded it by showing that, even if such a principle were to exist which started the universe on its way at the Big Bang with a zero value of the cosmological constant, there arise complicated elementary-particle processes which produce stresses that mimic the presence of a cosmological constant with an unacceptably large value, billions and billions of times larger than observation allows.””
