“In 1973 two {{W|Abdus Salam|Salam}} protégés (Derek Capper and the author) discovered that the conformal invariance under Weyl rescalings of the metric tensor gμν(x → Ω2(x) gμν(x) displayed by classical massless field systems in interaction with gravity no longer survives in the quantum theory. Since then these {{W|Weyl anomaly|Weyl anomalies}} have found a variety of applications in black hole physics, cosmology, string theory and statistical mechanics.”