Core–mantle boundary Core–mantle boundary The core–mantle boundary (CMB in the parlance of solid earth geophysicists) of the Earth lies between the planet's silicate mantle and its liquid iron-nickel outer core. This boundary is located at approximately 2891 km (1796 mi) depth beneath the Earth's surface. The boundary is observed via the discontinuity in seismic wave velocities at that depth due to the differences between the acoustic impedances of the solid mantle and the molten outer core. P-wave velocities are much slower in the outer core than in the deep mantle while S-waves do not exist at all in the liquid portion of
The Theatre and its Double The Theatre and its Double The Theatre and Its Double ("Le Théâtre et son Double") is a collection of essays by French poet and playwright Antonin Artaud and published in 1938. Artaud intended his work as an attack on theatrical convention and the importance of language of drama, opposing the vitality of the viewer's sensual experience against theatre as a contrived literary form, and urgency of expression against complacency on the part of the audience. The collection's more famous pieces include "No More Masterpieces", an attack on what Artaud believed to be the elitism of an irrelevant, outdated literary/theatrical canon,