The 18th letter of the modern English alphabet.(noun)
Any of the speech sounds represented by the letter r.(noun)
The 18th in a series.(noun)
Something shaped like the letter R.(noun)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "r" in a sentence
"An uncharged black hole has no inner horizon; it should come as no surprise, then, that as you increase the charge (keeping the mass of the black hole fixed), the two horizons at r+ and r - come together."
"In an extremal black hole, where all of the energy comes from the electric field itself, the two horizons coincide: we have r+ = r - (extremality)."
"A representation r is maximally consistent if and only if r is consistent and for any representation r², either r & not-r² is not consistent or r & r² is not consistent (assuming the appropriate conceptions of the negation and conjunction of representations)."