Human penis tension of the suspensory ligament that holds it in position. The following table shows how common various erection angles are for a standing male, out of a sample of 1,564 males aged 20 through 69. In the table, zero degrees is pointing straight up against the abdomen, 90 degrees is horizontal and pointing straight forward, while 180 degrees would be pointing straight down to the feet. An upward pointing angle is most common. Ejaculation is the ejecting of semen from the penis, and is usually accompanied by orgasm. A series of muscular contractions delivers semen, containing male gametes known as
Revolutions in Mathematics Revolutions in Mathematics Revolutions in Mathematics is a collection of essays in the history and philosophy of mathematics. The book was reviewed by Pierre Kerszberg for "Mathematical Reviews" and by Michael S. Mahoney for "American Mathematical Monthly". Mahoney says "The title should have a question mark." He sets the context by referring to paradigm shifts that characterize scientific revolutions as described by Thomas Kuhn in his book "The Structure of Scientific Revolutions". According to Michael Crowe in chapter one, revolutions never occur in mathematics. Mahoney explains how mathematics grows upon itself and does not discard earlier gains in understanding with