picture of the day

https://ift.tt/3wKZBW8

MAUD Committee

MAUD Committee.
The MAUD Committee was a British scientific working group formed during the Second World War to determine if an atomic bomb was feasible. The name came from a reference by Danish physicist Niels Bohr to his housekeeper, Maud Ray. The committee was founded in response to the Frisch–Peierls memorandum, which argued that a small sphere of pure uranium-235 could have the explosive power of thousands of tons of TNT. Its chairman was George Thomson and it met at Burlington House (pictured). Uranium enrichment, fissile materials, and the design of nuclear reactors and nuclear weapons were examined. The research culminated in two reports, known collectively as the MAUD Report. In response, the British created a nuclear weapons project. The report was made available to the United States, where it energised the American effort, which eventually became the Manhattan Project; it was also handed to the Soviet Union by its atomic spies, helping start the Soviet atomic bomb project.

picture of the day

https://ift.tt/3fRAs5i

Mysteries of Isis

Mysteries of Isis.
The mysteries of Isis were religious initiation rites performed in the cult of the goddess Isis in the Greco-Roman world. Alluding to the worship of Isis from ancient Egyptian religion, they were modeled on other mystery rites, particularly the Eleusinian mysteries, which honored the Greek goddess Demeter. By undergoing the mystery rites, initiates signaled their dedication to Isis. Many texts from the Roman Empire refer to the Isis mysteries, but the only source to describe them is a work of fiction, the novel The Golden Ass, written in the second century by Apuleius. In it, the initiate undergoes ritual purification before descending into the innermost part of Isis's temple, where he experiences a symbolic death and rebirth and has an intense religious experience. Some aspects of the mysteries of Isis and of other mystery cults resemble elements of Christianity, but the evidence for their influence on Christianity is unclear.

picture of the day

https://ift.tt/3fw0pbn

Menstrual cycle

Menstrual cycle.
The menstrual cycle is a series of natural changes in hormone production and the structures of the uterus and ovaries of the female reproductive system that make pregnancy possible. Naturally occurring hormones drive two concurrent and coordinated cycles that last about 28 days. The ovarian cycle controls the production and release of eggs and the release of the hormones estrogen and progesterone. The uterine cycle governs the preparation and maintenance of the lining of the uterus (endometrium) to receive a fertilized egg. Menstruation, a "period" in common parlance, begins on day one of the cycle, and lasts for about five days. Around day fourteen, an egg is usually released from the ovary. Estrogen stimulates the uterus lining to thicken to accommodate an embryo should fertilization occur. If implantation does not occur, the lining is released during menstruation. Menarche (the first period) usually occurs around age twelve, and menstrual cycles usually continue for 30–45 years until menopause.

picture of the day

https://ift.tt/3fSkrfm