In this task you will be given a text passage from a trivia quiz. You should choose the category this question belongs to from these categories: History, Science, Social Science, Fine Arts, Literature. You can only choose one category, so if in doubt, please choose the closest match.

His work explaining the instability of James Watt's fly-ball governor is regarded as the birth of modern control theory, and his mathematical analysis of the stability of Saturn's rings showed that they could be neither entirely solid nor liquid. He showed how to calculate stresses in suspension bridges and coined the term "curl" to use in the differential form of his most famous accomplishment; however, the only other real work he did on it was the addition of a term for "displacement current. "  FTP identify this British physicist best known for combining his revision of Ampere's Law with Faraday's Law and Gauss's Laws of Electricity and Magnetism to produce his four namesake "equations" governing electromagnetism.
Science

When it interacts with ryanodine receptors, this element upregulates its own release, and this compound forms the cell plates of coccolithophores. Stimulation of Gq ("g-sub-q") opens a channel that allows for this ion's movement, and proteins that bind this ion have an EF hand motif. Cellular concentrations of this ion are regulated by IP3. Parafollicular cells of the (*) thyroid produce a compound that reduces the concentration of this ion in blood, and its intestinal absorption requires vitamin D. This ion interacts with Troponin to stimulate muscle contraction, and the lumens of sarcoplasmic reticula have high concentrations of this ion. For 10 points, name this divalent cation that is stored in bones.
Science

The insertion of AQP2 into the apical membrane is caused by this hormone's GPCR stimulating the production of cAMP through the Gs protein. With CRH, this hormone is produced in parvocellular neurons and, also with it, stimulates the secretion of ACTH. The movement of this hormone is facilitated by neurophysin II. Deficiency of this hormone causes central diabetes insipidus. A syndrome of inappropriate secretion of this hormone normally results in hyponatremia. This nonapeptide is released from the posterior pituitary and is structurally similar to oxytocin. When bound to its V1 receptor, this hormone promotes vasoconstriction, and it increases the permeability of the distal convoluted tubules. For 10 points, identify this hormone that is downregulated by ethanol, thus making you have to pee a lot.

Science