- Patricia Lynn Murray (née Johns; born October 11, 1950) is an American politician who has served as president pro tempore of the United States Senate since 2023 and the senior United States Senator from Washington since 1993. A member of the Democratic Party, Murray served in the Washington State Senate from 1989 to 1993. She was Washington’s first female U.S. senator and is the first woman in American history to hold the position of president pro tempore. Murray is also the youngest senator to occupy the office of president pro tempore in more than five decades. As president pro tempore, Murray is third in the line of succession to the U.S. presidency.
- Black hole (Wikipedia)
A black hole is a region of spacetime where gravity is so strong that nothing, including light or other electromagnetic waves, has enough energy to escape it. The theory of general relativity predicts that a sufficiently compact mass can deform spacetime to form a black hole. The boundary of no escape is called the event horizon. Although it has a great effect on the fate and circumstances of an object crossing it, it has no locally detectable features according to general relativity. In many ways, a black hole acts like an ideal black body, as it reflects no light. Moreover, quantum field theory in curved spacetime predicts that event horizons emit Hawking radiation, with the same spectrum as a black body of a temperature inversely proportional to its mass. This temperature is of the order of billionths of a kelvin for stellar black holes, making it essentially impossible to observe directly.