Just as electricity can be generated at a central location and then distributed to customers, heat can be produced at a central plant using geothermal, nuclear, or solar energy and then sent out to customers to warm their homes and businesses. The heat is distributed by means of insulated pipes that carry water or steam. District heating is one of the most efficient and environmentally friendly methods of heating. What country heats approximately 95 percent of its houses using district heating?
Back in the day
Scientists Marie and Pierre Curie were working with pitchblende, a heavy mineral known to contain the radioactive element uranium, when they noticed something unusual. Somehow, the pitchblende was more radioactive than the uranium it contained. The culprit was radium, a previously unknown element present in pitchblende only in trace amounts—yet more than a million times more radioactive than uranium. What common household products contained radium until it was discovered to be dangerous?
Born on a day like today
One of the most highly regarded British prose writers of the 20th century, West began her career as a journalist for feminist and suffragist publications. She then served as a literary critic and political writer for American and British journals. Her admired reports on the Nuremberg Trials were collected in A Train of Powder, and her history of Yugoslavia, Black Lamb and Grey Falcon, is a classic work of travel literature. Why did West have to be evacuated from her home in 1980?