This week in history: Groundbreaking radio technology, identifying the origin of a terrifying disease, and a catalyst for change in the leadership of India. Read more below, and dive deeper with The Great Courses Plus.
January 15th, 1907 — Tune In; Same Time, Same Bat Channel

The early 1900’s brought many technological advances, many that still have an immense impact on daily life. In 1907, Dr. Lee De Forest patented the “Aduion” vacuum tube, the part of the radio that makes wireless broadcasting feasible. The Aduion was a three-element amplification device consisting of a heated filament, a grid, and a plate. The true value of this amplification device would be harnessed in 1912, and as radios became smaller and more affordable, every house would have one as their entertainment centerpiece. Soon the radio would be more than just entertainment; it would eventually be used for breaking news and the famous “Fireside Chats” as well as so much more. Mass communication as known today can tip its cap to the radio and Dr. Lee De Forest.
Learn about the technology of radio and television, the challenges broadcasters faced, the origin of radio commercials, and the cultural effects of these new communications technologies Understanding the Inventions That Changed the World
January 18th, 1978– Cause of Legionnaire’s Disease Found
The United States Center for Disease Control (CDC) isolated the cause of Legionnaire’s disease: standing water. Standing water is notorious for spreading disease, including typhoid fever, cholera, leptospirosis and hepatitis A, not to mention vector-borne diseases like malaria, dengue, yellow fever and West Nile Fever (WHO). Legionnaire’s disease is characterized by its pneumonia-like symptoms of cough, shortness of breath, fever, muscle aches, and headaches. It was named after an outbreak in 1976 among participants of an American Legion convention. Legionnaires can be treated with antibiotics, but sufferers typically have to spend a bit of time in the hospital first.
Learn more about how diseases have shaped our history and more in An Introduction to Infectious Diseases.
January 19th, 1966– India’s First Female Head of Government

After the death of Lal Bahadur Shastri, Indira Gandhi became the leader of the Congress Party. She was the prime minister and therefore the first female to lead the country. She was the catalyst for many changes in the late 20th century including the State of Emergency, the rise of ethnic political organizations such as the Sikhs and the Tamils, the nuclear arms race with Pakistan, and numerous transitions of leadership.