In linguistics, the comparative method is a technique for studying the development of languages by performing a feature-by-feature comparison of two or more languages with common descent from a shared ancestor, as opposed to the method of internal reconstruction, which analyzes the internal development of a single language over time.

The Doppler effect (or Doppler shift), named after the Austrian physicist Christian Doppler, who proposed it in 1842 in Prague, is the change in frequency of a wave (or other periodic event) for an observer moving relative to its source. It is commonly heard when a vehicle sounding a siren or horn approaches, passes, and recedes from an observer. The received frequency is higher (compared to the emitted frequency) during the approach, it is identical at the instant of passing by, and it is lower during the recession.

The Peace Corps is a volunteer program run by the United States government. The stated mission of the Peace Corps includes three goals: providing technical assistance; helping people outside the United States to understand American culture; and helping Americans to understand the cultures of other countries.

Six years ago, lawyer-banker-scholar Charles Morris wrote a prophetic book - 'Two-Trillion-Dollar Meltdown: Easy Money, High-Rollers and the Great Credit Crunch' - that foresaw the 2008 Great Recession before it clobbered America and the world. Now Morris has reversed course and sees good times ahead. His forthcoming book, 'Comeback,' predicts that surging U.S. energy independence will bring a buoyant rise in American manufacturing and jobs.

Ohio started the month of July with its pedal to the metal. The Buckeye State became the 34th state to adopt the 70 miles-an-hour speed limit. Drivers can now do up to 70 on more than 570 of Ohio's 1,332 miles of interstate highway. Congress repealed the 55 mph national limit in 1995. Despite predictions of calamity and carnage on the highways, the National Highway Traffic Safety Administration reported in October 1998 that "the traffic death rate dropped to a record low level in 1997". That pattern has continued since then.