You probably know about the Doppler Effect, the change in frequency and length of a wave (for example, a sound wave) perceived by an observer who is moving relative to the source of the wave. The Doppler Effect explains why a train whistle sounds louder as the train approaches you, and fainter as it moves away. (Update: Unsurprisingly, I got this wrong. See Regan's comment for the accurate definition.)
The Doppler Effect is named for the Austrian mathematician and physicist Christian Doppler (1803–1853). Here's a list of some other eponymous effects; see whether you can identify (a) the person the effect was named for and (b) what phenomenon the effect names. With one exception, none of these "special effects" is particularly arcane; all describe phenomena the average person can understand. Answers after the jump.
- Coolidge Effect
- Droste Effect
- Forer Effect
- Fujiwhara Effect
- Martha Mitchell Effect
- McGurk Effect
- Meissner Effect
- Named for U.S. President Calvin Coolidge, the Coolidge Effect describes the tendency in every species for males to exhibit high sexual performance when introduced to new females. According to the story, the president and his wife were touring a poultry farm. Mrs. Coolidge, noting the small number of roosters and the large number of fertile eggs, asked how such a thing was possible. The farmer replied that his roosters were capable of performing many times a day. "Tell that to Mr. Coolidge!" said the First Lady. The president overheard the remark and nudged the farmer. "Does each rooster service the same hen every time?" he asked. "No," came the reply. "He services a different hen each time." "Tell that to Mrs. Coolidge," said the president.
- The Droste Effect is named for the Dutch chocolate company Droste, whose classic package design carried the image of a nurse holding a package of Droste with a picture of a nurse holding a package of Droste ... and so on, presumably infinitely:
See other examples of the Droste Effect here; there's also a link to an explanations of the mathematics of the Droste Effect.
3. The Forer Effect--also known as the Barnum Effect, after the circus impresario P.T. Barnum--explains, among other things, the enduring popularity of astrology. According to the Skeptic's Dictionary, this effect "refers to the tendency of people to rate sets of statements as highly accurate for them personally even though the statements could apply to many people." It was named for the American psychologist Bertram G. Forer (1914–2000), who found that "people tend to accept vague and general personality descriptions as uniquely applicable to themselves without realizing that the same description could be applied to just about anyone." (Forer Effect was a Fritinancy word of the week last July.)
4. When two cyclones approach each other, their centers begin orbiting around the systems' midpoint. This "cyclone dance" is known as the Fujiwhara Effect, named after Dr. Sakuhei Fujiwhara, the Japanese meteorologist (1884–1950) who first described the phenomenon in a 1921 paper. He preferred this unusual transliteration of his surname, which often appears as "Fujihara" instead.
5. The Martha Mitchell Effect--the mistaken diagnosis of mental illness on the basis of improbable (or crazy-sounding) claims--is named for Martha Mitchell (1918–1976), the wife of President Nixon's attorney general, John Mitchell. After John Mitchell became implicated in the Watergate scandal, Martha Mitchell began contacting reporters and telling them that White House officials were engaged in illegal activities. She was vindicated by subsequent revelations; the Mitchells divorced in 1973. "Even paranoids have real enemies" is another way of summarizing the Martha Mitchell Effect.
6. The McGurk Effect refers to the integration of visual cues into speech perception. It's named for the British psychologist Harry McGurk, who with his research assistant, John McDonald, described the phenomenon in a 1976 paper ("Hearing Lips and Seeing Voices") in the journal Nature. Watch a demonstration of the McGurk Effect.
8. The Meissner Effect, named for German physicist Walther Meissner (1882–1974), is the expulsion of a magnetic field from a superconductor. Meissner and fellow physicist Robert Ochsenfeld identified the phenomenon in 1933, demonstrating the superconductors were more than just perfect conductors,