A term coined by psychologist Carl Jung to describe what he called “meaningful coincidences,” synchronicity is the experience of two or more causally unrelated events that are conceptually similar and have very little chance of occurring together randomly—such as the discovery of the same idea by two different people at approximately the same time. Although Jung had introduced the concept of synchronicity in the 1920s, he did not fully explain it until when? Discuss
Source: The Free Dictionary
Identified by the faithful as possessing special spiritual value, wish trees are individual trees which have been distinguished—often by species, position, or appearance—as the objects of wishes. Visitors commonly offer up coins, liquor, and other gifts in order to gain fulfillment of their desires. Among the most famous wish tree visitors was Queen Victoria, whose 1877 visit to an oak in the Scottish Highlands brought it much fame. How are Christmas trees connected to the concept of wish trees? Discuss
Source: The Free Dictionary
Simply speaking, a photographic mosaic is a picture made of smaller pictures. Often used to recreate iconic images such as the Mona Lisa, photomosaics are created by replacing rectangular sections of an image with smaller pictures or photographs of an average color. When viewed from afar, a primary image is visible. When examined closely, the hundreds or thousands of smaller images acting as pixels are revealed. In 1994, a photomosaic of John F. Kennedy was created with pictures of whom? Discuss
Source: The Free Dictionary
Found in oceans worldwide, orcas display sophisticated hunting techniques and social behaviors that have been described by experts as manifestations of a shared culture. Like other dolphins, orcas produce a variety of vocalizations used for communication and echolocation. Orca mothers have even been observed training their young in the group’s dialect, and it is said that groups that share ancestors are likely to have a similar set of call types. What does this suggest about orca vocal behavior? Discuss
Source: The Free Dictionary
An exabyte is a unit of information or computer storage equal to one quintillion bytes—an amount roughly represented by the number 1 followed by 18 zeros. Though the term is rarely encountered in any practical context, a popular, hotly contested assertion, which often cites as support a project at the UC Berkeley School of Information, is that “all words ever spoken by human beings” can be represented by approximately 5 exabytes of data. What is meant by the related term “exaflood”? Discuss
Source: The Free Dictionary
Some claim that mail art, an art form that uses the postal system as a medium, began when Cleopatra had herself delivered to Julius Caesar in a rolled-up carpet, but the thousands-strong, international network of mail artists as it exists today is a more recent development, evolving between the 1950s and 90s. Mail artists typically exchange ephemera in the form of decorated envelopes, illustrated letters, artist trading cards, and many other items. Who is deemed the pioneer of modern mail art? Discuss
Source: The Free Dictionary
If the universe is assumed to contain an infinite number of uniformly distributed luminous stars, then every point in the sky should be as bright as a star. So why is the sky dark at night? That is the question posed by Olbers’s paradox, named for astronomer Heinrich Wilhelm Olbers, who described it in 1823, more than 200 years after Johannes Kepler first posed the question as an argument against the notion of a limitless universe with infinite stars. How has the paradox since been resolved? Discuss
Source: The Free Dictionary
Informally labeled the “pain ray,” the Active Denial System (ADS) is a non-lethal weapon being developed by the US military. Designed for use in crowd control operations, the ADS emits electromagnetic radiation that excites water molecules in the epidermis, causing an intensely painful burning sensation. Though the device does not actually burn the skin, its effect is said to feel similar to a hot light bulb being pressed against it. How long do these painful effects last? Discuss
Source: The Free Dictionary
Long thought to cause feelings of fear or awe, infrasound is sound that is able to cover long distances with little dissipation at a frequency too low to be detected by the human ear. It is created by natural phenomena such as ocean waves and earthquakes and can be artificially produced by explosions or machines. Infrasound is used by some animals to communicate over long distances and by predators to “freeze” their prey. Why do some scientists believe infrasound is related to ghost sightings? Discuss
Source: The Free Dictionary
Used in machine guns since World War I, tracer ammunition contains modified bullets packed with a pyrotechnic charge that ignites upon firing, illuminating the bullets. This technology enables a shooter to check a bullet’s trajectory and adjust his or her aim accordingly. Since the tracer path can also betray a shooter’s position, many modern tracers are designed to become visible only once they have traveled a set distance. Why were tracers especially useful against Zeppelins in World War I? Discuss
Source: The Free Dictionary