Category Archives: Article of the Day

Tachyons

According to the theory of relativity, particles having nonzero rest mass can approach, but not reach, the speed of light, as their mass would become infinite at that speed. On the other hand, particles with zero rest mass, like photons, always travel at the speed of light. Theorists have argued that nothing in principle prohibits the existence of a third class of particles, named tachyons, whose velocity always exceeds that of light. What effect would a loss of energy have on a tachyon’s speed? Discuss

Source: The Free Dictionary

The Mali Empire

The Mali Empire flourished in West Africa between the 13th and 16th centuries. A trading empire, it developed from the upper Niger River state of Kangaba, whose inhabitants were middlemen in the gold trade in ancient Ghana. It expanded for a few centuries but eventually outgrew its political and military strength, and many of its subject areas revolted. Which Mali ruler distributed so much gold during his pilgrimage to Mecca that the metal was devalued in Egypt for more than a decade? Discuss

Source: The Free Dictionary

Simonetta Vespucci

Simonetta was the Genoese wife of the Italian nobleman Marco Vespucci of Florence. Renowned as the greatest beauty of her age, she was the subject of countless portraits, including many by the Italian master Sandro Botticelli. Some claim that the goddess depicted in Botticelli’s masterpiece, Birth of Venus, was modeled after Simonetta, even though she died at the age of 22—several years before it was completed. What fact about Botticelli’s burial place lends credence to the theory? Discuss

Source: The Free Dictionary

Ecdysis

In order for certain insects, crustaceans, and reptiles to grow, they must periodically shed, or molt, their outer layer of skin or other covering in a process known as ecdysis. Prior to shedding, a new soft and expandable layer is laid down underneath the existing one. Then the inner layers of the old cuticle are digested by a molting fluid secreted by the epidermal cells, the animal emerges from the old covering, and the new cuticle hardens. How often do insects undergo ecdysis? Discuss

Source: The Free Dictionary

Epinephrine

Epinephrine is a hormone secreted by the adrenal medulla and released into the bloodstream in response to physical or mental stress, as from fear or injury. It triggers a number of bodily responses, including increased blood pressure, heart rate, metabolic rate, and respiratory rate. It also raises glucose levels in the blood for use as fuel when more alertness or greater physical effort is needed. These reactions are known as the fight-or-flight response. Epinephrine is popularly known as what? Discuss

Source: The Free Dictionary

Soup

Following the invention of waterproof containers about 9,000 years ago, boiling became a common cooking technique, and soup became a staple food item in many cultures. Soups come in myriad varieties, many of which are specific to certain places, such as the pot-au-feu of France, the borscht of Russia, the mutton broth of Scotland, the minestrone of Italy, the chowders of various coastal regions, and gazpacho, the cold soup of Spain. How is soup related to the etymology of the word “restaurant”? Discuss

Source: The Free Dictionary

Fossilized Footprints

Known as ichnites or ichnolites, fossilized footprints or tracks of once-living organisms are studied by the branch of paleontology known as ichnology or ichnolithology. As well as providing information about foot structure and stride, ichnites provide important clues about the behavior of the animals that made them. For example, multiple ichnites of a single species found close together may suggest herd or pack behavior. What prehistoric creature is known exclusively by its footprints? Discuss

Source: The Free Dictionary

Polychaetes

About 5,400 species of often brightly colored marine worms are included in the annelid class Polychaeta. Worms of this class have a head with short sensory projections and tentacles and a segmented body covered with many setae, or bristles. They range in length from less than 1 inch (2.5 cm) to approximately 10 ft (3 m) long. Found worldwide, polychaetes perform the important function of turning over sediment on the ocean floor. What is the deepest point at which polychaetes have been observed? Discuss

Source: The Free Dictionary

Earwax

Known by the medical term cerumen, earwax is the waxy secretion of the ceruminous glands and hair follicles of the external auditory canal. Earwax protects the ears by trapping dust, microorganisms, and foreign particles and preventing them from entering and damaging the ear. However, excess or impacted cerumen can impair hearing, and a number of methods exist to alleviate earwax impaction. One method considered dangerous and ineffective by doctors is ear candling, which is what? Discuss

Source: The Free Dictionary

The Book of Martyrs

Popularly known as The Book of Martyrs, The Actes and Monuments of These Latter and Perilous Dayes was published by English Protestant clergyman John Foxe in the 16th century to praise Protestants martyred during the reign of Catholic monarch Mary I, who earned the nickname “Bloody Mary” for her religious persecutions. Lavishly illustrated, it was widely read and influenced popular opinion about Roman Catholicism for several centuries. How much did the book’s first edition cost? Discuss

Source: The Free Dictionary