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The Grand Prismatic Spring in Yellowstone National Park is the largest hot spring in the United States, and the third largest in the world, next to those in New Zealand.

The vivid colors in the spring are the result of pigmented bacteria in the microbial mats that grow around the edges creating the greens, yellows, oranges, reds, and the bright blue in the center of the pool.

Photo credit: Jim Peaco, National Park Service
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A dragonfly is a flying insect characterized by large multifaceted eyes, two pairs of strong transparent wings, and an elongated body. Dragonflies typically eat mosquitoes, midges and other small insects like flies, bees, and butterflies. They are usually found around lakes, ponds, streams, and wetlands because their larvae, known as "nymphs", are aquatic. Dragonflies do not bite or sting humans. In fact, they are valued as a predator that helps control the populations of insects that do.

Photo credit: André Karwath
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Manila is the capital of the Philippines. The city is located on the eastern shore of Manila Bay on Luzon, the country's largest island. Despite widespread poverty, it is one of the most cosmopolitan cities in the world. It is the second most populous city in the Philippines, with more than 1.5 million inhabitants, but is also the hub of the Metro Manila area — a metropolis consisting of 17 cities and municipalities, with over 10 million people.

Illustration credit: Seav
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"The Blue Marble" is a famous photograph of Earth. NASA officially credits the image to the entire Apollo 17 crew — Eugene Cernan, Ronald Evans and Jack Schmitt — all of whom took photographic images during the mission. Apollo 17 passed over Africa during daylight hours and Antarctica is also illuminated. The photograph was taken approximately five hours after the spacecraft's launch, while en route to the Moon. Apollo 17, notably, was the last manned lunar mission; no humans since have been at a range where taking a "whole-Earth" photograph such as "The Blue Marble" would be possible.

Photo credit: The Apollo 17 crew
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The Red Fox has the widest range of any terrestrial carnivore. They eat rodents, insects, fruits, worms, eggs, mice, and other small animals. They have 42 very powerful teeth that they use to catch their food. The foxes regularly consume from 0.5–1 kilograms (1–2 pounds) of food per day.

Photo credit: U.S. Fish and Wildlife Service
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The art of bonsai originated from China over two thousand years ago, where it has been called penzai; it spread to Korea during the Tang or Song Dynasty (the 7th–13th century). As the Chinese art is intended for outdoor display the plants tend to be somewhat larger than seen in Japanese bonsai. A bonsai is not a genetically dwarfed plant; it is kept small by shaping and root pruning.

Photo credit: USDA-ARS
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The Double-crested Cormorant is a North American member of the cormorant family of seabirds. Like all cormorants, it dives to find its prey, mainly fish, but also amphibians and crustaceans. This bird swims low in the water, often with just its neck and head visible, and dives from the surface. It uses its feet for propulsion and is able to dive to a depth of 1.5-7.5 m (5-25 feet) for 30-70 seconds.

After diving, these birds spend long periods standing with wings outstretched to allow them to dry, since they are not fully waterproofed.

Photo credit: Mdf
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McCoy Tyner is a jazz pianist from Philadelphia, Pennsylvania, best known for his work with the John Coltrane Quartet. Tyner joined Coltrane's group in 1960 and appeared on the saxophonist's popular recording of My Favorite Things. Tyner has recorded a number of highly influential albums in his own right. After leaving Coltrane's group, he began a series of post-bop albums released on the Blue Note label, starting with The Real McCoy in 1967.

Photo credit: Gisle Hannemyr
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A barrel organ is a mechanical musical instrument made of a series of pipes, and bellows, like any other traditional organ, and of a cylinder studded with staples or bridges or pins corresponding in their placement to a particular tune. The continuous rotation of the barrel causes the staples to come into contact with levers and rods which open valves to let air from the bellows into the organ pipes. The bellows is usually actuated by the same power source which, through reduction gearing or worm gearing, causes the drum to slowly turn around.

Photo credit: Chepry
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Photo credit: Diliff
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The Tughra (طغراء) of Mahmud II. A tughra is a Turkish paisley-like calligraphic seal or signature used at the beginning of sultans' decrees. These colorful emblems incorporated the ruler's name and title in intricate vegetal inscriptions designed by neshanis, or court calligraphers. Parallel to the European signet, tughras often appeared on coins and stamps of the Ottoman Empire.

Illustration credit: Baba66
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Saint Vitus Cathedral in Prague, Czech Republic, is the seat of the Archbishop of Prague. It is located within Prague Castle and contains the tombs of many Bohemian kings. Although the current building was founded in 1344 by the Holy Roman Emperor, Charles IV together with Arnost of Pardubice, it wasn't completed until 1929 — almost 600 years later.

Photo credit: Diliff
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Taking its name from a small, maneuverable fighting frigate, the first Chevrolet Corvettes were virtually handbuilt in Flint, Michigan. The outer body was made out of a revolutionary new composite material called fiberglass, offering the strength of steel without the weight. The tradition continues even today, as no Corvette has ever had anything other than a fiberglass outer skin.

Photo credit: Softeis
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Melbourne is the state capital and largest city in the Australian state of Victoria, and the second largest city in Australia (after Sydney), with a population of approximately 3.8 million. The central business district (the original city) is laid out in the famous mile-by-half-a-mile Hoddle Grid, its southern edge fronting on to the Yarra River.

Photo credit: Diliff
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Superconductivity is a phenomenon occurring in certain materials at low temperatures, characterised by the complete absence of electrical resistance and the exclusion of the interior magnetic field (the Meissner effect). The Meissner effect can be used to demonstrate superconducting magnetic levitation. Here a block of "high temperature" ceramic superconductor, cooled in a bath of liquid nitrogen, repels the round permanent magnet above. Flux pinning stops the magnet from sliding away.

Photo credit: Pacific Northwest National Laboratory
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The plough is a development of the pick, and was initially pulled by oxen or humans, and later horses. Modern ploughs are, in industrialized countries, powered by tractors. Ploughing has several beneficial effects. The major reason for ploughing is to incorporate the residue from the previous crop into the soil. Ploughing also reduces the prevalence of weeds in the fields, and makes the soil more porous, easing later planting.

Photo credit: Ralf Roletschek
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Maize is a cereal grain that was domesticated in Mesoamerica. Maize is grown in variety of cultivars, with many traditional varieties having predominantly blue colored ears, also known as blue corn.

In 1983, Barbara McClintock received the Nobel Prize in Medicine for discovery of transposons while studying maize. Maize is still an important model organism for genetics and developmental biology today.

Photo credit: Asbestos
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