A very neat visual proof for the formula of the first n square numbers.
Correction: as pointed out by @othermaterial, the right-hand side of the formula should have variables n instead of k.
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A giant predatory lizard swam in Antarctic seas near the end of the dinosaur age http://www.geologypage.com/2016/11/giant-predatory-lizard-swam-antarctic-seas-near-end-dinosaur-age.html
Dancer with a Fan by Edgar Degas
Medium: pastel
Stardust in the Perseus Molecular Cloud Image Credit & Copyright: Lorand Fenyes
Explanation: Clouds of stardust drift through this deep skyscape. The cosmic scene spans nearly 2 degrees across the Perseus molecular cloud some 850 light-years away. A triangle of dusty nebulae reflecting light from embedded stars is captured in the telescopic field of view. With a characteristic bluish color reflection nebula NGC 1333 is at left, vdB13 at bottom right, and rare yellowish reflection nebula vdB12 lies at the top. Stars are forming in the Perseus molecular cloud, though most are obscured at visible wavelengths by the pervasive dust. Still, hints of contrasting red emission from Herbig-Haro objects, the jets and shocked glowing gas emanating from recently formed stars, are evident in NGC 1333. At the estimated distance of the molecular cloud, legs of the triangle formed by the reflection nebulae would be about 20 light-years long.
∞ Source: apod.nasa.gov/apod/ap170114.html
The Pork Butcher by Camille Pissarro
Size: 66x54 cm Medium: oil on canvas
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Although there are no seasons in space, some cosmic vistas invoke thoughts of a frosty winter landscape. Here are a few stellar images of holiday wonderlands from across the galaxy…
Located in our galaxy about 5,500 light years from Earth, this region is actually a “cluster of clusters,” containing at least three clusters of young stars, including many hot, massive, luminous stars.
The outstretched “wings” of this nebula looks like a soaring, celestial snow angel. Twin lobes of super-hot gas, glowing blue in this image, stretch outward from the central star. This hot gas creates the “wings” of our angel. A ring of dust and gas orbiting the star acts like a belt, clinching the expanding nebula into an “hourglass” shape.
At this time of year, holiday parties often include festive lights. When galaxies get together, they also may be surrounded by a spectacular light show. This pair of spiral galaxies has been caught in a grazing encounter. This region has hosted three supernova explosions in the past 15 years and has produced one of the most bountiful collections of super-bright X-ray lights known.
What do the following things have in common: a cone, the fur of a fox and a Christmas tree? Answer: they all occur in the constellation of the unicorn (Monoceros). Pictured as a star forming region, the complex jumble of cosmic gas and dust is about 2,700 light-years away.
Resembling festive lights on a holiday wreath, this Hubble Space Telescope image of a nearby spiral galaxy is an iconic reminder of the impending season. Bright knots of glowing gas light up the spiral arms, indicating a rich environment of star formation.
The Hubble Space Telescope captured two festive-looking nebulas, situated so as to appear as one. Intense radiation from the brilliant central stars is heating hydrogen in each of the nebulas, causing them to glow red…like a holiday light.
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The Boatyard at Saint Mammes by Alfred Sisley
Size: 38.8x56 cm
Rhodochrosite with Quartz - Uchucchacua Mine, Lima Department, Peru
Интересно
Ancient rocks hold evidence for life before oxygen http://www.geologypage.com/2016/11/ancient-rocks-hold-evidence-life-oxygen.html
The Pork Butcher by Camille Pissarro
Size: 66x54 cm Medium: oil on canvas
Интересно
The Villa of the Papyri is the name given to a private house that was uncovered in the ancient Roman city of Herculaneum. This city, along with nearby Pompeii, is perhaps best remembered for its destruction during the eruption of Mount Vesuvius in 79 AD. When the villa was rediscovered, archaeologists were lucky to discover a library of 1800 scrolls. This is the only known library to have survived from the Classical world.
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