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Project

1-Wire Weather Station

The weather station in this project is quite basic, measuring only temperature, pressure, and humidity, but it may be easily expanded to measure other weather components, such as wind speed and rainfall. The design is based on using a series of…

Project

3D Skull Candy Mold

Whether preparing for Halloween or just a regular day, you can make skull-shaped edibles from this project's 3D candy mold. Like many molds, this one is a hollow container into which you can pour water or hot liquids, such as gelatin, chocolate, or…

Project

3x3x3 LED Cube

LEDs (light-emitting diodes) are rectifying semiconductor devices that convert electrical energy into electromagnetic radiation. You can use these devices to create a 3-dimensional light display. LED cubes require some care and good soldering skills…

Project

Chatbot, an Artificially Intelligent Microcontroller

The term "Chatbot" is used for a computer or computer program that is made to emulate some form of human intelligence through conversation. In this project, you will learn how easy it is to make a specific microcontroller—an Arduino™ Uno—seem as…

Project

Text-Controlled RGB LED

A red, green, and blue (RGB) light-emitting diode (LED) is a useful electronic component that can produce visible light in a variety of colors. This is done by varying the intensity of the light output of the three different color LED elements (red,…

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from article Information processing (psychology)

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The four major lobes of the cerebral cortex, that is, the frontal, parietal, temporal, and occipital lobes, are responsible for different aspects of information processing. (Copyright © McGraw-Hill Education)

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from article Information processing (psychology)

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Horizontal associative memory with a serious associative interference problem (who plays tennis—John, Peter, or both?) and no encoding of where each proposition begins and ends. (Copyright © McGraw-Hill Education)

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from article Information processing (psychology)

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Vertical associative memory where concepts are grouped into phrases and propositions by associating each concept to a higher-order node that represents the entire group. (Copyright © McGraw-Hill Education)

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from article Eclipse

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The August 21, 2017 total solar eclipse, as seen from Hopkinsville, Kentucky, USA at 2:25 p.m. EDT. (Credit: NASA)

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from article Eclipse

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Circumstances of solar and lunar eclipses (not to scale).

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from article Eclipse

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Diamond-ring effect at the beginning of totality during the solar eclipse of July 11, 2010, observed from Easter Island in the middle of the Pacific Ocean. (Credit: Jay M. Pasachoff/Science Faction, Muzhou Lu, and Craig Malamut, Williams College…

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from article Eclipse

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Total solar eclipse of July 11, 2010, observed from Easter Island in the Pacific Ocean. (a) Image composited from several exposures using radial filters in order to show a wide dynamic range of intensity of the corona and to bring out the structures…

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from article Eclipse

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Solar eclipse of April 8, 2005, observed during totality from a ship in the mid-Pacific Ocean, west of the Galápagos Islands. (Credit: Jay M. Pasachoff and Dava Sobel/Science Faction)

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from article Eclipse

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Paths of all total solar eclipses from 2001 through 2025. The point of greatest eclipse is indicated by an asterisk on each eclipse path. (Credit: Eclipse map by Michael Zeiler, www.eclipse-maps.com. Eclipse paths by Xavier Jubier, xjubier.free.fr.)

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from article Eclipse

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Cross section through the Earth's shadow cone (umbra) at the Moon's distance, showing the motion of the Moon at three types of lunar eclipses: penumbral eclipse, partial umbral eclipse, and total umbral eclipse.

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from article Eclipse

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Stages of the total lunar eclipse of December 21, 2010. (Credit: Glenn Schneider)

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from article Eclipse

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Total lunar eclipse of December 9, 1992, which was so dark that it rendered the Moon nearly invisible during totality. (Credit: F. Espenak)

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from article Strychnos

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Strychnos nux-vomica: close-up view of leaves and flowering branch. (Photo courtesy of Dinesh Valke)

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from article Planet

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An artist’s impression of a mere sampling of the planetary diversity expected to exist in nature. [Credit: C. Pulliam & D. Aguilar (CfA)]

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from article Planet

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Plan of the solar system's major and dwarf planets. (a) Solar system out to Neptune. (b) Dwarf planets in the outer solar system (Credit: Emily L. Schaller)

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from article Planet

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Orbital elements, which determine the position of a planet in its orbit and the orientation of the orbit in space. Symbols explained in text.

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from article Planet

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The interiors of the 8 planets and the dwarf planet Pluto. Mercury, Venus, Earth, and Mars are characterized by dense, metallic cores and lower-density mantles and crusts. Jupiter and Saturn have compositions that mimic the Sun's, though…

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from article Planet

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Complex lunar crater Bullialdus, 60 km (37 mi) in diameter, shows terraced sides, a central peak, and a flat bottom. It may be compared to the small (less than 8 km or 5 mi) crater in the foreground, which is simple and bowl-shaped. (Credit: NASA)

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from article Planet

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Ultraviolet images from the Hubble Space Telescope, which reveal auroral emission surrounding the north magnetic pole of Jupiter. [Credit: NASA, ESA, and J. Nichols (University of Leicester)]

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from article Neandertals

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Neandertal cranium excavated from Forbes' Quarry, Gibraltar. Note the pronounced brow ridges, large braincase, and receding forehead. (Credit: Clive Finlayson/Gibraltar Museum)

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from article Neandertals

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Gorham's Cave, Gibraltar, is the last known site of Neandertal occupation, being dated possibly to 30,000 years ago. (Credit: Clive Finlayson/Gibraltar Museum)

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from article Neandertals

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Reconstructed skull of a Neandertal from the cave at La Chapelle-aux-Saints, France. (Credit: Illustration adapted from an original drawing by M. F. Ashley Montagu)

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from article Root (botany)

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Kinds of roots. (a) Adventitious, on a cutting or slip (geranium). (b) Prop and other adventitious (corn). (c) Fibrous adventitious (grass). (d) Primary, or taproot (dandelion). (e) Fleshy taproot (carrot). (f) Fleshy, fascicled adventitious…

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from article Root (botany)

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Distribution of tissues in a typical root apex.

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from article Root (botany)

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Transverse sections of roots, showing primary and secondary tissues. (a) Soybean. (b) Barley. (c) Soybean; enlarged part of a, showing early formation of cambium. (d) Soybean with abundant secondary tissue.

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from article Root (botany)

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Diagrams of vascular transition in dicotyledonous seedling (beet, Beta vulgaris) from root tip upward to level of cotyledons. (a) Root is diarch; its vascular tissues are continuous with those of (e) the cotyledons through (b–d) the transition…

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from article Breadfruit

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Breadfruit (Artocarpus altilis), showing the rounded (or elliptic) fruit and the cylindrical staminate flower cluster. (Photo courtesy of Forest and Kim Starr)

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from article Wilkinson Microwave Anisotropy Probe

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WMAP sky-scan strategy. (a) Location of the satellite relative to the Earth and Sun (not to scale), and the orientation of the satellite and of the lines of sight to the spots on the sky focused by the primary reflectors, which continually changed…

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from article Wilkinson Microwave Anisotropy Probe

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WMAP full-sky CMB anisotropy map. The microwaves captured in this picture from WMAP are from when the universe was 378,000 years old, over 13 × 109 years ago. It is a “baby picture” of the universe, equivalent to taking a picture of an 80-year-old…

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from article Hydroponics

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Green- and red-leaf lettuce growing in a hydroponic vegetable garden on a bamboo fence. The pipes, which supply nutrients and water, are part of the hydroponic system. (Credit: Piyachok Thawornmat, Shutterstock)

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from article Hydroponics

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Hydroponic techniques: (a) aerated standing culture; (b) flowing-solution culture with standing solution; (c) nutrient film technique; (d) aeroponics.

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from article Mango

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Tommy Atkins cultivar of mango (Mangifera indica) growing in Florida. (Credit: Wilhelmina Wasik/Agricultural Research Service, U.S. Department of Agriculture)

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from article Flower

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Flower structure, median longitudinal section.

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from article Flower

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Diagrammatic section of an orange blossom. (After J. B. Free, Insect Pollination of Crops, Academic Press, 1970)

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from article Flower

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Flower of Penstemon, a member of the foxglove family, in section. (After C. E. Wood, Jr., A Student's Atlas of Flowering Plants: Some Dicotyledons of Eastern North America, Harper and Row, 1974)

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from article Flower

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Longitudinal section of a flower bud and one carpel in section of blackberry (Rubus betulifolius). (After K. R. Robertson, The genera of Rosaceae in the southeastern United States, J. Arnold Arbor., 55:344–401, 1974)

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from article Flower

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Placentation: (a) parietal, (b) axile, and (c) free central. (After P. H. Raven, R. F. Evert, and H. Curtis, Biology of Plants, Worth Publishers, 1976)

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from article Flower

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Nectaries. (a) Cherry flower (after W. H. Brown, The bearing of nectaries on the phylogeny of flowering plants, Proc. Amer. Phil. Soc., 79:549–595, 1938). (b) Flower of nasturtium (after B. J. D. Meeuse, The Story of Pollination, Ronald Press,…

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from article Flower

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Sunflower (Helianthus annuus) of the composite family. (a) Inflorescence in section. (b) Side view of ray floret. (c) Side view of tubular floret. (d) Section of tubular floret. (After J. B. Free, Insect Pollination of Crops, Academic Press, 1970)

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from article Flower

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Successive stages of flower formation in a wood sorrel. (a) Sepals and petals already initiated; the androecium begins as five bumps on the floral apex; five more will be added. At maturity, five long stamens will alternate with five short ones. (b)…

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from article Flower

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Lily anther. (a) Cross section of young anther showing four microsporangia with sporogenous tissue. (b) Cross section of mature anther with two pollen sacs containing pollen. (After A. W. Haupt, Plant Morphology, McGraw-Hill, 1953)

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from article Flower

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Gametophyte: (a) embryo sac and (b) pollen tube. (After O. Tippo and W. L. Stern, Humanistic Botany, W. W. Norton, 1977)

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