From today's featured articlePlanar transmission lines are flat, ribbon-shaped transmission lines with conductors, or in some cases dielectric (insulating) strips. They are used to interconnect components on printed circuits and integrated circuits working at microwave frequencies, since the planar lines are suited to the manufacturing methods for these components. Transmission line theory is used when the line is longer than a large fraction of a wavelength. At microwave frequencies, this distance is measured in millimetres, which is small enough that these lines can be used for constructing components as well as interconnecting them. The cross-section of the line is usually kept constant so that its electrical behaviour is highly predictable. The first planar transmission line, stripline, was conceived during World War II by Robert M. Barrett; other types in modern use include microstrip, suspended stripline, and coplanar waveguide. (Full article...)
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Retired professional soccer player Abby Wambach scored 184 goals in 255 appearances for the United States women's national soccer team, and holds the world record for goals scored at the international level by an individual player, female or male. Wambach broke previous record holder Mia Hamm's record on June 20, 2013, as she completed a hat trick against South Korea, in a friendly match. Wambach scored her first international goal in the seventh minute of a friendly against Finland on April 27, 2002, in her second game for the national team. She scored her first international hat trick during a friendly against Scotland, leading the national team to an 8–2 win in her fourth appearance for the team. Wambach completed her international career having scored a total of 14 goals in her 25 World Cup match appearances, placing second on the all-time World Cup scoring list behind Marta. (Full list...)
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Woman Reading a Letter is an oil-on-canvas painting by the Dutch painter Johannes Vermeer, produced in around 1663. The central element of the painting is a woman in blue standing in front of an unseen window, reading a letter. The woman appears to be pregnant, although as pregnancy was rarely depicted in art during this period, some scholars have argued that the woman's rounded figure is simply a result of the fashions of the day. While the contents of the letter are not depicted, the composition of the painting is revealing. The map of the Netherlands on the wall behind the woman has been interpreted as suggesting that the letter she reads was written by a traveling husband. Alternatively, the box of pearls barely visible on the table before the woman might suggest a lover, as pearls are sometimes a symbol of vanity. The painting is unique among Vermeer's interiors in that no fragment of corner, wall or ceiling can be seen. Part of the collection of the city of Amsterdam as part of the Van der Hoop bequest, it has been in the Rijksmuseum since its inception, and was thus the first Vermeer they acquired. Painting: Johannes Vermeer
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