ED50 is a geodetic datum, defined after World War II for the international connection of geodetic networks. Some of the important battles of World War II were fought on the borders of Germany, the Netherlands and France, the mapping of these countries had incompatible latitude and longitude positioning; this led to the setting up of ED50 as a consistent mapping datum for much of Western Europe. It was, still is, used in much of Western Europe apart from Great Britain, Ireland and Switzerland, which have their own datums, it used the International Ellipsoid of 1924. That spheroid was an early attempt to model the whole Earth and was used around the world until the 1980s when GRS 80 and WGS 84 were established. Many national coordinate systems of Gauss–Krüger are defined by ED50 and oriented by means of geodetic astronomy. Up to now it has been used in databases of gravity fields, small surveying networks in Europe and America, by some developing countries with no modern baselines. ED50 was part of the fundamentals of the NATO coordinates up to the 1980s.

The geodetic datum of ED50 was centred at the Helmertturm on the Telegrafenberg in Germany. The adjustments for versions of the datum used the Munich Frauenkirche as starting point; the longitude and latitude lines on the two datums are the same in the Archangel region of north-west Russia. As one moves westwards across Europe, the longitude lines on ED50 become further west than their WGS 84 equivalents, are around 100 metres west in Spain and Portugal. Moving southwards, the latitude lines on ED50 become further south than the WGS 84 lines, are around 100 m south in the Mediterranean Sea; this means that if the lines are further west, the longitude value of any given point becomes more easterly. If the lines are south, the values become northerly; this is due to the fact that the International Ellipsoid is larger than the GRS 80/WGS 84 ellipsoid, so a given north-south distance will cover more latitude on the new ellipsoid, a given east-west distance will cover more longitude. The datum shift for the Universal Transverse Mercator grid is different.

The eastings vary between 0 m in Eastern Europe and 100 m in the far west of the continent similar to the longitude shift, but the northings are about 200 m different across Europe, with the ED50 UTM northing lines south of the WGS 84 UTM northing lines. UTM northings are measured from the Equator; the French datum RGF93 The Great Britain datum OSGB36. For Ireland, the Irish Transverse Mercator; the Swedish datum RT90. The Switzerland datum CH1903

Pre-Columbian Gold Museum

The Pre-Columbian Gold Museum is a museum in San José, Costa Rica. It is located in a subterranean building underneath the Plaza de la cultura and is managed by the Banco Central de Costa Rica; the museum has a substantial collection of over 1600 artifacts of Pre-Columbian gold dating back to AD 500. The collection includes animal figurines, earrings, erotic statuettes and El Guerrero, a life sized gold warrior figure adorned with gold ornaments in a glass case. In Costa Rican history, gold was considered a symbol of authority and the items are testament to the craftmanship of the Pre-Columbian period. There is a replica of a pre-Columbian grave containing 88 gold objects, unearthed on a banana plantation in southeastern Costa Rica in the 1950s; the Museo Numismático is located in the same building on the ground level and features displays dating back to 1236, including coins and unofficial items such as coffee tokens. The "Casa de Moneda" is located on the ground level with information on the history of minting in Costa Rica and displays illustrating its development.

The collection includes Costa Rica's first coin, the Media Escudo, minted in 1825. Official site

Rhonda Lenton

Rhonda L. Lenton is a Canadian academic administrator and professor, she is the 8th and current president and vice-chancellor at York University in Toronto, Canada having succeeded Mamdouh Shoukri on 1 July 2017 for a five-year term. She served as Dean of Atkinson College and as York's Vice President Academic and Provost. Prior to her role in academic administration, Lenton was a Professor of Sociology. During her research career, Lenton led randomized public telephone surveys of social issues such as Internet dating and sexual assault in Canada. Lenton completed her Ph. D in sociology at the University of Toronto in 1989; the title of her dissertation was Parental Discipline and Child Abuse. Before becoming an academic administrator, she published research on a range of topics related to family violence, feminism in academia, online dating, her work included a 1999 national telephone survey of randomly selected women, asking them about their experiences with sexual harassment and assault. She has researched the impact that the inclusion of women's studies within academia has had on feminism, determining that it had made feminism more conservative.

She conducted randomized robocalls regarding Internet dating behaviours of the Canadian public in 2001. In 2018, Lenton began a study of how Jewish Canadians have reared their children and any experience they may have had with prejudice, conducted through surveys of up to eighty questions; as university Provost, Lenton supported male students in their requests to keep them away from female students due to their religious preferences. Lenton's appointment as university president became effective on 1 July 2017; as the university's chief spokesperson during a divisive part-time faculty strike in 2015, during which time she was on the university's negotiating committee, Lenton's anticipated presidential appointment generated widespread opposition from an alliance of university students and faculty members prior to its announcement. In 2018, during her first year, a second strike occurred at the university under her leadership. An undergraduate student occupation of the University Senate took place in support of the strike.

The sit-in lasted several months, during which the participants highlighted potential expense account spending issues from Lenton's term as Vice President Academic and President, in addition to various other tuition-oriented concerns. On May 1, 2018 President Lenton and the Chair of the Board of Governors both were admonished in an official letter sent by the Canadian Association of University Teachers for their concerted and repeated attempts to undermine academic self-governance at York University. At that time, there were several York University faculty councils and student associations that carried non-confidence motions in the conduct and leadership of Lenton as president. On May 11, the union representing the full-time tenured faculty stated the strike had lasted more than two months due to Lenton and the board's desire to break the union. In 2015, the Women's Executive Network named her one of the 100 Most Powerful Women in Canada during her past role as Provost of York University