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The chart was designed by Ian Bailey [5] and Jan E. Lovie-Kitchin at the National Vision Research Institute of Australia. [1] [3] They described their motivation for designing the LogMAR chart as follows: "We have designed a series of near vision charts in which the typeface, size progression, size range, number of words per row and spacings were chosen in an endeavour to achieve a ...
For 6/6 = 1.0 acuity, the size of a letter on the Snellen chart or Landolt C chart is a visual angle of 5 arc minutes (1 arc min = 1/60 of a degree), which is a 43 point font at 20 feet. [10] By the design of a typical optotype (like a Snellen E or a Landolt C), the critical gap that needs to be resolved is 1/5 this value, i.e., 1 arc min.
The rectangular field of play used for American football games measures 100 yards (91.44 m) long between the goal lines, and 160 feet (48.8 m) (53.3 yards) wide. The field may be made of grass or artificial turf. In addition, there are two end zones on each end of the field, extending another 10 yards (9.144 m) past the goal lines to the "end ...
The scale. The Douglas sea scale, also called the "international sea and swell scale", was devised in 1921 [1] by Captain H. P. Douglas, who later became vice admiral Sir Percy Douglas and hydrographer of the Royal Navy. Its purpose is to estimate the roughness of the sea for navigation.
1 m – approximate height of the top part of a doorknob on a door; 1 m – diameter of a very large beach ball; 1.29 m – length of the Cross Island Chapel, the smallest church in the world; 1.4 m – length of an Peel P50, the world's smallest car; 1.435 m – standard gauge of railway track used by about 60% of railways in the world = 4 ft ...
Two major mines employ more than 400 workers. The National Gypsum mine is located 2 miles (3 km) east of Shoals and is the United States' deepest at 515 feet (157 m). [10] The gypsum mine and factory in Shoals, Indiana, operated by National Gypsum. The mine, which started operations in the 1950s, is about 400-500 feet underground.
For instance the same angle of 0.1 mrad will subtend 10 mm at 100 meters, 20 mm at 200 meters, etc., or similarly 0.39 inches at 100 m, 0.78 inches at 200 m, etc. Subtensions in mrad based optics are particularly useful together with target sizes and shooting distances in metric units .
19 h 41 m 53.18 s: −46° 02′ 31.4″ Schematic view to scale of past and future close approaches of stars to the Sun (Up to 4.5 light-years) See also.