Asaph Hall Mars and Moons

On June 5, 1872 Hall submitted an article entitled “On an Experimental Determination of Pi” to the journal Messenger of Mathematics. The article appeared in the 1873 edition of the journal, volume 2, pages 113–114. In this article Hall reported the results of an experiment in random sampling that Hall had persuaded his friend, Captain O. C. Fox, to perform when Fox was recuperating from a wound received at the Second Battle of Bull Run. The experiment involved repetitively throwing at random a fine steel wire onto a plane wooden surface ruled with equidistant parallel lines. Pi was computed as 2ml/an where m is the number of trials, l is the length of the steel wire, a is the distance between parallel lines, and n was the number of intersections. This paper, an experiment on the Buffon’s needle problem, is a very early documented use of random sampling (which Nicholas Metropolis would name the Monte Carlo method during the Manhattan Project of World War II) in scientific inquiry.



As expected, coming in a range of materials means that there is extensive flexibility with respect to colour choice. Throughout their history the Moon Boot has always been a bright and happy addition to any winter wardrobe and now is no different. Colour examples include neutral and subtle tones such as ochre, grey, dark brown, black and ice through to light pink, violet, azure, petrol blue, orange and sea green. More conspicuous colours consist of silver, ivory, burgundy, bouganville, apricot, red and yellow especially since some also come in a metallic finish. This gigantic "King of Planets" is considered by some astronomers to be a "failed star". It is about as large as a gas giant planet can be, and still be a planet. It is composed of approximately 90% hydrogen and 10% helium, with small amounts of water, methane, ammonia, and rocky grains mixed into the brew. If any more material were added on to this immense planet, gravity would hug it tightly--while its entire radius would barely increase. A baby star can grow to be much larger than Jupiter. However, a true star harbors its own sparkling internal source of heat--and Jupiter would have to grow at least 80 times more massive for its furnace to catch fire. Cassini is an unmanned spacecraft sent to the Saturn system. It is the fourth space probe to visit the ringed planet, as well as the first to enter orbit. It has been studying Saturn and its many moons since arriving there in 2004.