The Following Calendar is Correct!!!!
Yes, it is. The tenth month of 1582 had 10 days less than what a month of October should have. What made it shorter? Precisely speaking, the Julian calendar (named after Julius Caesar, the Roman Emperor) that was followed at that time had to be corrected. It was a solar calendar. The function of a solar calendar is to denote the position of the earth in its orbit around the sun. We are visited by different seasons at different positions of the earth in its orbit. If the calendar fails to do so, seasons come when they are not supposed to come. We get warm weather when the calendar shows it is winter or vice versa. The calendar loses its utility. The Julian calendar used to count the length of the year as 365 days 6 hours (365.25 days). Actually the earth completes one rotation around the sun in 365 days 5 hours 48 minutes and 46 seconds (approximately 365.2422 days). That means when one year was believed to be completed, the earth was already advanced in its next round of rotation by (365.25- 365.2422) days or 0.0078 days. The difference is not perceptible in a few years. But it is cumulative and hence when it became perceptible during the sixteenth century, the calendar was lagging behind the rotation of earth by 10 days. As a corrective measure, 10 days had to be deleted from the month of October in the year 1582 and the calendar shown above had to be accepted. Some other measures had to be introduced. Earlier, the number of leap years in a span of 400 years was 100. In the revised system it became 97. Thus the mean length of the year was reduced from 365.25 days to 365.2425 days. The revised calendar which was dubbed Gregorian calendar commemorating Pope Gregory XIII, is the calendar that we are following today. The mean length of a year in this calendar is 0.0003 days more than the actual length (365.2422 days) of a year. Thus after every 10,000 years, the calendar has to be corrected again. The man, who made significant contribution in correction of the Julian Calendar and formation Gregorian calendar, was an Italian doctor named Aloysius Lilius (1510-1576) or Luigi Lilio. A crater on the moon is bearing his name.
It is 27th July Today
Today we have assembled here to talk about science. Incidentally today is the birthday of a number of eminent scientists. Let us commemorate some of them.
The British mathematician Sir George Biddell Airy (1) was born on 27th July 1801. He is famous for his research work on planetary orbits. He also determined the mean density of earth and established Greenwich as the point of prime meridian. Among various other contributions made by him, he found a new technique to determine the strain and stress field within a beam. His method contributed to the development of fracture mechanics. He served as the Astronomer Royal, a senior post in the Royal Households of the United Kingdom, from 1835 to 1881.The Swiss mathematician Johann Bernoulli (2) was born on 27th July 1667 at Basel. He is remembered for his contribution in infinitesimal calculus. The Hungarian physicist Lorand Eotvos (3), known for his work on gravitation and surface tension, was born on 27th July 1848. The Nobel laureate German chemist Hans Fischer (4) was born on 27th July 1881. His investigation on pigments in blood, bile and chlorophyll brought him in the limelight. He synthesized the bile pigments bilirubin, biliverdin and also haemin, the component of the blood pigment haemoglobin. Kenneth Tompkin Bainbridge, the American physicist (5) was born
27th July 1904. He is famous for his work on cyclotron. In 1932 he developed a high-precision mass spectrometer, which enabled him to determine the mass difference of nuclear isotopes and to verify the famous equation of Albert Einstein E=mc2.
There might be many more having significant contribution to the progress of science, born on the s day. The life and work of these people provide a never-ending source of inspiration to us.