This Day in History (13-Feb-1633) – Galileo Galilei arrives in Rome for trial after publishing his thoughts on heliocentrism

Galileo used his mathematics knowledge and technical skills to  build a telescope in 1609.  Galileo’s observations strengthened his belief in Copernicus’ theory (published in 1514)that Earth and all other planets revolve around the Sun. Galileo expected the telescope to quickly make believers in the Copernican system out of all educated persons, but he was disappointed. The Catholic Church, which was very powerful and influential in Galileo’s day, strongly supported the theory of a geocentric, or Earth-centered, universe. In 1616, on orders of the Pope Paul V, Cardinal Bellarmine called Galileo to his residence and administered a warning not to hold or defend the Copernican theory; Galileo was also forbidden to discuss the theory orally or in writing. After repeated convincing attempts by Galileo, Pope Urban VIII allowed him to write about the Copernican theory as long as he treated it as a mathematical hypothesis.

In 1630 he completed his book Dialogue Concerning the Two Chief World Systems in which the Ptolemaic and Copernican models were discussed and compared. Vatican cleared (conditionally) to publish the book. The book was printed in 1632 which was quickly sold out and soon became the talk of the literary public. Enemies of Galileo had convinced the Pope that the Dialogue was nothing but a thinly-veiled brief for the Copernican model. Pope Urban VIII, convinced by the arguments of various Church officials, stopped its distribution; the case was referred to the Inquisition and Galileo was summoned to Rome despite his infirmities, to answer the charges in February 1633. Old Galileo travelled for twenty-three days in cold winter from Florence to Rome.

He was formally interrogated for 18 days and on April 30 Galileo confessed that he may have made the Copernican case in the Dialogue too strong and offered to refute it in his next book.  Galileo was sentenced to life imprisonment. Because of his age and poor health, he was allowed to serve his imprisonment under house arrest until his death in 1642. The Church finally accepted that Galileo might be right in 1983.



This Day in History (11-Jul-1979) – Skylab crashes to Earth

Launched in 1973, Skylab was the world’s first successful space station. The first manned Skylab mission came two years after the Soviet Union launched Salynut 1, the world’s first space station, into orbit around the earth. Unfortunately, NASA spent far less time and energy planning how to gracefully bring the space station back to Earth at the end of its mission. Skylab carried the most varied assortment of experimental equipment ever assembled in a single spacecraft to that date. The crews of Skylab spent more than 700 hours observing the sun and brought home more than 175,000 solar pictures. They also provided important information about the biological effects of living in space for prolonged periods of time. Five years after the last Skylab mission, the space station’s orbit began to deteriorate–earlier than was anticipated–because of unexpectedly high sunspot activity. On July 11, 1979, Skylab made a spectacular return to earth, breaking up in the atmosphere and showering burning debris over the Indian Ocean and Australia. No one was injured.

All week there had been mounting speculation over where the spacecraft would come down. In India, the police in all states were put on full alert and the civil aviation department was planning to ban flights across the sub-continent during the crucial hours of re-entry. Beginning in June of 1979, as Skylab’s re-entry approached, many American newspapers jokingly proposed “Skylab insurance”. The San Francisco Examiner went one step further, offering a $10,000 prize to the first person to deliver a piece of Skylab debris to its office within 72 hours of the crash. Knowing the orbiter wasn’t coming down anywhere near the United States, the newspaper felt it was making a safe bet. In Australia, 17-year-old Stan Thornton of tiny Esperance awoke to the commotion when Skylab broke apart in the atmosphere and pelted his house with space station fragments. Thinking quickly, he grabbed a few charred bits of material from his yard, hopped on a plane without so much as a passport or suitcase and made it to the Examiner’s office before the deadline.



This Day in History (2-Apr-1845) – H L Fizeau & J Leon Foucault take 1st photo of Sun

Louis-Jacques Daguerre, inventor of the daguerreotype process of photography, put on a free course on his new photographic techniques in Paris, which was attended by the two college student friends Louis Fizeau and Lion Foucault. They watched Daguerre expose a plate in a camera pointing out the window, then after talking about his process for about 30 minutes, he developed the plate using a variety of chemicals to reveal the picture. Although Fizeau and Foucault were impressed they also realised the limitations of the process – it would be wonderful to be able to take portraits, they thought, but the subject could not be expected to remain motionless for 30 minutes. After the course ended they began to experiment to try to speed up the process, and Fizeau had the idea of sensitizing the plate using bromine. Experimentation led to them reducing the exposure time from 30 minutes to 20 seconds. The discovery did not have the impact that it might, however, for other photographic methods were coming into use.

François Arago, a French mathematician, was aware of the great scientific potential of the new methods of photography and, in particular, he was aware of the advances made by Fizeau and Foucault. He approached the two friends in 1845 and suggest that they might attempt to make photographs of an image of the sun produced by a telescope. After multiple attempt, on 2nd April, 1845, the first surviving daguerrotype photograph of the sun was taken by Fizeau and Foucault. The 5-inch image showed many details including a few sunspots.

Berkowski, a local daguerrotypist whose first name was never published, later made the first solar eclipse photograph on July 28, 1851, also using the daguerrotype process, at the Royal Observatory in Königsberg, Prussia (now Kalinigrad in Russia). A small 6-cm refracting telescope was attached to the 15.8-cm Fraunhofer heliometer and a 84-second exposure was taken shortly after the beginning of totality. By 1858, daily photographic records of the solar surface were taken by Warren de la Rue at the Kew Observatory in England, and by Jules Janssen at the Meudon Observatory near Paris. For the next 14 years, de la Rue record the complete 11 year solar cycle in a series of almost 3000 images that clearly showed sunspots and other features.