Tycho Brahe (1546-1601) - Danish astronomer

Born on December 14, 1546, Tycho [Tyge] Brahe was probably the greatest pre-telescopic astronomer. He was born in his parents’ large manor house at Knutstorp, in the Danish region of Scarnia, which is now in Sweden. Tycho Brahe was given the name Tyge by his parents Beate Bille and Otte Brahe. He is now known as "Tycho" since that is the Latinized version of his name that he adopted when he was about fifteen years old.

Otte Brahe, his father, was from the Danish nobility Beate Bille, Tycho's mother, also came from an important family which had produced leading churchmen and politicians. Tycho Brahe was brought up by his paternal uncle Jorgen Brahe and became his heir.

He was sent by his family to study in Copenhagen, then to Leipzig to study law, but also studied a variety of other subjects and became interested in astronomy. In 1565 and 1566 Tycho studied mathematics at the universities in Wittenburg and Rostock.

He began making observations and by August 1563, while still at the University of Leipzig, he began to keep a record of these observations. The second observation he recorded was a conjunction of Jupiter and Saturn which proved significant for Tycho's subsequent career.

In spring 1569, he arrived in Augsburg, where he spent 14 months learning how to make high-precision astronomical instruments. His ambition was to build instruments allowing him to make observations true to within one arc minute (one-sixtieth of a degree).

Tycho's reputation as an accomplished astronomer rose quickly, primarily through his

observations of and writings on the 1572 novae in Cassiopea, and of the 1577 comet.

On November 11, 1572 Tycho observed the new star in Cassiopeia. Observing the night sky from an uncle’s home, Tycho was amazed to see a new light brighter than Venus in the sky. In 1573, Tycho’s name became well-known in astronomical circles when he published De nova stella – The New Star.

In 1598 was appointed Imperial Mathematician to the Holy Roman Emperor Rudolf II. Tycho Brahe's contributions to astronomy were enormous. He not only designed and built instruments, he also calibrated them and checked their accuracy periodically. He thus revolutionized astronomical instrumentation.

His astronomical research program never really resumed, however. He died in Prague, Bohemia (now Czech Republic) on October 24, 1601, leaving his most recent assistant Johannes Kepler as his scientific heir.
Tycho Brahe (1546-1601) - Danish astronomer

Hans Christian Oersted: Danish physicist

Hans Christian Oersted (14 August 1777 – 9 March 1851) a distinguished Danish physicist and chemist was born in the town of Rudkobing, on the Danish island of Langeland, where his parents, Søren Christian and Karen (n´ee Hermansdatter), owned the local pharmacy. Because of family problems, Hans and his younger brother were placed with a German wigmaker while they were still young boys.

In 1794 the brothers, with no prior formal education, were accepted by the University of Copenhagen, where Hans studied astronomy, chemistry, mathematics, physics, and pharmacy. He completed his training in pharmacy in 1797. At age 22, in 1799, he graduated with a Ph.D. Between 1800 and 1820, he was a university teacher, researcher, publisher, and one of the most sought-after lecturers of his day.

Alessandro Volta discovered the galvanic battery in 1800, and this inspired Ørsted to ponder the nature of electricity and conduct his first electrical research experiments. Electromagnetism was discovered in the spring of 1820 by Oersted during a lecture to an advanced group of students, he demonstrated that electric current in a wire can deflect a magnetized compass needle, a phenomenon the importance of which was rapidly recognized and which inspired the development of electromagnetic theory.

By July of that year, he was certain that an electric current produced about it a circular magnetic field, and he published his results in a short paper, written in Latin, and carried by the major scientific journals of Europe.

Although he made no attempt to explain electromagnetic presence through mathematical formulas, Ørsted was credited with its discovery. Following this historic breakthrough, the pioneering field of electromagnetic study rapidly evolved, accompanied by a surge of new theories and fresh technological applications.

The Danish government funded Oersted to further his education in other European countries – he spent the years 1801 to 1803 in Germany and France.

Oersted's great discovery had an enormous impact on the scientific world. More than a hundred scientists published their comments and researches on electromagnetism within seven years of the discovery, and Oersted was showered with honors and awards. The Royal Society of London gave him the Copley Medal, and the French Academy awarded him a prize of 3000 gold francs.
Hans Christian Oersted: Danish physicist