William Gilbert, also known as Gilberd, was an English physician, physicist, and natural philosopher born in 1544. He studied at St Johns College in Cambridge and later practiced medicine in London, becoming president of the College of Physicians in 1600. His seminal work "De Magnete" published in 1600 described his magnetic experiments and correctly concluded that the Earth itself is a giant magnet. Gilbert was the first to argue the Earth's core is iron and that magnets can be cut to form new magnets, advancing understanding of magnetism and navigation. He died of bubonic plague in 1603.

1. William Gilbert.
Also known as Gilberd, was an English physician, physicist and natural
philosopher

2. LIFE
He was born in Colchester on May 24, 1544.
His father, Jerome Gilberd, was a borough recorder.
He was educated at St Johns college in Cambridge, and afterwards, left to go practice
medicine in London. In 1573 he was elected a Fellow of the College of Physicians... and in
1600 he was elected the President of that college. He also set up a medicine practice in
London in 1570.
He never married.

3. WORK
Gilbert's “De Magnete” (On the Magnet) was published in 1600 and quickly became the
standard work throughout Europe on electrical and magnetic phenomenon.
In his work, he described many experiments he did on his model earth called the
terrella . He concluded that the Earth was itself magnetic and that this was the reason
compasses point north.
He was the first to argue, correctly, that the centre of the Earth was iron, and he
considered an important and related property of magnets was that they can be cut, each
forming a new magnet with north and south poles.
Europeans were making long voyages across oceans, and the magnetic compass was one of
the few instruments that could save them from being lost!
Gilbert did not, however, express an opinion as to whether this rotating Earth was at the
center of the universe or in orbit around the Sun. Since the Copernican cosmology needed
a new physics to undergird it, Copernicans such as Johannes Kepler and Galileo were very
interested in Gilbert's magnetic researches. Galileo's efforts to make a truly powerful
armed lodestone for his patrons probably date from his reading of Gilbert's book.

4. Several of Gilbert’s unpublished works were published in 1651, by
his younger half brother.
Gilbert died on November 30, 1603 in London. His cause of death is
thought to have been the bubonic plague.