Ruđer Josip Bošković

Ruggero Giuseppe Boscovich / Roger Joseph Boscovich

Ruđer Bošković was a scientist, a philosopher and a diplomat, among the most esteemed scientists of his time, and certainly one of the most famous Croatian scientists ever.

Were it not for gravity, one man might hurl another by a puff of his breath into the depths of space, beyond recall for all eternity.

Ruđer Bošković was born on May 18th, 1711 in Dubrovnik. His father was Slavic and his mother was Italic, and both were Catholics. He received his primary education in the local Jesuit school (Collegium Ragusinum), and at the age of 14 moved to the Jesuit college in Rome (Collegium Romanum).

He successfully finished his schooling to become a professor of physics and mathematics, and started teaching in the (you guessed it) Jesuit schools in Fermo and Rome. In 1736, he started publishing his first papers (Dissertationes) in physics, maths, astronomy and geodesy, and in 1740 he became a professor at the Collegium Romanum.

In order to test the theory that the Earth was not an ellipsoid of revolution, he and Christopher Maire (Rector of the Jesuit college) started measuring a meridian arc between Rome and Rimini. This was requested by Pope Benedict XIV in order to verify/fix maps of the Papal State. After three years of work, in 1755 they published a major work called De literaria expeditione per pontifiam ditionem ad dimitiendos duos merdiani gradus et corrigendaam mappam geographicam, which later earned them the title of pioneers of geodesy.

He was also commissioned by the Church to repair the alarming fissures in the cupola of the Milan Cathedral, to reinforce the dome of Saint Peter's Basilica in Rome and to direct the drainage of the Pontine marshes. Bošković's good work on some of these projects and his status as a Jesuit scientist later helped to persuade the Pope Benedict XIV to remove Copernicus from the Index of Forbidden Books in 1757.

In 1758, Bošković published a treatise called Theoria philosophiae naturalis redacta ad unicam legem virium in natura existentium, which later became known as Theory of Natural Philosophy (published in Venice, 1763). In this work, he presented the concept of the atom as a point-like center of force. In order to explain cohesion on a microscopic level, he postulated the existence of forces between molecules, whose direction and intensity are distance-dependent.

He was one of the first scientists outside England to acknowledge the work of Isaac Newton, and he had many exquisite ideas of his own that others would later look upon. According to Bošković, as the distance between atoms decreases, the forces between them attract and repel them, making the potentials oscillate (and with an infinitely small distance the repelling force dominates, whereas with infinitely large distance, both of them disappear). The idea was later confirmed, albeit in a different way, in the van der Waals forces, and Rutherford's model of the atom is based on Bošković's.

He is also said to be the first one to apply probability to the theory of errors. Later mathematicians such as Laplace and Gauss acknowledged his work which led to Legendre's principle of least squares.

Overall, his views on the structure of matter (the so-called dynamic-atomistic theory) and the nature of movement, time and space defined the modern atomic theory a century "too soon", and assumed existence of subatomic physics. Werner Heisenberg acknowledged his contribution in one of the documents he wrote, in the 20th century, long after Bošković had passed away.

His progressive ideas, however, weren't exactly appreciated by the Jesuit General at the time, so in 1759 he took an extended leave. He accompanied marquis Romagnoli to France, where he would meet many of the famous French scholars of the time, such as Joseph-Jerome de Lalande, and became a member of the French Academie Royale des Sciences.

While in Paris, he presented diplomatic overtures on behalf of the Republic of Dubrovnik at the Court of Versailles, the seat of the French Government while he was in Paris.

The Republic rewarded him by paying his trip to England in May 1760. During his seven month stay, he went from not knowing English at all to being able to read scientific materials and being accepted among the English scientists. Among others, he met the astronomer James Bradley at the Greenwich Observatory, the philosopher Edmund Burke, writer Samuel Johnson and scientist William Thomson (Lord Kelvin). Bošković was also introduced to the American physicist Benjamin Franklin at the time.

He had a diplomatic mission in Britain as well: the English suspected that Dubrovnik was allowing French vessels to equip in the Republic’s ports and then carry the Dubrovnik flag, but Bošković successfully assured them that this was not the case.

When he returned to Italy, he found that another professor took his place at the Collegium Romanum. Later he took the chair of mathematics at the University of Pavia in 1764. He founded the Brera observatory and served as its director for a while.

In 1769, he was supposed to lead an expedition to California in order to observe a transit of Venus, but due to the opposition towards the Society of Jesus (the Jesuits), this didn't happen. In 1770 he moved to Milan to join a new department of astronomy and optics, but despite his investment of money and time, he wasn't appointed, so he grudgingly moved to Venice. From Venice he travelled to Istanbul to observe another passage of Venus by the Sun. However, again it was not to be: a tempest prevented his ship from arriving there in time, so he disembarked at the islet of Tened and studied the ruins of Troy instead! After that, he travelled to Bulgaria, Moldavia and then to Poland.

Throughout his travels, he maintained a link with his sister and two brothers back home in Dubrovnik. His letters to them written in Croatian witness that he did not neglect his mother tongue, and at the same time he was so proficient in Latin to be able to write poetry, like his song about the eclipses of the sun and moon De solis ac lunae defectibus.

He actually designed the ring-micrometer, and a telescope filled with water in all its components. At the time, such a telescope was impossible to technically implement, so it had to wait until 1871 -- 84 years after his death -- when such a device was first implemented in the Greenwich Observatory.

In 1773, the Jesuits were suppressed in Italy, so Bošković had to go to Vienna, from where he went back to France, to take up the post of director of optics for the marine, a post created specially for him on the king’s instruction. He worked in Paris until 1783, when he returned to Bassano del Grappa in Italy.

In 1785 he finally settled in Milan, invited by friends and followers. On February 13th, 1787, weakened by malady, Ruđer Bošković died famous yet alone. He was inhumed in the church of Santa Maria Podone.

It will be found that everything depends on the composition of the forces with which these particles of matter act upon one another: and from these forces, as a matter of fact, all phenomena of Nature take their origin.

He was a member of the Royal Society, Academie Royale des Sciences, St. Petersburg Academy, Bologna Academy and others. Proving how preeminent he was among the scholars of his time, Bošković was envied and has had his inventions contested by men as great as d'Alembert, Condorcet, Rochon or Huygens.

Some of the most important of his 66 scientific works are:

  • Theory of Natural Philosophy -- Theoria philosophiae naturalis redacta ad unicam legem virium in natura existentium
  • On the Sunspots
  • The Transit of Mercury
  • Aurora Borealis
  • The Application of the Telescope in Astronomical Studies
  • The Figure of the Earth
  • The Elements of General Mathematics
  • The Motion of the Heavenly Bodies in an unresisting Medium
  • The Various Effects of Gravity
  • The Aberration of the Fixed Stars
  • On the Divisibility of Matter and the Elements of Bodies
  • Researches on Unusual Gravitation
  • The Computation of a Comet's Orbit from a Few Observations

Most of his manuscripts are kept in a special section of the Rare Books library at the University of California in Berkeley, USA. Some of his work and one of his best known portraits have been preserved in the library of the Franciscan monastery ("samostan male braće", monastery of small brothers :-) in Dubrovnik.

A rather large lunar crater and the largest Croatian physics institute in Zagreb are named after Ruđer Bošković. His picture also appears on one of the kuna banknotes. Countless streets and squares around Croatia are named after him, in particular the square in front of the Jesuit church in his hometown.