Jean Buridan, a French philosopher and scientist, proposed the concept of impetus in the 14th century. He suggested that a moving object retains a certain amount of motion, which he called impetus, and that this impetus decreases over time.

The astrolabe was primarily developed as a navigational tool to determine the latitude of a ship at sea. It allowed sailors to measure the angle between the horizon and the sun or stars, which could then be used to calculate their latitude.

The University of Paris, founded in the 12th century, was a prominent center of learning and scholarship in medieval Europe. It was particularly renowned for its contributions to theology, philosophy, and science.

Johannes Gutenberg, a German goldsmith and inventor, is widely recognized as the inventor of the printing press in the 15th century. His invention revolutionized the production and distribution of books, making knowledge more accessible and contributing to the spread of ideas during the Renaissance.

Andreas Vesalius, a Flemish anatomist, made groundbreaking contributions to the study of human anatomy in the 16th century. His detailed observations and dissections led to the publication of his influential work 'De Humani Corporis Fabrica', which revolutionized the understanding of human anatomy and laid the foundation for modern anatomy.

The city of Milan in northern Italy is often credited with the invention of the first mechanical clock in the 14th century. The clock, known as the Torre dell'Orologio, was installed on the Palazzo della Ragione and became a symbol of the city's technological prowess.

Nicolaus Copernicus, a Polish astronomer and mathematician, proposed the heliocentric theory in the 16th century. His revolutionary idea that the Earth and other planets revolve around the sun challenged the prevailing geocentric model and laid the foundation for modern astronomy.

The compass first appeared in Europe in the 12th century, brought by Arab traders and explorers. It quickly became an essential tool for navigation, enabling sailors to determine their direction and course more accurately, leading to significant advancements in exploration and trade.

Ibn al-Haytham, an Arab scientist and mathematician, made significant contributions to the study of optics in the 11th century. His work on lenses and the refraction of light laid the foundation for the development of eyeglasses and optical instruments.

Gunpowder first appeared in Europe in the 13th century, likely introduced through trade with China. Its explosive properties led to the development of firearms and cannons, revolutionizing warfare and ushering in a new era of military technology.

Guy de Chauliac, a French physician and surgeon, made significant contributions to the field of surgery in the 14th century. His book 'Chirurgia Magna' was a comprehensive guide to surgical techniques and treatments, and he is considered one of the most influential surgeons of the medieval period.

The cross-staff was the primary method used by sailors to measure the angle between the horizon and the sun or stars when using the astrolabe. It consisted of two pieces of wood or metal arranged perpendicularly, allowing sailors to sight the celestial body and determine its altitude above the horizon.

Pierre de Maricourt, a French scientist and philosopher, made significant contributions to the study of magnetism in the 13th century. His experiments with magnets led him to propose the concept of magnetic poles and their interaction, laying the foundation for the understanding of magnetism.

The primary source of power for early mechanical clocks was weights. A weight was attached to a rope or chain wrapped around a wheel, and as the weight descended, it provided the power to drive the clock's mechanism and keep time.

Paracelsus, a Swiss physician and alchemist, made significant contributions to the field of alchemy in the 16th century. He developed new chemical processes and introduced the concept of using chemical substances for medicinal purposes, laying the foundation for modern pharmacology.