John E. Bortle is an American amateur astronomer well-known for his contributions to the field of astronomy, particularly in areas related to variable stars and observational astronomy. One of his notable contributions is the "Bortle Dark-Sky Scale," which he developed to classify the night sky's brightness and the quality of astronomical observing conditions.

John Gamble Kirkwood (1891–1979) was an American meteorologist and one of the key figures in the development of modern meteorological science. He made significant contributions, particularly in the field of meteorological dynamics. His work helped in understanding weather patterns and atmospheric phenomena, laying the groundwork for advancements in forecasting and climate science. Kirkwood is known for his research on the theories of fluid dynamics as applied to meteorology.

John H. Coates is a prominent law professor and legal scholar, known for his work in corporate law, securities regulation, and financial markets. He has held positions at prestigious institutions, including Harvard Law School. Coates has contributed significantly to the understanding of corporate governance, the role of corporate law in financial markets, and the implications of corporate actions on stakeholders.

John Moffat is a theoretical physicist known for his work in cosmology and gravitation. He is particularly recognized for his contributions to modified gravity theories, including his work on the Moffat theory of gravity, which challenges and extends the standard general relativity framework. Moffat has explored various aspects of cosmology, including dark matter and the dynamics of galaxies, proposing alternatives to existing models to explain gravitational phenomena without invoking dark matter.

John Read was a British inventor and engineer known for his contributions to the development of various mechanical devices during the 19th century. One of his notable inventions was the "bobbin net machine," which played a pivotal role in the textile industry, particularly in lace making. The bobbin net machine helped automate the process of producing netting, leading to increased efficiency and lower costs in manufacturing. In addition to his work in textiles, Read also contributed to the fields of mechanics and engineering more broadly.

John Tate (1925–2019) was an influential American mathematician known for his work in number theory, particularly in the areas of algebraic K-theory, arithmetic geometry, and the theory of motives. He made significant contributions to the understanding of L-functions and the behavior of various algebraic structures, such as abelian varieties.

John Vincent Atanasoff (1903–1995) was an American physicist and inventor who is best known for his role in the development of the electronic computer. He is most famous for creating the Atanasoff-Berry Computer (ABC) in the late 1930s and early 1940s, in collaboration with his graduate student, Clifford Berry.

Jonathan Lunine is an American astrophysicist known for his research in planetary science and astrobiology. He has made significant contributions to our understanding of the atmospheres and surfaces of planets and moons in the solar system, particularly in relation to potential habitats for life beyond Earth. His work often involves studying the conditions and environments of celestial bodies, including those in the outer solar system, such as Saturn's moon Titan and Jupiter's moon Europa.

Jordan's totient function, denoted as \( J_k(n) \), is a generalization of Euler's totient function.

A rectified truncated cube is a type of geometric shape that is derived from the standard cube (or regular hexahedron) through a combination of truncation and rectification processes. To understand what this means, let’s break it down: 1. **Truncation**: This is the process of cutting off the corners (vertices) of a solid shape.

Josef Geitler von Armingen does not appear to be widely recognized in historical or public records. It is possible that he may be a relatively obscure figure or a fictional character. Without additional context, it is challenging to provide a specific answer.

Joseph Valasek is a well-known figure in the field of cybersecurity, particularly in relation to automotive security. He gained prominence for his work in demonstrating vulnerabilities in connected vehicles, notably his collaboration with Charlie Miller, another security researcher. Together, they showcased how relatively simple techniques could be used to remotely hack into and control vehicles, drawing significant attention to the security risks associated with modern automotive technologies.