New content wrote to be added to the chapter about the following major contributors to astronomy.
Sir Frederick William Herschel (1738 –1822)
Herschel was a German born astronomer, musician and telescope maker. Using his homemade telescopes he made great contributions to astronomy and discovered numerous heavenly bodies. Originally a successful musician he became drawn to astronomy and began to profitably make and sell reflecting telescopes, these reflected and gathered more light than the usual lens used. He was eventually appointed the King of Englands own personal astronomer.
Herschel became most famous for the discovery of the planet Uranus, the first ever to be discovered by telescope. Initially the planet was named after George III but this was later changed to Uranus, after the mythodical Greek god of the sky. He also discovered the first of the planets moons – Titania and Oberon. All the moons of Uranus (of which there are 27) are now named after characters from the works of both William Shakespeare and Alexander Pope. Unlike the moons of other planets, which are each named after a Greek mythological character.
He was also the first to realize that the Milky Way was disc shaped and the first to name new space rocks found. For these he coined the word asteroid, from the Greek words for star and shape.
Sir Arthur Stanley Eddington (1882 –1944)
Eddington was an important British astrophysicist famed for his confirmation of Einsteins Theory of General Relativity by observing a solar eclipse. Eddington wrote numerous articles that helped to simplify and explain the scientific nature of the idea in the English language.
Eddington also investigated the inner structure of a star through theory, and developed an understanding of their activities. He suggested that stars gained energy from the nuclear fusion of hydrogen to helium and also gave his name to the “Eddington limit” – the natural limit of the luminosity of stars. When the luminosity produced by the star goes over the Eddington limit, it expels powerful solar winds from its outermost layers. He is thought to be the founder astrophysics and believed that the universe was expanding but did not believe in the Big Bang theory
Instead he believed that a cosmic constant (a theory from general relativity) must cause the universe had to either expand or shrink.
Edmond Halley (1656 –1742)
Halley, a well known English astronomer, geophysicist, mathematician, meteorologist, and physicist is most famous for calculating the orbit of the recurring comet, which is named after him. Halley studied the gravitational principles of Sir Isaac Newton and later published his own well-known books. He was an expert on the astronomy of comets and realized that they move in elliptic orbits around the sun and will eventually pass by in a cycle that orbits the earth approximately every 75 years,
He accurately predicted in 1705 that a short period comet would be visible again in 1758. This is the only comet visible to the naked eye, which can be spotted twice during a person’s lifetime. Halley died before this date but as his calculations proved accurate it was named in his honour. He also accurately predicted the solar eclipse visible in 1715 to within 4-minute timeframe!
Halley made many important contributions to the understanding of naval navigation and patented the world’s first diving bell with a replenishable air supply. This enabled divers to explore deep sea, they were able to remain submerged and have air restocked with supplies sent from the surface.
Albert Einstein (1879 –1955)
Einstein, a German physicist known as father of modern physics is the most well celebrated and influential scientist of the 20th century. His development of the theory of general relativity and also of the special theory of relativity was revolutionary and allowed for great advancements in physics, which led to him being awarded a Nobel Prize for Physics in 1921.
Einstein believed that the Newtonian theory did not support the laws of mechanics alongside the laws of the electromagnetic fields. This led to his own quest for answers and his development of the theory of general relativity, which he realized could also extend to gravitational fields. His theories changed the way scientists thought about the universe. In a nutshell, in his special theory Einstein believed there is no such thing as “absolute space or time” and that they are relative to the speed of light. The faster you go through space, the slower you move through time. The speed of light is always constant.
In the second theory – of general relativity, he included gravity. Einstein stated that it is impossible to tell the difference between gravity and the effect of inertia (a force that causes change) from a moving object. Sizable objects can cause outer space to curve and the larger the object, the larger the bend.
His theories led to what is probably the most famous equation, E = mc² relates mass and energy.
It can be wrote as Energy = mass x the speed of light squared
The equation states that matter and energy are both forms of the same thing and show that even a small amount of matter is the same as a larger amount of energy – they are same thing but in different states.
He is also well known for Brownian motion and also the photoelectric effect, which changed the way we see light. However we won’t attempt to explain this here!!