The Rise of Einsteinian Special Relativity
Uploaded by acnada on Oct 05, 2000
In 1905, Einstein’s Theory of Special Relativity was proposed. The reason that it is so "special" is because it was part of the more complex and extensive Theory of General Relativity, which was published in 1915. His theory reshaped the world of physics when it contradicted all previous laws of motion erected by Galileo and Newton. By mathematically manipulating these previous laws of motion, physicists in the nineteenth century were able to explain such phenomena as the flow of the ocean, the orbits of planets around the sun, the fall of rocks, and the random behavior of molecules in gases. At first, Einstein faced great opposition when he came up with his radical new theory because the previous laws of motion proposed by Galileo and expanded upon by Newton had remained valid for over two hundred years. However, it wouldn’t be long before the "cement" in the foundation of Newtonian and Galilean physics would begin to crumble.
Galileo had determined in 1608 that merely addition and subtraction could calculate relative speeds. Suppose that an observer stands on the side of the highway, and they watch two cars approach each other at 30 and 40 miles per hour. If they were to ask the question, "how fast is the 40 mile per hour car moving relative to the 30 mile per hour car?" They could solve the problem easily by adding the two speeds of the cars, which would equal 70 miles per hour. This means that the 40 mile per hour car sees the 30 mile per hour car advance at a speed of 70 miles per hour and vice versa.
At the core of Newtonian physics was the fact that space and time were absolute. Newton’s absolute space was the space of everyday experience with its three dimensions: east-west, north-south, and up-down. This space gives us our sense of length, breadth, and height; according to Newton. We all, regardless of our motion, will agree on the length, breadth, and height of an object, so long as we make sufficiently accurate measurements. Newton’s absolute time was the time that flows inexorably forward as we age. It is a time whose flow is experienced in common by all humanity.
The maximum speeds of birds in nature are regulated by air. No matter what direction a bird flies, it always has the same maximum speed. Newton had proposed something similar for light, which he...