History of physic

Philosophical implications

For more details on this topic, see Philosophy of Physics.

Physics in many ways stems from ancient Greek philosophy. From Thales' first attempt to characterize matter, to Democritus' deduction that matter ought to reduce to an invariant state, the Ptolemaic astronomy of a crystalline firmament, and Aristotle's book Physics, different Greek philosophers advanced their own theories of nature. Well into the 18th century, physics was known as "Natural philosophy".

By the 19th century physics was realized as a positive science and a distinct discipline separate from philosophy and the other sciences. Physics, as with the rest of science, relies on philosophy of science to give an adequate description of the scientific method.^[13] The scientific method employs a priori reasoning as well as a posteriori reasoning and the use of Bayesian inference to measure the validity of a given theory.^[14]

“	Truth is ever to be found in the simplicity, and not in the multiplicity and confusion of things.	”
—Isaac Newton

The development of physics has answered many questions of early philosophers, but has also raised new questions. Study of the philosophical issues surrounding physics, the philosophy of physics, involves issues such as the nature of space and time, determinism, and metaphysical outlooks such as empiricism, naturalism and realism.^[15]

Many physicists have written about the philosophical implications of their work, for instance Laplace, who championed causal determinism,^[16] and Erwin Schrödinger, who wrote on Quantum Mechanics.^[17] The mathematical physicist Roger Penrose has been called a Platonist by Stephen Hawking,^[18] a view Penrose discusses in his book, The Road to Reality.^[19] Hawking refers to himself as an "unashamed reductionist" and takes issue with Penrose's views.^[20]

History

Main article: History of physics

Isaac Newton (1643-1727)

Since antiquity, people have tried to understand the behavior of the natural world. One great mystery was the predictable behavior of celestial objects such as the Sun and the Moon. Several theories were proposed, the majority of which were disproved.

The philosopher Thales (ca. 624–546 BC) first refused to accept various supernatural, religious or mythological explanations for natural phenomena, proclaiming that every event had a natural cause. Early physical theories were largely couched in philosophical terms, and never verified by systematic experimental testing as is popular today. Many of the commonly accepted works of Ptolemy and Aristotle are not always found to match everyday observations.

Even so, many ancient philosophers and astronomers gave correct descriptions in atomism and astronomy. Leucippus (first half of 5th century BC) first proposed atomism, while Archimedes derived many correct quantitative descriptions of mechanics, statics and hydrostatics, including an explanation for the principle of the lever. The Middle Ages saw the emergence of an experimental physics taking shape among medieval Muslim physicists, the most famous being Alhazen, followed by modern physics largely taking shape among early modern European physicists, the most famous being Isaac Newton, who built on the works of Galileo Galilei and Johannes Kepler. In the 20th century, the work of Albert Einstein marked a new direction in physics that continues to the present day.