The goal of physics
To discover the physical forces, interactions, and properties of matter, including the physical properties of the atom and sub-atomic particles.
What do physicists study?
Physicists study gravitation, motion, space, time, force, and energy. This entails the study of mechanics, heat, light, sound, electricity, magnetism, and the constitution of matter.
Physics' key question
What are the physical properties of matter and energy insofar as both can be measured, expressed in mathematical formulas, and explained by physical theories?
Physics' key concepts
Physics key concepts include matter, energy, mass, space, time, light, work, entropy, motion, volume, density, weight, magnitude, direction, displacement, velocity, acceleration, momentum, inertia, equilibrium, friction, gravitation, mechanics, heat, sound, electricity, magnetism, chaos theory, quantum, and relativity.
Physics' key assumptions
That the universe is controlled by laws, that the same laws apply throughout the universe, that the laws guiding the universe can be expressed in mathematical terms and formulas, that physical properties can be distinguished from chemical ones, that the velocity of light is constant throughout, that space and time are interrelated, that all motion is relative, and that the forces of inertia, gravitation, and electromagnetism are different manifestations of a single force.
Data gathered
The data or information physicists gather focus on the causal relations or statistical correlations of physical occurrences or phenomena. They use information from many physical sources to come to conclusions about the physical world. The physical world provides a virtually unlimited store of data for the various types of physicists to observe. Physicists study atoms, particles, neutrons, and electrons; observe the ways in which moving bodies behave and stationary bodies react to pressure and other forces; observe wave and small particles; and observe how physical forces affect living things.
Inferences, generalisations, or hypotheses physicists make
When possible, physicists seek general hypotheses or physical theories that they can test, modify, and perfect by extended study and experimentation. When successful, they predict new physical phenomenon in line with a given theory and then conduct further observations or experiments to confirm or falsify it.
Implications
The huge growth in knowledge and understanding of the physical world as a result of advances in physics carries with it important implications for quality of life in many dimensions of human existence. It has provided the foundations of engineering. It enables us to build power plants, trucks, aeroplanes, trains, televisions, and phones. Most machinery and tools, for example, are dependent on knowledge of physics. Most construction of buildings, irrigation and sewer systems, solar power alternatives, and the instrumentation of modern medicine are products of modern physics. Our knowledge of physics has also (arguably) been misused in the building of weapons of mass destruction, in our polluting of the environment, and in our use of mechanisms by which to invade the privacy of citizens.
Physics' point of view
Physicists see the universe, as well as the physical world and everything in it, as ultimately explainable and understandable through physical theories and laws. Many physicists see the universe as open to almost unlimited exploration and discovery.
From Elder, L., Paul, R., "The logic of physics", in The miniature guide for students and faculty to scientific thinking, Foundation for Critical Thinking Press 2008.
Most people think that genius is the primary determinant of intellectual achievement. Yet three of the most distinguished thinkers had in common, not inexplicable genius, but a questioning mind. Their intellectual skills and inquisitive drive embodied the essence of critical thinking. Through skilled, deep, and persistent questioning they redesigned our view of the physical world and the universe.
Consider Newton... When asked how he had discovered the law of universal gravitation, he said: "By thinking on it continually. I keep the subject constantly before me and wait till the first dawnings open slowly, by little and little, into a full and clear light." This pattern of consistent, almost relentless questioning, led to depth of understanding and reconstruction of previous theories about the universe.
Newton acutely recognised knowledge as a vast field to be discovered: "I don't know what I may seem to the world, but, as to myself, I seem to have been only like a boy playing on the sea shore, and diverting myself in now and then finding a smoother pebble or prettier shell than ordinary, whilst the great ocean of truth lay all undiscovered before me."
Consider Darwin... He found traditional instruction discouraging. "During my second year at Edinburgh I attended lectures on Geology and Zoology, but they were incredibly dull. The sole effect they produced in me was the determination never as long as I lived to read a book on Geology, or in any way to study the science."
His experience at Cambridge was similar: "During the three years which I spent at Cambridge my time was wasted... The work was repugnant to me, chiefly from my not being able to see any meaning in [it].
In pursuing intellectual questions, Darwin relied upon perseverance and continual reflection, rather than memory and quick reflexes. "I have never been able to remember for more than a few days a single date or line of poetry." Instead, he had, "the patience to reflect or ponder for any number of years over any unexplained problem...At no time am I a quick thinker or writer: whatever I have done in science has solely been by long pondering, patience, and industry."
Einstein, for his part, did so poorly in school that when his father asked his son's headmaster what profession his son should adopt, the answer was simply, "It doesn't matter; he'll never make a success of anything." In high school, the regimentation "created in him a deep suspicion of authority. This feeling lasted all his life, without qualification."
He showed no signs of being a genius, and as an adult denied that his mind was extraordinary: "I have no particular talent. I am merely inquisitive." He failed his entrance exam to the Zurich Polytechnic. When he finally passed, "the examinations so constrained his mind that, when he had graduated, he did not want to think about scientific problems for a year."
Einstein had the basic critical thinking ability to cut problems down to size: "one of his greatest intellectual gifts, in small matters as well as great, was to strip off the irrelevant thrills from a problem."
When we consider the work of these three thinkers, Einstein, Darwin, and Newton, we find, not the unfathomable, genius mind. Rather we find thinkers who placed deep and fundamental questions at the heart of their work and pursued them passionately.
An extract from Elder, L., Paul, R., "The questioning mind in science, Newton, Darwin, and Einstein", in The miniature guide for students and faculty to scientific thinking, Foundation for Critical Thinking Press 2008.