About 5 years ago, when I read the chapter on optics in Feynman`s lectures, I began to wonder why the principle of least time is called a “principle” and not a “law” like Newton`s laws of motion. I have believed for a very long time that this has to do with the origins of the declaration. If the statement/theory comes from observations about nature, we call it a law, like the law of gravity. Instead, when it begins completely theoretically, we tend to call it a principle like the principle of least action. While still believing in this explanation, I began to appreciate a new perspective I heard in this lecture (the following video begins with the relevant timestamp): A theory is a set of concepts, laws, and equations in science designed to explain a specific subset of observations. It is also used for theories that describe worlds of thought different from our own. There is also a related word “model”, which is distinguished by a theory in that it is truly specific, while a “theory” can leave some details adjustable, and “framework”, which, on the contrary, is less specific than a theory and fully determines the general methods and the type of objects and arguments allowed in the search. The boundary between the terms is not very clearly defined. The terms scientists use to describe what they study may seem arbitrary. It may seem that the words they use are just words that have nothing else for them.

But studying the terms scientists use to describe various phenomena will help you better understand their meaning. There are other examples of scientific principles in everyday life. It is impossible to distinguish between a gravitational force and the inertial force, the acceleration force of an object, known as the equivalence principle. It tells you that if you`re in free fall in an elevator, you wouldn`t be able to measure the gravitational force because you wouldn`t be able to distinguish between it and the force pulling you in the opposite direction of gravity. Examining the rhetoric behind how scientists communicate tells you more about what they mean when they describe the universe. Understanding the use of these terms is relevant to understanding their true meaning. Other terms may not be as clear. The difference between a rule and a principle can be debated, but rules usually refer to how to determine the correct answer from different possibilities. With the rule of law, physicists can determine how electric current, magnetic field, and magnetic force depend on each other in terms of direction. Although it is based on fundamental laws and theories of electromagnetism, it is used more as a general “rule of thumb” when solving equations in electricity and magnetism.

That makes perfect sense! You can derive all the laws of ray optics from the principle of least time. Or, in general, you can derive the equations of motion (and Newton`s laws) from the principle of least action. All I can say for sure is that you should not make assumptions about whether an idea is speculative or confirmed, general or specific, etc., simply based on its name theory, law, rule, principle or whatever. While laws and principles describe these two different ideas in physics, biology, and other disciplines, theories are collections of concepts, laws, and ideas to explain observations of the universe. The theory of evolution and the theory of general relativity describe how species have changed over generations and how massive objects distort space-time through gravity. Laws are general rules and ideas that adhere to the nature of the universe, while principles describe specific phenomena that require clarity and explanation. Other terms such as theorems, theories, and rules can describe nature and the universe. Understanding the differences between these terms in physics can improve your rhetoric and language when talking about science.

Heisenberg used the German word “inaccuracy,” which means “inaccuracy” rather than “uncertainty,” to describe what we would call the uncertainty principle. The momentum, the product of the speed and mass of an object and the position are always compromised with each other. S. Hussain Ather is a master`s student in science communication at the University of California, Santa Cruz. After studying physics and philosophy at Indiana-Bloomington University, he worked for two years as a scientist at the National Institutes of Health. He researches and writes primarily on neuroscience and philosophy, but his interests include ethics, politics, and other fields relevant to science. For example, is “Archimedes` principle” synonymous with “Archimedes` right”? Laws describe the fundamental interactions and relationships between the things that apply with undeniable certainty. Law-type events are the most likely to occur and their probability is extremely high. One such example is the laws of classical mechanics, which have been observed to apply in all cases.

Laws can be so fundamental that they have little or no explanation. A principle (in physics) is a statement about the limits of intrinsic natural properties. It differs from a statute in that it is not a statement of some kind of observation, but a statement of the models that govern laws and theories. A principle is a powerful statement; it can never be ignored; There are absolutely no exceptions to any principle. A rule can easily be ignored by changing conventions. A theory may have exceptions that often suggest that the theory is incomplete, but they will not necessarily disprove it. A law cannot be ignored or have exceptions within the limits set by the principles of nature (remember that these are statements about the limits of nature). Outside these limits, all laws are subject to the “law of exceptions” – every law has exceptions, no exceptions. Consider, for example, Heisenberg`s uncertainty principle.

It describes the limits of how much information you can have about something. Within this limit, laws are immutable, but if you consider (for example) distances or time scales below the Heisenberg limit, processes that violate the law of conservation of energy are allowed. These are just principles that should never have exceptions. A principle usually has the form “All natural systems are subject to (given limits) with respect to (given intrinsic property)”. Usually, when someone says “law” or “principle,” they are referring to a general idea that applies to many different situations, but not always. More speculative ideas are usually called theories, but the use of the word “theory” does not always mean that an idea is speculative. But what is the difference between a law and a principle? Physics Stack Exchange is a question and answer site for active researchers, academics and physics students. Registration only takes one minute. Basically, I understand the difference between a “theory” and a “theorem,” but I`m pretty confused when it comes to “law,” “rule,” and “principle.” .