What is Laws of physics: Definition and 98 Discussions

Scientific laws or laws of science are statements, based on repeated experiments or observations, that describe or predict a range of natural phenomena. The term law has diverse usage in many cases (approximate, accurate, broad, or narrow) across all fields of natural science (physics, chemistry, astronomy, geoscience, biology). Laws are developed from data and can be further developed through mathematics; in all cases they are directly or indirectly based on empirical evidence. It is generally understood that they implicitly reflect, though they do not explicitly assert, causal relationships fundamental to reality, and are discovered rather than invented.Scientific laws summarize the results of experiments or observations, usually within a certain range of application. In general, the accuracy of a law does not change when a new theory of the relevant phenomenon is worked out, but rather the scope of the law's application, since the mathematics or statement representing the law does not change. As with other kinds of scientific knowledge, scientific laws do not express absolute certainty, as mathematical theorems or identities do. A scientific law may be contradicted, restricted, or extended by future observations.
A law can usually be formulated as one or several statements or equations, so that it can predict the outcome of an experiment. Laws differ from hypotheses and postulates, which are proposed during the scientific process before and during validation by experiment and observation. Hypotheses and postulates are not laws, since they have not been verified to the same degree, although they may lead to the formulation of laws. Laws are narrower in scope than scientific theories, which may entail one or several laws. Science distinguishes a law or theory from facts. Calling a law a fact is ambiguous, an overstatement, or an equivocation. The nature of scientific laws has been much discussed in philosophy, but in essence scientific laws are simply empirical conclusions reached by scientific method; they are intended to be neither laden with ontological commitments nor statements of logical absolutes.

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  1. KobiashiBooBoo

    B Observable universe and overlapping spheres

    We observe a very distant galaxy, thanks to the JWST. That galaxy has the same laws of physics as we do. Now imagine yourself in that galaxy, in your observable sphere of the universe, using your own telescope, looking in a direction opposite our current one from earth. Would we be able to...
  2. S

    I Topological phase transitions for the whole Universe...?

    Physicist Grigory Volovik has put forward some ideas about the universe undergoing a topological phase transition (especially in the early stages of the universe). He published a book called "*The Universe in a Helium Droplet*" where he explained his ideas. You can find a brief discussion here...
  3. S

    I Models where all symmetries would be approximate?

    I found this interesting discussion here in Physics Forums (https://www.physicsforums.com/threads/are-all-symmetries-in-physics-just-approximations.1005038/) where the topic of all symmetries being approximate is discussed Is there any model (for instance, some type of spacetime metric or...
  4. S

    I Non-homogeneous and anisotropic metric and laws of physics...?

    In this popular science article [1], they say that if our universe resulted to be non-uniform (that is highly anisotropic and inhomogeneous) then the fundamental laws of physics could change from place to place in the entire universe. And according to this paper [2] anisotropy in spacetime could...
  5. S

    I My spectacles defy the laws of physics

    For curiosity (obviously not having anything better to do with my time) I turned my spectacles the ’wrong way round’ - so that they were upside down, with the arms pointing outwards - and looked though them. (This gives the correct lens for each eye of course.) The image is noticeably worse...
  6. Ahmed1029

    I Reflection, refraction, and Snell's law

    Where do the laws of reflection, refraction, and Snell's law come from in geometric optics? Are they derivable from basic laws of physics?
  7. M

    B Questions about Feynman's contrasting Definitions and Laws in physics

    https://www.feynmanlectures.caltech.edu/I_10.html (From the paragraphs after equation 10.5) 'It is not just a definition to say the masses are equal when the velocities are equal, because to say the masses are equal is to imply the mathematical laws of equality, which in turn makes a prediction...
  8. S

    I If the Universe had a different size, would physics change?

    I found an article by James Bjorken (https://arxiv.org/abs/hep-th/0210202) which argues that universes with different size would have different physics (like different Standard Model parameters). When applying this reasoning to our own universe, Is this pure conjecture? Or is there some truth...
  9. S

    I Are there types of spacetime where no symmetries are valid?

    We derive the most basic laws of physics from several fundamental symmetries (those from Noether's theorems, gauge symmetries, Lorentz symmetry...). But are there any types of spacetime where no symmetries, no matter how fundamental, would be valid? Any special metric, geometry or shape?
  10. S

    I Could the Lorentz symmetry be theoretically broken in vacuum?

    In this paper [1] which considers the possibility that the Lorentz symmetry could be broken, at page 4-5 the author says: "We now introduce a Higgs sector into the Lagrangian density such that the gravitational vacuum symmetry, which we set equal to the Lagrangian symmetry at low temperatures...
  11. S

    I Varying laws of high energy physics in inflation?

    I am have some questions that have arisen while reading an old but interesting article by Andreas Albrecht [1] that cites an article by Andrei Linde in the 90s on cosmic inflation [2]...Albrecht's paper is related to his ideas on "clock ambiguity" in which he proposes that the laws of physics...
  12. S

    I Changing or breaking the most fundamental laws and symmetries?

    There are some theoretical processes (like vacuum decay in quantum field theory) that could change the physical constants of the universe. Similarly, in inflation theory, various models predict that multiple regions that would stop inflating would become "bubble universes" perhaps with different...
  13. S

    A Branes with any number "n" of dimensions and laws of physics?

    I had a few questions about this paper by Nima Arkani-Hamed, Georgi Dvali and Savas Dimopoulos (https://arxiv.org/abs/hep-th/9907209) which is closely related to the concept of branes (https://en.wikipedia.org/wiki/Brane) 1. The authors of the paper mention that the branes in the model could...
  14. Thytanium

    I Are Newton's Laws of physics compatible with thermodynamics?

    Good day friends. I want to know and ask you if Newton's laws are incompatible with thermodynamics.
  15. S

    A Any model or theory in physics akin to "Law without law"?

    When trying to explain from where did all the laws come from, John Wheeler proposed the anaphorism of "Law without law". He proposed that at the "beginning" there were no laws whatsoever, only pure chaos, and that they emerged from randomness and chaos when our universe was created. In his own...
  16. S

    I Are the Laws of Thermodynamics still applicable in modern physics?

    Hello All We have Newton's Laws of Motion, which have been superseded by Einstein's Theory of General Relativity. Who determines what's a Theory and what's a Law? best regards ... Stef
  17. S

    I Are there other renowned physicists who believe in evolving laws of physics?

    The Canadian physicist, Lee Smolin proposed in the 90's that laws of nature may evolve and change over time. He begun proposing that only the constants of nature would evolve, while the most fundamental laws would remain the same, but recently he has change a little bit his ideas and has...
  18. S

    I Models and theories of laws of physics emerging from chaos?

    Some physicists (like John A Wheeler, Holger B Nielsen or Ilya Prigogine) have proposed that all the laws of physics (including the most fundamental ones) emerged from a primordial chaos (for example, in the case of Wheeler, he proposed that laws of physics emerged from an initial random and...
  19. S

    I Is there any inflationary model without a fundamental theory?

    Cosmological inflationary models are general models in the sense that they could be applied to a variety of fundamental theories. Most physicists working in inflation assume that there is only one (but yet unknown) fundamental theory which through inflation would produce multiple regions or...
  20. S

    I Laws of physics from initial conditions?

    Are there any models, theories or physicists who propose that the fundamental laws of nature come from the initial conditions? Are there any physicists who propose that the most fundamental laws of physics emerged from initial conditions at the origin of the universe? And according to this view...
  21. S

    A Different symmetries or no symmetries in string theory?

    I was reading the book "A Fortunate Universe" by Geraint Lewis and Luke Barnes and something caught my attention: At page 195 the authors say that universes with different symmetries could be modeled and they would have dramatic results like having different conservation laws. I asked Mr...
  22. S

    A What would it mean if symmetries in physics would not be fundamental?

    Physicist Joseph Polchinski wrote an article (https://arxiv.org/pdf/1412.5704.pdf) where he considered the possibility that all symmetries in nature may not be fundamental. He says at page 36: "From more theoretical points of view, string theory appears to allow no exact global symmetries, and...
  23. S

    A High energy symmetry breaking and laws of physics?

    In some models of the beginning of the universe, like for example in chaotic inflation, space would stop expanding in some points, creating Hubble volumes that could experience different spontaneous symmetry breaking, which would result in different properties, such as different physical...
  24. J

    If you break the laws of physics, do you go to jail?

    If you break the laws of physics, do you go to jail?
  25. S

    A Can there be a lawless universe (according to Hawking)?

    I got a phrase from a book that Stephen Hawking and his daughter Lucy Hawking published in 2011. The book is "George and the Big Bang" which is a science fiction book prepared for children. I read a phrase on that book that interested me. It was: "Perhaps there are many universes, each with...
  26. S

    I Could fundamental laws change in Dirac's Large Numbers Hypothesis?

    Paul Dirac proposed a hypothesis called "Large Numbers Hypothesis" (https://en.wikipedia.org/wiki/Dirac_large_numbers_hypothesis), where he basically stated that, if he was correct, laws of physics would change with time. But what about fundamental laws and constants? (Not only 'effective'...
  27. J

    B Quantum Entanglement Violates the Laws of Physics

    The problem with this is that only one push's worth of energy was expended. One push's worth of input cannot produce two push's worth of output, for this would violate the law that says you can't get more movement out of something than the amount of force you exert onto it (to put is very...
  28. G

    How would you adapt the laws of physics for two dimensions of time?

    So imagine there are now two dimensions of time, instead of the one dimension which we're used to. The laws of physics which we're used to won't make anymore sense unless they're adapted for the two dimensions of time. How would you adapt them?
  29. D

    Explain what laws of physics were violated in this scenario....

    Homework Statement From reliable information, once Baron Münchhausen was stuck in a swamp, he pulled himself out of it by the hair. What laws of physics did the baron break? (Find the answer analytically) Homework Equations None. The Attempt at a Solution Well, I think that he breaks the...
  30. T

    Foundation of the laws of physics

    The “Laws of Physics” arise from and reflect the lawful regularity of the physical universe. Absent that underlying lawful regularity there would be no laws of physics.Is it true that the laws of physics are descriptive of that underlying order, but are silent on the nature of its origin, of how...
  31. I

    News There are no laws of physics theres only the landscape.

    In my post that I have been ranting on trying to figure out how to solve things on everyday occurrences. Which was titled "Mass of a Piston" That is to say, can you use physics on the spot to calculate a golf swing that projects a ball off a cliff that you have never seen before. You don't know...
  32. S

    A Multiverse theory with impossible universes?

    I found an article written by physicist George Ellis that confused me a little. http://citeseerx.ist.psu.edu/viewdoc/download?doi= At some part, he says: 3.2 Non-uniqueness: Possibilities There is non-uniqueness at both steps. Stating “all that is possible...
  33. TheQuestionGuy14

    B How do we know our laws of physics are correct?

    I was just curious to know, how do we know our laws of physics are correct? How do we know the laws about time or space aren't overruled (we say time flows forward, but how do we know that it can't skip back or flow backwards), because we just haven't seen it or can't perceive it?
  34. S

    I Why are the laws of physics what they are?

    In physics, at least at my level of knowledge and understanding, a lot of the most basic facts of reality start to seem a bit arbitrary. Mostly this seems to be the case with the various universal constants such as the speed of light or plank's length or the gravitational constant. So what I...
  35. kolleamm

    B Do multiverses follow the same laws of physics?

    Recently I was watching Lawrence Krauss on YouTube talking about the universe originating from empty space, which seemed to make sense when he described that nothing isn't really nothing. Then he later in the video he asked the question of whether multiverses would also follow the same laws of...
  36. TheQuestionGuy14

    B Are the Laws of Physics consistant and universal?

    Was just curious if there are any holes in the major laws of physics making them not consistent. Or could they change over time? And are they universal, as in, are they the same in all regions of the universe?
  37. Vagulus

    Were the Laws of Physics designed for torture?

    Here is an issue to distract the scientific mind for a restful Festive Season. This is a gumnut. They fall from trees round here (Perth, Western Australia) by the tonne. They are quite small (about 9 mm in diameter) and the pointy end is sharp. You do not want to stand on the pointy end...
  38. S

    B Can energy change physical laws?

    Could huge amounts of energy change the universe's nature (fundamental physical constants, laws, dimension)? Could it change it so much that it would enable our universe to be a multiverse of level 1, 2, 3 or 4? https://en.wikipedia.org/wiki/Multiverse
  39. S

    A Could vacuum decay fundamentally change our universe?

    If the universe suffered a false vacuum decay, would this change physical laws? Could it change the universe so much that it would allow our universe to be a multiverse of level 1, 2, 3 and 4? https://en.wikipedia.org/wiki/Multiverse
  40. Delta2

    I Invariance of the laws of physics

    The invariance of the laws of physics in space-time is a corner stone of physics and all science. A.Is this an axiom or can be derived from other more fundamental axioms? B. Are there any books that discuss how science could be if the laws of physics could be changed (for example if we could...
  41. Pushoam

    I Laws of physics and inertial systems

    It is not the laws of physics, but the forms of laws of physics which are the same in all inertial frames. Comment."The forms of laws of physics are the same in all inertial frames" is a necessary condition (put by scientists ) to get satisfied by something which has to be called as a law of...
  42. M

    Exploring the Boundaries of Physics: A Scientist's Journey

    New here figure when i make my inventions in the near future i might as well put it somewhere where it's easier to study if you want to know a little about me my favorite saying is "The laws of physics are not just boundaries of limitation but a guideline to surpass limitations." and I'm not...
  43. Sullivan Stockwell

    B The Early Universe and the Laws of Physics

    I've heard it said multiple times on here and elsewhere that as we "wind back the clock" of our Universe and the Big Bang that our laws of physics kind of begin to fall apart, in a sense. If this is true, can anyone explain exactly which laws become more difficult to work with, and why? Thanks.
  44. T

    I Do laws of physics apply below the event horizon?

    Do laws of physics apply below the event horizon? It appears as if black holes had such gravity as to have an escapr velocity higher than c, which means that things are pulled inwards at higher speeds than the speed of light. Or am I overlooking something?
  45. V

    A Geometry and integral laws of physics

    Reading the English translation of Einstein's seminal paper on GR. http://einsteinpapers.press.princeton.edu/vol6-trans/90?ajax This paragraph below on p78 doesn't make much sense to me. Could you provide a second English translation or even adding math notation. "Before Maxwell, the laws...
  46. Akshat

    Exceptions to the Laws of Physics: Newton's Third Law

    I've been noticing that there are exceptions to every scientific law. For Example, with Newton's First and Second Laws are totally invalid at the quantum level, but I'm failing to find such an example for Newton's Third Law. Is anyone able to help me?
  47. Xico Sim

    I Method to know if a reaction is allowed

    Hi guys. This is my first post here. Here it goes. I'm attending an introductory course on particle physics. By now, I'm supposed to know how to find out if a given reaction, say νμ+p→μ++n (for example) is possible or not. Unfortunately, the rules by which a reaction must abide are still foggy...
  48. d w

    What are some common misconceptions about Newtonian mechanics?

    I like basic math and physics, I am able to understand them enough to talk about them so that is what I talk about mostly. I like to consider weird theories and destroy them if I can, if I can't I keep them around. Talk to me in math and physics and use analogies when possible, that is what I...
  49. bcrowell

    A Laws of physics in noninertial frames

    In a previous thread, the OP asked for answers at the "I" (i.e., undergraduate) level to the following question: S/he received a variety of contradictory answers, and the discussion may have been hindered by attempts to present more sophisticated mathematical ideas as the appropriate level...
  50. Stephanus

    Understanding the Laws of Physics in SR: Questions & Answers

    Dear PF Forum, Before I go further, I'm stuck and need clarification. Two postulates of SR 2. the velocity of light is the same for all inertial observers. Okay..., this one I can understand, at least can grasp. 1. the laws of physics are the same in all inertial frames of reference; What laws...