What is Physics: Definition and 993 Discussions

Physics (from Ancient Greek: φυσική (ἐπιστήμη), romanized: physikḗ (epistḗmē), lit. 'knowledge of nature', from φύσις phýsis 'nature') is the natural science that studies matter, its motion and behavior through space and time, and the related entities of energy and force. Physics is one of the most fundamental scientific disciplines, and its main goal is to understand how the universe behaves.Physics is one of the oldest academic disciplines and, through its inclusion of astronomy, perhaps the oldest. Over much of the past two millennia, physics, chemistry, biology, and certain branches of mathematics were a part of natural philosophy, but during the Scientific Revolution in the 17th century these natural sciences emerged as unique research endeavors in their own right. Physics intersects with many interdisciplinary areas of research, such as biophysics and quantum chemistry, and the boundaries of physics are not rigidly defined. New ideas in physics often explain the fundamental mechanisms studied by other sciences and suggest new avenues of research in academic disciplines such as mathematics and philosophy.
Advances in physics often enable advances in new technologies. For example, advances in the understanding of electromagnetism, solid-state physics, and nuclear physics led directly to the development of new products that have dramatically transformed modern-day society, such as television, computers, domestic appliances, and nuclear weapons; advances in thermodynamics led to the development of industrialization; and advances in mechanics inspired the development of calculus.

View More On Wikipedia.org
  1. DennisN

    Physics experiments that changed the world (video)

    If you enjoy both physics/science and history like me, you may enjoy this video from the Royal Institution. It's about groundbreaking experiments (no theoretical physics); X-rays, particles etc. I'm only 45 minutes in so I haven't seen the entire video yet, but I wanted to share it...
  2. F

    Career Direction after rough end to Physics degree

    I recently graduated last year with a BS in Physics. To say that it was rough would be an understatement. I started off my degree very well, getting nearly all A's and A-'s. My performance would decline for various reasons, though mostly due to mental health which spiraled and became a bad...
  3. Manuel Cardoso

    Calculus book for 14 year old physics enthusiast

    Hello, I'm trying to learn calculus, what books would you recommend? For a beginner.
  4. Y

    Wanting to get an Online Bachelor's Degree in Physics

    Can I get an online bachelor in physics because I live in a country with law education rank in natural sciences
  5. Glenstr

    Lake Hydrology Physics: Observing Shoreline Changes

    I live on a lake, and have for almost 3 decades now. Every year I watch shoreline changes, from year to year and shorter timespans, sometimes just days. The lake is large in surface area at 236 km2 (91 sq mi), but with an average depth of only 28' probably relatively small in volume for its...
  6. A

    Programs Advice for majoring in theoretical physics

    I am going into my senior year of hs next year and I am meditating on what I should major in. I have a keen interest in physics but also a love of math. The field in physics I would like to major in is theoretical physics/astrophysics, and the pure maths I am interested in are diff, algebraic...
  7. H

    A Is there a lost information paradox for quantum physics?

    Hi Pfs, When Stephen Hawking proposed the idea of black hole information it appeared that information could be lost. it was a problem in GR which is a dererminitic theory. Knowing initial data and Hamiltonian tells you what was and will be. It is not the case in quantum physics. things evolve...
  8. S

    JavaScript Physics engine with "angular stiffness" at joints

    I have been experimenting with a minimal "toy" physics engine for JavaScript, called verlet.js but now I want to switch to a more versatile and feature rich engine. One feature I would like to use is the ability to assign a reference angle to a pair of segments (i.e. links, i.e. distance...
  9. TGV320

    Studying Should I first study the math or math and physics at the same time?

    Hi everyone, After completing high school, I will enroll this fall at a 3 year technical school in China studying industrial robotics, but I still plan on getting into an undergrad physics program at a later time. (Some colleges can allow a transfer to their undergrad program after technical...
  10. J

    I AI Discovers Alternate Physics - What Do You Think?

    There is a recent article, see below, where an AI equipped computer viewed a classic physics experiment with a double pendulum. The AI algorithm determined some different variables to describe the motion. One problem with this is the AI suggested 4.7 variables - that I don't understand - but...
  11. I

    What is the approach to forum discussions on this science forum?

    I was searching for some science forums online yesterday, so I could join one to learn and contribute back. The Forums that operate like early 2000 ones, and their goals are more aligned toward users than creating content for monster spiders. I am glad that I have ended up here now. I visited a...
  12. cemtu

    Solid State Good Condensed Matter Physics Books and Semiconductor Physics Books

    Can you please recommend me some condensed matter physics study books and semi-conductor physics study books? Much Appreciated!
  13. J

    B Are there any unsolved physics problems?

    I was curious if there were any unsolved physics problems and if so which is the most important or intriguing. I have been meaning to contribute to the scientific field in some capacity and I think solving an unresolved issue in physics could do just that. Thanks!
  14. bigmike94

    How much of first year Intro physics do you remember?

    Summary: I am just curious I know 🧐 Im coming up the end of intro university physics mechanics chapters. It has been quite enjoyable, especially chapters on energy, momentum and fluid mechanics. There’s so much information packed into these chapters though. I am wondering what was your...
  15. G

    Programs Evaluating Physics Master's Programs

    If you were to rank potential components of a Physics Master's program, which do you think are the most important for preparing you for a PhD: courses, research, project report, thesis? Also I've seen programs ranging in duration from as short as 9 months all the way up to 2 years. How much...
  16. A

    Exploring the Calculus of Area: A Journey Through Space and Physics

    Umm.. yes I think. Not sure what I’m getting into, but the pursuit of knowledge eh? Teach me please. I’m just here to share thoughts and bounce between fellow big brains. Haha this strange. Good luck!
  17. bbbl67

    I Strange Star Physics: Existence of Baryons?

    I wasn't sure if I should post this in astrophysics or particle physics, so I'll try particle physics first, mods feel free to move it to a more appropriate forum. So I was wondering if hypothetical Strange stars exist, would the strange quarks arrange themselves into baryons (i.e. Lambda-0 or...
  18. S

    Questioning a Physics Problem: Taking Different Reference Frames

    for (a): I basically got the correct answer, but when resolved with taking different reference lines/frames I got a different answer. for the 1st attempt I took y = 0 (for both ##U_{el}## and ##U_{grav}) at the position where the spring is uncompressed. for the 2nd attempt (with wrong solution)...
  19. S

    I Exploring the Impact of Non-Stretchy Mat Materials on Trampoline Physics

    Trampolines are in effect coupled springs, with the mat being the much softer spring generally. E.g. On my Acon, when jumping about 1 meter, there is a max cone of depression about 60 cm deep and 1 meter across (1 meter point has a depression of only about 10 cm) At this same point the 160 or...
  20. malawi_glenn

    High Energy (free kindle) Gauge Theories in Particle Physics by Aitchison & Hey

    Free Kindle via Amazon, both part 1 and part 2 Part 1: https://www.amazon.com/dp/B00OD49Z96/?tag=pfamazon01-20 Part 2: https://www.amazon.com/dp/B00OD49Z00/?tag=pfamazon01-20 Enjoy
  21. XcgsdV

    Courses Is Pure Mathematics required to be a top-tier Physics student?

    Hey y'all, I'm starting college as a Physics major this fall and I started working through Steve Warner's Pure Mathematics for Beginners in my downtime because I love the math courses I've had, wanted to learn more about proofs and how those things came to be, and most importantly had nothing...
  22. atyy

    High Energy Mathematics for Physics by Adam Marsh

    Adam Marsh's Mathematics for Physics is available online. Subodh Patil recommends the algebraic topology section, and as a primer to Nakahara.
  23. 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...
  24. P

    Undergraduate modern physics and condensed matter physics courses

    Do they really teach and help anything? I am taking them for my nanoengineering undergraduate program. The textbooks are solid state physics by j r hook and concepts of modern physics by mcgraw hill and r b singh introduction to modern physics and introduction to quantum mechanics by david j...
  25. T

    Engineering Aerodynamics textbook at the graduate physics level

    Hello, Can someone recommend me a good textbook to (self-)study aerodynamics, optimally with focus on aircrafts. I am a graduated student in physics and therefore familiar with all the basic concepts of fluiddynamics and calculus. But, apart from that, I have no further knowledge in the field...
  26. W

    Could Localised Variations in Physics Occur?

    Hi I'd be grateful for views / thoughts on whether there was potentially a particular event, change, set of circumstances etc which could cause localised variations in the laws of physics (as we understand them). For example, you could be traveling somewhere, when you unexpectedly chance upon...
  27. B

    Switching from Biology undergrad to Physics grad....

    I will try to keep this concise. I have always loved physics, but was convinced by my parents to pursue biology for career in medicine. Over my undergrad, it really became clear to me that I love physics, and want to pursue a career in the field (a Master's, and then a PHD). I am currently in...
  28. Bertin

    I Nuclear Physics: Yearly Time Measurement

    Halves-lives and average lifetimes, when studying nuclear decay, are often expressed in years even though years are not standarized, at least in SI (as far as I know). Borrowing the convention from astronomy and astrophysics, I usually take 1 \mathrm{yr} to be equal to 365.25 days of 86400...
  29. R

    Physics Does a datascience job help in applying for PhD or physics scholarship

    I have a math degree and currently pursuing a BS in physics, I've been offered a job as a data scientist with occasional machine learning stuff. 1) Would this be helpful for my career in physics? If yes then how? (I'm aware that machine learning is being used in various areas of physics, but...
  30. modellatore

    Studying Theoretical Physics Study Path (it's about tetrads....)

    I'm a graduate theoretical physics student at the (almost) end of his master's degree with a fairly varied curriculum, as I attended both QFT (and sub-courses on qed qcd etc) and GR courses. However in my latest intro to quantum gravity classes I familiarised with tetrads and, after a lot of...
  31. Bertin

    Applied Bibliography on integration and ODE/PDE solving techniques for physics

    Hi, you all, I open this thread to ask for any recommendation concerning integration as well as ODE/PDE solving techniques for physics. I love mathematics, and I usually read material on pure mathematics (most notably abstract algebra and a bit of topology) but here I'm more interested in the...
  32. LCSphysicist

    Is there anything such as "Magazine of Physics problems"?

    The question is on the title. I was just thinking if exist some magazine on physics and maths whose only focus is to publish interesting problems and solutions?
  33. J3J33J333

    Choosing Physics or Electrical Engineering

    Hello, I'm trying to decide between physics and electrical engineering. I like building electrical stuff, and I like solving physics problems, but my main goal is to try to build power systems that integrate things like what can be found in this paper https://arxiv.org/abs/1401.0520. I would...
  34. P

    Why I Love Physics: A Personal Reflection on the Fascinating World of Science

    Summary: I always feel so satisfied when I self-study physics. It takes me time to truly appreciate what I'm learning when I'm under the pressure of university exams, but eventually when I understand it, I love it too. However, I can't explain why I love it. Hey everyone, I appreciate this...
  35. Hurcane

    Answer the question about time of cooling of a ball

    Hello, I'm not sure if this is the right place to post my question, however I still want to know. Recently, my teacher asked me the following question: "In which of the cases will the cooling time be the least: 1. the ball is suspended from the ceiling 2.the ball lies on a stand with a thermal...
  36. A

    Other Transitioning from Theoretical Physics to Software Dev: Steps & Difficulties

    I'm going into my final year of undergraduate theoretical physics. I have had a bit of a deviation in what I want to do and would really like to work in software development in the future. How difficult would it be for me to deviate from my current position and what steps should I take to to...
  37. 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...
  38. A

    B Space, Reflection: See Earth's Past in Mirror?

    can you theoretically put a mirror in space, take a photo of earth/dirts reflection and see it in the past?
  39. starpower1824

    I Physics behind making a mango milk shake

    Hi Folks!I have limited understanding of physics. I am trying to put into words the working principles of a mixer grinder, specifically for making a mango milkshake. So far, these are the steps I have come up with: Where am I wrong? What things have I gotten right? Thanks!
  40. P

    Environmental Physics - Radiative forcing effect on greenhouse effect

    I think part (a) is simple enough. Here is what I have done. (a) ##G=\sigma T^{4}_{s} - OLR## $$ =\sigma (294)^{4} - 160 = 254 Wm^-{2} $$ Part (b) is where I am confused. I think I'm supposed to apply the second relevant equation, in order to get the change in average surface temperature due to...
  41. Admiralibr123

    Physics Quantum Computing masters with Theoretical physics background

    I want to do a masters related to quantum computing from a physics background and my criteria for the place is: 1. A quantum computing group with experimental realizations and industrial ties. 2. A strong theoretical physics department with research in fundamental physics 3. A good chance of...
  42. G

    Admissions Do I have a chance at doing a physics Ph.D. in quantum ML?

    I graduated with Physics and Applied math degrees ~4 years ago with a really low gpa ~2.7 with research experience on CMS. I then completed a B.S. in Electrical Engineering last year with a 3.7 and a MS in Artificial Intelligence with a 4.0. Over the past 4 years I've been working as a...
  43. vegbird

    How Does Out of Phase Interference Affect Sound Perception?

    However, I do not understand it at all. Since two point sources at A and B are exactly out of phase. The mid point is a node where the amplitude is zero with zero oscillation. How can part (a) be zero? Should that be a quarter of the wavelength away from the mid point?
  44. R

    Can I manage to do both: Computer Science and Research in Physics?

    I'm a physics graduate from Delhi University, India. Aspirant of Theoretical Physicist . Right now , cleared Clerk in Govt. of India exam. About to get Job. I want to go for some top notch college in USA/Europe for Graduate physics. But also interested in Computer Software Engineering. Want to...
  45. Ian_at_YorkU

    Math Applied math with physics or applied math with comp sci?

    I'm currently pursuing B.Sc degree with major applied math and minor physics. Do you guys think is it worth to switch to comp sci as my minor in terms of employability?
  46. F

    Question about response time in PF threads

    Summary: How fast is the response time? Just a quick question? How fast is response time here?
  47. bigmike94

    Griffiths & University Physics by Young & Freedman

    I apologise if this has been answered before. I am about half way through the mechanics chapters in the classic University Physics I am wondering when I get to the chapters on electromagnetism is it worth reading them if I’m going to be reading Griffiths anyway? Would it be best just to get...
Back
Top