Physics Definition and 987 Threads

P=mv *momentum equals mass X velocity. Light particles or "photons" are said to be "massless". And yet they have momentum. How is that possible? (p.s. I used to know the answer)

I’m sure I’m not the first to ask about this but I could use some advice from the internet: I am a sophomore lost in the world and somewhat recently decided I was going to major in physics with my eyes on grad school. I am on track to get a math minor but I am weighing the trade-offs of picking...

I'm currently a college freshman studying physics. The only previous research experience I had was a virtual one with the EPA on things not really related to physics (it was about 3D printer emissions). I'm trying to look for something for the summer and I've already applied for a bunch...

At first, I tried to calculate the heat energy required by doing this: I realized I should calculate heat energy separately instead of grouping glass and water together so I did this: But the answer is supposed to be 6.29 x 10^4. I don't know how to solve this. Can anyone help please? Thank you

I am working through the wonderful book called University physics by Young & Freedman, it’s seems like a thorough introductory textbook. My question is, instead of waiting till the end of the book to branch out into more advanced textbook that focus on mostly one topic for example classical...

I assume you people are all so preoccupied with all the hard sciencemastering going on that you're missing out on the more basic [sic] research abundantly present under the "Popular Physics" header at arxiv.org. Particularly: Futurama, Marvel's Supervillains and Boltzmann Brains. I'm not...

Without trying to sound too wistful, back in school there was a good selection of miscellaneous problem books like Professor Povey's perplexing problems, 200 Puzzling physics problems, Irodov, Jaan Kalda and all the olympiad stuff, etc. Do there exist equivalents of these puzzle books aimed at a...

Hi, The solution for this question is thermal energy lost= thermal energy gained 0.200x450x(300-T)=1.0x4200x(T-20) T=26 degrees celcius. However, I am struggling to grasp why (300-T) is used. I have always known a change in something to be final - initial. Therefore change in T= Final-...

Suppose there is a nonprofit that wants to order a piece of research in theoretical physics. The research is rather small; it consists in considering an issue and writing a 8-10 pages article. The physicist to do the research will be from a high income country; he/she should be an experienced...

I have a doubt regarding the basic function of vectors and scalars in physics- What is the guarantee that every quantity(measured) in physics can be classified as either a vector or a scalar, and that while performing operations on said quantities, they will obey the already established rules...

in classical physics, when a charged particle oscillates, it emits an electromagnetic wave, and the frequency of the wave depends on the frequency with which the particle oscillates. But in quantum physics, when an excited atom emits a photon, the energy of the photon depends on the magnitude of...

[Mentor Note -- thread spun off from a thread in the Advisor forums] Both Feynman and Einstein have famous quotes about explaining physics concepts to those not well schooled in physics.(freshman undergrad and a six year old respectively). Yet both hedged a bit on this: Einstein Things should...

The correct solution uses angles and trigonometry. My solution is as following: - Suppose the forces exerted by friends 1 and 2 are F1 and F2 respectively. - There are no net force in the x-direction, so F(total x) = 0. - F(total y) = F1 + F2 - mg = 0 (initially). Rearranging gives g =...

Ive been reading University physics by roger freedman, I’m on section 3 motion in 2d. I can solve most of the problems ag the end of the chapter, or at least understand the solutions. But there is a small extra section called challenge problems. There’s only 3 but I found them very difficult...

Greetings! I'm a 4th year physics undergrad looking for a program/tablet that I can write/type equations into and type (or dictate!) sentences into for clarification. I have Word but the equation editor is clunky. I also tutor so being able to screenshare a large area in Zoom and easily...

Summary:: I'm looking for physical models/phenomena that can be replicated in the art of creating sound/music. Hey everyone, I'm an experimental music composer/researcher who just got addicted to watching Youtube videos on quantum physics. The entire field absolutely fascinates me now. The...

When creating sensors to record images from much larger wavelengths of radiation, must the sensor be at least as deep as the wavelength, or is there a way to make it more compact?

TL;DR Summary: Gerald Burns's book: Solid State Physics: is it good for begginers or there are best books? Hello, I am looking for the best book to study solid state physics for begginers. Some one recommended Gerald Burns's book: Solid State Physics. So, what is your opinions about this book...

Just to keep this from being a long post: I went to a local CSU for Materials Science and Engineering in the fall of 2018 after graduating high school in the spring of 2018. I really like learning about everything that makes up the world around me, and why things are the way they are, and in...

Hello all! I have been taking an academic break from school for certain mental health reasons that I won't waste your time talking about. Now, I am only a freshman in college. My school's physics department currently offers 2 majors: Physics and Physics/Astronomy. Obviously, I have lots of time...

I am about to start a physics with theoretical physics major, I've taken calculus before but I've not been satisfied with the "memorization of formulas" type books. I started to read Spivak and found it enjoyable, but since it's a major undertaking I am also concerned for the practical value...

Reif, statistical physics "The equilibrium macrostate of a system can be completely specified by very few macroscopic parameters. For example, consider again the isolated gas of ##N## identical molecules in a box. Suppose that the volume of the box is ##V##, while the constant total energy of...

An IQ of 120 is plenty good, but the average IQ of Physics and Astronomy majors is higher. It's even higher for brilliant theoretical physicists and Physics PhD holders. So is it possible, with enough hard work and dedication, that someone with a 120 IQ could become a theoretical physicist? Or...

Question is in file please these questions and send it to me Q1: A 2 kg piece of cheese is placed on a vertical spring of negligible mass and force constant k= 2000 N/m that is compressed 16 cm. when the spring is released, (I) How high does the cheese rise from this initial position? (II)...

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I tried to find states in direct method using ##\frac{E}{E_0}=\:nx^2+ny^2+nz^2## and ##100\:<nx^2+ny^2+nz^2\:<\:136## But it was too long, found it using phi approximation there are around 300 energy states, and Python find around 271 states using direct method but I need manual or recursive...

how does the first step use mean value theorem? I don't get it , can anyone explain , thanks.

I am on my first year of my master's degree in nuclear and particle physics, and right now i am ending my first semester, where i decided to take a course in physics of semiconductors. As i end this semester i start to wonder if there was any use in learning about this subject, as it seems like...

I stumbled across this series of 28 lectures by Dr Frederic Schuller of the university of Twente whilst searching for lectures about Lie theory. Having watched through lectures 13 to 18, I think they are simply superb (of course I'm assuming the rest are of similar quality). I only wish he would...

One is fr. worker at U. Karlsruhe, another fr. Israeli res. The latter argued findings can be integrated into classical physics.

Summary:: Lottery physics- balls placement and positions Hi all, I am not a Ph.D. in physics or even close to that, I only had some physics classes when I was at high school . the thing is that I like to examine things. I came across the lottery one time in my life and heard many assumptions...

I am 18 and currently in the middle of taking a gap year from high school to college. I am going to college this fall, and I want to go into college with a better grip on what I want to do than I have now. I absolutely love physics, science, and math. I also have a huge attachment to the idea of...

Summary:: I am learning particle-in-cell (PIC) python 3X code. PIC currently represents one of the most important plasma simulation tools. It is particularly suited to the study of kinetic or non-Maxwellian effects. I am learning particle-in-cell (PIC) python code. PIC currently represents one...

Springer has a 50% currently till the end of December. I know plenty of good math textbooks from Springer, but what are some good physics books? Particularly at the undergraduate level.

An interesting article about theoretical physicist Chris Isham (by Michael Duff) has been posted on the arXiv, https://arxiv.org/abs/2112.13722 Combine this with (from "Group Theory for the Standard Model of Particle Physics and Beyond" by Ken Barnes) Isham has written two books that I quite...

Hello, I am ready to apply to grad schools and would like to have a few insurance schools just in case. What are the easiest physics fields (biophysics,nuclear physics...etc) to get into a PhD for? Regards,

I am an avid physicist and I am most interested in Quantum Mechanics, Particle Physics, and relativity in the universe.

This is the beginning of an online reading course of the book "Statistical physics" by Reif, volume 5 in the Berkeley physics course, using PF. We'll start with chapter 3 and loop back to the initial 2 chapters if necessary. All questions should be specifically about what is written in the this...

I was in graduate school for an Applied Physics PhD program for 3 years, where I got my Master's and took all the required classes for the PhD. I left because I wanted to try my hand at teaching, and I LOVED it. Now I am 34 years old, and I am wondering if there is any possibility of going back...

Rewarding career after physics graduation - Mysterious money ? ====================================================== Thanks for your response to my threads. This is an interesting forum to seek an insight on this subject. I am surprised by recent piece . Physics professor mysteriously sent...

Hello, I'm about to graduate with undergraduate degrees in physics and computer science. I'm considering applying to graduate school because I want to do physics research, but I also need a decent job at the moment (I don't believe that graduate students get paid more than a survival wage). Is...

Hello, I'm a first year university physics student, and I'm having a hard time understanding the material, which badly affects my grades. I'm posting this thread hoping to get some tips for how and where to learn physics(reading materials, online lectures) aside from my university lecture, which...

Advice for useful math books for a college student studying physics

Such as Lisa Randall, Fabiola Gianotti, Shirley Ann Jackson, Ingrid Daubechies, Donna Strickland or Jocelyn Bell Burnell

Summary:: I’m a beginner trying to get into Quantum Physics, and want some good resources (e.g. books) to get me started. Hi everyone! I’m a beginner trying to get into Quantum Physics, and want some good resources (e.g. books) to get me started. I have a very basic knowledge of physics (10th...

Hi! I’m @schrodingers_cat, and I am new to this forum. While I currently have a limited knowledge of physics, I am excited to learn more about the field. I am interested in the idea of researching quantum physics, however I do not know where to get started. I hope this forum helps me in my...

The mathematician and mathematical physicist Alain Connes has expressed in many occasions that he is a Platonism and he thinks that mathematics itself does exist in the same level (or even in a "stronger" level) as physical reality. This is very similar to Max Tegmark's hypothesis of the...

This is rather a philosophical question, so I will limit it to a topic in physics. I'm interested in knowing your opinion, and perhaps your thoughts on how physics is being developed and progressed today.

Namashkar everyone. This is Annwoy Roy Choudhury from Kolkata, West Bengal, India. I am a first-year student at the Indian Institute of Petroleum and Energy, Visakhapatnam Chemical Engineering under the Indian Institute of Technology, Kharagpur. As everything got delayed here because of the...