Matter Definition and 1000 Threads

  1. 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!
  2. afcsimoes

    B Dark matter, Higgs boson, gravity

    How are related these 3 concepts?
  3. A

    I Is the Bullet Cluster Evidence for or Against Dark Matter?

    Is the bullet cluster evidence for or against dark matter? I understand the explanation that it is evidence in favor of the existence of dark matter, and it convinces me. However, some argue that it is evidence against its existence? Why?
  4. ohwilleke

    A LQG Legend Writes Paper Claiming GR Explains Dark Matter Phenomena

    A new group of investigators are attempting something similar to Deur's work, which seeks to explain dark matter phenomena with general relativity corrections to Newtonian gravity is systems like galaxies. Deur's most similar publication to this one along these lines was: One thing that makes...
  5. mfb

    I Seminar: First LUX-ZEPLIN dark matter search results

    Today 16:00 UTC, in ~7.5 hours. Announcement, Link to Zoom meeting (why is this just an image on the website, not a link?) LUX-ZEPLIN (LZ) uses several tonnes of xenon to search for signals of dark matter interacting with it. It started taking data last year and it should easily set better...
  6. 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...
  7. C

    B What is the focus of Atkins' popular textbook in physical chemistry?

    What exactly is condensed here?
  8. P

    Other Does prestige of school matter for post-graduate research positions?

    Apparently I always find myself back here when bad things happen lol..like damn it’s been six years. Recent college graduate. I want to take a year or two working and honing my skills before graduate school. One, because I’m tired and need the break but also, two, for reasons beyond my control...
  9. lindberg

    I Relativistic Velocity Addition: Calculating Electron Speed

    If we imagine launching an electron wave in a reference frame S with speed v, should someone viewing the electron from frame S1, which is in inertial motion referring to S, use the relativistic velocity addition to calculate the speed of the electron?
  10. P

    I Ultra-high energy photon interactions with matter

    While this was inspired by another thread, I think the question is different enough that it can be asked separately. It's also more suited to this forum than the forum where the question that inspired this one was asked. Wiki gives four possible interactions for interactions of gamma rays with...
  11. B

    But in the end, it doesn't even matter

    in the grand scheme of things, our life is an imperceptible blip on the universe's timeline. we are insignificant, and we don't really matter. no matter how successful we are in life, or how our lives end, all our accomplishments will be erased during the heat death of the universe, along with...
  12. Philip Koeck

    I Phase velocity and frequency of a matter wave

    The relationships for matter waves are (see e.g. https://en.wikipedia.org/wiki/Matter_wave): λ = h / p and E = h f, where E = m c2 From this the phase velocity can be derived and we get vph = c2 / v. v is the group velocity, which is also the velocity of the particle. If I consider these...
  13. alexandrinushka

    B Sagnac effect for matter beams

    Hello, I have recently come across this article by Rizzi and Ruggiero, called "The Relativistic Sagnac Effect: Two Derivations": https://arxiv.org/pdf/gr-qc/0305084.pdf In section 3, the authors derive the Sagnac proper time difference for all beams (light beams and matter beams, including...
  14. G

    I Conventional description of the matter wave

    I have been working on a relatively simple problem. Just take a quantum wave function for which a physical requirement is that an arbitrary displacement of x or an arbitrary shift of t should not alter the character of the wave, and I want to find the state function solution. A possible guess...
  15. A

    B Rotation of Galaxies: Mass vs Dark Matter?

    Is it possible that galaxies are spinning faster than expected due to a particular configuration of the moving mass and not due to dark matter?
  16. S

    How to describe and discuss different solid matter states?

    The possible forms of solids can be more than just amorphous solids and crystalline solids. I tried a look at a couple of wikipedia articles and one of them showed descriptions of Plasticity, elastic, and Viscoelasticity, but those are not enough. I can only think to give some real world...
  17. K

    I Modified Newtonian Dynamics + dark matter sterile neutrinos or PBH?

    what about Modified Newtonian Dynamics + dark matter both right and both correct Are sterile neutrinos consistent with clusters, the CMB and MOND? Garry W. Angus arXiv:0805.4014 [ If no sterile neutrinos then Modified Newtonian Dynamics + primordial black holes Primordial Black Holes...
  18. S

    A Does Spacetime Absorb Energy in General Relativity?

    Some physicists prefer to explain the problem of conservation of energy in General Relativity by considering the gravitational potential energy of the universe that would cancel all the other energies and therefore the energy in the universe would be conserved this way. However, many other...
  19. Oldman too

    I A new concept in Low Mass Dark Matter detection

    Summary:We propose a search for low mass dark matter particles through momentum recoils caused by their scattering from trapped, nanometer-scale objects. The Paper linked details a novel concept for detecting WIMPs. I hope to see more work performed on the idea in the future...
  20. Godot_

    I Does Dark Matter Fall into Black Holes?

    Does dark matter(DM) fall into black holes(BHs)? IMHO it should... ...as it does interact with normal matter gravitationally. Once it's done so, does it add to the BH's mass? Again, IMHO it should. AFAIK it does have mass... Would that "quasi-convert" it to normal matter? ...after all, this...
  21. T

    A Which galaxies have the best studied evidence for dark matter?

    Unsurprisingly the Milky Way seems to have been studied a lot. We have really good luminous mass profiles (e.g. McMillan 2011) and increasingly accurate circular velocity observations for stars at various radiuses (e.g. Eilers 2019) meaning we can confidently infer dark matter models. So the...
  22. M

    B Big Bang Question -- How was the first matter formed?

    Big Bang singularity can never be solved, so Could the "big bang" have been an event where a large sum of highly-dense dark energy converted into mass, and in doing the result is like a nuclear explosion? Could the "big bang" just have been a large sum of matter where the core becomes super...
  23. MevsEinstein

    What has a shape but no volume?

    I was reading a Chemistry book when I read about the three states of matter. Everyone knows what they are, but I didn't know the simplest way to describe each of the three until I read this book. It said that a solid has a shape and a volume, a liquid has no shape but has a volume, and a gas has...
  24. mollwollfumble

    I Has anyone done a PPN formalism on Dark Matter? Or other non-GR?

    This thought surprisingly came from thinking about the definition of temperature and the symmetry breaking that separated time from temperature. Which led to thoughts about symmetry breaking that separated QM from GR. Which led to to the symmetry breaking that separated dark energy from baryonic...
  25. warhammer

    Classical Properties of Matter: A Modern Textbook

    Hi. This semester I have chosen "Properties of Matter" as my Physics Elective. The university syllabus generically prescribes texts by Newman & Searle to be studied in this regard but tbh I find them somewhat outdated. Below I have attached a small snippet of my course syllabus. I shall be...
  26. A

    B Light and the black matter (Dark Matter)

    Originally Answered: If light reaches the Earth from the sun, why is the space between the sun and the Earth dark? Because light illuminates surfaces, objects. Space is not an object, is the lack of matter. If you turn on a flashlight in a dark room you will illuminate the floors and the walls...
  27. C

    A Electron EM Field as Local Gauge Variation of Electron Matter Field

    The EM field seems to be required for for local gauge symmetry of the electron matter field under local phase variation. Following is a description (not my verbiage): There is a symmetry in physics which we might call the Local Phase Symmetry in quantum mechanics. In this symmetry we change...
  28. Zeal Faust

    B What Function Does Dark Matter or Energy Serve?

    I have read that almost 80 to 90% of our space is made of dark matter or Dark Energy. But what is the function of this Dark matter or energy? Is this something that binds stars, galaxies, etc? If not then what is the actual matter with Dark energy?
  29. Carlos Torres

    B Does the inertia of matter change in a black hole?

    Hi everyone, I was in physics class and the professor asked if the inertia of matter changes in a black hole and I would like to know if anyone has the answer to this question.
  30. P

    Difference between the words "material" and "matter"

    Summary:: Difference between the material and matter They look similar but I know they differ. What might be the possible difference between them? Let's discuss.
  31. CyclicAvatar

    PhD in condensed matter theory or theoretical cosmology

    Hi all, I just graduated from my master's program in theoretical physics. I did 60% of the coursework in high energy physics and rest in condensed matter theory plus a few experimental physics courses. I did my master's thesis in what can be called as theoretical cosmology, studying particle...
  32. Buckethead

    B What is the mass distribution and rotation curve of galaxy IC1101?

    I've been reading up a little on IC1101, the largest known galaxy and there is not a lot of info on it, but it seems to have an unusually large mass to light ratio according to this popular article (see half way down): According to this article at 20kpc it's got 12:1 mass to light, at 200kpc...
  33. D

    I Does gravity compress matter in planets?

    Will there be a compression of matter that the planet is made out of due to gravity when we are talking about planets? If so I would like to know what the effect would be in the example given in the summary.
  34. orochi

    Learning about condensed matter physics as a particle physicist

    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...
  35. D

    B Breit Wheeler Matter Production

    Are there any limitations on producing a significant number of electron-positron pairs (say, 10E24 electrons) in one second using the Breit-Wheeler Process or Nonlinear Breit-Wheeler Process? What variables affect this outcome? I suspect it mostly comes down to the pulse repetition rate and...
  36. C

    B Is matter a particular form of energy?

    Energy and mass are interdependent and electrons can manifest as particles and fields as do all other particles, but is it generally true that physical(classical) matter is a peculiar type of energy that can(for some reason? What?) manifest as physical objects?
  37. A

    I Dark Matter as a condensation of photons in a space

    if we assume each photon of light as a very very light piece of matter (by famous E = mc^2 and then: m = E / c^2) and sum up all photons that have been made from the creation time of a galaxy (also considering limitation of speed of light) and also photons that accidentally passing throw that...
  38. binis

    I Does Dark Matter Have a Temperature?

    A black-body absorbs and emits radiation if heated, but it does not reflect or transmit radiation.What is the temperature of dark matter?
  39. MadDog66

    I Simplification of Dark Matter effects

    What would be the distribution galactically, universally etc? How might distribution of DM change if involved forces, masses, energies or other fundamental components of DM occurred at different weights ie: Could there be less but stronger or perhaps "more but weaker" models of DM? What would...
  40. N

    B Are quarks fundamental elements of matter?

    I would like to ask scientists or anybody: what do you think about qwarks, do you consider them to be the littiest parts of matter or that matter is cyclically or infinitaly smalling, like numbers, or that there are some smaller parts, which have not been observed, but they have an end in their...
  41. L

    What Are the Lesser-Known Subjects Studied in Physics?

    Summary:: What does physics study? Other than matter/antimatter and energy what does physics study? And in what ways are matter and energy similar? Are there additional substances that physics measures?
  42. F

    Cosmology Dark Matter Textbooks: Learn Core Topics in Astrophysics & Cosmology

    Hello, could you please recommend some good introductory textbooks for studying core topics in astrophysics/cosmology, and especially dark matter? I know that 'An Introduction to Modern Astrophysics' by Caroll and Ostlie is a good book, but I 'm looking for something more concise, so to speak...
  43. L

    A Interaction between matter and antimatter in Dirac equation

    I'm new to relativistic quantum mechanics and quantum field theory and was trying to learn about the Dirac equation. Unfortunately, I got a little stumped by the interaction between matter and antimatter. It seems like the time derivative of matter is dependent on the spatial derivative of...
  44. TheTuringTester

    B How Matter Bends Space & Slows Time: Physical Mechanism

    Given that we know experimentally that time slows and space bends in the presence of matter, what is the actual physical mechanism that enables matter to bend space and slow time?
  45. Ranku

    I Is Dark Matter Composed of Low-Mass Particles?

    Does the diffused distribution of dark matter as halos over galaxies imply dark matter is made up of low-mass particles?
  46. M

    What are some possible future applications for supersolids?

    Scientists finally created a 2D Supersolid! There existence has been predicted since the 60’s and now we have them. The scientists who created it don’t really know what it could be used for as it’s so much in the infancy stages, it’s practically a zygote. As an aspiring futurist, I was wondering...
  47. C

    I Dark matter + gravity is 'right', or our understanding of gravity is wrong?

    My understanding, possibly my ignorance, is that dark matter is calculated to exist from observations that there's not enough matter to fit observations if the current theory of gravity is right. Is it possible to put into a nutshell why the case for dark matter together with current...
  48. P

    I Could dark matter consist of primordial black holes?

    Could dark matter consist of black holes formed shortly after the big bang? They would form the perfect development seed. If they all have Sun-like masses then they are not detectable from here (they are just 3 kilometers wide!). They have virtually no collisions with stars and could form a...
  49. S

    I Static rotational friction: does diameter matter?

    Imagine a bolted joint with a washer between the bolt and the surface. Assuming the washer is always covered by the bolt head so it's getting a consistent load, does the washer's diameter impact the static friction being imparted on the surface? I see two conflicting ways of viewing this...
  50. Buzz Bloom

    I An apparently obscure question re dark matter

    Question: How accurately does the observation of the current dark matter to baryonic matter ratio fit with its influence on the BBN? Some good references would be very helpful. Here are some references that I think might be a little helpful. (Mar 6, 2004)...
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