What is Fields: Definition and 1000 Discussions

FIELDS is a science instrument on the Parker Solar Probe (PSP), designed to measure magnetic fields in the solar corona during its mission to study the Sun. It is one of four major investigations on board PSP, along with WISPR, ISOIS, and SWEAP. It features three magnetometers. FIELDS is planned to help answer an enduring questions about the Sun, such as why the solar corona is so hot compared to the surface of the Sun and why the solar wind is so fast (a million miles per hour).The host spacecraft, Parker Solar Probe, was launched by a Delta IV Heavy on August 12, 2018 from Florida, USA. On August 13, 2018 FIELDS became the first instrument to be activated including beginning deployment of the 4 whip antenna (clamps unlocked) and extension of the magnetometer boom. On September 4, 2018 the whip antennas were deployed.

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  1. Spinnor

    I Plane wave decomposition of the fields of a dipole antenna

    A dipole antenna will have near fields and far fields. Can both the near and far fields can be decomposed into an infinite sum of plane waves? If so, are the plane waves for far fields and near fields of different type or class? Near fields must die off at infinity but far fields do not. Thanks.
  2. HighPhy

    I "Wave-particle duality" and double-slit experiment

    Sorry to open a new thread. There are plenty of threads on PF dealing with the issue of "wave-particle duality". Although not unanimously, many agree that the concept of "wave-particle duality" is outdated. Electrons, photons and all of the underlying entities are neither waves nor particles...
  3. mister i

    B What is currently known about fields other than gravitation?

    As far as I know a field is spatial&time region in which each point has a physical quantity associated with it (vector or scalar). We know from GR that in the case of the gravitational field it is due (only?) to a curvature of space. But what about the other fields? What gives the value...
  4. Pradyuman

    A How can gauge fields be associated with real particles?

    When we make our lagrangian invariant by U(1) symmetry we employ the fact that nature doesn't care how I describe it, but, how come that I can associate the real physical particles with the coordinates I use to describe? Even though gauge symmetry is not a physical Symmetry,
  5. M

    Faraday's law and Magnetic Fields

    I am not really sure which direction i am moving in with this solution
  6. S

    Exploring Propulsion with Light & Magnetic Fields

    while browsing for new propulsion methods I found the following interesting: https://en.wikipedia.org/wiki/Radiation_pressure "Radiation pressure (also known as light pressure) is the mechanical pressure exerted upon any surface due to the exchange of momentum between the object and the...
  7. C

    B How do fields retain their uniformity with interposing objects?

    Why don't interposing objects interfere with the integrity of a field's energy between the source and its absorber? For example, the Sun's gravitational field spreads uniformly through space. If there are interposing objects like Mercury or Venus between the Sun and the Earth, why don't they...
  8. milkism

    Field transformations in the z-direction

    Question: Eq. 12.109: My solution: We’ll first use the configuration from figure 12.35 in the book Griffiths. Where the only difference is that v_0 is in the z-direction. The electric field in the y-direction will be the same. $$E_y = \frac{\sigma}{\epsilon _0}$$ Now we're going to derive the...
  9. Sciencemaster

    I Gravitational Field Transformations Under Boosted Velocity

    Let's say we have some observer in some curved spacetime, and we have another observer moving relative to them with some velocity ##v## that is a significant fraction of ##c##. How would coordinates in this curved spacetime change between the two reference frames? For example, imagine a...
  10. N

    B Exploring the Intersection of Oscillations/Waves & Particles in EM Fields

    For an upcoming presentation I am looking for a topic which covers both the field of oscillations/waves and particles in electromagnetic fields. Do you have any interesting ideas for a possible topic? Many thanks for your help in advance!
  11. E

    A Symmetries of particle interacting with external fields (Ballentine)

    I am following along with Ballentine's (in his *Quantum Mechanics: A Modern Development*) construction/identification of symmetry generators as operators representing the standard observables (observables here being used in the sense of a physical concept which have operators representing them)...
  12. milkism

    Electric and magnetic fields of a moving charge

    Part a) My solution: Big R basically becomes r, and the electric and magnetic field lines are doubled because of superposition principle. Am I right?
  13. S

    What research fields in physics are you working in?

    Hi everyone. I thought I would pose the question in the title to those on Physics Forums that are currently working in physics research (either as faculty, postdoctoral fellows, or graduate students). I was thinking of setting up a poll, but the last time I had asked a similar question I...
  14. S

    I Behaviour of Magnetic Fields Underwater

    I've been trying to pick up the fundamentals of electromagnetic theory and I reckon I'm doing alright, but I've run into a some questions about how magnetic fields behave in an anisotropic fluid medium like the ocean. There is an awful lot of conflicting information online. Ultimately, I'd like...
  15. A

    A Completeness of the formal power series and valued fields

    I had difficulty showing this no matter what I tried in (a) I am not getting it. Here for p(t) in K[[t]] : ## |p|=e^{-v(p)} ## where v(p) is the minimal index with a non-zero coiefficient. I said that p_i is a cauchy sequence so, for every epsilon>0 there exists a natural N such that for all...
  16. davidj

    Magnetic and Electric Fields problem

    Would i assume that fg = fm (force gravity holding straight wire down is equal to the magnetic force) and isolate for I? Help if you're available please!
  17. Drakkith

    Resources on Simulating Charges in Magnetic Fields

    Hey all. I started messing around with making a simulation involving charged particles moving in magnetic and electric fields and I was wondering if anyone had any good resources on the subject. I should be fine on equations, as I already have a book that should have everything I need about the...
  18. PlanTer254

    B Magnetic fields attracting two disc-shaped magnets

    I had 2 small magnets in my mouth for distraction while working on something else,and I had this wierd question.the two magnets were not that strong,so just a force was easy to separate them with my teeth.then they would attract to be attached to each other and then the question hit me,the 2...
  19. Euge

    POTW Semisimple Tensor Product of Fields

    Let ##L/k## be a field extension. Suppose ##F## is a finite separable extension of ##k##. Prove ##L\otimes_k F## is a semisimple algebra over ##k##.
  20. Lotto

    B What magnetic fields can this hollow rod shield?

    I suppose it can shield only the external magnetic field, not the field of the magnet itself. But I am not completely sure.
  21. W

    A Lagrangian density for the spinor fields

    hi, i have seen lagrangian density for spin 0 , spin 1/2, spin 1 , but i am not getting from where these langrangian densities comes in at a first place. kindly give me the hint. thanks
  22. M

    I Fundamental - Magnetic fields generated by moving electrons

    Trying to understand something fundamental about how magnetic fields are generated by moving electrons in a conductor. I have read many forums, studied Emag and am left with more questions. Looking for some practical insight not Bio-Savart derivations, etc. These still do not explain why the...
  23. M

    How do I incorporate electric fields into capacitors?

    I know that I’m supposed to use proportional reasoning, but where does electric field even fit in? For whatever equation, I know I’m supposed to see how increasing the voltage by either 2 and 4 volts related to electric field. If electric field is the same as “U”, then wouldn’t it be...
  24. S

    B High Temperature in Gravitational Fields: Exploring the Possibility?

    Sir, heat is proportional to the vibration of atoms. If the vibration of atom is restricted to large extent due to intense gravitational field but has high quantity of total energy in the atom then does it mean it has high tempearture like the stars?
  25. S

    B Lorentz Transformation of Electric & Magnetic Fields Visualized

    I made a tool for calculating and visualizing how the electric and magnetic fields transform under a Lorentz boost. Thought I'd share it here, in case anyone finds it interesting. https://em-transforms.vercel.app/
  26. P

    I Defining the Forces from Magnetic Fields and Electric Fields

    We define Electric Field Intensity vector at a point as the force experienced by a unit positive charge kept at a point. Is it correct to define B vector similarly that is, is B vector the magnetic force acting on an unit magnetic north pole and is it correct to call B vector Magnetic Field...
  27. LarryS

    I EM Four-Potential and INDUCED Electric Fields

    Say we have a long solenoid with a current that is fluctuating in time. Then the changing magnetic flux in the solenoid will induce an electric field around the outside of the solenoid (Faraday's Law). This induced electric field is not conservative and therefore cannot have a corresponding...
  28. V

    I Induced electric fields and induced magnetic fields confusion

    So changing magnetic fields induce electric fields (Faraday's law when the magnetic field is changed by either moving the source or by changing the current in the source that's causing the magnetic field, ie. we're not moving the conductor where an emf is induced so there's no f=qvXB). Also...
  29. hagopbul

    I Drawing Direction Fields for Higher Order ODEs

    Hello : Trying to find references on drawing direction fields of higher order differential equation by hand as 1st step then by computer , do you know any reference I can read ( PDF , books ,...) , and hope it is not only some short notes Best regards HB
  30. Javelin

    A Quantum Properties of Quasi Static Electric Fields

    Assume I could produce a stream of calcium ions from a 2nm diameter nanotube by pushing them through the nanotube using coulomb repulsion. Assuming these coulomb repulsed ions produce a stream of entangled ions which then create a slowly emitting quasi static electric (near) field. Even if...
  31. Astronuc

    I Hugo Duminil-Copin, permanent professor at IHES, 2022 Fields Medalist

    IHES = Institut des Hautes Études Scientifiques (IHÉS)https://www.ihes.fr/en/ Hugo Duminil-Copin, Mathematician, Permanent professor since 2016 https://www.ihes.fr/en/professeur/hugo-duminil-copin-2/ https://www.ihes.fr/~duminil/ - personal webpagehttps://www.ihes.fr/en/scholars/professors/
  32. S

    I Explaining how the Higgs fields gives particles mass

    Physicists say the Higgs Field is like syrup and slows particles down from the speed of light. Wouldn’t it be easier and more correct to say there are no particles, just fields, and the strength of the coupling of the electron, photon, quark etc. fields with the Higgs field determines their...
  33. bbbl67

    B Are magnetic fields generated through radio frequencies?

    I seem to hear about huge astronomical events that generate radio waves seem to come from objects with huge magnetic fields, such as neutron stars and black holes. Does that mean magnetic fields only come from the radio end of the spectrum, and not higher frequencies, like IR, UV, X-rays, etc?
  34. A

    I Does electron beam in empty space generate magnetic fields?

    Does electron beam in empty space generate magnetic fields around them just as with current in conductor. If yes, then is it experimentally proven that two parallel electron beam would attract each other.
  35. Field physics

    Welcome! Investing, Athletics & Physics: Exploring New Fields

    Hi I am new to the forum. I am a investor, athlete, and a "field physicist." I got a bachelors in physics and Hopefully soon can get a phD. I like to do basic experiments that demonstrates physics.
  36. A

    A Multiplying divergent integrals using Hardy fields approach

    I wonder if the following makes sense. Suppose we want to multiply ##\int_0^\infty e^x dx\cdot\int_0^\infty e^x dx##. The partial sums of these improper integrals are ##\int_0^x e^x dx=e^x-1##. Now we multiply the germs at infinity of these partial sums: ##(e^x-1)(e^x-1)=-2 e^x+e^{2 x}+1##...
  37. A

    I What is wrong with crossing electric fields? Why can't you sum them?

    I do not understand why electric fields cannot cross. Can't you just sum the two electric fields vectors to get a net electric field?
  38. DuckAmuck

    A Unifying Lagrangians in Electrodynamics: Fμν, Aμ Jμ, & Lorentz Force

    How would you unify the two Lagrangians you see in electrodynamics? Namely the field Lagrangian: Lem = -1/4 Fμν Fμν - Aμ Jμ and the particle Lagrangian: Lp = -m/γ - q Aμ vμ The latter here gives you the Lorentz force equation. fμ = q Fμν vν It seems the terms - q Aμ vμ and - Aμ Jμ account for...
  39. DC2

    A Calculation of EM fields induced by an antenna in the near field

    The title pretty much covers it. I'm having to calculate the field induced inside the human body by an antenna in the near field (essentially, a phone placed close to a user's head), and I'm drawing a blank on how to relate the field generated by the antenna to the field induced inside the...
  40. S

    I Magnetic fields are exceptions to the second law of thermodynamics?

    Einstein famously said “{Thermodynamics} is the only physical theory of universal content, which I am convinced, that within the framework of applicability of its basic concepts will never be overthrown.” I don't think any of us want to argue with Einstein, but it's worth noting the "within the...
  41. E

    I Schwartz derivation of the Feynman rules for scalar fields

    Hi everyone, In his book "Quantum field theory and the standard model", Schwartz derives the position-space Feynman rules starting from the Schwinger-Dyson formula (section 7.1.1). I have two questions about his derivation. 1) As a first step, he rewrites the correlation function as $$...
  42. M

    A QED Formulation with Massive Photon Fields

    I was reading Diagrammatica by Veltman and he treats the photon field as a massive vector boson in which gauge invariance is disappeared and the propagator has a different expression than in massless photon. After some googling, I found that this is one way to formulate QED which has the...
  43. R

    I Relation between electric & magnetic fields in terms of field strength

    Hi. A electromagnetic wave consists of an electric and a magnetic component. I believe that the electric field strength is measured in volts per meter. The magnetic field I think is measured in Tesla. Let's imagine that I measure the electic field strength of two different radio stations and...
  44. B

    I Induced Electric and Magnetic Fields Creating Each Other

    Hi, We know that a varying magnetic field creates and induced electric field, and a varying electric field creates an induced magnetic field. If there is a varying electric field (let's say sinusoidal), then this electric field creates an induced magnetic field. And if this produced magnetic...
  45. jellybean-spider

    Fields (Gravitational fields) -- Escape Velocity from the Moon

    It's an MCQ, and I chose 4/81 v(esc). Is this correct? There isn't a marking scheme... :cry:
  46. ergospherical

    I Ex. 19 Gauge Fields, Knots & Gravity: Is Rotation Correct?

    Wanted to check with you guys that I'm not going crazy... Exercise 19: Let ##\phi : \mathbf{R}^2 \rightarrow \mathbf{R}^2## be a counterclockwise rotation by angle ##\theta##. Let ##\partial_x, \partial_y## be the coordinate vector fields on ##\mathbf{R}^2##. Show, at any point of...
  47. G

    I Stem fields in Galois theory

    I'm not sure the following passage is so trivial as it was supposed to be: I mean, what does exactly prove it? That's my question. The step is the following: if ##P## has a root ##\alpha## in ##\mathbf L## - an extension of ##\mathbf K## of degree <= ##\frac n 2## where n is the degree of ##P##...
  48. J

    Physics Easiest Physics PhD fields to get into in the US?

    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,