What is Source: Definition and 1000 Discussions

Open source is source code that is made freely available for possible modification and redistribution. Products include permission to use the source code, design documents, or content of the product. It most commonly refers to the open-source model, in which open-source software or other products are released under an open-source license as part of the open-source-software movement. Use of the term originated with software, but has expanded beyond the software sector to cover other open content and forms of open collaboration.

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  1. Brian in Victoria BC

    My emphasis has always been on simplicity in my projects

    I made the "pulser pump" https://en.wikipedia.org/wiki/Pulser_pump (Specifically to pump water from a small stream to water my garden without any effort.) Following that, I emigrated from Ireland to Canada, and did some work on very low pressure airlift pumps. I currently use air at about 1...
  2. Christian Thom

    I Problem with the polarization of entangled photons

    Consider this thought experiment : we use a source of identically vertically polarized photons, such as produced by a type 0 SPDC. One beam go to Alice and the second to Bob. 1. Whatever measurement Bob makes on its beam, if Alice use a vertically polarized detector, all photons are detected...
  3. Anisur Rahman

    What is the physical significance of WGT and SBn in MCNP source specifications?

    What is meant by SP1,SI1 and SB here? I actually can't get the physical significance. And What is the physical significance of WGT here? Sorry for my this kind of questions. I am novice in MCNP.
  4. S

    Is Wikipedia considered to be an appropriate source for discussion?

    I was just reading a thread which cited a Wikipedia article; I had thought that Wikipedia is to be considered as unreliable as the Public Broadcasting System (i.e., that has programs like NOVA, etc.), and therefore not appropriate since it is "pop science".
  5. E

    Efficient MCNP Lattice Source Help: Defining Universes and Tallies in Cell File

    This is what I hate about MCNP, not a lot of documentation. How do I define all of a universe as a source and a tally? I have a lattice like the below code. How do I get this code to work with tallies for positions 1,2, and 3 in the lattice; and a source for the 2's. I get the error "sampling...
  6. S

    I Optics: infinite light source illusion question - can you help?

    Hi. I’m trying to solve an optics problem and really struggling. The problem is best described as follows… Imagine you have a section of a wall that you want to look like a window on a spaceship. So you want to look at this “window” and see through it some “stars” (i.e. pinpoints of light) that...
  7. D

    If we have a non combustible power source

    If i create a non combustible self-sustaining energy source that generates zero radiation, what kind of propulsion system could be designed? Is someone out there with that type of propulsion system already?
  8. I

    Need a voltage divider for a capacitor source voltage

    The end goal is I need to convert a sinusoidal into a square wave using a zero crossing circuit. I have a voltage that ranges from 0 to 400vrms @70kHz from a capacitor that is part of an induction heater tank circuit. My comparator has a peak differential input of +/- 35v so I need to reduce the...
  9. H

    A Determination of electron temperature in an ion source

    How to correctly determine the temperature of electrons in an ion source based on ECR? Is it possible to use the Saha equation? ##\frac{n_en_i}{n_a}=\frac{g_eg_i}{g_a}*3*10^{21} T^{3/2} e^{-J/T}## Using the search, I found the McWhirter criterion for the applicability of the formula above: ##n_e...
  10. MrFlanders

    A GW Binary Merger: Riemann Tensor in Source & TT-Gauge

    In the book general relativity by Hobson the gravitational wave of a binary merger is computed in the frame of the binary merger as well as the TT-gauge. I considered what components of the Riemann tensor along the x-axis in both gauges. The equation for the metric in the source and TT-gauge are...
  11. Gwen

    Thermal lattice Boltzmann model ignoring source term -- python code help please

    LBM model for phase change- relevant equations found here. Also here. #Thermal LBM #solves 1D 1 phase phase-change #D2Q5 Lattice nx=100 # the number of nodes in x direction lattice direction ny=5 # the number of nodes in y...
  12. ergospherical

    I Observed Redshift from Moving Source: Deriving the Result

    If a galaxy is receding from us, then the 1+redshift observed on Earth is the product ##(1+z_{pec})(1+z_{cosm})## of the doppler redshift due to the peculiar motion of the galaxy and the cosmological redshift due to the FRW metric. It makes sense if we think about some intermediate observers...
  13. orangephysik

    Doppler effect and acceleration of source

    Hi. I need help with part a). I calculated the wavelength of the source by using the formula f_0 = v_phasefront / λ and got λ = (343 m/s) / (520 Hz) = 0.6596 m. And then I set up an equation for the velocity of the source v(t) = a*t (with v(t = 0 )= 0 m/s) and s(t) = 1/2 * at^2 + s_0. But I...
  14. 1

    MCNP6.2 - Source particle started in a cell of zero importance

    Hi everyone, My plan is defining a surface source on a cylindrical object (cylindrical surface+top end+bottom end) and I am interested in what happens outside the cylindrical body. To avoid distortions of particles starting on the surface, directed inwards and emerging on the other side of the...
  15. T

    B What is the best source for this star data? (M44 Beehive Cluster)

    Hi I need the below data for the thousand or so stars in M44 the Beehive Cluster. What would be the easiest way to get this data? Thank you. RA, Dec, distance, apparent magnitude, absolute magnitude, spectrum
  16. Bandersnatch

    A Black hole mass coupled to expansion -- astrophysical source of dark energy?

    Observational evidence for cosmological coupling of black holes and its implications for an astrophysical source of dark energy Comments?
  17. C

    Amplitude of a circular ripple at distance r from source

    For this problem, The solution is, Does anybody please know another way to solve this problem? EDIT: Why do they assume that no energy is absorbed by the water? Many thanks!
  18. J

    Trying to analyze a half wave rectifier with inductor and DC source

    I am trying to analyze a half wave rectifier with an inductor and DC source load. I understand the circuit but I guess I do not get the math. I am reading a book and this is the circuit and equations they came up with. I understand how they got from the first equation to the second equation but...
  19. FriedFish

    Other Need to find a source for Difficult Math Problems to work for practice (Calc-2 level and above)

    I've been getting bored of the problems I'm being assigned in math and I've been reading that Richard Feynman worked on a lot of creative math puzzles when he was in high school. I can't find a good repository of any math puzzles that require more imagination or thought than just solving...
  20. Marilyn67

    I Construction of an Entangled Photon Source

    Hello, Happy New Year 2023 ! Interested in spontaneous parametric down-conversion (SPDC), and the possibility of creating entangled photon pairs, I studied several possible configurations with type 1 and type 2 nonlinear crystals. When using these crystals, the dominant phenomenon is second...
  21. A

    Energy absorbed by water illuminated by an LED source

    Good morning, I was wondering if I am thinking correctly. I am trying to establishing some step by step to calculate the amount of energy is being absorbed by a water body when a LED pendant is shining right above. Being the parameter that I want to calculate, the energy absorbed by the...
  22. tracker890 Source h

    Question about source flow rate across line AB.

    Q:Please hlep me to understand which ans is correct.To determine the flow rate in Line AB. $$\mathrm{Known}:V_A,q,r_A = constant.$$ so/ select:## A,{B}^{\text{'}},B,A,## is control volume $${Q}_{AB}={Q}_{A{B}^{\text{'}}}=\iint _{A}^{}({V}_{A})dA={\int }_{{\theta }_{A}}^{{\theta...
  23. tracker890 Source h

    Question about flow rate in the source flow

    Please help me to understand what wrong with method 2. ref.Flowrate Between Streamlines (Thank you for your time and consideration.)
  24. codebpr

    A Can a black hole horizon act as a source of Chaos?

    I was going through this paper where on page 5 they argue that in the given Poincare section: I am a bit confused by this statement. How does the given saddle point correspond to the black hole horizon and is it necessary that it acts as a source of chaos? Any explanation would be truly...
  25. G

    Power generated by this current source

    Figure: My attempt at a solution: 1st kirchoff law: $$J=2I_0+I_0=6\, \textrm{A}$$ $$V_1+8=10\rightarrow \boxed{V_1=2}$$ $$V_1=6-V_S\rightarrow \boxed{V_S=-4\, \textrm{V}}$$ We are looking for ##P## generated in ##J## $$V_J=V_1-2\cdot J=2-2\cdot 6=-10\, \textrm{V}$$...
  26. shivajikobardan

    Comp Sci Is VPN all about encapsulating the source and destination IP address?

    What’s encrypted here? Is the source and destination IP address encrypted? Is the firewall1 address and firewall2 address encrypted? Is the payload also encrypted? Is this all what a VPN does? I can’t really believe that VPN only encapsulates and encrypts. If it’s encrypting the source and...
  27. Bob Walance

    B Could the source of dark energy be our parent black hole feeding?

    About a year ago, I heard Leonard Susskind discussing how entangled black holes could create spacetime. As I was listening to Prof. Susskind describe the mechanisms for creating entangled black holes, and how these black holes might create their own spacetime, it occurred to me that if we were...
  28. R

    Heat Transfer Through a Two Material System due to a Light Source

    I have been given the task of modeling the heat transfer from a light source of known power into a system consisting of two connected materials. I must find the temperature change in the bottom surface. The two materials are initially in thermal equilibrium with the surroundings. My first...
  29. G

    Model Fuel Assembly w/ Gamma Source: Solving a Sampling Problem

    Hi everyone, I'm making a fuel assembly model and I would like to have a cylindrical gamma source on each fuel rod to measure the decay heat of a fuel assembly but I'm struggling to define the source since it is in a repeated structure. This is the geometry of my model: Level 2 : cells 1, 2 3...
  30. tysonman166

    Troubleshooting MCNP6: 'Bad Trouble in Subroutine Source' & More

    Hi! so i kinda stuck when i tried to run my code in MCNP6 because the output keep showing me "bad trouble in subroutine source of mcrun you need a source subroutine." While I am sure i already put my KCODE and KSRC in my code (on the picture below). Could anyone help...
  31. A

    I Inductor questions (generate a voltage opposing the source voltage?)

    1) Why does there have to be an inductor to generate a voltage opposing the source voltage? Doesn't the circuit create back voltage without an inductor? 2) In ##U = \frac{1}{2}LI^2 + \frac{1}{2}\frac{Q^2}{C}## ##E = \frac{1}{2}mv^2 + \frac{1}{2}kx^2## where ##x(t) = Acos(wt + \phi)## following...
  32. L

    I What's the source of energy for the universe's expasion?

    In case it's true that the universe is expading, what's the fuel for this expasion? I do not admit the idea that it's a case of spontaneous generation of space... so there must be a limit for this expasion. What's the limit for the expansion of the universe?
  33. user366312

    Polymer simulation source code in C++ and Python

    I am absolutely new to Polymer simulation. I am trying to understand the simulation by analyzing source code written by others. Can anyone tell me what are the differences between the following three source code in terms of their objectives? Monte-Carlo-simulation-of-polymers...
  34. Purpleshinyrock

    Engineering Need help answering questions (Voltage source and 3 Resistors)

    Hello. I need help arriving to the answers to the following question above. You will find the circuit attached for Number 1 I though that crrent would be maximum when resistance is replaced with a wire but I couldn't get a an expression for ut. as for question number 2 I tried applying node...
  35. Monsterboy

    Comp Sci Using Single Source Shortest Path Algorithm to find the longest path

    This is the weighted, directed acyclic graph I created in JavaScript class WeightedDirectedGraph { constructor() { this.adjacencyList = {}; } addNode(node) { if(!this.adjacencyList[node]) { this.adjacencyList[node] = []; } } addEdge(node1, node2, direction, weight) {...
  36. A

    I Deriving Doppler Effect Frequency w/ Stationary Person & Moving Source

    Can you derive the formula for frequency observed from doppler effect with stationary person and moving sound source away from the person like this: ##v_t = v + v_s## where ##v_t## is the total velocity observed by stationary person from moving sound, v is velocity of sound and ##v_s## is...
  37. D

    Dispersion diagram of light source seen through prism

    I know that red light has a lower index of refraction than blue light, but that’s not what I’m seeing. The blue light is where the red light should be. I can’t afford to join CHEGG. Any chance that someone would help me out for free? I’d really appreciate it. [Link to chegg removed by the Mentors]
  38. Joshy

    Engineering Source impedance using given voltage swing and power

    Hi! I normally have a pretty good grasp of what the source and load impedance for these types of problems; however: This textbook is giving me peak to peak voltage swing 6V33 and 1 W of power. I'm a little bit confused at converting this into an input impedance and am worried I'll be off by a...
  39. theycallmevirgo

    Is there a good source for construction blueprint symbols?

    I've seen quite a few websites but I don't know how far to trust them. Is there a book I could use? Thanks so much Joe
  40. M

    I Light speed independent of source

    Please bear with me I am trying to get a grip with underlying principles. Starting to try and understand Einstein’s second postulate and distinguish that the speed of light is independent of the speed of the source – v - of objects, other than light with travel initiated independent of the...
  41. altruan23

    Engineering Constant current source transistor circuit - differences between 2 types?

    So basically we can have a constant current but i don't understand this circuit. for example: i can have the Ia what ever I want with current divider rule: Ia = Iq * R2/R3. So Ia is proportional to the ratio of R2/R3. And if i give a resistor at the collector terminal, if i change it between...
  42. Melbourne Guy

    Any suggestions for an open source Windows 10 disk encryption app

    The summary says it all, really, but in addition, I've done a lot of googling and am finding it hard to identify trustworthy options. LibreCrypt, DiskCryptor and VeraCrypt are candidates, but I have not used any of these tools so am wary of jumping in and finding that I have bricked my PC.
  43. A

    Help Identifying Source of Sliding Adhesion Coefficient Equation

    Hello all, I am a graduate student working on a thesis in tire dynamics and simulation. I have came across the following equation for sliding adhesion coefficient for the HSRI tire model (source: Schramm et. al. Vehicle Dynamics, Modeling and Simulation, pg. 182): Unfortunately, Schramm et...
  44. D

    Trying to source a chemical product

    Freezable. Maintains flexibility when frozen. Re-usable. Non toxic. Need to know the chemical name to enable sourcing for a manufacturer.
  45. JD_PM

    Understanding the source code for an OpenFOAM solver (CFD)

    I am trying to understand the following code (it starts from line 59) and there are pieces I do not understand. argList::addNote ( "Solver for two incompressible, isothermal immiscible fluids with" " phase-change.\n" "Uses VOF (volume of fluid) phase-fraction based...
  46. G

    I Collimating a fibre-coupled LED light source

    Summary:: I have a fibre coupled LED light and an achromatic doublet lens, I know by placing the collimating lens at a distance equal to the focal length of the lens, the light will get collimated. But is the a simulation software available where I can input the parameters I can so as to...
  47. miyelmunshi

    Engineering RC circuit where source depends on capacitor current

    I did a kvl loop and got V + 5Io - 15 Io = 0 So, V = 10Io Then, substituted dq/dt for Io and q/c for V I get to dq/dt - 50000q = 0 solving this equation i get q = C x e^50000q (c for constant) my Io = dq/dt so Io now is 50,000Ce^50000q now my Q(0) is 3 x 10^-5 So my Io (0) should be...
  48. elcaro

    Storing program source as relations in a database instead of text file

    Almost all (compiled or interpreted) programming langues store the program source in the form of a series of bytes (using an encoding like ASCII or UTF-8) into a text file, enforcing the grammer of the programming language using a parser (as part of the compilation process or interpretation of...