Origin Definition and 668 Threads

  1. larpal

    I How does an arbitrary choice of the origin affect real observations?

    Problem I can't seem to get my head around, if anyone can help - consider: - a stationary frame S containing an infinite line of clocks in the x direction - an (initially) stationary frame S', also containing an infinite line of clocks in the x direction - the clocks in S and S' are synchronized...
  2. BillTre

    New and Interesting Publications Relevant to the Origin of Life

    Exciting times for Origin of Life enthusiasts. There have been three recent publications that are relevant to origin of life issues. They are: A) The moon forming impact may have gotten plate tectonics started early. A Giant Impact Origin for the First Subduction on Earth Open access from...
  3. C

    I If we had a TOE, would we be able to explain why there is something rather than nothing?

    If we could have one day theory of everything thing, would we be able to explain why there is something rather than nothing and would we be able to know why there are physical laws?
  4. chwala

    Find the equation of the invariant line through the origin

    My approach - i think similar to ms approach. The required Equation will be in the form ##y=mx## ##\begin{pmatrix} a & b^2 \\ c^2 & a \end{pmatrix} ⋅ \begin{pmatrix} k \\ mk \end{pmatrix} = \begin{pmatrix} x \\ y \end{pmatrix} ## ##ak+b^2mk=x## ##kc^2+amk=y## ##x=k(a+b^2m)##...
  5. Astronuc

    What Are the True Origins of the Hungarians?

    Kevin MacLean has an interesting narrative on the origins of Hungarians, or Magyars. "The Hungarians, or Magyars, have a very unique language and origin which has long been debated. With the most recent genetic studies together with medieval legends and archaeology, the real origins of the...
  6. M

    F(x) row isn't shown in origin software

    My PC : There is no option ! Origin's website:
  7. Arasvo

    B Where does the original singularity get its energy from?

    Where does the original singularity get its energy from?
  8. Count

    A 3.5 nC charge is at the origin and a -10 nC charge is at x = 2 cm

    Apparently the answer is not 2.9 cm or 7.4mm. I've looked at similar questions in this thread and solving the exact same way gives me the same answers. I set it up as (3.5/x^2)=(10/(.02+x)^2). What am I doing wrong?
  9. Ken_S

    What Drives the Quest to Uncover the Origins of Mass, Energy, Time, and Charge?

    Studying physics and related topics for 3 decades. Working on a project to better understand the origin of mass, energy, time and charge.
  10. B

    A What is the origin of the Dipole Repeller and similar structures?

    I can see how slight unevenness in density of the early universe could result in matter grouping due to gravity however I would think that this would lead to more focal regions of higher density and more disperse regions of lower density. I can't visualise a mechanism that would support...
  11. P

    I Why didn't the Big Bang form a Black Hole?

    (pop science) It seems like the mass in the universe at the point of origin was way higher and the size way smaller than required to form a black hole, so why didn't our universe just sit forever as a single black hole? From a figure for the mass of the universe you could calculate the event...
  12. M

    I Big bang occuring everywhere vs everything "compressed"

    Hi I am trying to reconcile the concept of the Big Bang of occurring "everywhere" (an infinite Universe) - v - the concept of the origin of the Big Bang occurring in a particular compressed state and then expanding? Thanks Martyn Arthur
  13. DaveC426913

    Origin of this phrase: "We shall see what we shall see..."

    My wife learned this adage from her mother many, many moons go."We shall see what we shall see when we shall see what we shall see." It bugs me because it is a truism and my gut tells me it's been corrupted from something more pithy. The only reference I've been able to find is from the Bible...
  14. S

    Is the Origin of Korotkoff Sounds Rooted in the Resonance of the Arterial Wall?

    What is the "official" thinking today about the origin of Korotkoff sounds? Has this 2015 paper found general acceptance? https://www.sciencedirect.com/science/article/pii/S1933171115007068 The idea IIUC is that the stretched arterial wall acts as a resonant system, and what we hear are...
  15. S

    I Smallest subspace if a plane and a line are passing through the origin

    Hi all, I am a beginner in Linear Algebra. I am solving problems on vector spaces and subspaces from the book Introduction to Linear Algebra by Gilbert Strang. I have come across the following question: Suppose P is a plane through (0,0,0) and L is a line through (0,0,0). The smallest vector...
  16. S

    A Origin of BH Entropy & Info Missing Puzzle Resolution

    Dear everyone, I wish to discuss in this thread a classic/semi-classic interpretation on the origin of Bekenstein-Hawking entropy and the related resolution to Hawking's information missing puzzle, which were published in Nucl.Phys.B977 (2022) 115722 and Nucl.Phys.B990 (2023) 116171 after...
  17. Astronuc

    300 Silver Coins of Danish, Arab and Germanic origin found

    1,000-year-old Viking coins unearthed by young girl with metal detector https://www.yahoo.com/news/1-000-old-viking-coins-104000120.html https://nordjyskemuseer.dk/hele-to-vikingeskatte-fundet-naer-fyrkat/?fbclid=IwAR1_EIaf7CmKeero2yeIq-q0jRdx54E_QPfcc0zjI9lsNayBp1tRwtGYA6o?ftag=YHF4eb9d17
  18. BillTre

    Origin of Life Chemistry interview with Bill Martin

    This video is an interview of Bill Martin (Martin wikipedia link) (one of the godfathers of modern origin of life chemistry) by Jitender Kumar about several origin of life issues. He has a lot chemical knowledge and expresses it clearly. Interesting to me, he places the formation of membranes...
  19. J

    Thin heartshaped wire - Calculate the magnetic field at the origin

    Hi, So I know I am to use Biot Savarts law dB= (my_0/4pi)* (I dl x (r-r')/|r-r'|^3 where r=0 because its in origo and r'=r'_c(r'_hat). This makes (r-r')= -r'_c(r'_hat) and |r-r'|^3= r_c^3. From previous questions, I have defined dl' as the infinitesimal displacement of r'(phi) when phi' is...
  20. M

    Solving a Problem with an Easier Way: Moving the Origin

    For this problem, The solution is However could the bracket circled in red also be ## (x - \frac {L} {2})^{2} ## since the terms are squared? Also if anyone else knows a simpler way to solve this problem please let me know. I though an easier way to solve this problem would be moving the...
  21. S

    Origin of Annona: Etymology & Sanskrit Meaning

    It says here https://en.wikipedia.org/wiki/Annona_(mythology) that "annona" comes from the word "annus", i.e. Latin for "year". OTOH, https://en.wiktionary.org/wiki/annona says it's from a PIE word that means harvest or crop. Which etymology is true? Also, "anna" in Sanskrit means grain -- so...
  22. T

    I Origin of the Earth's magnetic field

    How can the motion of liquid iron consisting of neutral iron atoms in the earth's core create magnetic fields? What am I missing?
  23. G

    I The Christoffel symbols at the origin -- Why zero?

    "the christoffel symbols are all zero at the origin of a local inertial frame" Why must it be at the origin? If it is not?Thanks!
  24. R

    On the origin and the evolution of information in the Universe

    [Mentor Note -- thread moved from the schoolwork forums to the technical forums] Homework Statement:: Tentative Note and summary on the origin and the evolution of information in the universe. Relevant Equations:: none As a teacher of physics I got many questions asked by my students when...
  25. BillTre

    Origin of Life Podcast with Nick Lane & Sean Carroll

    Here is a link to a recent (and good) Sean Carroll podcast with Nick Lane. I consider Nick Lane to have one of the most interesting views of Origin of Life issues. I consider his perspective to be biochemical and biochemical pathway heavy, which is very useful for these issues of...
  26. B

    The Mystery of Equation (3.1.3) and the Origin of the Universe

    I tried setting the Universal time T = Tp as when T = 0 there was no universe and thought Tp would be the first instance of the universe, but I still can't figure out how equation (3.1.3) implies that M0 = Mp/2
  27. C

    What Caused the Strange Flash of Light in My Bedroom at 3:57am?

    (edit.. not the red light, that's my emergency power outage light in every frame, I'm referring to 3:57am and exactly 15 seconds, blink and you will miss it) turn up the volume Strange white/yellow flash appeared in my room and the sound it made when the light hit my security camera sounded...
  28. Astronuc

    Did Wild Animals in Wuhan Seafood Market Play a Role in SARS-CoV-2 Origin?

    Striking new evidence points to seafood market in Wuhan as pandemic origin point Two claims in the article: Live animals that are susceptible to COVID-19 were in the market in December 2019 Live susceptible animals were held in a stall where SARS-CoV-2 was later detected on a machine that...
  29. patric44

    I What is the origin of Lorenz force?

    hi guys one of my friends asked me about the origin of the electromagnetic induction, I know somehow that its related to the Lorenz force as the electrons in the conduction band of say the coil interact with the magnetic field ,which results in separation of electrons and positive ions which...
  30. sergiokapone

    I What is the origin of spatial inhomogeneities in the Universe?

    We get the following picture of the formation of inhomogeneities: Initially, all eternally existing fields (possibly fermionic-lepton-quark-DM-field and GUT-field) lived in a vacuum state --- no real particles (only virtual ones), just fluctuated (##\left\langle\Delta E\right\rangle = 0##...
  31. D

    I A New Idea for the Origin of Earth's Water

    I will begin with the concept that the Moon was originally a rocky terrestrial planet that orbited at roughly one AU from the Sun and lost the majority of its lighter volatiles including water during the T-Tauri phase of the Sun's transition into a Main-Sequence yellow dwarf star. A similar...
  32. brotherbobby

    A line integral about a closed "unit triangle" around the origin

    Problem statement : As a part of the problem, the diagram shows the contour ##C##above on the left. The contour ##C## is divided into three parts, ##C_1, C_2, C_3## which make up the sides of the right triangle. Required to prove : ##\boxed{\oint_C x^2 y \mathrm{d} s = -\frac{\sqrt{2}}{12}}##...
  33. BillTre

    Origin of Modern Domesticated Horses Found

    Using genomics on DNA collected from ancient horses that lived between 2,000 and 10,000 years ago, scientists have identified an area in western Eurasian steppe where the predecessors of modern horses came from. Science mag News article here. This is the second domestication of horses (DOM2)...
  34. Rikudo

    Confusion in choosing an origin point for angular momentum

    I am currently reading David Morin book and found this statement : ##\,\,\,\,\,\,\,\,## "It is important to remember that you are free to choose your origin from the legal possibilities of fixed points or the CM" Is it really alright to choose the center of a...
  35. M

    I What is the origin of translational motion?

    Take a single atom in a vacuum chamber at T=0 K. The atom is motionless. Add thermal energy to the vacuum chamber. Does this cause the atom to move? If so, by what mechanism?
  36. Poetria

    Equation for a line through an origin

    Why is this wrong? $$-4*y+x=0$$ $$\vec (-1, 4)\cdot\vec (4,1)=0$$
  37. sergiokapone

    I Can Electromagnetic Fields Exist Independently of Charges?

    Interesting thing, the undergraduate courses of electromagnetism states the electromagnetic field caused by electric charge: d∗F=4π/c∗J, and students, in my opinion, mistakenly imagine the electromagnetic field as a product of charged particle. In my opinion, it is more correct to say that...
  38. T

    I FRBs (Fast Radio Bursts) -- New clues of their location and origin

    The Hubble space telescope has tracked down a few FRBs that originate in the spiral arms of galaxies. The NASA video on YouTube: Text version if you prefer: https://scitechdaily.com/magnetic-monsters-hubble-tracks-down-location-of-mysterious-radio-signals-from-intergalactic-space/ Cheers, Tom
  39. H

    Where Did I Go Wrong in Calculating Net Current Through a Circle?

    Here's what I did: ∮ B * dl =μ0 * I ∮ AR * 2π*R =μ0 * I ∮ 2π*AR^2 / μ0 = I ∮ 2π*AR^3 / 3μ0 = I Where did I do wrong?
  40. J

    I Origin of Probabilities in Quantum Mechanics?

    The non-normalized wavefunction of a general qubit is given by: $$|\psi\rangle=A|0\rangle+B|1\rangle.$$ The complex amplitudes ##A## and ##B## can be represented by two arrows in the complex plane: Now the wavefunction can be multiplied by any complex number ##R## without changing the...
  41. K

    Charged particle oscillation about the origin

    Hello! This is probably something simple but I am getting confused about it. Assume we have an electric field along the z axis given by ##E = -kz##, with ##k>0##, so the field on both sides of the xy-plane points towards the origin. Let's say that we have a positively charged ion at the origin...
  42. wizzy

    Plotting points evenly around an origin

    Say I have phi starting at 0 and ending at 360 degrees. Theta starts at 0 and ends at 360, and I input 10 points for phi and theta. I am trying to 3d plot phi * theta number of points around a center point. I can plot a coordinate around a sphere using the following, which I think is correct...
  43. S

    Any clues to the origin of this pic (cross section of teeth)

    At [01:02], this video youtu.be/qwbIu2PzCRs?t=62 shows the following picture. I'm guessing it's either Arabic or Persian. Can someone read the text and say if it gives any clues to its age and origin? If it's even of medieval vintage, it would be pretty remarkable, implying that they may have...
  44. Baums Mizushala

    Point on a graph nearest to the origin

    The Attempt at a Solution I know the answer is supposed to be ##(-1,0)##. However when I differentiate the above expression I get. $$ 2x+{\frac 5 2} $$ Then the shortest distance would be when the expression equates to 0. $$ 2x+{\frac 5 2}=0 $$ I should be getting ##x=-1## but solving for ##x##...
  45. G

    Origin of the "underpressure" or "negative phase" in a blast wave

    In the blast wave generated by an explosion, after a first violent increase in the air pressure, there is a "negative phase" in which the pressure drops below the initial atmospheric pressure (see e.g. https://en.wikipedia.org/wiki/Blast_wave ). According to wikipedia, this underpressure is the...
  46. karush

    MHB APC.3.1.2 shortest distance between curve and origin

    Find the x-coordinate of the point on $f(x)=\dfrac{4}{\sqrt{x}}$ that is closest to the origin. a. $1$ b. $2$ c $\sqrt{2}$ d $2\sqrt{2}$ e $\sqrt[3]{2}$ not real sure but, this appears to be dx and slope problem I thot there was an equation for shortest distance between a point...
  47. G

    Origin of Potential Energy - 65 Characters

    I think the right choice is c. I'll pass on my reasoning to you: We can think that if the formula of the potential is V(r)=\dfrac{kq}{r} If r tends to infinity, then V(r)=0. But the correct answer is d).
  48. B

    A Could the fields for the particles and forces have the same origin?

    I was watching this terrific lecture by David Tong and there was a section at the end from around 50:12 - 54:00 that I found particularly fascinating. I am very much a layman when it comes to these topics and my question may be silly, but what sort of ideas are there that state that all the...
  49. G

    E-field at the origin from two point charges

    Using superposition and "breaking up" the vectors into three components ax, ay, az on points should solve the task. For Q1 there is no effect on x-axis. On the y-axis the distance from Q1 to origin is 2. Using coulombs law will give us -> (-Q/4) * k , where k is the constant 1/(4*pi*e0). On...
  50. A

    A Superluminal origin of Quantum Mechanics

    A relativistic origin of QM is proposed in https://iopscience.iop.org/article/10.1088/1367-2630/ab76f7 It is proposed that lorentz transformation that include superluminal observers (whether those observers exist or not) explain the indeterministic behavior of QM. Not only that, it also would...
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