Physics, Math and Science Articles
Independent Research: Thinking Outside The Box Versus Knowing What’s In The Box
/1 Comment/in Physics Articles/by fresh_42In Memory of Dr. Thomas J. LeCompte (1964-2025), Detector Designer and Champion of Education and Science. Prologue Someone who shows interest in science is initially a welcome development. So are fresh ideas from unexpected quarters. In contrast, there is a scientific community that is meticulously organized down to the last detail, allowing little to no…
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Recent Entries

A First Idea of Quantum Field Theory – 20 Part Series
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8 Comments
These notes mean to give an expository but rigorous introduction to the basic concepts of relativistic perturbative quantum field theories, specifically…

The What and Why of Circuit Analysis Assumptions
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A Journey to The Manifold SU(2): Representations
Part 1 Image source: [23]
Some useful bases of ##\mathfrak{su}(2,\mathbb{C})##
Notations can differ from author to author: the…

A Journey to The Manifold SU(2): Differentiation, Spheres, and Fiber Bundles
Part 2
Differentiation, Spheres, and Fiber Bundles
Image source: [24]The special unitary groups play a significant role in the standard…

10 Math Tips to Save Time and Avoid Mistakes
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Some of the most visible features in our sky are solar system objects: the Sun, the Moon, and the planets. These objects are generally much brighter than…

Learn Further Sums Found Through Fourier Series
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Introduction to Perturbative Quantum Field Theory
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Find Out the Results Shown at 2017 CERN EPS Conference
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Super p-Brane Theory Emerging from Super Homotopy Theory
A notorious open problem:
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Learn an Integral Result from Parseval’s Theorem
Introduction:
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Assessing the Physics in Edmond Hamilton’s “The Second Satellite”
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Lesson on Entanglement Entropy in Quantum Field Theory
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What Is a Tensor? The mathematical point of view.
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From Biology to Sysadmin: Career Insights & Advice
Interview: From Biology to Programming, Sysadmin, and Life in New Mexico
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I was an amateur naturalist as a kid. I…

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Name the Scientist Quiz and Trivia
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Pamela Gay Interview — Astronomy, Citizen Science & Outreach
Please give us a bit of background into your educational and professional life.
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Exploring the Spectral Paradox in Physics
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How to Ask Questions Effectively and Avoid Cold Questions
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Learn Entanglement Entropy in Quantum Mechanics
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Learn Relativity Using the Bondi K-calculus
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Revamping Undergraduate Introductory Physics Laboratory
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Q&A With Universe Today’s Astronomer Fraser Cain
Video Q&A: Fraser Cain (Universe Today)
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Lenses and Pinholes: What Does “In Focus” Mean?
In introductory physics, the optics unit often teaches about virtual and real images, focal lengths, indexes of refraction, etc. Some questions that are…

Sabine Hossenfelder: Dark Matter, Gravity & LIGO Interview
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The Pantheon of Derivatives – Important Theorems (V)
Implicit Function Theorem [1]
Jacobi Matrix (Chain Rule).
Let ## (x_0,y_0 ) ## be a point in$$U_1 \times U_2 = \{x \in \mathbb{R}^k\,\vert \,||x-x_0||<…

Relativity Variables: Velocity, Doppler-Bondi k, and Rapidity
Traditional presentations of special relativity place emphasis on "velocity", which of course has an important physical interpretation... carried over…

The Pantheon of Derivatives – Lie Derivatives And Others (IV)
Lie Derivatives
A Lie derivative is in general the differentiation of a tensor field along a vector field. This allows several applications…

The Pantheon of Derivatives – Sections, Pullbacks And Pushforwards (III)
Some Topology
Whereas the terminology of vector fields, trajectories, and flows almost by itself suggests its origins and physical relevance,…

Ultra-Wide Lenses: Field of View, Design & Tips for Photographers
Note, unless otherwise specified, all focal lengths are in terms of the 35mm image format.
Overview: why ultra-wide-angle lenses matter
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The Pantheon of Derivatives – Manifolds And Vector Fields (II)
Generalizations Beyond ##\mathbb{R}## and ##\mathbb{C}##
As mentioned in the section on complex functions (The Pantheon of Derivatives - Part…

The Pantheon of Derivatives – The Direction (I)
Differentiation in a Nutshell
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The Diffraction Limited Spot Size with Perfect Focusing
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What Is The Most Important Thing That You Learned?
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Trick to Solving Integrals Involving Tangent and Secant
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Frames of Reference: Linear Acceleration View
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PF Insight Scavenger Hunt 2
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Types of Programming Languages: Uses, Examples, Overview
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Learn Frenet Equations in 2-D Which Result in the Cornu Spiral
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Learn About History’s First Science Experiments
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Real Research in Unexpected Places; Boat Ramps
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When Simple Geometry Unveils Deep Math
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Learn About Vacuum Fluctuations in Experimental Practice
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Permanent Magnets Explained by Magnetic Surface Currents
Introduction:
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NASA Quiz and Trivia: Test Your NASA Knowledge
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Jim Hardy: Nuclear Engineer — Energy Insights & Hobbies
Give us a little background on Jim Hardy
Born and raised in Miami, Florida, to parents with roots in Springfield, Missouri. So at heart I'm a small‑town…

Why Higher Category Theory in Physics?
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Interview with Physics Mentor: Stevendaryl
Give us a brief history on stevendarylI was born and raised in the American South, mostly living in Georgia. It's a Southern tradition, for some reason,…

Fabry-Perot and Michelson Interferometry: A Fundamental Approach
Fabry-Perot Effect:
The Fabry-Perot effect is usually treated in most optics textbooks as the interference that results from multiple reflections of the…

Using the Fourier Series To Find Some Interesting Sums
Preliminaries
If f(x) is periodic with period 2p and f’(x) exists and is finite for -π<x<π, then f can be written as a Fourier series:
[itex]f(x)=\sum_{n=-\infty}^{\infty}a_{n}e^{inx}…

The Schwarzschild Geometry: Physically Reasonable?
In the last article, we looked at various counterintuitive features of the Schwarzschild spacetime geometry, as illustrated in the Kruskal-Szekeres…

The Schwarzschild Geometry: Spacetime Diagrams
When we left off in part 2, we were looking at the metric for the Schwarzschild geometry in Kruskal-Szekeres coordinates:$$
ds^2 = \frac{32…

The Schwarzschild Geometry: Coordinates
At the end of part 1, we looked at the form the metric of the Schwarzschild geometry takes in Gullstrand-Painleve coordinates:$$
ds^2…

Spotting Fake Science News: Wendelstein 7‑X & Media
Fake News, Data, and the Need to Check Sources
During and even after the recent US election campaign, numerous reports of fake or misleading news were…

The Schwarzschild Geometry: Key Properties
Not long after Einstein published his Field Equation, the first exact solution was found by Karl Schwarzschild. This solution is one of the…

Learn About Quantum Amplitudes, Probabilities and EPR
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Real Research in Unexpected Places: Backyards, Barns, Bayous
21st-century science labors under the myth that good experimental science requires expensive lab facilities in a university or institutional setting.…

Stephen Hawking Quiz: Think You Know Stephen Hawking?
Stephen Hawking has been a giant in the science world for decades. He has been a accessible figure with his willingness to reach out to the public in various…

Linear Representations and Why Precision is Important in Math
First of all: What is a representation? It is the description of a mathematical object like a Lie group or a Lie algebra by its actions on another space…

Can Angles be Assigned a Dimension?
1. Some Background on Dimensional Analysis
... if you are not already familiar with it.
1.1 Dimensions
Dimensional Analysis is a way of analyzing…

Why Study Physics? A Bit Goes a Long Way!
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Explore The Vacuum Fluctuation Myth in Quantum Theory
This Insight Article is a sequel of the Insight Articles ”The Physics of Virtual Particles” and “Misconceptions about Virtual Particles“ which…

Learn The Main Conceptual Ideas of Anyon Particles
Every quantum physicist knows that all particles are either bosons or fermions. And the standard textbook argues that this so does not depend on the number…

Camera Tripod Guide: Choose Stable Tripods for Photos
Why use a tripod?
A tripod holds a camera still while the shutter is open, preventing motion blur. It must maintain stability on uneven ground, in wind,…

DSLR Camera Guide: Lenses, Aberrations & Tips—Enthusiasts
I'm ready for a DSLR!
These cameras were originally designed for professionals. Users of DSLRs are expected to already understand basic digital photography…

Learn Partial Differentiation Without Tears
Differentiation is usually taught quite well. Perhaps that's because it is the first introduction to calculus, which is considered a big step in a student's…

Frames of Reference: A Skateboarder’s View
My essay Explaining Rolling Motion raised some commentary about frames of reference and their equivalence when solving physics problems. I wish to pursue…

Exploring General Relativity as a Gauge Theory
The fundamental interactions of the Standard Model are described by Yang-Mills theory. This is a gauge theory, which means the following: (1) Choose a…

Astrophotography Mounts, Tracking & Post-Processing Tips
"I’ve tried astrophotography and want to know how to improve."
Choosing a mount
Here’s where I assume you are contemplating the purchase of a…

Astrophotography Level 2: Camera Setup & Techniques
Level 2: I know how to use a camera — what do I need to know for astrophotography?
Image processing, optics, and sensor basics
Image-processing methods…

Astrophotography Guide for Beginners — Essential Tips
For this Insight series (three total), I assume you either have a camera (with an attached lens) or already know how to attach your camera to your…

David Hestenes on Geometric Algebra: Applications & Learning
For those who don't know the great David Hestenes, he is the inventor of the geometric algebra formalism of physics. Here we go!
1) What is the best application…

Interview with Science Advisor DrChinese
We are pleased to share with you an interview with PF Science Advisor and one of our founding members: DrChineseWho is DrChinese and share some early…

Blaming Government for Teacher and Scientist Failures in Integrity
The article, "Governmental policy is wrecking science," makes some interesting points but is fundamentally in error, because government policy is only…

Learn How to Solve the Cubic Equation for Dummies
Everybody learns the "quadratic formula" for solving equations of the form [itex]A x^2 + B x + C = 0[/itex], even though you don't really need such a formula,…

Digital Camera Buyer’s Guide: Bridge Cameras
This article is geared towards:I've never owned a camera, but I want to get a 'real' camera (that doesn't cost too much).
I've owned an entry-level…

Learn The Basics of Rolling Motion
Although rolling wheels are everywhere, when most people are asked "what is the axis of rotation of a wheel that rolls without slipping?", they will answer…

David J. Griffiths Interview: Teaching Quantum Mechanics
We are pleased to introduce David J. Griffiths, one of the most successful physics textbook authors. Odds are if you studied physics in college, you've…

Spectral Standard Model and String Compactifications
The Connes-Lott-Chamseddine-Barrett model is the observation that the standard model of particle physics -- as a classical action functional,…

Ultimate Digital Camera Buyer’s Guide: Compacts, DSLR and Tripods
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First, congratulations! Camera technology has advanced to the point where a complete novice, using an entry-level camera right out of the…

A Poor Man’s CMB Primer: Cosmic Acoustics
Before decoupling, photons and charged particles were in good thermal contact: though the primordial plasma might have varied in temperature…

Digital Camera Buyer’s Guide — Choose the Best Camera
Introduction
First, congratulations! Camera technology has advanced so much that a complete novice using an entry-level camera straight out of the box…

Struggles with the Continuum: Spacetime Conclusion
We've been looking at how the continuum nature of spacetime poses problems for our favorite theories of physics --- problems with infinities.…

11d Gravity From Just the Torsion Constraint
It is familiar that Einstein gravity may be formulated in terms of a vielbein field together with a "spin connection", subject to the constraint…

Struggles with the Continuum: General Relativity
Combining electromagnetism with relativity and quantum mechanics led to QED. Last time we saw the immense struggles with the continuum this…

Name the Science Photo Quiz
Summer is almost over, but the fun doesn't have to stop! Take a look at the photos below and see if you can identify them. Post your score in the comment…

Learn Why Ohm’s Law Is Not a Law
At first, I wanted this title to say “Ohm’s law is not a Law.” But someone else used that phrase in a recent PF thread, and a storm of protest…

Why Road Capacity Is Almost Independent of the Speed Limit
Let us start with a familiar situation. Take a familiar part of a road, for example, the one from your home to work. How long will it take you to drive…

Why Quantum Mechanics Feels Difficult — Mathematical Bridge
QM's formalism
Strangely enough, quantum mechanics (QM)'s formalism isn't any more difficult than other areas of physics. The mathematics of the "standard"…

So I Am Your Intro Physics Instructor
I posted this elsewhere (on my blog), and someone mentioned that maybe it might also be useful here on PF. So I'm reproducing the entire entry here in…

How to Determine the Change in Entropy
How do you determine the change in entropy for a closed system that is subjected to an irreversible process?Here are some typical questions we get…

Learn About Supersymmetry and Deligne’s Theorem
In 2002, Pierre Deligne proved a remarkable theorem on what mathematically is called Tannakian reconstruction of tensor categories. Here…

Learn Orbital Precession in the Schwarzschild and Kerr Metrics
The Schwarzschild Metric
A Lagrangian that can be used to describe geodesics is [itex]F = g_{\mu\nu}v^\mu v^\mu[/itex], where [itex]v^\mu = dx^\mu/ds[/itex]…

