# Physics Articles

Here contains the collection of expert Insight articles that deal with physics topics. These span all skill ranges and may include astronomy and cosmology topics.

### Why the Quantum | A Response to Wheeler's 1986 Paper

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Wheeler's opening statement in his 1986 paper, How Come the…

### The 10 Commandments of Index Expressions and Tensor Calculus

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Having more than 10 years of experience in teaching vector and…

### Direct Echo-Based Measurement of the Speed of Sound

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Figure 1: Distance vs. time a firecracker report echoed off…

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### Lessons From the Bizzaro Universe

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The terms Bizarro and Bizarro World originated in Superman comics,…

### Either the Sun Is Getting Smaller or Gravity Is Getting Weaker

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Paper discussion: Solar system expansion and strong equivalence…

### Statistical Mechanics: The Ideal Gas

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Read Part 1: Equilibrium Systems The Ideal Gas: Boltzmann's…

### "Classical Physics Is Wrong" Fallacy

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One of the common questions or comments we get on PF is the claim…

### Mathematical Quantum Field Theory - Renormalization

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This is one chapter in a series on Mathematical Quantum Field…

### Mathematical Quantum Field Theory - Interacting Quantum Fields

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This is one chapter in a series on Mathematical Quantum Field…

### Mathematical Quantum Field Theory - Free Quantum Fields

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This is one chapter in a series on Mathematical Quantum Field…

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### The Fundamental Difference in Interpretations of Quantum Mechanics

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A topic that continually comes up in discussions of quantum mechanics…

### Mathematical Quantum Field Theory - Quantization

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The following is one chapter in a series on Mathematical Quantum…

### Coordinate Dependent Statements in an Expanding Universe

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In this Insight we will discuss the general Robertson--Walker…

### The Schwarzschild Metric: A Newtonian Comparison

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A Short Proof of Birkoff's Theorem derived the Schwarzschild…

### The Schwarzschild Metric: The Photon Sphere

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A Short Proof of Birkoff's Theorem derived the Schwarzschild…

### Mathematical Quantum Field Theory - Gauge Fixing

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The following is one chapter in a series of Mathematical Quantum…

### The Schwarzschild Metric: GPS Satellites

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A Global Positioning System (GPS) device gives your…

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### Mathematical Quantum Field Theory - Reduced Phase Space

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The following is one chapter in a series on Mathematical Quantum…

### Mathematical Quantum Field Theory - Gauge Symmetries

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This is one chapter in a series on Mathematical Quantum Field…

### Mathematical Quantum Field Theory - Propagators

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This is one chapter in a series on Mathematical Quantum Field…

### Mathematical Quantum Field Theory - Phase Space

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The following is one chapter of a series on Mathematical Quantum…

### Mathematical Quantum Field Theory - Observables

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The following is one chapter in a series on Mathematical Quantum…

### Mathematical Quantum Field Theory - Symmetries

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The following is one chapter in a series on Mathematical Quantum…

### Mathematical Quantum Field Theory - Lagrangians

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This is one chapter in a series on Mathematical Quantum Field…

### Mathematical Quantum Field Theory - Field Variations

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This is chapter 4 of a series on Mathematical Quantum Field Theory.The…

### Using the Spaghetti-Twist to Align DNA

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A new paper from a collaboration of Canadian physicists has demonstrated…

### Mathematical Quantum Field Theory - Fields

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The following is one chapter in a series on Mathematical Quantum…

### Mathematical Quantum Field Theory - Spacetime

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The following is one chapter in a series on Mathematical Quantum…

### Mathematical Quantum Field Theory - Geometry

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This is the first chapter in a series on Mathematical Quantum…

### A First Idea of Quantum Field Theory - 20 Part Series

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These notes mean to give an expository but rigorous introduction…

### Introduction to Perturbative Quantum Field Theory

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This is the beginning of a series that gives an introduction…

### How I Stopped Worrying and Learned to Love Orthodox Quantum Mechanics

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Many people here know that I am a "Bohmian", i.e. an adherent…

### 15 of the Best PF 2017 Eclipse Photos

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The 2017 August Eclipse really was something special. Fortunately…

### A Poor Man's CMB Primer: Quantum Seeds

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The CMB establishes a record of ancient acoustic…

### Results Shown at EPS Conference

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The EPS conference was a week ago, and many new results and future…