Tag Archive for: General

Revisiting the Velocity-Time Function
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Kinematics: The Velocity-Time FunctionAuthor's Preface: A Collaborative Approach to Lesson Development
The intention behind what I hope will be…

Remote Operated Gate Control System
Introduction
This project began life in 2017 when the author had just begun experimentation with GPIO pins on a Raspberry Pi 3. At that point in time…

Inside the Scientific Box: History and Challenges Today
In Memoriam
In Memory of Dr. Thomas J. LeCompte (1964-2025), Detector Designer and Champion of Education and Science.
Prologue
Defining "the box"
Someone…

Hybrid AI Video Codecs and Modern Streaming Techniques
Introduction
AI and Hybrid Codecs
Modern Video codecs are all based on similar principles. Recently, these have been complemented by AI techniques,…

Why Division by Zero Is Impossible: 10 Mathematical Reasons
A division by zero is primarily an algebraic question. The reasoning therefore follows the indirect pattern of most algebraic proofs:What if it was…

Modern DACs, Dither, DXD & High-Res Audio Explained
Introduction
First, we need some background in Digital Signals. This can be mathematically quite advanced, but since I would like this article to be accessible…

The Poor Man’s Milli-Ohm Meter
Introduction
In a previous article on measuring battery internal resistance, a simple technique for low-resistance measurement was outlined. In this article,…

Beginners Guide to Precalculus, Calculus and Infinitesimals
Introduction
I am convinced students learn Calculus far too late. In my view, there has never been a good reason for this.In the US, they go through…

Why ChatGPT Is Unreliable: Design Limits and Misconceptions
ChatGPT's reliability
I'll start with the simple fact: ChatGPT is not a reliable answerer to questions.
Wolfram's explanation
To try to explain why from…

What Are Infinitesimals – Simple Version
Introduction
When I learned calculus, the intuitive idea of infinitesimal was used. These are real numbers so small that, for all practical purposes (say…

Popular Science Communication: Bridging Science & Public
Abstract
Famous Science Communicators
There is so much to say about the many endeavors by professional scientists to explain to us the world. The list…

A Lesson In Teaching Physics: You Can’t Give It Away
A central principle of Physics Forums regarding homework help is not to provide solutions on demand but to guide students along a path to the answer. The…

Mathematics Fields & Applications: A Structured Guide
Introduction
I often read questions about our classification scheme that we use on physicsforums.com to sort posts by science fields and subjects, what…

Program ATmega8A with Arduino: Step-by-Step Guide
Introduction
If you are interested in programming and electronics, you probably do not need an introduction to Arduino. If you want to make your Arduino…

Quantum Computing Explained: Qubits, Algorithms & Applications
Overview
This article provides an accessible introduction to quantum computing, a cutting-edge technology that processes certain types of information…

How Can We Jump When the Ground Does No Work?
Common mistaken argument
It is relatively common on Physics Forums to see arguments that are effectively similar to the following:
When we jump off the…

A Trick to Memorizing Trig Special Angle Values Table
In calculus classes when you are asked to evaluate a trig function at a specific angle, it's 99.9% of the time at one of the so-called special angles we…

Raspberry Pi Cluster Guide: Parts, MPI & Slurm Tips
INTRODUCTION
As a long-time computer programmer and almost as long a High-Performance Computer (HPC) user, I didn't know anything about how these machines…

Physical Applications of the “Tan Rule”
Introduction
Every secondary school student who has encountered trigonometry in his/her Math syllabus will most likely have come across the sine, cosine,…

Quantum Mechanics and the Famous Double-slit Experiment
Double-slit Key PointsQuantum mechanics is known for its strangeness, including phenomena like wave–particle duality, which allows particles to…

Safety Factors: Why Forums Avoid Design Advice Online
Forum Guidelines
There are often questions on Physics Forums related to building machines or structures that are left unanswered because of this guideline…

LCEVC and EVC: Efficient Video Encoding Guide for 8K
Introduction
Background: H.264 and H.265
First, for background, here is an overview of the most common video compression standard in use today, H264:…

10 Math Things We All Learnt Wrong At School
Some of these could even lead to heavy debates within the scientific community, so maybe I should say: from my point of view. So before you get excited…

Valentine’s Reflections: Mathematical Matters of the Heart
Introduction
Being a somewhat geeky Maths 'nerd', I spent days leading up to Valentine's Day trying to find a Maths function appropriate to the day. In…

Ambiguous SSA Case in Triangles — Law of Sines Explained
What is the ambiguous case?
In U.S. high schools, students are often introduced to geometric proofs for the first time. A common task is to use a small…

Equations of Motion Revisited
Introduction
In any school Physics course, the Newtonian equations of motion are very much a 'stock' item. Students learn the equations and are given…

How to Master Projectile Motion Without Quadratics
Introduction
In a homework thread a while back a PF member expressed dismay along the lines of "Oh no, not another boring projectile motion problem."…

I Know the Math Says so, but Is It Really True?
I'm sure anyone who has hung out long enough here on Physics Forums has encountered threads that go something like this (I'll use an example based on threads…

Does the Block Universe of Physics Mean Time is an Illusion?
I have written many Insights (and coauthored an entire book) explaining how the puzzles, problems, and paradoxes of modern physics can be attributed to…

AI and Learning: How It Impact Our Future
PF Advisors: How AI Will Affect STEM — Part 3We asked our PF Advisors, "How do you see the rise in AI affecting STEM in the lab, classroom, industry,…

How AI Is Changing STEM Labs, Classrooms & Industry
We asked our PF Advisors: “How do you see the rise in A.I. affecting STEM in the lab, classroom, industry, or in everyday society?” We received so…

How the Rise of AI Is Transforming STEM: Labs to Classrooms
We asked our Physics Forums (PF) Advisors: "How do you see the rise of AI affecting STEM in the lab, classroom, industry, and everyday society?" We received…

Interview with Engineer jrmichler
Today we get to know a little more about Engineering Mentor jrmichler!
Tell us a bit about your education and academic years
Two years college (UW-Madison)…

How Non-Scientists Should Evaluate Scientific Claims
How should non-scientists evaluate scientists' public claims?
In a previous article, I discussed why scientists (among others) are rarely interested…

Big Bang Evidence: CMB, Redshift & Element Abundances
Big Bang: Key PointsHubble's law (redshift of galaxies) and the Doppler effect provide direct evidence that the universe is expanding away from our…

Why Uranus Spins on Its Side: Tilt, Theories, Models
Uranus' Peculiar Tilt
Uranus spins on its side. It has an obliquity (tilt) of 98° — its rotation axis lies closer to the ecliptic plane than any other…

Introduction to Evolution: Key Concepts & FAQs Guide
Introduction to Evolution
Overview
The study of evolution has dominated biology for over a century. Explaining why life is the way it is fascinates both…

Mary Somerville: Scottish Polymath & RAS Honorary Member
Mary Somerville & Caroline Herschel: Google DoodleGoogle Doodle: Mary Somerville and Caroline Herschel
The Google Doodle for 2 February 2020 celebrated…

Why We Don’t Discuss Perpetual Motion Machines (PMM)
Authorship
Authorship Contributions From Anorlunda
Introduction
You may want to believe the article you read, or the video you saw, or you may be very…

Beginner C++ Tutorial — Compiler, Types & I/O Basics
ContentsGetting a C++ Compiler and Compiling Your First Program
Simple Datatypes and Declarations
Operators and Expressions
Input and Output…

Tell One Wood from Another: Basic Wood Anatomy
Introduction
About the author
As a long-time woodworker, I enjoy being able to tell one wood from another. In the process of learning how to do that,…

Grab Bag Science Quiz and Trivia
Time to test your science knowledge with a fun 10 question quiz with random questions across all sciences. Difficulty is easy to medium. As always, post…

SOHCAHTOA: Seemingly Simple, Conceivably Complex
What is SOHCAHTOA
SOHCAHTOA is a mnemonic acronym used in trigonometry to remember the relationships between the sides and angles of right triangles.…

Android Rooting & Magisk Guide: Systemless Root Tips
Android Rooting & Magisk Guide: Systemless Root Tips
Overview
What you can learn from this article:What is meant by rooting an Android phone
…

Debloating Android Phones: Risks, Myths and Safe Tips
What is bloatware?
Stock firmware and preinstalled apps
When you unbox a new phone, it comes with Android pre-installed by the manufacturer. This is…

How to Ask ‘What If’ Physics Questions: Avoiding Pitfalls
Overview of "What If" Questions
We receive many "what if" questions here on Physics Forums. This article explores three common types and offers suggestions…

First-Order Linear Equation: Definition & Solutions
Definition / Summary
This article summarizes the first-order (linear) polynomial equation in one variable, its solution, and natural extensions to matrices…

Significant Figures: Rounding Rules & Examples for Science
Definition / Summary
Significant figures (commonly called "sig figs") are the digits in a number that are considered when rounding a value to reflect…

Evaluate Camera Lens Performance Using an LCD Display
Introduction
I've done plenty of imaging performance testing on a variety of systems, from millimeter wave to UV. Until very recently, such testing required…

Parabola Explained: Properties, Equations & Practical Uses
What is a Parabola?
A parabola is a U-shaped curve that appears frequently in mathematics, physics and engineering. It is a conic section defined by a…

When Renewable Energy Meets Power Grid Operations
Introduction
The electric power industry faces much turmoil in the coming decades. The business model of the electric utility company (public or private)…

Revolutionary Technologies and Discoveries in 20 Years
Experts weigh in: Most revolutionary technologies and discoveries in the next 20 years
We asked our Physics Forums science advisors, "What technology…

How to Create a Universe: Instructions for an Apprentice God
Preface
(-: ##~~~## A fantasy to be read at leisure time ##~~~## :-)Background & Links
Written October 7, 1999 to relax from the strains of…

Aiming High and Managing Distractions as Keys to Success for Science Majors
Overview
Over the years, I've noticed some distinct trends among the physics and chemistry majors I've mentored and worked with.
Those with GPAs in…

Suanpan & Soroban: History, Design, and Usage Guide
Introduction
Overview
Abacuses are commonly seen in ancient civilizations around the world as a convenient tool for simple calculations. In this article…

Michio Kaku Interview — Peak Oil, String Theory & Space
Don't forget to read Part 1 of this interview.
Peak Oil and Future Energy Sources
Professor Kaku, what do you think of "peak oil"? How serious is it,…

Michio Kaku Interview — Physics, String Theory & Future
We are happy to present this archived interview with Dr. Michio Kaku, conducted in 2004. Michio Kaku is an American theoretical physicist, futurist, and…

Are Magnetic Field Lines Real?
Introduction
We recently had a question in the relativity forums that mentioned the behavior of magnetic field lines and reminded me of my confusion at…

Inventions and Inventors Quiz and Trivia
Time to test your inventions, inventors and patent knowledge. As always there is no prize, so try without Google. Post your score in the comment thread.…

Interview with Engineer Mentor anorlunda
Tell us about your school years?
Part of my story is sad but common. I was a poor student. I didn’t pay attention, and I never did homework even once;…

Interview with Physics Mentor bhobba
Give us an executive summary on bhobba
I was born in Toowong Brisbane Australia 17/11/1955, and was raised in suburbs around Toowong - Toowong itself,…

Beginner Telescope Guide: Choose the Right First Scope
What telescope should a beginner buy?
Overview for beginners
People often ask what telescope an aspiring amateur astronomer should buy. There isn't a single…

What Are Your Favorite Science or Math Blogs?
We asked our PF Advisors to tell us what their favorite science or math blog is (other than PF Insights).We also have a physics blog list here.Here…

Match the Scientist with the Story Quiz
Among the most famous people are often geniuses. It's hard to tell whether this is the reason for the many anecdotes which are told about them, or whether…

Direct Echo-Based Measurement of the Speed of Sound
Figure 1: Distance vs. time a firecracker report echoed off of a building at different distances on both a cold and a warm day.Introduction
The…

Interview: Niels Tuning — LHCb Run Coordinator at CERN
Physics Forums is pleased to introduce Niels Tuning. He's a physicist working as the Run Coordinator for the LHCb experiment at CERN. Apart from the questions…

What Academic Advice Would You Tell Your 18 Year Old Self?
We asked our PF Advisors to tell us what academic advice would you tell your 18 year old self. Here are their responses…
PF Advisors' Academic AdviceThanks…

What’s Your Most Memorable Textbook?
We asked our PF Advisors to tell us their most memorable or influential textbook and why. Here are their responses...
PF Advisors' Favorite TextbooksThanks…

Lessons From the Bizzaro Universe
The terms Bizarro and Bizarro World originated in Superman comics, where strangely imperfect versions of Superman, other action characters, and even Earth…

Adam Becker — What Is Real? Quantum Foundations Explained
Adam Becker is an astrophysicist and science writer whose first book, What Is Real?: The Unfinished Quest for the Meaning of Quantum Physics, has just…

Addressing the “Classical Physics Is Wrong” Fallacy
Introduction
One of the common questions or comments we get on PF is the claim that classical physics or classical mechanics (i.e. Newton's laws, etc.)…

Clifford V. Johnson: The Dialogues & Science Outreach
Clifford V. Johnson is a professor in the Physics and Astronomy Department at USC. He says, "I mainly work on (super)string theory, gravity, gauge theory…

Name the Science Book Author Quiz
Let's see how well you know your science book authors. Some are classic, some modern! Don't forget to post your score in the comment thread linked at the…

Intro to the Big Bang and Infinity Concepts
In the cosmology section of the Physics Forums, I encountered many Big Bang and related infinity problems. Hence, in this article, I want to explain the…

Interview with a Mentor: Drakkith
Give us an early bio on yourself
Well, I was born and raised near Dallas, Texas as the only boy of 4 children. I grew up with 3 sisters, though I had…

3 Tips for Calmer, Civil Debate and Better Conversations
Introduction
Civil discussion and debate are critical to Physics Forums. But it is also important in everyday life. When arguments get overheated, people…

The Birth of a Physics Textbook: An Author’s Journey
It is said that you should accomplish three things in life:Plant a tree.
Have a child.
Write a book.Out of the three, I have…

Why Work Ethic Is a Key to Success for Science Majors
Student Success and Key Factors
After earning a 4.0 GPA in his first semester as a Physics major at an esteemed state university, our son (and homeschool…

Arnold Neumaier Interview: QFT Foundations & Thermal
Please give us a brief background on yourself
Over 40 years ago, I studied mathematics, physics and computer science in Freiburg and Berlin (Germany).…

How to Make Units of Measurement Work for You
How do we use units? You may see one of these speed limit signs, nearly every day. Even though neither of them displays units, drivers know they are implied.…

Exam Tips & Test Strategies: Practical Study Techniques
Managing Exam Stress
Exam situations are always situations of stress. It comes with our endeavor to be as good as possible and our fear of failure. Some…

Solar System Imaging: Telescope, Camera & Filters Guide
Introduction
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…

15 of the Best PF 2017 Eclipse Photos
The 2017 August Eclipse really was something special. Fortunately Physics Forums has great photographers and snapped some remarkable shots. Here are a…

From Biology to Sysadmin: Career Insights & Advice
Interview: From Biology to Programming, Sysadmin, and Life in New Mexico
What got you interested in biology?
I was an amateur naturalist as a kid. I…

Name the Scientist Quiz and Trivia
Time to test your scientist photo recognition skills! As always please post your score in the comment thread at the end.Ready for your next quiz?…

Pamela Gay Interview — Astronomy, Citizen Science & Outreach
Please give us a bit of background into your educational and professional life.
I'm a public school kid through and through. After going to the local…

How to Ask Questions Effectively and Avoid Cold Questions
Common Questions We Receive
We frequently get questions such as these:"What is energy?""What are Cooper Pairs?""What is conservation of momentum?"etc...etc.
Why…

The Joy of Processing
In the early days of the personal computer revolution, computers were small, simple, and easy to operate. It was always great fun to write BASIC games…

Revamping Undergraduate Introductory Physics Laboratory
Introduction
This is a compilation of my blog entry on this singular "project" to change the way we conduct the introductory physics laboratory in most…

Q&A With Universe Today’s Astronomer Fraser Cain
Video Q&A: Fraser Cain (Universe Today)
Special thanks to Universe Today founder Fraser Cain for this fascinating video Q&A. All questions were…

Sabine Hossenfelder: Dark Matter, Gravity & LIGO Interview
We are pleased to introduce Sabine Hossenfelder. Sabine is a theoretical physicist at the Frankfurt Institute for Advanced Studies. She also authors…

Ultra-Wide-Angle Lenses: Design, Use, and Guide
Note, unless otherwise specified, all focal lengths are in terms of the 35mm image format.
Overview: why ultra-wide-angle lenses matter
Recently there…

Learning to Learn: Key Skill for Aspiring Physicists
Context: The Question I Get Asked
I mentioned in an earlier Insight what I think are the most important things you can learn by being on Physics Forums.…

PF Insight Scavenger Hunt 2
We have an amazing count of over 320 Insights published at Physics Forums. Now we test to see how much you remember from some of them. If you need a hint…

Types of Computer Languages: From Machine to High-Level
Introduction
In this Insights Guide, the focus is entirely on types of languages, how they relate to what computers do, and how they are used by people.…

Ancient Experiments: Elijah, Psammetichus, Early Science
Overview
In this Insight, I'm going to talk about two of the first science experiments in recorded history. One was allegedly performed by the Prophet…

Real Research in Unexpected Places; Boat Ramps
Read part 1 -Backyards, Barns, Bayous
Air Force Academy appointment
When I was offered a job at the Air Force Academy, it seemed like an opportunity to…

When Simple Geometry Unveils Deep Math
Introduction
It is a remarkable fact that consideration of very elementary concepts in geometry often leads quickly into deep and unexpected mathematical…

NASA Quiz and Trivia: Test Your NASA Knowledge
Since the mid 20th century NASA has been a force in aerospace research and programs. Let's find out just how much you know about it's history, programs…

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…
