1. Homework Help

   1. Introductory Physics Homework

      Dependence of Coulomb's law on the medium

   2. Advanced Physics Homework

      Time evolution of wave function in an infinite square well potential

   3. Precalculus Mathematics Homework

      Real number x s.t. relation is satisfied?

   4. Calculus and Beyond Homework

      The minimum of a function in a given domain

   5. Biology, Chemistry and Earth Homework

      Which mechanism and which step would best fit the data?

   6. Engineering and Computer Science Homework

      What is the gain error for this opamp driven by a voltage

2. Science Education and Careers

   1. Science and Math Textbooks

      Multivariable calculus without forms or manifolds

   2. Academic Guidance

      Jobs in general relativity

   3. Educators and Teaching

      Hall's Marriage Theorem

   4. Career Guidance

      How much money can you make in physics?

3. Physics

   1. General Physics

      Perceived gravity

   2. Classical Physics

      Moment of inertia of a thin uniform rod

   3. Quantum Physics

      Use spacetime perturbance to figure out which way

   4. Special and General Relativity

      A Geometrical View of Time Dilation and the Twin Paradox - Comments

   5. Atomic and Condensed Matter

      What causes solidity of objects?

   6. High Energy, Nuclear, Particle Physics

      Moving Center of Mass Collisions

   7. Beyond the Standard Model

      spin sums ?

4. Astronomy and Cosmology

   1. Astronomy and Astrophysics

      Why is there rust on Mars?

   2. Cosmology

      Total number density of galaxies and problematic expression

5. Mathematics

   1. General Math

      Math Challenge - December 2018

   2. Calculus

      Proof about Fourier transform

   3. Differential Equations

      Chaos Theory Constants

   4. Topology and Analysis

      Trying to understand why a set is both open and closed

   5. Linear and Abstract Algebra

      How to properly understand finite group theory

   6. Differential Geometry

      Tangent spaces at different points

   7. Set Theory, Logic, Probability, Statistics

      Rare Entropy and Hidden Markov

   8. MATLAB, Maple, Mathematica, LaTeX, Etc

      Problem with line integrals in Mathematica

6. Engineering

   1. General Engineering

      Keeping food hot in food delivery bag

   2. Mechanical Engineering

      Race car suspension Class

   3. Electrical Engineering

      UHF HDTV reception (Freeview) in the UK

   4. Materials and Chemical Engineering

      Searching for a strong inflexible plastic that is transparent

   5. Nuclear Engineering

      Geiger (or other ionizing ray) Probe for Vacuum Conditions

   6. DIY Projects

      Recommendations: Project inspiration w/ a budget

7. Other Sciences

   1. Chemistry

      Co2 ppm exposure relative to room m3 and air ventilation

   2. Programming and Computer Science

      TOR protocol clone

   3. Biology and Medical

      Why does photosynthesis produce O2 from CO2?

   4. Computing and Technology

      Can't see PDF contents as well as Google does

   5. Earth

      Freezing fog creates rare light pillars in Wisconsin on Sunday

8. Uncategorized Thought Field

   1. 2018 PF Member Award Polls

      Physics Award

   2. General Discussion

      Lame Jokes

   3. Science Fiction and Fantasy Media

      Lasers Versus Psychic Force Bubble

   4. Feedback and Announcements

      2018 PF Member Awards Are Coming!

   5. New Member Introductions

      Greetings fellow nerd type organisms

• Log in with Facebook
• Log in with Twitter

Your name or email address:

Do you already have an account?

• No, create an account now.
• Yes, my password is:
• Forgot your password?

Stay logged in