Physics is one of the hardest scientific subjects to grasp. The increased level of difficulty for students can make a physics professor's job even tougher. Yet, there are many tools that can be used to assist in the teaching of physics. For instance, experiments and simulations can be used to in explaining certain concepts. Here are the Physics Professor's Ultimate Resources.

**Geometry/Trigonometry**

- The Geometry Junkyard: Provides lesson plans and notes
- Gallery of Interactive Geometry: Interactive geometry activities relating to Orbifold Pinball, projective conics, and more
- Geometry Online: Various activities that involve geometry like measuring isosceles triangles and working with circles around Pythagoras
- Geometry, Surfaces, Curves, Polyhedra: Provides information on harder geometry subjects
- Geometry in Art: Explains how geometry comes out in art
- Differential Geometry: Shows how to use differential geometry
- Trigonometry Exercises: A few good trigonometry exercises
- Trigonometry Applets: A site with animations for different subjects like sin, cos, etc.
- Trigonometry Archives: A great resource page on trigonometry

**Chaos & Fractals**

- Chaos Demonstration Overview: Explains the chaos theory by demonstrating it via java
- Chaos Demonstration Software: A list of links to chaos demonstrations and teaching materials
- Unification and Emergence in Physics: Explains how unification and emergence fit together
- Lorenz Butterfly: Online video representation of the phenomenon
- Billiards and Pool Physics Resource: Great collection of resources for billiards ball computer
- Catastrophe Teacher: The article by Lucien Dujardin, for all experimentalists

**Tools**

- Contour Plot: Explains a contour plot and its uses
- Contour Plotting Using Java: Interactive site that allows the user to do contour plotting
- Algorithms and Data Structure: Great resource page for research and reference
- Online Conversion: Popular conversion for mathematics and real life
- Using Graphing Calculators: Explains how to use graphing calculators for physics problems
- Online Scientific Calculator: Online scientific calculator for everyone to use
- 50 Famous Curves: Provides diagrams of 50 famous curves with equations, facts, and questions

**Mechanics**

- Laws of Planetary Motion: A discussion of Johannes Kepler’s laws of planetary motion
- Kepler's Three Laws of Planetary Motion: Explains these laws in detail
- Basic Trajectory Simulation: An interactive simulation about trajectory
- Trajectory Simulation: Another simulation that involves working with trajectory
- Torsion Pendulum Experiment: Experiment involving physics and pendulums
- Physics and Momentum: A look at how momentum works in physics
- The Friction Lab: A list of links to Friction experiments

**Optics**

- Rainbows: A great explanation of rainbows
- Catastrophe Optics: Provides information on catastrophe optics
- Caustics: An overview of caustics
- Visual Illusions: Relates about how visual illusions work
- Spiral Illusion: Displays a spiral illusion
- Newton’s Color Wheel: An explanation with illustrations
- Spectra Code: A chart that displays when the red, green, and blue color streams

Simulations and experiments can help the mind grasp some physics concepts faster and fuller. Whether it’s a simple experiment or a difficult one, they are very valuable. With these resources, teaching physics can never be easier and more beneficial to students of physics!