Perhaps you remember Interactive Physics—it was a great piece of physics simulation software that allowed you to simply draw objects on a screen—springs, spheres, ramps, pulleys, and then set the parameters for the world, like the strength of the drag force or gravitational field, and then run the simulation to observe the behavior of the system, visualizing the not just the motion of the object, but also individual force and velocity vectors. It was great, but unfortunately, it seems like it’s development died back in mid 2005, especially for the mac, where it no longer runs at all.

Enter Algodoo physics—it’s got everything you love and remember from Interactive Physics, and so much more, wrapped up in a beautiful interface. And it runs on mac and PC.

## Getting started

Algodoo comes in two versions, education and regular. For teachers, the primary advantage of the more expensive education version is the ability to create graphs and view vectors in your simulations. This is pretty much an indispensable feature in my book, so I encourage you to spring for the more expensive version.

When you start Algodoo, you’re presented with a wide open canvas to begin to draw objects. Controls are pretty intuitive—you can quickly use the tool palette to begin to draw objects, and double clicking on any object will bring up a control panel with a host of options.

The material menu for an object

Once you’ve set up the objects in your simulation, adding vectors to represent force, velocity or momentum can be easily done with a few clicks. Similarly, it’s easy to create a graph of any quantities you choose, which you can also export to a csv file to plot in excel.

Here’s an example of how easy it is to create a simulation of the classic problem:

Three balls are thrown from the edge of a cliff with a speed of 20 m/s. One ball is thrown straight upward, one straight downward, and one horizontally. Which ball reaches the ground first? Which hits the ground with the greatest speed?

The education version of Algodoo also makes it very easy to create graphs based on the motion of objects, but one unfortunate limitation appears is that you can’t have plots of multiple objects on the same graph. You can, however, export the data as a CSV file to plot in another application, such as Microsoft Excel. Here’s an example of a simple bus chase problem I created:

Algodoo does give you full control over the forces in the simulation, allowing you to create drag forces (with both linear and quadratic velocity terms), and gravitational forces, including inverse square forces to allow you to create simulations of satellite motion.

## Optics demos

One of the things that makes Algodoo unique among the physics simulation engines I know is its ability to simulate optics demos. Algodoo comes with a laser tool, a number of basic optics elements (lenses, prisms, etc) and the ability to control the index of refraction of elements. This makes it possible to create a simulation of a rainbow:

Simulation of rainbow. It took less than 5 minutes to create this.

The optics elements are pretty basic, and while you can use the various editing tools to modify them, I don’t think they’re quite customizable enough to serve as some sort of virtual optics lab—it’s pretty hard to create a lens of a given focal length, for instance. But it is pretty awesome for simulating basic light refraction and reflection in various media. Overall, these features show great promise, and I hope that the developers will add to it, perhaps making it easier do ray diagrams by making it possible to add reference lines and objects that one could then use to locate real and virtual images.

## Networked features

Algodoo promises to allow you access to a library of ready made simulations for use in your classroom. Currently, the library is somewhat limited, and focused mostly on intricate (and pretty cool) simulations of working machine guns. Some of these simulations are so amazing that I find myself wondering how they were created by the users—they are an order of magnitude more complex than anything I could imagine creating myself.

The education version also allows you access to the lesson browser, which contains a large set of lessons created by users around the world describing how to use Algodoo to teach various physics topics. Unfortunately, the lessons I checked out were somewhat lacking—most are fairly basic descriptions of steps to follow to explore why wheels are round, etc, and don’t include links to simulation files to get you started. The attachment below does contain a number of the better lessons you’ll find.

View this document on Scribd

## Other features

Algodoo has built-in support for graphics tablets, and I found it to be incredibly easy to use with my Wacom tablet. In addition, the education version comes with settings to make it easier to use on interactive whiteboards as well.

## Overall

As someone who once truly loved Interactive Physics, I really enjoy playing with Algodoo Physics—it’s an incredible refined physics simulation engine compared to what I worked with previously. I can also imagine that it would be very powerful for all of my students to have this when we go 1-1 next year. It also gives me one more very useful tool for exploring computational thinking, and more to think about in how to help students learn to determine the best tool for solving a particular physics problem (Aglodoo, VPython, Mathematica, etc).

The developers seem to be making rapid improvements to the software, so I wouldn’t be surprised if in the near future you’ll find it possible to plot multiple object in the same graph. If they’re taking requests, I’d love some simple annotation tools, so that one could easily place arrows and text on the screen without having to tie them to an object.

The cost for the Education Version of Algodoo Physics 45 euros (\$60 USD), and you can purchase a site license for 1 euro per student per year (3 year contract required). If you own a Mac, you can purchase it Mac App store for \$41.99 (currently on sale for 30% off—regular price \$59.99).

I wrote the developers, and they also generously offered a 10% discount to anyone who purchases the app through their online store (not the Mac App Store) using the discount code: Quantum. This discount will work for both the mac and pc version of the software.

Full disclosure: I purchased the basic version of Algodoo Physics, and then enquired about a possible upgrade to the education version through the app store. When I mentioned I would like to write a review for the software, the authors kindly gave me a promotional code to download the app.