In most browsers, pressing F11 will enter Full Screen Mode. For a short demonstration on YouTube by the programmer, click here. or here: http://www.youtube.com/watch?v=2LLAwJW3GLk
If you see no applet, you may need to Download Java.
With this demonstration, I was seeking to find a way to make Special Relativity more accessible by creating a computer animated Space-Time canvas. on which pairs of events could be painted, and then allow the user to perform a Lorentz Transformation around the center of the image, either by dragging the events around the page, or by using the acceleration buttons.
To see the difference between a hyperbolic rotation and a regular rotation, see the images here: http://www.physicsforums.com/showpost.php?p=3405177&postcount=20
Space Time Diagrams? Why would I want to animate that?
You should first familiarize yourself with the idea of a spacetime diagram. In this diagram we have one dimension of space (left and right), and one dimension of time (up and down). Any point on the space-time diagram is called an Event, as it happens at a particular place in space and time.
In an ordinary space-time diagram, of course, those events are stuck wherever you pen or pencil them in. So the first advantage of this simulation is that you may press a button "Pass Time" and those events begin marching steadily down from the future, to the present, into the past.
There is a special point on the screen, at the center of the big X, called the Origin. It is at t=0 (Here) and x=0 (Now). That is an important point, because it represents the Observer. Anything coming toward that point is coming toward the observer. When you press one of the accelerate buttons, it is that Observer who is accelerating.
As you watch the events scroll down the screen, you can also see that the "Proper Time" entry is increasing. This "Proper Time" is measuring the time that has past for the Observer.
The second thing you cannot do in an ordinary space-time diagram is accelerate the observer. When an observer accelerates, you could say he is dodging events. If an event is coming directly in his future, but he accelerates to the right, then that event will happen, instead, to his left. Hence events can be moved, by the observer's change in velocity, either straight left, or straight right, but under ordinary understanding, one should not be able to take an event and push it into the future or the past.
However, with Special Relativity, it turns out that events do not move straight left and right, but instead along parabolic arcs of the form c^2 t^2 -x^2=Constant.
By sliding the Scale Slider all the way over to the left, you can see a nearly non-relativistic treatment, where events can move only left and right--a simulation of what we perceive in our day-to-day lives. But when the slider is more centered, or to the right, you can see the events moving on these hyperbolic arcs.