Compatibility with Apple iPad
Unfortunately, the iPad cannot display the Flash animations used on this site. There are two main reasons.
First, the iPad does not support Flash content. The interactive animations on this site
are written in the Flash internal language called ActionScript.
Much has been written about this decision at Apple, but whatever the reason,
it means a large body of educational material will not work on the iPad.
Second, all the applets were created assuming a mouse. They depend on the user being able to accurately
put the cursor on say the vertex of a triangle, and then drag it. With the touch interface of the iPad this is not possible.
You don't know where your finger is going to touch until it makes screen contact, and then the point of interest is covered by your finger.
The conversion plan
A major effort is underway to recode all the applets in HTML5. It expected to take until the late summer of 2013 to get them all done, but
if you would like a preview, there one page already converted for test purposes. Take a look at
It will display the Flash version on most machines, but on an iOS machines it will display the HTML5 version.
As of today (May 15 2013) approximately half the applets have been converted. The remaining 150 or so will be done over the weeks.
For those yet to be done you will see a temporary static image in place of the Flash applets.
The HTML5 design
In order to make it easier to drag small points, a new style of pointer is used. If you touch the applet anywhere, a mouse-like cursor appears that will follow as you move around the screen.
When it gets close to a vertex, it 'magnetically' grabs it allowing you to drag it.
To accommodate both left and right-handed users, touching on the right or left half of the screen offsets the cursor appropriately.
Your opinion of this design would be welcome. Send a message to John Page