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Physics Education Technology - University of Colorado, Boulder

New, Improved Plate Tectonics and Molecule Shapes

Plate Tectonics

Have you tried Plate Tectonics or Molecule Shapes, but couldn’t get these sims to run on your computer?

Well, try again! We’ve upgraded both to work on as many platforms as possible. Please note that the simulations use LWJGL for the 3D graphics. Unfortunately, at this time LWJGL does not support Java 7 on Mac OSX. For to run these simulations, it is necessary to downgrade your Java to version 6. To learn how to do this, see

If you’re still having troubles, please let us know so we can ensure that it works for everyone.

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Feb 5


3 Comments | Add your comment ↓

  1. Brian Kent #

    The Phet simulations are all broken now that I’ve installed OSX Mavericks and Java 7. I am unable to downgrade to Java 6 despite following the guide linked above and trying every other installation I can think of. It even crashes in my virtual Windows environment, running Java 6. Sims ran fine on OSX 10.7 before I upgraded, but I am not able to get back to that.

    • Hi Brian,
      Unfortunately, the problem with Molecule Shapes (the 3D VSEPR sim) shows up on all Mac OS X 10.8+ and many 10.6 and 10.7. This is due to an incompatibility between the graphics hardware on those systems and the 3D graphics library used in the simulation (LWJGL). At this time the incompatibility problem is out of our hands and unless Oracle or Apple address this issue, it is unlikely the sim will run successfully. It is possible that updating the graphics drivers on your computers will resolve the problem – I have had success with this on some CU computers.

      We are hoping incompatibilities like this will be a thing of the past once we move most of our sims to HTML5. But until we get the funding necessary to convert these sims, the existing sims will be the only option.

      I will keep you updated on any developments.


  2. Nick Mitchell #

    I am also having trouble getting this sim to run in Mac OS- downgrading Java is not really a workable option. I hope you would give sims like this priority when developing your HTML5 versions, since there’s probably a large number of teachers out there like myself who are unable to use this great sim.

    Keep up the good work!

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