Course Entry Information for Learning Courses Guest access is turned off because I want all users to get the full effect but you can gain quick first-visit access to the Learners courses.  To do so, click on Login, create an account, check your email, activate your account, and click on one of the Learners courses.  First-time users will be asked to enter a key.  The key for both Learners courses is currently cbphysics. By carrying out the steps above, you will have enrolled yourself in the course.  The next time you want to enter the course you simply log in and click on the name of the course.  If, after enrolling in a course, at some time in the future you wish to unenroll yourself from that course, you can do so by means of a link inside the course.