Yes, that is on purpose. I use them when I change subject or when I want the audience to look at me, instead of at the screen. It is quite a smart trick. The following article neatly describes the effect of a black screen: http://www.bertdecker.com/experience/2007/03/blog_entry_date.html
I agree that it looks strange outside the context of the presentation. --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to [email protected] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://sage.scipy.org/sage/ and http://modular.math.washington.edu/sage/ -~----------~----~----~----~------~----~------~--~---
