Optical illusion in Firefox

Steps to reproduce:

  1. Select "About Mozilla Firefox" from the "Help" menu.
  2. Click the "Credits" button.
  3. Read the credits as they scroll by.
  4. After the end of the credits list (don't bother trying to read the copyright stuff at the bottom), look at somthing else, such as the titlebar of the About Mozilla Firefox dialog.


At least for me, the titlebar appears to sag.

13 Responses to “Optical illusion in Firefox”

  1. ant Says:

    Doesn’t do it for me… :/
    Maybe it depends on the title bar colours, I’m using blackbox which has a fairly grey default theme.

  2. Jesse Ruderman Says:

    It might help to try to keep your eyes around the middle of the area where text scrolls.

  3. Jaosn Barnabe Says:

    Haven’t you ever noticed the effect when watching movie credits? As soon as they stop scrolling, it looks like everything else is moving down.

  4. Jesse Ruderman Says:

    No, I hadn’t noticed the same effect with movie credits, but I’ll look for it in the future.

  5. David Naylor Says:

    Yeah, I can see it too, sorta.

  6. Caspar Says:

    Nope. But the scroll is definitely not smooth at the end (the copyright stuff).
    (FF 1.5 RC3 OSX ~ iBook 12″)

  7. Jonathan Says:

    Wow, I never noticed before how jerky the credits scrolling was.

  8. James Pole Says:

    I notice the same effects as Caspar. The copyright part is rather shocking, it skips and shutters quite a bit. I’m using the Fredora Core 4’s Firefox v1.0.7 build which is Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.12) Gecko/20050922.

  9. Ritchie Says:

    I’m on OS X 10.4.3 with FF 1.5 RC3.

    – Credits are jerky at some point.
    – Copyright stuff goes slower as it reaches the end.
    – Nothing happanes to the Dialog’s title bar.



  10. James Says:

    I thought it was thoughtful and appropriate to include Nigel McFarlane. I wanted to mention that before, but I thought nobody read the credits.

  11. James Says:

    I’m going to throw this random link out there. It concerns making firefox’s memory footprint significantly, 5.5 times, smaller. Not my biggest concern; however, for many users it is. Interesting concept. Interesting reading. Saw on digg.com


  12. Nils Says:

    Watch a tall waterfall for about a minute (keeping your gaze on the same spot) and then look at the rocks next to the waterfall. The effect is geologically impressive. I highly recommend trying it.

  13. Scott Says:

    I don’t have the patience to wait for all those names to scroll, but thanks anyway. ;-)