Macro to scroll through 3 workbooks on timer if no activity

I am using excel 2010 and I have three workbooks - Book1.xlsm, Book2.xlsm, and Book3.xlsm. All three of these workbooks are open at the same time. What I'm looking for is...

If there's no activity on Book1, count 5 seconds and show Book2.
If there's no activity on Book2, count 5 seconds and show Book3.
If there's no activity on Book3, count 5 seconds and show Book1.

So if someone is looking at the computer screen and not making changes to the workbooks or moving the mouse, it'll open the next workbook in 5 seconds.

Is such a thing possible?

Thanks in advance.