Digital Print Edition *NOTE: The digital edition is an EPUB file. Windows 10 users will need install an eBook reader such as the free Calibre app. Microsoft Edge can also open most EPUB formats if you set it as the default app for the .epub file.
I'm taking a physics course, and we discussed how objects with hollow cores revolve slower. So I was wondering: Exactly how much dirt would I have to dig out of the ground and move to the surface before I'd notice the days getting longer?
— Mark D. Baragary, Ames, Iowa
Your question inspired my assistant Una to new heights of invention, Mark. She announced you'd given her an idea for an...