Astronomers build larger telescopes not only to collect more energy but also to resolve finer detail in the objects to be studied. While groundbased optical telescopes with "filled" apertures of up to 10 m have been built, and 30 m and larger-aperture designs are being studied, another method of observations permits equivalent apertures spanning tens to hundreds of meters to be used. Radio astronomers have used these instruments, called interferometers, for decades, with equivalent apertures spanning thousands of kilometers.

It is easy to take our calendar, with its system of weeks and months, for granted. But this system is really just a societal choice -- it has been debated and modified in the past. It will also have to be re-examined when humans colonize other planets. 'Making Months' illustrates a use of factoring, in a decision-making process.