A. Once in 7 years, Torah directs us to let the land lie barren in Israel. We don’t plant or harvest that year (which happens to be the Jewish Year 5761/2000, which was the year when this question was first posted on www.shabboshouse.com, and as of this reposting, this coming year 5775 (2014-15) will be a Shemittah year as well). But this law only affects vegetation and growth, so we can dig up and research as much as we want.