Two Bridgewater residents will discuss their insights into space and American history in presentations at the public library. This Tuesday Gary L. Hylander, an adjunct professor of history and education at Framingham State University and Stonehill College, will speak on the Declaration of Independence. On Aug. 6, Stephen LaFlamme will share anecdotes and photographs he has collected over 31 years as an amateur astronomer. Both talks will be held in the Flora T. Little Meeting Room on the lower level of the library, 15 South St., starting at 7 p.m. The programs are free of charge, and pre-registration is not required.