What did the Liberty Bell sound like? Science is on the case.

The Liberty Bell, with its famous crack, hasn't been rung in 180 years, but that hasn't stopped scientists from pondering what the bell might have sounded like when tolling. In honor of the nation's 250th anniversary, researchers at Penn State University have modeled its acoustic properties, drawing on data collected from one of the bell's replicas. The work was first presented at a meeting of the Acoustical Society of America in Philadelphia earlier this year, followed by an article in Physics Today.

Historians aren't sure when exactly the Liberty Bell acquired its distinctive crack, just that it occurred sometime between 1817 and 1846. An 1846 account in the Public Ledger described the ringing of the bell on February 23 that year and mentioned that the bell had developed a crack, which someone had attempted to fix by filing the sides down. …