<b>Q:</b> Photons have mass? <b>A:</b> I didn’t even know they were Catholic! <font size="1">This joke was reprinted from "<a href="http://www.actapublications.com/detail.html?&id=9780879463779" target="_blank">The Book of Catholic Jokes</a>" by Deacon Tom Sheridan, with permission of <a href=" http://www.actapublications.com " target="_blank">ACTA Publications</a>. Copyright 2008. All rights reserved.</font>