404. That’s an error.

The requested URL /bookmarks/mark?op=edit&bkmk=https://astarmathsandphysics.com/index.php?option=com_content&view=article&id=184:longitudinal-and-transverse-waves&catid=90&Itemid=480&title=Longitudinal+and+Transverse+Waves was not found on this server. That’s all we know.