Hi people, I have a question which i hope you helpful guys/gals can help to shed light on. We all know when we strike one end of a solid metal rod with a hammer sideways (i.e. from left to right), longitudinal vibrations will be set up across the length of the rod. Textbooks and websites always say that when we hold with our fingers in the centre of the rod, that location becomes a node. My question is why does our fingers introduce a node? Are our fingers so strong that we can force every metal atom to remain still and not vibrate to and fro? Sounds a bit far stretched to me... Thanks for the advice.