{ "cells": [ { "cell_type": "markdown", "metadata": {}, "source": [ "Here we discus how material line elements evolve in a fluid and further we show that in an inviscid fluid vorticity lines move with the flow, that is vorticity lines move **as if they were** material lines." ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## How material line elements move in a fluid?\n", "\n", "