What Is the Source of the Transport Equation?

So remember T is on the vertical, which is where we think about this. And yeah, so that's actually where you can also think about what the solutions of these transport equation and therefore wave equation mean coming from this one point. So if your curve is a straight line, like a slope, right, it has a slope, you say at zero, it equals this. Then that piece of information that starts at time equals zero, but then goes off diagonally, right? That piece of information travels along the integral curve and then touches the point that you're trying to find the solution. Your solution is just the sum of the two.