The gradient is the measure of slope of a line. In order to work with gradients and straight lines successfully, a good understanding of coordinates and linear graphs is needed. The gradient of a ...

therefore the bigger the gradient the steeper the line is. A positive gradient is a straight line which slopes up to the right. A negative gradient is a straight line which slopes down to the right.

If the air is all the same temperature--cold or hot--light travels through it in a straight line. If a steady temperature gradient exists, however, light will follow a curved path toward the ...

This is more obvious if your gradient has a straight line of color in it. if you compare the images before and after the warp you will see that the straight line of color is the same in both.