Hello everyone, Quick questions What happens to the light ray that passes through the mid point of the lens(dotted line). Does it go straight or diverge? Is moon concave? If the light passes right through the midpoint travel straight wouldn't the umbra have some light in the middle. Why is penumbra a shadow? Why are eclipses rare. It is so easy for moon's shadow to fall on the earth. How is moon big enough to provide light for whole one side of earth. Thank you so much!!