A passenger on the ground shines a laser up at an airplane at an altitude of 35,000 feet (violating one or more laws, though not physical ones).

1. Assuming a constant gravitational field the same as at the surface of the Earth, if the laser emits light of 671 nm wavelength, by how many nm does the wavelength differ when the light is detected by someone on the plane?
2. Is the wavelength at the plane longer or shorter?