The dispersion effects of light cause Chromatic Aberration in which colored rings circle the image. The lens can only be supported at its periphery since light must pass through it. The mirror on the other hand can be supported on the entirety of its backside. There is much less material that must be absolutely perfect. So refracting telescopes can be much larger and built much more cheaply than refractors.
Researches prefer reflecting telescopes for many reasons.
Modern telescopes are often collections of smaller mirrors operating in conjunction with one another, their shapes driven by a computer program. Other telescopes mirrors can change their shape in real time response to the seeing conditions, again under computer control. This is called Adaptive Optics. Newton also formulated the laws of motion relating cause to effect which are still used today by engineers, with only minor corrections due to Einstein sometimes included when very high velocities or gravitational fields are involved. The final point of natural philosophy this chapter addresses is the idea of action at a distance.