Newton's and Galileo's telescopes?

Question

can anyone tell me TWO differences between Galileo's astronomical telescope and Newton's later and better telescope?

Answer 1

Galileo's telescope (which he did not invent) was a refractor, using a glass lens as an objective. Newton's telescope was a reflector, using metal mirrors. Galileo's telescope provided upright views; Newton's telescope inverted the image.

Newton devised his telescope to avoid chromatic aberration, the prismatic separation of light into different colors that marred the performance of refractors. He mistakenly thought that it was not possible to correct this error by using two or more glasses of differing properties.

However, the reflectivity of mirrors at that time was poor, and when the surface tarnished, the objective had to be re-polished and re-figured. So the refractor was the dominant telescope until the late nineteenth century, when it became possible to make large silvered glass mirrors. Early refrators were made very long, to reduce the effect of chromatic aberration. In the mid eighteenth century, achromatic refractors, using two or more lenses of different glass to correct the color error, became available.

Answer 2

Newton used Galileo's idea and made it better?
I think the big difference was Newton had better quality mirrors and optics at the time. Galileo had the idea, but, not the quality materials Newton had.

Answer 3

1. Newton's came later.

2. Newton's was better.