Question

Which optical instrument was invented by Isaac Newton?

Hint:

This instrument uses a curved mirror instead of a lens to gather light for viewing distant objects.

Answer 1

Correct answer: Reflecting telescope
Isaac Newton built the first practical reflecting telescope in the year 1668.
Earlier telescopes used only glass lenses to bend and focus light, a design known as the refracting telescope.
These lens based telescopes suffered from a problem called chromatic aberration, where different colors of light focused at slightly different points, blurring the image.
Newton solved this by using a curved mirror instead of a large front lens to gather and focus light.
His design used a small flat mirror to redirect the focused light to an eyepiece on the side of the tube.
This reflecting design removed most of the color blurring problem and allowed for a smaller, more compact telescope body.
Modern large telescopes, including many observatory telescopes, are still based on Newton's reflecting principle.