* Isaac Newton: He is credited with creating the first practical reflecting telescope in 1668. He used a concave mirror to gather and focus light, eliminating the chromatic aberration (color distortion) that plagued refracting telescopes at the time.
* James Gregory: While Newton gets the credit for the first functional design, Scottish mathematician James Gregory proposed the concept of a reflecting telescope in 1663. His design, however, proved difficult to construct at the time.
So, while Newton is often solely credited, Gregory played a significant role in laying the theoretical foundation for this crucial astronomical tool.
