[1]
In the early nineteenth century, navigating the coastal waters of Europe and North America at night was a perilous endeavor. Existing lighthouses relied on crude metal reflectors and thick glass lenses that absorbed most of the light, casting weak, scattered beams that were barely visible a few miles out. Mariners frequently ran aground because they could not see the warning beacons until it was too late.
[2]
The solution came in 1821 from French physicist Augustin-Jean Fresnel, who designed a revolutionary lens system. Instead of using a single thick, heavy piece of glass, Fresnel assembled a series of concentric glass rings shaped like prisms. These rings bent the light from a central lamp and concentrated it into a single, intense parallel beam. This design allowed the light to travel over twenty miles across the ocean surface, significantly increasing the visibility of the lighthouses.
[3]
Fresnel's invention transformed maritime safety worldwide. Within decades, his lenses were installed in lighthouses across the globe, dramatically reducing the number of shipwrecks and saving countless lives. Even today, despite the advent of modern satellite navigation and radar, many historic lighthouses still employ Fresnel's ingenious design, demonstrating the enduring legacy of his scientific achievement.
Suppose the writer's goal had been to write an essay that describes how a specific scientific innovation directly addressed a historical challenge in transportation safety. Would this essay fulfill that goal?
- AYes, because it details how French and American mariners worked together to develop new navigation technologies in the nineteenth century.
- BNo, because the essay focuses primarily on the life of Augustin-Jean Fresnel rather than the practical impact of his lens design on ship safety.
- Yes, because it explains how Fresnel's prism-based lens system solved the problem of weak lighthouse beams, thereby reducing shipwrecks.Answer
- DNo, because the essay does not mention any specific transportation safety challenges faced by nineteenth-century sailors.