Final answer:
The Duke graduates built the Sloan Digital Sky Survey (SDSS) telescope, a 2.5-meter telescope that creates three-dimensional maps of the universe, which is still in use today.
Step-by-step explanation:
The system that Duke graduates built, which is still in use today, is the Sloan Digital Sky Survey (SDSS) telescope. The SDSS, represented by a 2.5-meter telescope, provides comprehensive three-dimensional maps of the universe, involving over 500 million objects and spectra of over 3 million. Remarkably, it covers more than a quarter of the celestial sphere. The SDSS is an example of a high-quality product of rigorous design and engineering that has withstood the test of time, similar to how the Golden Gate Bridge remains a testament to good design after more than seven decades. Both represent the pinnacle of engineering and technological advancement, underlining the importance of applying science and mathematics in the design process to achieve lasting, functional structures and systems in society.