In Eugene, Oregon, space is the final frontier, captivating researchers, astronomers, and stargazers alike. One of the universe’s most fascinating mysteries relates to the distance between us and the twinkling constellations in the sky. The closest group of stars, located a mere 150 light-years away, appears almost mystically distant. These glowing entities, although seemingly close, are actually separated from our planet by astronomical distances. Such celestial phenomena raise thought-provoking questions about measuring vast distances like these. How far away are these glittering beacons of night, and what methods do scientists use to measure distances? These questions lead us on an in-depth exploration of the history of astronomical measurements from prolific scientists throughout history.
Rewinding the pages of history, we encounter a diverse array of pioneering researchers, each grappling with this cosmic enigma in their own unique way. The simplest and most direct approach, arose from the notion of stellar parallax which dates back thousands of years. A suggestion to measure stellar parallax is the essential tool for our childhood game. This game involves closing one eye, raising a thumb at arm’s length, switching which eye is open, and observing the thumb shifting concerning the background. The phenomenon, known as parallax, could theoretically measure the distances to the closest stars.
However, early scholars in the 1600s, namely Robert Hooke, appeared to have a distinct approach in using parallax to measure the distance to stars. He developed precise protocols to measure the position of Zenith stars and any variations in their position concerning a plumb line. In contrast, Christiaan Huygens formulated a method utilizing the Sun’s brightness as a standard to measure star brightness. He drilled holes in a telescope, cutting back the sunlight filtering through and aimed to match that brightness with a chosen star. Unfortunately, the pioneering work of Hooke and Huygens both proved to be inaccurate and fraught with experimental uncertainties.
Meanwhile, Isaac Newton invented a more sophisticated method to calculate astronomical distances, using our Solar System’s planets as a reference. By 1840, revolutionary developments in photography signaled the dawn of a new era of astronomical measurements. These photographic advancements eventually led to the breakthrough first photographs of stars in 1850.
When evaluating the accuracy of these early estimates, it becomes evident that Hooke’s claimed “parallax” distance was far from accurate. Although, with the advent of Parallax through the European Space Agency’s Gaia satellite, modern science finally has a definitive way to measure distances to the stars. These early estimates have paved the way for more profound knowledge about our universe, the techniques we use highlighting the significance of scientific inquiry and reproducibility.