One night in a cornfield — Part Five

Posted by David Eicher
on Wednesday, July 20, 2011

In 1687, with the publication of Isaac Newton’s Philosephiae Naturalis Principia Mathematica (“Mathematical Principles of Natural Philosophy”), the telescope’s journey had already lasted 77 years, but really it had just begun. For the first time in history, humans were elevated intellectually to looking up at the sky at night and seeing almost limitless heavens with numerous surprises waiting. Still to come was William Herschel’s discovery of Uranus, the first planet found with a telescope. The unlikely story of the construction of the world’s largest telescope in rural Ireland would also take place. So would a Boston blueblood’s rapid pursuit of Mars and its imagined living beings, driven by the boyhood reading of books about the Red Planet.

Photo credit: Adam Block and Tim Puckett
In the early 20th century, Harlow Shapley and Edwin Hubble would revolutionize astronomy by uncovering the nature of galaxies and the fact that all were receding away from each other at breakneck speeds. A farm boy’s discovery of Pluto lay in the vast future. So too did the spectacular era of launching telescopes into Earth orbit, which led to the discovery of the elusive dark energy and the true size of the universe.

Over the course of time, astronomers discovered that telescopes are really time machines. Because of the fixed speed of light, when we see a distant object, we see it as it was long ago. Light from the Sun reaches Earth in about 8 minutes, so we see the Sun as it was 8 minutes ago. Light from Alpha Centauri, the closest star to the Sun, reaches us in a little more than 4 years, so we see it as the star appeared 4 years earlier. The Andromeda Galaxy appears as it was 2.5 million years ago. Distant galaxies close to the edge of the observable universe, captured in frames by the Hubble Space Telescope, appear as they were 12 billion years ago when the universe was in its infancy.

These time machines allow us to travel throughout the universe, freely roaming space and time. Astronomy is unique among sciences, in fact, in that the primary laboratory professionals use every night is freely available to anyone who wants to look. To that kid in the cornfield, the 8-inch telescope unlocked as many mysteries about the cosmos as any of the great historic telescopes of the past. That 15-year-old kid was me, the night now etched in a 30-year-old memory. But the meaning of the telescope, how it has revolutionized science, is as alive and real as ever.

Links to Part One, Part Two, Part Three, and Part Four

 

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