100 Stars That Explain the Universe by Florian Freistetter

Author:Florian Freistetter
Language: eng
Format: epub
ISBN: 9781615197378
Publisher: The Experiment, LLC
Published: 2019-02-15T00:00:00+00:00

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Creative Roads to Discovery

for 100 hours, the Hubble space telescope surveyed a very particular place in the sky: a tiny spot in the Ursa Major constellation where, as far as we knew at the time, there was nothing whatsoever to see. Yet there was method in the madness, because nowhere in the universe is there “nothing whatsoever.” And if you’re imaginative enough you may discover new things precisely in those places where, at first glance, there’s nothing to see.

It was the American astronomer Robert Williams who first thought of closely examining this nothingness. At the time—in 1995—he was the director of the Space Telescope Science Institute, the organization responsible for overseeing the Hubble space telescope operations. Which was, from a scientist’s standpoint, lucky for him, because you can only get a certain amount of observation time with Hubble, and not all who want to use it to explore the skies can do so. You have to submit an application, and only the best projects succeed in convincing the committee to allow you a glance through the telescope.

To gaze upon nothingness for 100 hours is an undertaking that would normally stand no chance of being approved, given the strictly limited observational time available. But because Williams was the director, he had a certain quota of observational time at his disposal to do with as he pleased. And what Williams wanted to know was how galaxies form and develop. To find out, he had to look as far as possible into the depths of space; the more remote an object is, the longer it will have taken for its light to cover the interval between it and Earth, and the further we can see into the universe’s past—the place where you can observe galaxies in their infancy.

But you can do this only if the light from those distant galaxies is able to make its journey to us unimpeded, and if it isn’t outshone by the other stars in the neighborhood. In short, where the sky is completely empty. Or looks empty: because, according to Williams, there must be galaxies all over the universe, and as long as nothing blocks your view and nothing disrupts your observation, when you look closely even an apparently empty region of the sky will be teeming with galaxies.

He turned out to be right. By the end of his observational campaign, Williams had photographed more than 3,000 galaxies in that tiny segment of sky he’d been looking at. This galactic panorama became famous as the Hubble Deep Field, and to date more than 500 scientific papers have been written about it. The supposedly empty sky has proved to be a veritable fount of knowledge about the young universe.

A few years later, Konstanze Zwintz from the Vienna University Observatory and her colleagues came up with a creative way of obtaining new insights without needing to be granted observational time with the Hubble telescope. Zwintz was interested in a particular type of fluctuation in the brightness of starlight, which is

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