As I’ve noted elsewhere (Beyond the infinity of black holes), it wasn’t long ago — maybe a 100 years or so, that our view of the cosmos was much more circumscribed. Those who studied cosmology — physicists, astronomers, et al, viewed our cosmos in a much different way, at a much different scale — basically an island universe: Earth, the solar system and the Milky Way. We existed in a galaxy, but a singular one.
Now, almost one hundred years later, it is difficult to fully appreciate how much our picture of the universe has changed in the span of a single human lifetime. As far as the scientific community in 1917 was concerned, the universe was static and eternal, and consisted of a single galaxy, our Milky Way, surrounded by a vast, infinite, dark, and empty space. This is, after all, what you would guess by looking up at the night sky with your eyes, or with a small telescope, and at the time there was little reason to suspect otherwise. — Krauss, Lawrence. A Universe from Nothing: Why There Is Something Rather than Nothing (pp. 1-2). Atria Books. Kindle Edition.
The game-changing discovery was highlighted back in 2011 by this Space.com article “Star That Changed the Universe Shines in Hubble Photo” (May 23, 2011).
In homage to its namesake, the Hubble Space Telescope recently photographed a star that astronomer Edwin Hubble observed in 1923, changing the course of astronomy forever.
The star is a variable star that pulses brighter and dimmer in a regular pattern, which allowed scientists to determine its distance, suggesting for the first time that other galaxies exist beyond our own Milky Way.
“I would argue this is the single most important object in the history of cosmology,” said astronomer David Soderblom of the Space Telescope Science Institute in Baltimore, Md., who proposed pointing the Hubble Space Telescope at the star.
Can you say Cepheid variable?
When I get bogged down in the 10^-n scale of things, a reminder about standard candles at the other end of the scale of things helps restore my perspective on how science works — that, at its best, science moves us beyond circumscribed views.