Viewing A Universe In Flux

May 20, 2015
Originally published on May 20, 2015 4:36 pm

The phenomenally successful Hubble Space Telescope turned 25 last month.

To celebrate the occasion, the Hubble team released a spectacular photo of a "stellar nursery," a region of space where huge amounts of gas and dust churn dramatically under gravity's never-resting arms to create new stars and, with them, new planets. Known as Westerlund 2 in the constellation Carina, it houses some 3,000 stars, some of them the hottest and brightest in our galaxy.

At only 2 million years old, the cluster is a baby in astronomical terms. Just think that, as it was forming, the first hominids were grazing the African plains. In terms of distance, it's also not that far, according to astronomical standards — only 20,000 light years away. This means that what astronomers see is the cluster as it was 20,000 years ago, which is the time it takes for light to travel from there to here.

Looking at the night sky is like looking through a time machine into the past; every image comes from a different past, a sort of kaleidoscope of times, each telling a different story. To think that at Westerlund 2 — and at every other stellar nursery in the galaxy — there are new worlds forming, while at other spots, stars are exploding as they die after billions of years of nonstop light-producing, tells of a cosmos in flux where matter is constantly recycled from place to place. Who knows where the atoms making up your body came from? They are a collage of different stories, coming from different regions, remains of stars that died 5 or more billion years ago in the neighborhood of what would become the solar system.

What we see in Westerlund 2 is, in a sense, the story of our own origins, even if every creation story takes its own path. Like snowflakes, each star shares similar properties with others while also being unique in its composition and formation history.

Variation in regularity, this is the theme that plays out across space. The staggeringly beautiful Westerlund 2 should be shown prominently at every public school in America as a reminder of the vastness of the universe, and of the power of human creativity, that can stretch its reach so far beyond our own small globe.


Marcelo Gleiser is a theoretical physicist and cosmologist — and professor of natural philosophy, physics and astronomy at Dartmouth College. He is the co-founder of 13.7, a prolific author of papers and essays, and active promoter of science to the general public. His latest book is The Island of Knowledge: The Limits of Science and the Search for Meaning. You can keep up with Marcelo on Facebook and Twitter: @mgleiser.

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