The early 2020s were a chaotic time, as one crisis after another befell humanity: the Covid-19 pandemic, inflation and supply chain turmoil, political instability and extremism, climate change… the list goes on. But what does it all really mean, or does it matter, when you zoom out and look at the big picture?
An astronomy professor from Johns Hopkins University gave us a chance to zoom in way both on time and off room with an interactive map of the observable universe. By investigating it, not only our problems can be solved quickly, but also our lives, this century, the earth and our whole universe in a stunning (and somewhat unsettling) perspective.
“On this map we are just a dot at the very bottom, just one pixel. And when I say we, I mean our galaxy, the Milky Way with billions of stars and planets. said card maker Brice Menard. “We are used to seeing astronomical images of one galaxy here, one galaxy there or maybe a group of galaxies. But what this map shows is a very, very different scale.”
The map shows the position of 200,000 galaxies, using different colors to indicate how far they are and how long it takes for their light to reach telescopes on Earth. Specifically, a telescope at the Apache Point Observatory in New Mexico, where the Sloan Digital Sky Survey recorded data from different segments of the night sky since 2000.
The full map, the website explains, is a sphere, but it is not possible to represent all of its data in a two-dimensional representation. The online map shows a portion of the sphere that is about 10 degrees wide.
If you scroll up from the Milky Way dot at the bottom of the map, you’ll first encounter other spiral galaxies shown in light blue. Spiral galaxies consist of a bright core surrounded by a flat, rotating disc of stars; about 70 percent of the galaxies closest to the Milky Way are spirals.
If you keep scrolling up, i.e. further back in time, you will see next elliptical galaxies yellow. This is the most common type of galaxy in the universe, but the orbits of their stars are random and elongated rather than revolving around a fixed center. Their stars are much older than those in spiral galaxies; astronomers think elliptical galaxies formed when spiral galaxies collided and merged.
About four billion years ago you encountered redshifted elliptical galaxies (“as the universe expands, photons stretch and objects appear redder. This is the case for the elliptical galaxies”, the sidebar explains), followed by quasars (massive black holes at the centers of distant galaxies), redshifted quasars, and finally the edge of the observable universe: a real photo of the first flash of light emitted after the Big Bang.
The time of light travel to Earth from anything beyond this point, the map says, is greater than the age of the universe. How’s that for perspective?
However, it seems that Menard’s concern was not so much to provide that perspective, but rather simply to show how fascinating the universe is.
“Astrophysicists around the world have been analyzing this data for years, leading to thousands of scientific papers and discoveries. But nobody took the time to create a map that is beautiful, scientifically accurate and accessible to people who aren’t scientists,” he says. said. “Our goal here is to show everyone what the universe really looks like.”
Image credit: B. Menard and N. Shtarkman/Johns Hopkins University