Bookmarked An Atlas of the Cosmos (Longreads)

We’ve mapped Mars, the Moon, the solar system, even our own galaxy. Which means there is only one thing left to understand in this symbolic way and that is the entirety of the cosmos.

Shannon Stirone discusses the challenge of mapping the universe as it continues to expand.

One day, googols and googols of years after you and I have died, the universe will end. Just like us, it is currently in the process of its death. It is expanding outward at unfathomable speeds, so much so that eventually all matter in the universe will begin to separate, growing further and further apart. As a result of this expansion the universe and all the matter in it will cool off until everything is the same temperature. This is one of the most popular theories for the end of the universe called the Heat Death — literally the death of heat. Over time, stars will die, galaxies and their solar systems, globular clusters and everything we’ve ever known will get consumed by black holes — the last things to exist in this universe. Eventually the matter inside of those black holes will evaporate until there is nothing left. (If you could move forward in time when the only thing left were black holes, where average temperatures hover just a fraction of a degree over absolute zero, you would be the hottest thing in existence. The radiation emitted from your body would glow hotter than anything else.) This goes far beyond Sagan’s pale blue dot — everything we’ve ever known will be gone, every human ever born and died, every person we’ve ever loved, every work of art, every book, every planet, every galaxy, every star, every atom that was ever created will cease to be.

Meanwhile, you and I are going about our days on an average rocky planet in just one of trillions of solar systems. Our planet orbits around an average star that moves around the third arm of the Milky Way galaxy, local group Virgo supercluster in an ancient universe that is moving ever outward. Where are we? The answer is always changing.

Bookmarked Big space by Katie Mack (AEON)

The cosmic horizon defining our observable universe is a hard limit. We can’t see beyond it, and unless our understanding of the structure of reality changes drastically, we can be confident we never will. The expansion of the cosmos is speeding up; anything beyond our horizon now will be carried away from us faster and faster, and its light will never be able to catch up. While we might never be able to say with certainty what lies beyond that border, what all the theories have in common is that our observable universe is part of a much, much larger space.

Whether that space contains a multiverse of bubbles, each with different physical laws; whether it’s part of an ever-growing cosmos of which we are only one part, in one cycle; or whether space extends outward in directions we can’t conceive, we currently just don’t know. But we’re seeking clues.

The patterns in the cosmic microwave background light, the distribution of galaxies, and even experiments testing gravity and the behaviour of particle physics are giving us insight into the fundamental structure of the Universe, and into its evolution in its earliest moments. We are getting closer and closer to being able to tell our whole cosmic story. We can already see, directly, the fire in which our universe was forged, the moments just after its beginning. With the clues we are gathering now, we might, someday, follow the story all the way to its end.

In an extract from Katie Mack’s book, The End of Everything (Astrophysically Speaking), she unpacks our understanding of the size and space of the universe and whether in fact there are multiverses at play.