Exploring the Cosmic Limits of Humanity

“Look again at that dot. That’s here. That’s home. That’s us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives. The aggregate of our joy and suffering, thousands of confident religions, ideologies, and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilization, every king and peasant, every young couple in love, every mother and father, hopeful child, inventor and explorer, every teacher of morals, every corrupt politician, every “superstar,” every “supreme leader,” every saint and sinner in the history of our species lived there-on a mote of dust suspended in a sunbeam” — Carl Sagan

We inhabit a small and relatively quiet region of the Milky Way galaxy, nestled within the Orion Arm, one of the galaxy’s spiral arms with a supermassive black hole at the center. Our galaxy mostly consists of empty space. There are large clusters with thousands of galaxies within our local group. With our current technology, it would take thousands of years for us to reach the nearest star, the Andromeda galaxy.

What if?

For the sake of argument, let’s assume humanity has reached a Type III civilization. We developed interstellar travel, and what a good time it would be to be alive. With our current technological advancements and understanding of physics, how far could we possibly go? Experts say in this best-case scenario, we could only reach 0.0000000001% of the observable universe. The fact that we could only reach a small percent of the observable universe is sad and frightening.

Why can’t we go further?

The short answer is that the universe is expanding. In 1922, Russian scientist and mathematician Alexander Friedmann published a paper detailing multiple possibilities for the history of the universe. The paper, which was based on Albert Einstein’s theory of general relativity published in 1917, included the possibility that the universe is expanding. In 1929, astronomer Edwin Hubble confirmed that the universe was expanding using observations made by his associate, astronomer Milton Humason. The pair found that objects like galaxies are moving away from Earth faster the farther away they are, at upwards of hundreds of thousands of miles per second.

If we could leave our Milky Way, our local cluster group, and travel into the darkness, we would only become more and more stranded. But look at the bright side: the local group is large enough and full of opportunities for us to explore. We still haven’t found a way to leave our solar system, and we have billions of years to explore our galaxy before it eventually merges with the Andromeda galaxy.

We are incredibly lucky to exist in the perfect moment in time where we not only see our future but also our most distant past.