Keep Looking Up
Beautiful, aren’t they? Like illustrations in a book. Only these are real. No one drew them. These exist. And there are at least 200 billion of them. The nine images above are just a few of our galactic neighbors, millions of light years away. They may seem obvious to us now, but not even a hundred years ago their existence was in doubt.
Under the only magnifications possible until the 20th century, most notably until the 100-inch telescope on Mount Wilson in California was built, these fuzzy objects were considered outlying parts of our own galaxy - clouds of gas, perhaps. Other nebulae (“planetary nebulae”, or supernova remnants) had been proven to exist within the Milky Way, and the assumption was that “spiral nebulae” were similarly on the edge of our galaxy, which might just be the edge of the universe.
A great debate about the make up of the universe went on well into the 1920s, when Edwin Hubble, charting Cepheid variable stars in the Andromeda “nebula” with the Mount Wilson scope, showed that their distance from us was something near a million light years - much too far to be part of our own Milky Way. Finally proven to be immense conglomerations of stars millions of light years away, they were termed what Immanuel Kant had first called in 1755 the idea of separate Milky Ways: island universes.
Although that term eventually fell out of favor, I’ve always preferred it to galaxy, which sounds like a car model. Galaxy actually comes from the Greek galaktos, literally “milk” (the shared root of our words lactate, lactation, lactic). The myth is that Zeus, desiring his mortal-born son Heracles to have godlike powers, allowed him to suckle on his divine wife Hera’s breast, which, when discovered, caused her to push the baby away, and the resulting spurt of milk created the Milky Way. I think island universe, in addition to separating itself from this mythological nonsense, better communicates the immense solitude of galaxies, surrounded as they are by the vast emptiness of intergalactic space. It also makes me feel like there’s an implied sense of life in those galaxies.
Pause one of those images up there. Imagine that’s our galaxy: dusty disc, spiral arms, supermassive blackhole in the center. Zoom in and pick out one of the tiny pinpricks of light in that whirling disc. It’ll be hard to choose; there are billions. Got it? Now imagine that’s our Sun. And around that sun, visualize our planetary system, a whirling disc too. Along that elliptical plane, on a tiny blue planet circling a tiny yellow star, is, as Carl Sagan wrote, “everyone you love, everyone you know, everyone you ever heard of, every human being who ever was.”
A humbling thought, to say the least. Humankind is nothing. NOTHING to the Universe. We’re a flicker on a speck on a mote. We’ve been lucky enough, thanks to several cosmic coincidences, to not only arise as life, but evolve to intelligence (relatively speaking), and remain protected from the myriad catastrophes surrounding us. Our relatively stable star; our location in the “Goldilocks Zone” of the Solar System (not too hot, not too cold); the axial tilt of the Earth causing seasons; the tidal forces of an overly-large satellite (the result of an unlikely collision between a Mars-sized planetoid and the proto-Earth) creating the right conditions for life; Earth’s strong magnetic field protecting us from radiation; Jupiter, playing gravitational center field, catching our would-be asteroid strikes; the Moon, playing goalie, planting its far side firmly in the face of incoming shots: if it weren’t for these, and a billion other random events, no one would be here at all.
It seems incredibly unlikely that all of the dominoes would fall just so, but they have. And in fact, that’s why we’re here. It’s not a coincidence if these are the prerequisites for intelligent life arising. But as unlikely as it seems, when you’re faced with images like these, how can you not imagine that this has happened countless times, not just in our galaxy, but in the nearly infinite number of other galaxies out there? How can you not believe that right now a vast multitude of individuals across the universe are contemplating images just like these, images that may even include our galaxy, and are attempting to understand their place in the universe - no different than us?
Lets be friends, K?
Reblogged from This Corner of the Cosmos.