The Universe is like Moose...

A friend who’d lived in Alaska once told me “However large you think moose are, they’re three times as big.”

I responded “I already think they’re pretty fucking big,” and he nodded solemnly, looking out somewhere towards the middle distance in deep contemplation, before replying “And they’re three times bigger than that.”

That’s kind of how I think about the universe. However large you think it is, it’s bigger. By a lot. And the reality is that it’s probably teeming with life. But we’ll never meet them.

If you’ve ever spent any time considering the possibility of life somewhere out there, you’ve come across a concept called the Fermi Paradox. If you’re unfamiliar, the Fermi Paradox is, essentially, asking the question “If the universe is so big, and there are so many galaxies with stars and planets, then … where is everyone?” I.e. if there are so many opportunities for life to develop and grow and learn and shout out into the void of the cosmos, then why haven’t we found alien life?

You’ve probably heard a number of terms that have been used to answer this question: the Dark Forest theory, or The Great Filter or the like. Alternately, you may have never heard them in context before, but every five years a new sci-if series is named after one of them because they all sound just so compelling and evocative. Each one is a hypothesis for why this seemingly vast amount of space is, by all aspects of how we can understand it, silent.

To me, there’s a simpler answer to the Fermi Paradox. One which feels like the most likely answer for humanity and whatever else comes after us (sorry for the existential crisis that sentence provokes) - the universe is like moose. No matter what it looks like when we glance up above us at night, the distance between objects in the universe is so much more painfully, impossibly, massively, huge than we can really inherently understand. And that we are a very, very young species.

Let’s start by acknowledging that we’re taught some concepts through convenience, where for the sake of overall understanding and conceptualization, we might not get the most … absolutely factually-accurate representation of reality. What I’m specifically thinking about is that when we’re learning about the planets, we memorize their place in relation to the others, and we do so with convenient visuals that place them all in some form of relation to each other. We all remember that overly simplified image of all the planets mostly equally spaced from each other as we memorized some variant of MVEMJSUN(P). Perhaps not dissimilar to this.

It’s all so wonderfully organized. So clean. So neat. So wrong. Don’t get me wrong: they’re in that order (most of the time, anyway) so no issue there. But what it doesn’t, and simply cannot properly communicate is the distance between objects in the universe, because that distance is so much more unfathomable huge than we can really understand.

So what would it look like if we wanted to be scientifically accurate? Well, if we chose to represent Earth with a soccer ball, and if we wanted to maintain relative scale to that soccer ball, the sun would be about 3 kilometers (a little under 2 miles) away, and Neptune would be a little more than 80 kilometers (or 50 miles) away.

We don’t talk about Pluto.

Let that sink in. If Earth was a soccer ball, Neptune would have to be placed in another town, and maybe even in another state, in order to be accurately represented in scale and distance. Okay, hold on that for a moment, because I’m about to make it both easier and harder for you.

Let’s get smaller, for our travel convenience. If we were to shrink Earth down to a coffee bean, and proportionally shrink everything else to maintain accurate distance and scale, Neptune would still be 1.7 kilometers (more than a mile) away from our coffee bean Earth. Not another town, most likely, but probably a different zip code at least.

But Neptune isn’t the end of the Solar system, even when we think of it that way. It’s just the furthest thing that we’ve (arbitrarily) designated to be a planet. If we want to use a better definition of “end” we’d find the end of the gravitational influence of the sun, in which case we’d be talking about the Oort Cloud. These are the most distant objects gravitationally captured by the sun, and are so far away, so dim, and so cold, that we don’t actually have any hard proof they exist. At coffee bean proportions, the end of the Oort Cloud would be about 7,000 kilometers away from coffee bean earth.

And if we want to get extra-solar, at these coffee bean sized proportions, the closest neighbor star, Proxima Centauri, would be 16,000 kilometers (almost 10,000 miles) away, or roughly a third of the way around the Earth if measured at the equator.

Moving back to real world scale, Neptune is “only” about 4.5 billion kilometers away. Or maybe it’s better we switch to AU now for simplicity (Astronomical Units: the equivalent distance from the Earth to the sun.) Neptune is about 29 AU away from Earth - 29 times the distance from the Earth to the Sun, on average. The solar system’s gravitational influence to the outer edge of the Oort Cloud extends another 200,000 AU (or 29,919,574,052,121 - just under 30 trillion - kilometers - see why we switched to AU?).

Voyager 1 is currently the most distant human-made object in the universe. It passed Neptune in 1989 and is currently about 158.8 AU away from Earth. It’s moving at about 40,000 miles an hour, roughly a million miles a day. It will enter the Oort Cloud in about 300 years. It will leave the Oort Cloud in 30,000 years. 

30,000 years, moving at a million miles a day, just to leave the gravitational influence of the Sun. If it were headed in the direction of Proxima Centauri (it’s not) it would take about 73,000 years to get there. 

Okay, so in the realm of meeting aliens, we can probably take physical travel off the table.

What about radio signals though? Those move at the speed of light. Nothing moves faster. It’s the fastest any object or signal can move between objects in the universe (don’t come at me about quantum communication until we can actually make it viable outside of a lab and a scale larger than a few meters, to say nothing of the reality that quantum communication between entangled particles still requires physically sending them somewhere according to the speed limits of physical objects.)

So let’s move to light years as our distance measurement - the amount of distance the fastest moving object(ish) in the universe can travel in a year. One light year is as near as matters 63,241 AU, so that’s as fast as any communication from earth can go: 63,241 times the distance from the earth to the sun in a year. It sounds pretty far, right? But again, the distance between objects in the universe is so much more unfathomable huge than we can really understand.

We have been blasting radio waves out into the universe for 100 years. Want to see how far they’ve gone? Here you go. That’s how far our transmissions have gotten into the Milky Way Galaxy at light speed. That’s not showing how far they’ve gone into the whole universe, just the Milky Way galaxy. It will take 26,000 years for any trace of our radio signals, traveling at the speed of light, to reach the center of the Galaxy.

Our species has been around for 250,000 years or so (give or take, depending on how you define our species) and we’ve been only communicating loudly enough to go beyond our planet for the past hundred of so. That’s the furthest any and all human communication has ever gone from home. And those communications - like all signals - fall off in strength the farther they get from their originating broadcast point. 

How many stars and planets are within that 100 light year radius? Kinda depends who you ask, because every time we put up a new telescope, we see and discover dimmer and smaller stars, but it’s in the measure of thousands of total stars are within that radio signal range. Maybe 5000, maybe 50,000. We’re guesstimating at this point. The closer you get into the center of the Milky Way (we’re out in the boonies) the denser the stars get. Overall we’re guessing that the Milky Way has somewhere between 100 billion and 400 billion stars (some singular, some binary systems, some trinary systems. And we’ve been able to send signals that have reached … a couple thousand.

Going back to our plucky little space probe, if it were headed straight towards the center of the Milky Way, at 40,000 miles an hour, it would take over 450,000,000 years to get there. 

And lest we forget, the Milky Way is but one galaxy. There are others. So many others. Larger and smaller. (Don’t worry - we’ll come back to this.)

The next nearest galaxy is Andromeda. If we forget about the massive amount of gravity that the Milky Way has, and freeze the relative movement of massive bodies in the universe, and pretend that Voyager was able to just keep plugging along to exit one galaxy and enter another, it would take roughly 44 billion years to leave the Milky Way, cross intergalactic space, and touch the outer edge of the Andromeda galaxy.

44 Billion years is roughly 10 times longer than the Earth has existed, and a little over three times longer than the current age of the universe. But lucky for Voyager, Andromeda is coming to us and will merge with the Milky Way in about 4 and a half billion years, so it can just hang out here until Andromeda comes over to play.

Yes, a whole-ass galaxy is moving towards us 10X more quickly than we could send a single object to it.

So I said above that there were a lot of galaxies. How many are we talking? We used to think there were about 100 billion galaxies in just the observable universe. Then 200 billion. Then we got better telescopes, and started being able to check mass and relative movement and whatnot. So now, our best guess as of 2023 is that in the amount of the universe that we can see alone (the “observable universe”) there are around 2 trillion galaxies, with some theories placing it up to 10X higher. Not planets, galaxies. Some of those galaxies have 100,000,000 stars apiece; some have 100,000,000,000 stars; some have 100,000,000,000,000 stars. Most of those stars will have planets. Some of those planets will be in the right orbit to be conducive to the current known requirements for life. Either way, we’re talking something in the order of 2 trillion galaxies X billions of stars per galaxy X some amount of orbital objects (planets and moons and whatnot) in order to create the right conditions to harbor and grow intelligent life.

That’s a lot of space for life to potentially exist. And when you think about it in detail, it’s almost unfathomable that we’re alone out here in a vast deep dark void. But again: space is huge. And even though there are a lot of things in that space, and a lot of options for those things to make and grow life, the distance between objects in the universe is unfathomable huge.

So why haven’t we ever seen or met intelligent extraterrestrial life, if there are so many possibilities for it to develop? This is the answer to the Fermi paradox: space is too big to meaningfully visit, and too big to meaningfully search for communications even if we knew what we were looking for. The original question posed was “If there are so many stars, why is it so quiet?” And the answer we now understand is “because you’re shouting across an ocean.”

Even as advanced as we think we are, what with our half dozen trips to the moon and robots on Mars, our loudest screams into the interstellar void are only detectable by a couple thousand stars at best - and that’s assuming they have very sensitive equipment and can separate our signals from the background noise. So we will never see, communicate, or commune with intelligent life so long as we remain a primarily Earth-bound species.

That’s the bad news. The good news is that the distance between objects in the universe is so much more unfathomable huge than we can really understand. There are possibly, and even perhaps likely billions of intelligent species out there in the universe. Depending on the makeup of their system, some might even leave their planet and visit others nearby or, depending on the lifespan of the species and the distance between neighboring stars, they may even discover life forms that evolved independently from themselves and their system.

Either way, the likelihood is that the universe is full of life, of all kinds, teeming across the void. From single-celled organisms to intelligent species; each finding their own hold on and in rocks, clouds, and oceans; building civilizations and having their own epic stories of love, loss, victory, defeat, war, and peace.

We even think there could be a chance there’s some kind of non-Earth-related life here within our own solar system on one of Jupiter’s moons called Europa. And wouldn’t that be neat: to know of two planets which each developed life independently of each other. To know of two different paths in the universe for energy and raw materials to advance to growth and reproduction. To know of two different mechanisms by which the universe can gaze upon and explore itself in wonder.

That’s the beauty of the universe. That it’s so much more unfathomable huge than we can really understand - so within that unfathomable huge universe are all manner of possibilities for life, regardless of whether or not we ever see or know them. But it allows for infinite wonder from that which was once little more than base elements and energy but is now complex enough to ask “is there more like me somewhere out there?” 

And because the universe is so much more unfathomable huge than we can really understand, the answer is very likely “yes, of course, everywhere” even if we never get to meet them; and that doesn’t seem like a paradox at all.

In fact, to me it seems beautiful.