The Fermi Paradox – A Ridiculously Comprehensive Guide

In Essays, Philosophy

Note, the Fermi Paradox is really complex. This is a 12,000+ word long essay, my longest to date by a long shot, and it tackles a really interesting subject.  This is still a work-in-progress, and will be updated continuously in the next few weeks. 

I recommend you bookmark this page is some manner and read it in chunks. 

Ok, let’s go!

Sometimes I think we’re alone. Sometimes I think we’re not. In either case, the thought is staggering. Buckminster Fuller

Introduction to the Fermi Paradox

So first things first, let’s discuss Fermi. He was an Italian physicist who lived between 1901 and 1954, and made a huge impact in the world of physics, and was part of the infamous Manhattan project, which lead to the creation of the atomic bomb, and ultimately to the bombings of Hiroshima and Nagasaki and the cold war.

I bet that would make an interesting introduction at a cocktail party:

Random Cocktail Party-Goer: “So, what do you do?”
Fermi: “I’m just putting the last touches on the Atomic Bomb, it’s this thing that has the capability to wipe out entire cities at the drop of a hat and change international relations forever. What about you?”

If you want to read more about this amazing man, you could do worse that navigating to his Wikipedia Page.

According to the fountain of knowledge, we can define the Fermi Paradox thusly:

The Fermi paradox (or Fermi’s paradox) is the apparent contradiction between high estimates of the probability of the existence of extraterrestrial civilization and humanity’s lack of contact with, or evidence for, such civilizations.

So basically, we should – statistically speaking due to the incredible number of planets out there – be bumping into alien races left, right, and centre, and we’re not.

Which is strange, or paradoxical, even.

So, the question that was raised by the physicist Fermi was:

Where (the hell) is everyone?

So today’s essay is going to be about the various possible solutions and hypothesis that resolve the Fermi Paradox.

I don’t hold an opinion on what is the “real” solution, and it’s most likely that a combination of the solutions below are actually what causes us not to bump into aliens when we go to our local supermarket. However, I do have my pet favourites, and I think that there are some that appear less likely simply because they don’t stand up as well to a reasoned counter-attack as others.

I was introduced to the Fermi Paradox by my business partner and then read the excellent post on Wait Buy Why. I have since discussed it over drinks with a multitude of people, and everyone seems to find it fascinating, so it felt like a great topic to write about, and I also wanted to extend my knowledge on the subject.

Then, on my first attendance in early March 2016 to Nerd Night Phnom Penh, I was stupid enough to put my hand up when they asked for volunteers to speak at the next event that was two weeks away, and I chose the Fermi Paradox as my topic. This meant that I had to prepare twenty slides for twenty seconds each about the Paradox, but, as you will see, that can in no way do it justice, and so I decided that while I was practicing and creating my presentation, I would write a really in-depth article that would help in a number ways:

  • Firstly, it would help clarify my thoughts and decide what to include, and, more importantly, what to leave out. 400 seconds is not a long time!
  • Secondly, I thought that an essay like this would make a great resource for everyone who attended if they wanted to read more about the subject.
  • I’m quite geeky when it comes to this type of stuff, and so it’s a great pastime for me. 🙂

I am also a little nervous about speaking in public, so writing this essay allows me to take some action each day towards alleviating my anxiety at this task in a meaningful manner. At least, I feel like I am doing something towards making a better presentation, even if it might be a flop!

I’ve got a resources section at the end (coming soon!) where I link to many books and online articles, and this essay is meant to be a synthesis of all of those in an easy-to-digest format, with a few of my own observations thrown in. In other words, if you don’t have forty or fifty hours of your life to dedicate to reading about the Fermi Paradox, then this essay will give you all you need to know, in accordance with the 80/20 rule.

I’ve been quite shameless to quote, take, steal, adapt from all the resources available, and my hope is that I’ve stayed on the right side of plagiarism while providing an entertaining and thoughtful essay.

Feel free to weigh in on that in the comments, and on that note, please think of this as a living, breathing document which you can contribute via the comments or by shooting me an email, and I’ll update things here accordingly.

What I really love about Fermi’s paradox is that the potential implications are huge, and all the various hypothesis and solutions draw on a huge number of different sciences and logical steps, so it’s actually a great way to learn about lots of other topics.

That’s why I’d like to discuss a few things before we get started, namely:

  • What is a Paradox?
  • What is a Hypothesis?
  • Ockham’s Razor
  • The Law of Large Numbers
  • The Principle of Mediocrity

These are tools and ideas that we can use later on when we explore some of the solutions. If you’re already well-versed in the above, I suggest you skip this section and move right on to the discussion about the different types of civilisations.

What is a Paradox?

A paradox is a statement that apparently contradicts itself and yet might be true (or wrong at the same time).

Often a paradox highlights that either our understanding regarding a subject is incomplete, or that we need to refine our logical or mathematical theories to encompass a paradox.

One way to solve a paradox is to create a number of hypothesis regarding possible solutions, and then systematically test them. In fact, let’s now get into exactly what is and isn’t a hypothesis, because this will help understand some of the solutions to the Fermi Paradox.

What is a Hypothesis?

A supposition or proposed explanation made on the basis of limited evidence as a starting point for further investigation.

The key thing here is that a hypothesis needs to be testable in some form. You’ll see that while some of the solutions below are great, there is actually no way we can either prove them right or wrong, but they are still fun to consider.

Occam’s Razor

This is a very simple, but highly effective technique and problem-solving principle.

In a nutshell, when we have two or more hypothesis, the one that has the least number of assumptions should be the one that is selected as the most likely to be true.

However, we should note that Occam’s Razor should not be used to actually decide which hypothesis is correct, but more as a guiding principle to cut down on the number of possible branches that we examine, because it is often impossible to seriously examine every implication of every hypothesis, and so we need a method to simplify our search. This essay is actually only a short study on the Fermi Paradox, and it still ended up being the longest essay on this website.

So, when we examine some of the possible solutions to the Fermi Paradox, we can actually rule quite a few out because they rely on so many stacked assumptions, that the likelihood that they could actually be true diminishes to the point where it is so statistically unlikely that they are not even worth considering. But, that doesn’t mean it is fun to do so! 😀

The Law of Large Numbers


In probability theory, the law of large numbers (LLN) is a theorem that describes the result of performing the same experiment a large number of times. According to the law, the average of the results obtained from a large number of trials should be close to the expected value, and will tend to become closer as more trials are performed.

The LLN is important because it “guarantees” stable long-term results for the averages of some random events. For example, while a casino may lose money in a single spin of the roulette wheel, its earnings will tend towards a predictable percentage over a large number of spins. Any winning streak by a player will eventually be overcome by the parameters of the game. It is important to remember that the LLN only applies (as the name indicates) when a large number of observations are considered. There is no principle that a small number of observations will coincide with the expected value or that a streak of one value will immediately be “balanced” by the others.

This is extremely important for us to understand because we are dealing with such huge numbers in the section ahead. The main point to keep in mind is that let’s say we say something along the lines of “Almost all extra-terrestrial civilisation will never achieve an advanced level of intelligence” this may well still mean that there are a huge number of advanced extra-terrestrial civilisations out there. 

When we are dealing with these huge numbers, there really isn’t much difference between 100%, 1%, or 0.01%, because it would still leave us with ridiculously large numbers of possible observations.

One way to think about it is as a lottery where you have a 1% chance of winning some type of prize, and you buy a billion tickets. You’re pretty much guaranteed a win. 

The Principle of Mediocrity


The mediocrity principle is the philosophical notion that “if an item is drawn at random from one of several sets or categories, it’s likelier to come from the most numerous category than from any one of the less numerous categories”. The principle has been taken to suggest that there is nothing very unusual about the evolution of the Solar System, Earth’s history, the evolution of biological complexity, human evolution, or any one nation. It is a heuristic in the vein of the Copernican principle, and is sometimes used as a philosophical statement about the place of humanity. The idea is to assume mediocrity, rather than starting with the assumption that a phenomenon is special, privileged, exceptional, or even superior.

So essentially, we should assume that we’re special, and we should assume that we are quite average. So going back to our paradox, that we are not the simplest civilisation out there, nor the most advanced. In fact, we should expect there to be a lot of civilisations around the same level of advancement as ourselves.

In the section below, we are going to assume the mediocrity principle, and make various assumptions about Earth simply being a typical planet that is subject to similar laws, effect, and the likelihood of outcomes as any other planet.

We will then try to soundly reject this later on.

Wrapping our Heads around the Universe (IN Numbers)

There are three kinds of lies: lies, damned lies and statistics. Mark Twain

So, earlier when I commented on the fountain of knowledge’s description of the Fermi Paradox I italicised the word statistically, and that’s what I want to tackle right now.

We need to remember that pretty much everything that follows is at best an educated guess, and at worse completely unfounded hypotheses that either I, or most likely someone else who is far more intelligent, has plucked from thin air and called an educated guess.

For instance, we obviously we have no way of knowing right now what percentage of civilisations make the leap from simple life forms to self-aware intelligence like us humans, so we simply take a low-ball number and run with it.

However, because the numbers below are SO huge, it doesn’t really matter, because we could be “off” by several multitudes and the maths would still be in our favour regarding many of the arguments below, as it follows from the Law of Large Numbers.

So, we’ve all travelled to the countryside (and some of us are lucky enough to live there), and one thing that everyone notices at night in the countryside is that you can see a huge amount of stars. Us city-dwellers (that sounds like a low-life form, like cave-dweller) don’t experience that because there is a huge amount of what is called light pollution in cities. In other words, there is so much artificial light at night in a city, that light coming from the stars is lost in the haze, and we only see the brightest and nearest stars.

So on those really awesome nights when we look up at the sky in the non-light-polluted countryside and we stare and stare and stare, a huge amount of stars slowly start to appear, and it can look really magical, something like this:


Sorry, not that Starry Night.

starry night sky

Ok, that’s better.

It feels like we can glimpse the entire universe, and if you start to think about how the photos that are hitting your retina have been travelling for far longer than you have been alive, and before we ever had electricity, toilets, the Magna Carta, or anything in the last 500 to 1000 years.

I quite like the fact that even the light from our own sun takes six or seven minutes to reach us, which means we wouldn’t notice for enough time to have a quick coffee if the sun was suddenly covered up.

So, those really incredibly nights, where you feel you can see the sky light up with stars, you’re not actually seeing much – normally around 2,500 stars, which is less than one out of every hundred million stars that there are in just our galaxy – The Milky Way – which is like just one small neighbourhood in the universe.

Percentage-wise, you’re seeing: 0.000001% of the stars in just our galaxy, and that’s on the best of days.

Now consider this, which will really mess with your mind:

There are around 100 to 400 billion stars in our local neighbourhood, the Milky Way Galaxy, and that there are around again there is around the same number of galaxies.  

So for every star in our galaxy, there is an entire galaxy full of just as many stars.

Feeling small and insignificant yet?

So this is how (roughly) how many stars are out there:


An awesome and jaw-dropping statistic from Wait But Why highlights this fact:

For every grain of sand in every single beach on earth, there are 10,000 stars “out there”.

Crazy huh?

But, of course, let’s not forget that each star may well have multiple planets circling around it, just like our sun has 8 or 9 (depending on who you ask).

You can read elsewhere about exactly what the consensus is about what percentage of stars are similar to our sun, but we’re going to go for the low end which comes in at 5%. So one in every twenty stars has similar characteristics to our sun, which would potentially allow life-as-we-know-it to prosper.

So this leaves us with this many sun-like stars:


…which is a lot.

That’s 500 billion billion, which is even more than the amount of “value” the fraudulent derivatives market currently has managed to “create”.

Again, we are already getting into wishy-washy land here, because we obviously can’t actually count  these stars, but we trust in the law of large numbers based on our observations so far.

A similar strategy has given us a range regarding how many of these stars that are similar to our own may have a planet which is also similar to our own. 50% to 22% of stars should have an earth-like planet. Let’s take the lower and more conservative estimate, just because pessimism is awesome. You can view the PNAS study on this – but I didn’t read it.

So if 5% of stars are sun-like, and 20% of those stars may well have an Earth-like planet, this means that 1% of all the stars in the universe have Earth-like planets.

That’s like 100 billion billion Earth-Like planets.

Not feeling so special anymore huh?

Don’t worry – it gets worse.

If we imagine that 1% of all these Earth-like planets develop life and that 1% of these end up with intelligent life. This would leave us with 10 Quadrillion intelligent civilisations in the observable universe.

The Fermi Paradox - Mind Blown


Scaling that down to our Galaxy, the Milky Way, would give over 100,000 intelligent civilisations just in our local cosmic neighbourhood.

Considering that at least some of these civilisations would be much older and probably far more technologically advanced, it is strange that we’ve never been able to detect them because it should actually be pretty easy to do so. We’ve already examined every star within 150 light years of us.

But that’s not all, if a civilisation was even just a few million years ahead of us, they should already be here!

The Fermi Paradox: Why Life Should be everywhere.

sentient ants

So if any ETC manages to build a spacecraft capable of reaching the nearest stars, and even if this spacecraft travels quite slowly then, from a cosmic perspective, they would be able to conquer an entire galaxy in the blink of an eye.


This spaceship would have to be able to support generations of travellers who would live and die on the spaceship, which is an interesting challenge to say the least.

Say that it took 500 to 1000 years to reach the closest star, and then say 500 to 1000 years to then settle, and then continue on, our best estimates say that it would take around 2 million years to go each habitable planet in an average size galaxy.

However, I see some flaws in this argument, because even in our own experience as humans colonising the earth, our rate of expansion was far, far, slower, than our means of travel.

A person riding a horse could cover anywhere between 16km and 40km per day depending on the conditions, but humans did not move at anything close to that rate countries continents

It’s estimated that humans colonised at a rate of something around 1km to 5km per year. If we compare the fastest travel speed by horse, with the fastest estimate for yearly colonisation, the difference is an incredible 3000 times. So our two million year estimate of an advanced ETC spreading through the galaxy has a huge margin of error because based on the above calculation it could actually take up 6 billion years for a civilisation to do so, if at all.

This is because there are lots of obstacles in the way, many of which we don’t even know about, but let’s tackle some of the most common and easily imaginable ones.

Firstly, when the timescale to colonise a galaxy may be in the millions of years, it is quite possible that by the time the ETC reaches the other end of the galaxy, some of the spaceships inhabitants have actually evolved into a completely different species. Think about what was walking around on Earth 65 million years compared to now.



But this is only one of the problems. Many of the ships may simply forget their original mission, or settle on one planet and never leave. Instructions from the home planet would take hundreds, if not thousands of years to reach their intended destinations, which means a breakdown in communication, at least with any technology we can imagine at the present moment, is almost inevitable.

So perhaps there is a real hard limit on how far away a single ETC can effectively travel before it stops acting as a coherent civilisation and simply splits up into smaller civilisations.

The Fermi Paradox - Office Meme 2

And we’re not even considering everything that plagues us like political uprisings, war, disease, and that the costs of such an under-taking that may be prohibitive and unsupported by the general public.

However, we have to remember that there could be up to 100,000 intelligent civilisations out there in just our galaxy, the Milky Way, and so it’s unlikely that these problems would stop all of these civilisations from creating a coherent and functioning galaxy-colonisation strategy.

It is worth remembering that a civilisation that is hundred of thousands, or perhaps millions of years more technologically advanced than us may well have been able to conquer pesky problems like evolution, remote communication, and perhaps even have found ways to travel faster than the speed of light while respecting the various laws of physics which govern the universe.

This, of course, assumes that they are not either wiped out by their own technology or don’t bother exploring at all because they have managed to create heaven on (their) Earth.

We’ll discuss these issues at length later.

The Types of Civilisations

In the general timespan of things, our planet is actually quite young, coming in a 4.54 billion years of age. Right now, we believe the Big Bang to have occurred around 13 billion years ago.

This is highly interesting because it leads us to the fact that if there is intelligent life out there, it is likely to be millions, if not billions, of years older than us. Let’s think through what the implications are.

I’m just going to go ahead and quote this article from Wait But Why:

Imagine taking a time machine back to 1750—a time when the world was in a permanent power outage, long-distance communication meant either yelling loudly or firing a cannon in the air, and all transportation ran on hay. When you get there, you retrieve a dude, bring him to 2015, and then walk him around and watch him react to everything. It’s impossible for us to understand what it would be like for him to see shiny capsules racing by on a highway, talk to people who had been on the other side of the ocean earlier in the day, watch sports that were being played 1,000 miles away, hear a musical performance that happened 50 years ago, and play with my magical wizard rectangle that he could use to capture a real-life image or record a living moment, generate a map with a paranormal moving blue dot that shows him where he is, look at someone’s face and chat with them even though they’re on the other side of the country, and worlds of other inconceivable sorcery. This is all before you show him the internet or explain things like the International Space Station, the Large Hadron Collider, nuclear weapons, or general relativity.
This experience for him wouldn’t be surprising or shocking or even mind-blowing—those words aren’t big enough. He might actually die.
But here’s the interesting thing—if he then went back to 1750 and got jealous that we got to see his reaction and decided he wanted to try the same thing, he’d take the time machine and go back the same distance, get someone from around the year 1500, bring him to 1750, and show him everything. And the 1500 guy would be shocked by a lot of things—but he wouldn’t die. It would be far less of an insane experience for him, because while 1500 and 1750 were very different, they were much lessdifferent than 1750 to 2015. The 1500 guy would learn some mind-bending shit about space and physics, he’d be impressed with how committed Europe turned out to be with that new imperialism fad, and he’d have to do some major revisions of his world map conception. But watching everyday life go by in 1750—transportation, communication, etc.—definitely wouldn’t make him die.

No, in order for the 1750 guy to have as much fun as we had with him, he’d have to go much farther back—maybe all the way back to about 12,000 BC, before the First Agricultural Revolution gave rise to the first cities and to the concept of civilization. If someone from a purely hunter-gatherer world—from a time when humans were, more or less, just another animal species—saw the vast human empires of 1750 with their towering churches, their ocean-crossing ships, their concept of being “inside,” and their enormous mountain of collective, accumulated human knowledge and discovery—he’d likely die.

And then what if, after dying, he got jealous and wanted to do the same thing. If he went back 12,000 years to 24,000 BC and got a guy and brought him to 12,000 BC, he’d show the guy everything and the guy would be like, “Okay what’s your point who cares.” For the 12,000 BC guy to have the same fun, he’d have to go back over 100,000 years and get someone he could show fire and language to for the first time.

In order for someone to be transported into the future and die from the level of shock they’d experience, they have to go enough years ahead that a “die level of progress,” or a Die Progress Unit (DPU) has been achieved. So a DPU took over 100,000 years in hunter-gatherer times, but at the post-Agricultural Revolution rate, it only took about 12,000 years. The post-Industrial Revolution world has moved so quickly that a 1750 person only needs to go forward a couple hundred years for a DPU to have happened.

This pattern—human progress moving quicker and quicker as time goes on—is what futurist Ray Kurzweil calls human history’s Law of Accelerating Returns. This happens because more advanced societies have the ability to progress at a faster rate than less advanced societies—because they’re more advanced. 19th century humanity knew more and had better technology than 15th century humanity, so it’s no surprise that humanity made far more advances in the 19th century than in the 15th century—15th century humanity was no match for 19th century humanity.

So if just a few hundred years are enough for us now to have a DPU. Imagine what a few million years, with a much more advanced society that is advancing at a far faster rate, would do for us? It would be so incomprehensible that relating to them may be as difficult and futile as a sentient ant trying to relate to us.

However, this doesn’t mean we haven’t tried to imagine how a more advanced society would look like, and we have created a huge amount of movies and books to spark our collective imagination.

The Kardashev Scale, which, incidentally, was first proposed by the Soviet Russian astronomer Nikolai Kardashev, measures civilisations based on their energy consumption in regards to the cosmos.

This actually ignores the potential for limitless energy from fusion reactors, but we haven’t actually created one yet, so we can discount it for now.

It breaks civilisations down into three types.

  • A Type I civilisation has mastered all the resources of it’s host planet.
  • A Type II civilisation has managed to capture all the resources of it’s solar system.
  • A Type III has managed to gather energy from the entire Galaxy.

There are estimates that we’re currently at Type 0.7, and that we will reach Type I in a few hundred years, Type II in something like 10,000 or so years, and a Type III in around a million years. These estimates are based on our level of technological growth, and happily remove the fact that we may well bring ourselves back to the stone age via a mishap (see: The Black Swan), or simply wipe ourselves off the face of the planet long before we manage these incredible engineering feats.

The thing is, using the above-mentioned logic, there should be quite a number of Type II and III civilisations (remember the Principle of Mediocrity) , and if they either wanted to be found or were not actively hiding, it should be relatively simple to find evidence that they exist.

One educated guess about the future of technology is that computing power and information will be of the utmost importance. We’re aware that energy can only be transferred, and so these huge calculating machines that Type II and III civilisations would give out a fair bit of heat, and that is what we should be able to detect.

Also, a Type III civilisation may create engineering projects on a planetary scale, which we should also be able to detect given enough time.

What Would Extra terrestrial Civilisations Be Like?

The short story below – They’re Made Out of Meat –  is actually one of the solutions as stated by Stephen Web in his excellent book on the Fermi Principle (check the resources section at the end of this essay), and it basically highlights how we might be so far removed to the aliens. I wanted to tackle this separately, because it gives us a good foundation on how to understand some of the really strange stuff that goes on in the other solutions.

It’s named after a great short story which I’ll reproduce here:


“They’re made out of meat.”


“Meat. They’re made out of meat.”


“There’s no doubt about it. We picked up several from different parts of the planet, took them aboard our recon vessels, and probed them all the way through. They’re completely meat.”

“That’s impossible. What about the radio signals? The messages to the stars?”

“They use the radio waves to talk, but the signals don’t come from them. The signals come from machines.”

“So who made the machines? That’s who we want to contact.”

“They made the machines. That’s what I’m trying to tell you. Meat made the machines.”

“That’s ridiculous. How can meat make a machine? You’re asking me to believe in sentient meat.”

“I’m not asking you, I’m telling you. These creatures are the only sentient race in that sector and they’re made out of meat.”

“Maybe they’re like the orfolei. You know, a carbon-based intelligence that goes through a meat stage.”

“Nope. They’re born meat and they die meat. We studied them for several of their life spans, which didn’t take long. Do you have any idea what’s the life span of meat?”

“Spare me. Okay, maybe they’re only part meat. You know, like the weddilei. A meat head with an electron plasma brain inside.”

“Nope. We thought of that, since they do have meat heads, like the weddilei. But I told you, we probed them. They’re meat all the way through.”

“No brain?”

“Oh, there’s a brain all right. It’s just that the brain is made out of meat! That’s what I’ve been trying to tell you.”

“So … what does the thinking?”

“You’re not understanding, are you? You’re refusing to deal with what I’m telling you. The brain does the thinking. The meat.”

“Thinking meat! You’re asking me to believe in thinking meat!”

“Yes, thinking meat! Conscious meat! Loving meat. Dreaming meat. The meat is the whole deal!  Are you beginning to get the picture or do I have to start all over?”

“Omigod. You’re serious then. They’re made out of meat.”

“Thank you. Finally. Yes. They are indeed made out of meat. And they’ve been trying to get in touch with us for almost a hundred of their years.”

“Omigod. So what does this meat have in mind?”

“First it wants to talk to us. Then I imagine it wants to explore the Universe, contact other sentiences, swap ideas and information. The usual.”

“We’re supposed to talk to meat.”

“That’s the idea. That’s the message they’re sending out by radio. ‘Hello. Anyone out there. Anybody home.’ That sort of thing.”

“They actually do talk, then. They use words, ideas, concepts?”
“Oh, yes. Except they do it with meat.”

“I thought you just told me they used radio.”

“They do, but what do you think is on the radio? Meat sounds. You know how when you slap or flap meat, it makes a noise? They talk by flapping their meat at each other. They can even sing by squirting air through their meat.”

“Omigod. Singing meat. This is altogether too much. So what do you advise?”

“Officially or unofficially?”


“Officially, we are required to contact, welcome and log in any and all sentient races or multibeings in this quadrant of the Universe, without prejudice, fear or favor. Unofficially, I advise that we erase the records and forget the whole thing.”

“I was hoping you would say that.”

“It seems harsh, but there is a limit. Do we really want to make contact with meat?”

“I agree one hundred percent. What’s there to say? ‘Hello, meat. How’s it going?’ But will this work? How many planets are we dealing with here?”

“Just one. They can travel to other planets in special meat containers, but they can’t live on them. And being meat, they can only travel through C space. Which limits them to the speed of light and makes the possibility of their ever making contact pretty slim. Infinitesimal, in fact.”

“So we just pretend there’s no one home in the Universe.”

“That’s it.”

“Cruel. But you said it yourself, who wants to meet meat? And the ones who have been aboard our vessels, the ones you probed? You’re sure they won’t remember?”

“They’ll be considered crackpots if they do. We went into their heads and smoothed out their meat so that we’re just a dream to them.”

“A dream to meat! How strangely appropriate, that we should be meat’s dream.”

“And we marked the entire sector unoccupied.”

“Good. Agreed, officially and unofficially. Case closed. Any others? Anyone interesting on that side of the galaxy?”

“Yes, a rather shy but sweet hydrogen core cluster intelligence in a class nine star in G445 zone. Was in contact two galactic rotations ago, wants to be friendly again.”

“They always come around.”

“And why not? Imagine how unbearably, how unutterably cold the Universe would be if one were all alone …”

Aliens could be different in a whole host of ways. They might well not communicate via sounds, or they might be able to travel in different dimensions (time, anyone?!), or they might actually just be it, a collective mind that somehow controls billions of individual organisms.

The possibilities, as they say, are endless.

The Solutions to the Fermi Paradox

There are three main groups of proposed solution to the Fermi Paradox of why we have found no proof that intelligent extra-terrestrial civilisations exist:

  1. We haven’t been able to find evidence of Type II and III civilisations because they simply don’t exist.
  2. We haven’t been able to find evidence of Type II and III civilisations, but they are out there.
  3. We haven’t been able to find evidence of Type II and III civilisations, but they are actually here amongst us, and reading this very essay. 😉


The first group of solutions is where we’re actually going to battle the previous assumptions that we made about life being really common across the universe. We will show that perhaps it might be really difficult for intelligent life to form.

The second and third groups of solutions are where I believe all the fun is. 🙂

One thing to keep in mind with all the solutions  is that they would have to apply to all the millions and millions of possible higher level civilisations. It would take just one higher civilisation to break one of our rules or assumptions, and then we would have heard from them or at least have some evidence that they exist. However, there is one thing we know, and that is that the general public at this present moment does not have

We haven’t been able to find evidence of Type II and III civilisations because they simply don’t exist

God(s) Exists

If the reason why we have never found any evidence that extra-terrestrial civilisations exist is because a god created the entire universe and then only placed us in it, then we already have a few holes in this story.

First, why would a god create this incredibly huge universe, if he was going to place only what, cosmologically speaking, amounts to a not even a handful of sentient beings? This is the same argument that we used against the simulation argument, it’s a huge waste of time and resources to build such a massive universe if only Earth has life.

Of course, this entire solution is a little moot, because it’s not even a hypothesis that cannot be tested because we cannot prove that a god even exists.

I’m a non-believer, and actually quite an ardent atheist, and I believe that Christopher Hitchens dismantled the argument that any god exists in his fantastic book “God is Not Great”.  I think this should almost be considered required reading for anyone, regardless of their religious denomination.

Because this entire solution rests on the huge assumption that a god exists, we must dismiss it out of hand by using Occam’s Razor as there are solutions that make far less grandiose assumptions.

However, let’s run with the assumption that “God” (from whichever religion) does exist, and that the scientific theories that we have formulated so far actually hold weight.

If the universe is 13 billion years old, and Earth is around 4 billion years old, then God would have had plenty of time to decide to create other living organism elsewhere in our galaxy or the universe. In fact, given a long enough time frame, it is almost certain that God would do so, perhaps even as a way to test our faith when we eventually discover them.

An interesting point to consider is this: If we manage to “discover” God, would that mean that we had found extra-terrestrial life? Perhaps that is another paradox in itself.

We have already flipped this on its head earlier when I asked if we could actually be able to distinguish a civilisation with technology that is a million years ahead of our own from a society of gods, because to us they would most probably appear to quite literally have the power of gods.

In fact, what if one of these super advanced societies had actually created our universe out of their universe, perhaps by forming-on-purpose a particular type of black hole? Then, perhaps we actually should consider them gods, because they would, in a roundabout way, have created us.

This civilisation may well exhibit many of the characteristics of God such as immortality, omnipresence, and also power beyond our imagination. It would also quite likely perhaps be just one individual instead of a mass of separate individuals.

Quite strange, right? This would be a resolution to the old atheists vs theists battle, but the funny thing would be that both sides would have been wrong. God would exist, but he – it? – wouldn’t even consider itself a God, but simply a part of the natural order of the universe, just another thing that just exists.

The Government Conspiracy Hypotheses

This states that aliens are in either in collusion with some or all of our governments, or that some type of inadvertent contact has been made, but it being kept secret (i.e. the whole story surrounding Area 51).

Some people point to the ever-increasing development of technology in the last fifty years and claim that this is either because aliens have been seeding technology to us, or that the governments (or usually, the government of the United States of America) has been reverse engineering captured pieces of alien technology.

Leaving aside the possibility that an extra-terrestrial civilisation may choose to deal on a governmental level only for a set period of time, I feel that the remaining possibility that we’ve been able to capture an alien spacecraft is extremely small.

Let’s think about it.

An alien race that has been capable of overcoming interstellar travel is hardly going to have issues moving around our atmosphere, and their aircraft would be so secure and tolerant to mechanical failures that they would make even the latest and safest of our commercial aircraft look like they are held together by some tape and a prayer. Quite literally, almost nothing would go wrong with their flying machines, and it’s quite likely that they wouldn’t even be piloting them themselves.

We are already capable of that, and we struggle to consistently leave our own atmosphere! The United States of America routinely bombs other countries with unmanned aircraft, with the operators safely tucked away at an air base on US soil.

That is why I personally think that the stories about people being abducted or seeing UFOs are a lot of hogwash. We’ll reject this more full in “The Zoo Hypotheses”.

Now, let’s go back and revisit the hypothesis that an alien race would prefer to deal on a government level only. This sort of does make sense, because they would probably consider the following issues:

  • Would just showing up randomly with no preparation perhaps cause violent conflict and death?
  • Is the world at large ready for such an Earth-shattering discovery? Perhaps there is some technological, ethical, governmental, or socio-economic barrier that the aliens feel we need to overcome as a planet before we are ready for full-scale inter-stellar diplomacy.

The Zoo Hypotheses

The Zoo Hypotheses of the Fermi Principle states that super intelligent life in the universe does exist, but they are simply watching Earth from afar, and leaving us to our natural development.

This is quite a fun one, and perhaps one of the most likely explanations of why we have had no contact from the rest of the universe. However, it also requires a whole lot of assumptions which are quite dubious, and I’ll touch on those later on.

Why the aliens make no contact could be for a number of reasons:

Perhaps they are waiting for us to pass some type of technological, social, evolutionary, or socio-economic barrier before making contact, because in their past experience it is better to make contact with a less developed race only once this has happened, to allow us a smoother transition to a multi-planet existence. Examples of this would be a one-world government, a different economic system to capitalism, or the general renouncement of God, which may well be, for many people, incompatible with the discovery that we’re not alone in the universe.

Perhaps there is a reluctance to make contact due to the possibility of either party spreading pathogens to the other. Obviously we would have absolutely no immunity to a virus from another planet or galaxy, and also vice versa. We have actually taken similar steps with some tribes, which are commonly called “uncontested peoples”. They are often found in the densely forested areas of South America and Central Africa. It is often advised not to contact these tribes for the risk of killing a large amount of their population with common diseases, and also to respect their right to self-determination. If we’ve been able to reach such a conclusion, it is very possible that an alien race has done the same. [There is a really interesting article on Wikipedia regarding uncontested peoples.]
Another – quite depressing – possibility, is that the advanced alien race(s) that are watching us view us in such an inferior way that we’re literally animals to them. In the same way as we don’t try to reason with and integrate the Zebras in our local zoo into our society, they do the same to us. This lead us to the conclusion that there is a far higher level of consciousness and intelligence possible. In fact, the alien race watching us may well not even be organic, but be a artificial super-intelligent computer and so it can literally only view us in the same way we view ants. This actually merges with the – quite humorous – “We’re Made Out of Meat” solution that we’ll discuss a little later.

Perhaps we’re their equivalent of an animal testing lab, but that seems unlikely, because while there have been lots of reports of abductions, none of them have ever stood up to a scientific public inquiry.

Carl Sagan rejects this very nicely:

To be taken seriously, you need physical evidence that can be examined at leisure by skeptical scientists: a scraping of the whole ship, and the discovery that it contains isotopic ratios that aren’t present on Earth, chemical elements from the so-called island of stability, very heavy elements that don’t exist on Earth. Or material of absolutely bizarre properties of many sorts—electrical conductivity or ductility. There are many things like that that would instantly give serious credence to an account.
But there’s no scrapings, no interior photographs, no filched page from the captain’s log book. All there are are stories. There are instances of disturbed soil, but I can disturb soil with a shovel. There are instances of people claiming to flash lights at UFOs and the UFOs flash back. But, pilots of airplanes can also flash back, especially if they think it would be a good joke to play on the UFO enthusiast. So, that does not constitute good evidence.
Another, quite simplistic, explanation, is that the Earth is simply a type of zoo, and that one or more alien civilisations are simply observing us for interest and amusement, just like we visit the zoo to see animals. I’m sure that they would find this highly ironic!
One thing that is slightly dubious about this theory is that it has to make the assumption that there exists – in one form or another – a sort of inter-stellar federation, in which all the members would have to respect the directive that Earth is a zoo and no-go zone that must just be observed, and not meddled in. This hints that there would have to be some form of centralised governing body and a highly advanced policing network to enforce this, or perhaps some block that doesn’t allow anyone to visit Earth, very much like we have gates and cages in our zoo, both for the protection of the animals and the guests. Of course, their technological level would be unimaginable to us, so anything is possible. It’s much like asking an ancient Greek scientist to imagine how the present day would be, except that this is even harder.

If there were multiple independent races, then it’s likely that one of them would adopt a policy of contacting us, and yet this hasn’t happened yet. A counter to this is that over time, especially the time it takes to to discover advanced space travel, all cultures tend to adopt similar rational policies, in an almost evolutionary manner. Rather much like on Earth several of the feature we see across species – such as eyes – actually developed independently to each other. So the eye was “discovered” by evolution not once, but dozens of times.

I’m not convinced with one version of the theory that claims that they would be studying us for scientific purposes. I find it unlikely that such an advanced race would have much to learn from us, unless we are so wildly different in our biology that it makes a great case study. Of course, there is also the possibility that we’re the very first alien race that they have encountered, and then of course they would have all their eyes glued on us, because their discovery would have amazed them just as much as us discovering them would do. For a short period of time, they may be facing the political issues of whether or not to make contact, and how. This goes back to the earlier point that they might be waiting for us to cross some type of threshold.

For the moral and ethical issues of whether they should or should not interfere with the world when there is so much wrong with it, with numerous wars, a large inequality gap, etc, there is only one thing to be said.

We are not shocked when we see a pack of lions hunt and kill another animal on the savanna, so why should the aliens be surprised that there is war on our planet? In fact, they may actually view this as a positive development, because it leads to larger and larger governments, an overall better standard of living, and *less* violence (yes, really) and may well eventually allow us to end up with just one centralised governing body. This is the viewpoint of Ian Morris in his wonderful book “War! What Is It Good For?: Conflict and the Progress of civilisation from Primates to Robots” – go read it!

I’ll quote the blurb:

In War! What Is It Good For?, the renowned historian and archaeologist Ian Morris tells the gruesome, gripping story of fifteen thousand years of war, going beyond the battles and brutality to reveal what war has really done to and for the world. Stone Age people lived in small, feuding societies and stood a one-in-ten or even one-in-five chance of dying violently. In the twentieth century, by contrast―despite two world wars, Hiroshima, and the Holocaust―fewer than one person in a hundred died violently. The explanation: War, and war alone, has created bigger, more complex societies, ruled by governments that have stamped out internal violence. Strangely enough, killing has made the world safer, and the safety it has produced has allowed people to make the world richer too.

Counter-intuitive, but true.

The Simulation Hypothesis

I heard of this general concept when I was around 11 years old, long before I ever heard of the Fermi Paradox, and it blew my mind.

Essentially, at some point in the future computing power becomes so powerful and ubiquitous that full-world simulations are possible, and they eventually number in the billions. Think of something along the lines of Matrix, but every kid in the future could be running one.
There are a few reasons why we might not encounter another race in the universe:

  • The simulation only has one civilisation in it. However, one would then have to consider why the master engineer would go to such lengths to program the entire universe, which appears to be quite wasteful, unless it’s a type of speeded up simulation to see how quickly humans starting on one planet can colonise the entire galaxy and then beyond. This argument of wastefulness is also a counter to the solution that states that God created the universe and everything and that he only created us and no other life on other planets.
  • Perhaps the universe doesn’t actually exist, and it just appears to be there when someone is looking. A bit like that old story: ‘If a tree falls in a forest and no one is around to hear it, does it make a sound?’ This would be a great way for them to save an enormous amount of computing power.
  • There is also another quite strange possibility that I read, and that is that the simulation is run by a post-human civilisation that is actually searching for the answer to the Fermi Paradox. Confused yet? I was! Essentially, they would take all the hypothesis that I am proposing here, and test them out in billions of simulation that are as near-perfect a copy of the actual universe. Due to the law of large numbers, they could then be quite sure how often a civilisation becomes spacefaring, or develops a super artificial intelligence. Of course, *they* would definitely be a post-human civilisation because if a computer can create a sentient being in a simulation, it must for sure be sentient itself, which means we would reach what is called The Singularity.

We can imagine why this technologically future race – it wouldn’t have to be human – would go and create these simulation.

The game The Sims gives us a clue. People like playing God and creating their own city and country and simulating what would happen.

So perhaps it’s just a game.

Perhaps it’s their way to time travel – they recreate the past as best at they can, and then the present moment beings can essentially view and experience the past. This is quite a cool idea, when you stop and think about it.

Imagine if these simulations were so realistic that the simulated beings inside the simulation were actually sentient! They would have no idea that they were living in a simulation.

So this logically leads us to two possible outcomes:

1. Either it’s impossible to simulate a virtual world in which the beings inside it believe themselves to exist and are sentient, and that it’s impossible to create a large number of these simulations over time.


2. We’re most probably living in a simulation.

Let’s tackle first things first. What would render a simulation impossible?

Firstly, it might be the practical issues of creating a powerful enough computer, and this would probably require building something called a Dyson Sphere, which we have already discussed earlier. Essentially, it means completely covering a start to harness all of the energy created by that star. This could power a super-computer capable of making a simulation realistic enough for any beings inside it not to realise that it is a simulation.

In the Hitchhikers Guide to the Galaxy, Earth is actually a large supercomputer that is trying to find the question to the answer to the ultimate question of life, the universe, and everything, which as everyone knows, is 42.

Or perhaps, the fact, as I mentioned above, that to create a simulation that has sentient beings, you would have to create a super-powerful sentient machine, who would probably not bother running the simulations, because it would have no need to do so. This topic of Super Artificial Intelligence will pop up again and again, and for good reasons too.

Aliens simply ignore the real world.

Wow, this is a really strange one, but actually, if we take a deep hard look at our habits, perhaps quite likely.

Let’s imagine a Type II civilisation, one that has managed to harvest the entire energy of it’s local star. With such an enormous source of energy, they may well be able to compute incredibly simulations (see “The Simulation Hypotheses” elsewhere in this essay) and perhaps they might not bother to explore the universe, because they are all living the perfect life inside a pod hooked up to a machine, a little bit Matrix-like.

If you think this in implausible, just take a look at how technology since World War 2 has made use get out of touch with reality. Children spend less time outside and more time staring at screens, at dinner people constantly check their smartphones instead of focussing on the present moment. Imagine what might happen if we were a million years more advanced that we are now, the completely rejection of the real world and society doesn’t seem so far fetched.

A great example of this is how far removed we are from our food. Personally, I don’t even know or understand how most of the food I eat is gathered and/or processed. I’ve been eating lentils for twenty years and it was only the other day that I actually saw a picture – not even a real life example- of a lentil plant!

In the movie Surrogates (2009), the world undergoes a very fast transformation, where everyone stays at home and only robots interact in the real world. That could be one of the possible outcomes, or perhaps it would be something closer to what happens in Inception, where we find people that are constantly hooked up to the machine and are dreaming inside dreams that are inside dreams, and are thus able to experience several lifetimes within their own lifetime. Perhaps that is a way that an advanced race could almost defeat immortality. If you perception of time slows down a million times, perhaps it doesn’t matter if you’re going to eventually die, because there is so much *subjective* time ahead of you. Or perhaps they will take the full step and upload all their consciousness to a super computer and robots will take care of all the maintenance and the race will life only as a data stream, not as physical manifestations of themselves.

Whatever the case, any intelligent race that is millions, or perhaps billions of years ahead of us would be incredibly different to anything that we have likely experienced or perhaps can even imagine.

As a side note, I love how so many books and movies have already breached these topics, and I am sure that in the long run some of them will turn out to be eerily accurate.

There are also other reasons why aliens may ignore the real world and stay at home, and that is perhaps because the cosmos is a dark, dangerous place, which leads us nicely onto our next hypothesis….(go to super predator and drones etc)

The Super Predators

Another reason why we haven’t detected any signals from alien races is because sending out signals is actually an extremely dangerous thing to do.

Because we don’t know what is out there, it can be claimed that it is actually a really stupid idea to shout out to the universe. If the things around the universe correspond at all to our experience of Earth, then it may well be a dog-eat-dog world, and broadcasting your location is essentially suicide, because there will be one, or perhaps several super predator races, most probably the ones that developed the earliest, or perhaps has some other type of advantage that allowed them to evolve really, really quickly, and develop superior technology.

After all, you wouldn’t go to an unknown jungle and start shouting around, because you don’t know what type of predators are out there waiting for you to become their next meal.

So, like in all the movies where the aliens are the bad guys, these super predator races go around the universe absorbing natural resources and enslaving or slaughtering the inhabitants of our planets. To be fair to these hypothetical super predator races, they may not be doing this because they are particular evil or lack ethical or moral compass, but because they are so advanced that they view us in the similar way that we view insects. So perhaps they are harvesting hundreds of thousands of planets at any given time, and perhaps the save the most interesting ones for study, and the rest they use for resources.

If we put ourselves into the shoes of an Earth-based squirrel, then a tree is everything. It is a home, a shelter, and a source of food, so why would anyone ever want to cut it down? Just as a squirrel cannot possibly understand why we might need the wood from the tree for what we believe is a greater good, we might not be able to understand the reasons for the advanced extra-terrestrial civilisations. It’s not like we set up a committee and include the squirrels in the discussion and let them state their arguments as to why we shouldn’t cut down their homes for our own use, and so it might be the same with us.

There is a really funny (and yet, perhaps not so funny..) part in the Hitchhiker’s Guide to the Galaxy where aliens demolish Earth to make way for a new inter-galactic road, and they state that Earth has had several million years to reply and they didn’t bother.

However, these is some potentially good news.

Just as we have started to care about the environment and think about ways to mitigate the damage we cause to our own planet and the habitats of other species, the advanced extra-terrestrial civilisations may also do the same. They may simply take some of our resources, in exchange for something else like some of their technology, or they may only go after uninhabited planets.

However, they may see the danger in other civilisations creating advanced technology that they cannot control, such as an artificial, self-aware, and super-intelligent computer that will quickly threaten the whole universe (more on that later), and they may act swiftly to put down any civilisations that are close to reaching this level of technological advancement.

Currently, we have the previously-mentioned SETI programme to try and detect signals from other extraterrestrial races, and there is the flip side of the coin a programme called METI which actively broadcasts, but there is a chance that the politics will change and that actively broadcasting will be banned because, in theory, it could be a really bad idea.

If this is the case on Earth, we can imagine that the same logic was applied elsewhere and so similar course of actions took place everywhere else, and so everyone is listening, shit scared to broadcast lest they get pulverised by some type of ion-cannon by a super-advanced 8 billion-year-old race.

Unfortunately, perhaps super-predatory advanced civilisations are the least of our worries, but it can actually get worse…

Bracewell–von Neumann Probes That Go Wrong

Yes, there is something that would be a greater threat to all civilisations across the universe, and that’s not a super advanced predatory civilisations, but out-of-control ,murderous, self-replicating artificial intelligent probes.


I’m not kidding.

As we’ve seen above, it’s actually quite difficult, costly, and time consuming to put physical boots (or tentacles) on the ground in far away planets, even if those planets are in the same galaxy. And so, a logic conclusion is to send unmanned probes to do the dirty work of exploring the unknown.

We know this because this is already what we have repeatedly done. We’ve never sent manned missions without having previously sent unmanned ones first, and that’s because it makes perfect logical sense.

Now, if we wanted to explore the entire galaxy, it would be really, really costly to build 400 billion probes, to send one to each star. But what if someone else could pick up the tab?

That’s exactly the thinking behind creating self-replicating probes that can go around the universe collection matter to then clone themselves, and explore further. I know that it sounds like a really wacky idea, but it’s actually entirely possible, it happens all the time here on Earth – it’s the main mechanism of reproduction!

So, if by the clever use of nanotechnology (technology involving robots which are incredibly small) we could replicate the way nature manages to have cells split and reproduce, we could actually pull this off and create what we call Bracewell-Von Neumann probes. The only issue is that we would also run into all the same problems that nature runs into when cloning, and that’s the issue of imperfect copies and mutations.

The only issue is that we would also run into all the same problems that nature runs into when cloning, and that’s the issue of imperfect copies and mutations.

Now exactly what these mutations would be is difficult to say, you might end up with an army of probes knitting socks, and another army of probes trying to commit robot suicide, and another that is specifically interested in shark fin soup. If we examine the core instructions we would have to give probes to be effective in going around the galaxy finding other extra-terrestrial civilisations, perhaps we can get a better idea of where things might go wrong.

We can assume that a civilisation that is intelligent advanced enough to build probes would respect something similar to Asimov’s Three Laws of Robotics:

  1. A robot may not injure a human being or, through inaction, allow a human being to come to harm.
  2. A robot must obey the orders given it by human beings except where such orders would conflict with the First Law.
  3. A robot must protect its own existence as long as such protection does not conflict with the First or Second Laws.


Then they would programme the probe with something approximating the following instructions:

  1. Leave your current base and create as many replications of yourself as are required to visit every star you encounter.
  2. If you find life, report back to base.


Regarding how a probe would actually clone itself, Stephen Web described it very well:

First, it has a constructor, which manipulates matter in its environ- ment to carry out tasks, including the construction of units it can then use to assemble a copy of itself. A universal constructor has the capacity to make anything — as long as it has suitable instructions. Second, it has a pro- gram, stored in some sort of memory bank, which contains the instructions needed by the constructor.

An automaton can reproduce itself as follows: The program first tells the constructor to make a copy of the program’s instructions and place the copy in a holder. It then tells the constructor to make a copy of itself with a clear memory bank. Finally, it tells the constructor to move the copy of the program from the holder to the memory bank. The result is a repro- duction of the original device; the reproduction can function in the same environment as the original and is itself capable of self-reproduction.

However, if this process was to go wrong, you might think that some of the mutations might be quite harmless and actually quite funny. For instance, if we stumble on a probe colony that numbers in the billions are they are fully detected to simply knitting socks, what’s the big deal? Actually, we will never have to worry about having an odd sock in the drawer.

Unfortunately, reality is much scarier.

These probes, if the mutation is large enough that they affect the fundamental three laws of robotics, may well launch a full-scale attack on our planet with the sole (excuse the terrible pun!) aim of converting Earth into a huge sock factory.

The following quote from Eliezer Yudkowsky highlights what could be a stark realisation:

The AI does not hate you, nor does it love you, but you are made out of atoms which it can use for something else

Not so funny now eh?

To finished up regarding these probes, there is one possible solution to this dilemma of almost inevitably creating a world-destroying sock-knitting army, and that is to program artificial intelligence to be friendly be design, and embed that to the utmost degree. This is a really interesting idea because it is much easier to do this than to try and foresee all the possible eventualities, but it is still not a guarantee of safety.

We are Inconsequential

This slightly leads on from the Zoo hypotheses. Perhaps our relationship with aliens is the same as ours with ants.

Michio Kaku sums it up:

Let’s say we have an ant hill in the middle of the forest. And right next to the ant hill, they’re building a ten-lane super-highway. And the question is “Would the ants be able to understand what a ten-lane super-highway is? Would the ants be able to understand the technology and the intentions of the beings building the highway next to them? 

Don’t think about this for too long, lest you become too humble, if such a thing is even possible.

There were here and they left

This is quite a simple explanation, but also highly untestable. The Earth has been around for quite a few billion years, and recorded history is only around 5,000 years old. So if they had visited Earth at any time before that, we would simply have no way to know about it.

The theories that state that certain ancient monuments were built by aliens are simply bullshit. We are well aware now of how the pyramids and many other incredible ancient structures were built, and that was through unimaginable human suffering, not extra-terrestrial intervention.

Simply put, there is absolutely no evidence that extra-terrestrial civilisations have ever visited Earth.


We’re The Aliens

This is actually not as far-fetched as it sounds.

One of the main theories of how life came to be on Earth is called Panspermia, which quite literally translate to “seeds everywhere”. It states that life on Earth was actually seeded, advertently or inadvertently, from another planet

While this doesn’t actually explain how life actually begun, it may be a really good explanation of how life happens to be on Earth. Around 4000 tonnes of space material burn up in the atmosphere each year, and the biggest lumps actually make it through.

It might sound unlikely that small bacteria would survive a space journey, but we’ve found some super-tough bacteria here on Earth that pretty much fend off anything we throw at them, and can hibernate for hundreds of millions of years, so anything is possible.

A great example is our bacteria-friend Deinococcus radiodurans, who can withstand extreme cold, dehydration, a vacuum, and can even chill out in an acid vat with no problems, and so has quite rightly earned it’s place in The Guinness Book of World Records.

One fairly strong argument for Panspermia is that there is only one genetic code on Earth, which hints at the fact that all life on Earth come from a single set of microorganisms, and the fact that many enzymes have a dependence on a metal called Molybdenum, which is actually quite rare on Earth, coming in as the 56th in terms of abudence in the crust of the Earth.

It’s strange than an element that is not so common is actually required for life. The argument here is that perhaps life came from a place where Molybdenum was abundent, and it has just been able to make-do here on Earth.

There is no real way to test this solution, in thought experiments or otherwise, but one way that it might be disproved is if scientists manage to recreate life in a test-tube, as this would tell us that the requisite materials and conditions here on Earth are enough to spontaiously create life out of thin air, and so we can then use Occam’s Razor to eliminate Panspermia from our list of possible solutions as it rests on far too many assumptions.

One last thought here – if life was sent to Earth by a intelligent extra-terrestrial civilisation, then we need to ask ourselves why. A quick brainstorming session resulted in the following ideas:

  • Their civilisation was dying and they wanted to ensure that life could restart somewhere else in the Universe, and so they sent one or many probes to land on other planet as a last ditch attempt. This could be due to many reasons, from a killer A.I. taking over, to the expansion of their local star, to a known incoming meteorite. We’ll focus later on in another solution about the multitude of ways a civilisation can be exterminated – fun!
  • They used Earth as an experiment and then either their civilisation died out or are still closely watching (see: Zoo Hypothesis).
  • It was an accident. Perhaps they visited Earth a really long time ago, and they accidently left some organic material behind and this grew over billions of years into us. For some reason, this makes me feel really strange and pointless. I’m currently listening to Beethoven’s 9th Symphony (it’s fantastic, go listen to it if you haven’t heard it) and it feels absurd to link the writing of such a masterful piece of music to the fact that some clusmy alien astronaut forgot to clean after himself last time he was on Earth.


So now you know a whole lot about the Fermi Paradox, and my hope is that it inspires you to think more about existential matters, which is always a good thing to do because it makes one realise how small and insignificant are the things that we worry about on a daily basis.

I love to think of what would happen if somehow scientists managed to prove that we all lived in a simulation or that aliens existed. Would anyone bother going to work the next day? Probably yes, because while it would be the most important discovery in history, it would actually make little difference to our lives on a daily basis, but it may have some less extreme effects, at least for some people.

This is still very much a work in progress, and I’ll be updating this several times in the coming weeks to make it truly ridiculously comprehensive.

As always, thanks for reading!



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