One of the most commonly used tropes in science
fiction is that of the notion of an alien invasion. Hundreds of variations on this theme have
been written over the years, typically focusing on us having something that is useful enough
for aliens to expend the time and energy in conquering earth. While all of this makes for a good story,
it doesn’t make for a good reality. After all, this planet has been here for 4.5
billion years and does not appear to have ever been invaded. Why that is is anyone’s guess, but here
are ten possible reasons why aliens might not invade earth. 10. The Galaxy has Nothing But Room Everywhere we look in the Milky Way we see
star after star to the tune of billions and so far not one, other than our own solar system,
has ever been shown to be inhabited by a civilization. Some of them may yet be, but we see no evidence
of Kardashev type III galactic empires present in this, or any other galaxy. In fact, so far, we have yet to see even a
Kardashev Type II civilization. This could change, but the one thing that
can be said is that there appears to be millions of stars that are not being used for anything. Great nebulas rich in raw materials are not
rare, but seem to only be forming stars rather than being harvested by someone. Often in science fiction, raw materials are
used as a justification for invasion. But in the great scheme of things, there appears
to be no one picking the low hanging fruit much less looking at relatively sparse sources
of raw materials such as our star system. 9. We Don’t Make for Good Slaves Another common theme found in science fiction
alien invasions is a desire for slave labor. This is not without precedent, a number of
human cultures have employed it. But those cultures also were dealing with
primitive technologies and required human labor. The problem is, biological human labor will
some day go obsolete. It already is in our world as technological
unemployment increasingly becomes a problem. Simply put, robots can be better at it almost
anything we do, if they become advanced enough. Any civilization in the galaxy capable of
long-distance space travel and the technologies implied by it would likely have robotics so
advanced that no biological labor at all would be needed. And besides, as long as you keep the technology
under control and don’t go all crazy with artificial intelligence, mindless robots will
never revolt. Humans would every chance we could making
us useless to the aliens. 8. Our Planet is Fundamentally Useless Yet another common theme within invasion sci
fi is the idea that earth, or we, have something an alien civilization wants. This could be something like water, or even
information, and they invade to get it from us. Trouble is, we don’t have much of anything. Earth is nothing special, it’s made up of
the same materials that we see out in the galaxy at large. Immense quantities of water exist in the universe,
both in frozen and liquid form. In fact, it appears to be common in our own
solar system, you see it almost everywhere. It’s much the same for information. What could we tell the aliens that they didn’t
already know or couldn’t learn on their own? The truth is, not much. About the only information we have unique
to ourselves is information about ourselves. It’s highly unlikely that an alien civilization
would expend invasion level resources on finding out what a potato chip is. 7. We Are Very Likely Not Tasty Speaking of foods, take a look at your planet. Surrounding you are millions of species, from
bacteria to plants to animals. Now, ask yourself. How many of them would you eat? Out of all life on this planet, we eat only
a comparative handful of species. Many are fundamentally unpalatable, such as
most plants, but many are outright poisonous causing anything from intestinal discomfort
to death. Now imagine an alien species with radically
different biochemistry. They would have evolved on a world eating
flora and fauna unique to that planet. It’s unlikely that anything here, or anything
they might have, would be appealing to either species and there’s no guarantee that they
even eat in the same way we do. Life here doesn’t always, so the idea of
aliens eating us is a hard sell in much the same way as an oak tree munching on pineapples
would be. And, we might even be poisonous. 6. Our Genetics Aren’t Useful Another culturally pervasive notion is that
of mating with an alien. From Captain Kirk’s green lady to The Alien’s
xenomorph facehuggers using us as a reproductive resource, there are many takes on this idea. But in reality, genetics doesn’t really
work that simply. The vast majority of species on earth can’t
reproduce with each other despite being related, there are no jelly-fish bonobo hybrids slithering
about. And while parasitic types of reproduction
do occur, yay for the xenomorphs, that’s using a host as grounds for reproduction,
not reproduction with a mate. Genetic compatibility with a species you have
zero relation to, something truly alien from another world, would be so unlikely that lottery
odds are better. But even if there was compatibility, would
there be attraction? Kirk’s green lady was a human in green makeup,
remember. Alien life would be alien, and might be about
as attractive as kissing a facehugger. But there’s an even deeper problem hiding
within this. Each day we learn more about genetics and
DNA. While we don’t yet know everything, there
will come a time when we have a full command of that science. It’s likely that an alien species capable
of space travel would have that as well. Even if they didn’t have DNA of their own,
which is unlikely, it’s still just a matter of chemistry. As a result, they could probably do whatever
they wanted with genetics, possibly building DNA strands from the ground up to build any
kind of programmable creature they wish. If so, what use would they have for our natural
and rather messy DNA? 5. The Human and the Ant Ants usually go unnoticed. Unless they bother us, we pass by their dwellings
and rarely pay them any mind. Even less do we stop and speak to them. Only a scientist studying ants would take
further interest, but even then they typically don’t plant a flag in the ant hill and declare
themselves the new queen. We have to consider that aliens may have no
interest in us at all. For anything. They may be a billion years more advanced
and messing around with us might be no different than junking your idea for a Caribbean cruise
in favor of trekking to a plain in Africa to study one specific ant hill that you once
saw a picture of that may or may not even still be there. In short, why would you invade an ant hill? 4. We’re More Interesting Alive Than Dead Or say they are interested. Say they are consummate scientists and historians
interested in all aspects of alien cultures. This isn’t unreasonable, we certainly would
be. And, well, have to say it, an alien ant hill
would still be extremely interesting to us to the point that we would go to great lengths
to study it. But what we likely wouldn’t do is willfully
exterminate it in order to study it. Such things happen on earth, but for very
different reasons than scientific curiosity. As a result, the scholar aliens probably would
not declare themselves our overlords and plant a flag in our cosmic ant hill, but instead
they might just show up, enter orbit and tell us not to mind them, they just want to watch
us. With cameras everywhere. 24 hours a day. For millions of years. 3. It’s Not Worth It, Given the Distances The universe is enormous in a way that can’t
really be visualized in terms of earth travel. You can say that alpha centauri is 25 trillion
miles away, or about 40 trillion kilometers, but it’s hard to visualize just how far
that is. If you shrink the scales down and make earth
the size of a grain of sand, that star is still several thousand miles away. That’s still extremely close in terms of
the rest of the galaxy, so needless to say the distances involved for interstellar travel
at sublight speeds are daunting and limiting. This works the same whether you are an exploration
craft or an alien invasion force. The logistics of moving around the assets
you need on those distance scales and the time involved change the equations for whether
you would invade and conquer a planet. With enough distance, no planet is worth it,
especially when you consider that such distances also prevent you from anything close to real
time reconnaissance until you get close by. In other words, what you saw as a primitive
civilization from the deck of your fleet flagship 1500 years before you reached your target
could well have developed advanced weaponry and technology by the time you were finally
in proximity to invade. That uncertainty would make any such expensive
undertakings likely not feasible. 2. We are Already Obviously and Flagrantly Dangerous Sci fi often depicts us as woefully unprepared
for an alien invasion once it happens, but often the writers of that kind of sci fi have
to essentially tone down or negate the weapons we do have, most typically giving the aliens
shields that can withstand nuclear weapons. Little attention is paid to just how those
shields function, and there really isn’t much of a basis for such a strong yet invisible
shield of this type in science. But look at our weaponry in terms of sci fi. If I were to tell you a story about an interstellar
war where one side possessed weapons that had the effect of recreating a piece of a
star right next to a space ship, you would assume that the ship would be destroyed. But, that’s more or less what a hydrogen
bomb is, an advanced nuclear fusion device designed specifically to destroy something. While bigger bombs can be envisioned, the
fact that we have H-bombs at all, and as a civilization achieved that technology so early
means that anyone else in the galaxy probably has them too, and that may be enough to keep
otherwise hostile alien civilizations from messing with us or anyone else. And, there’s more reason to think this than
simply blowing up the alien’s flagship. At sub-light speeds, we’re probably going
to detect a giant invasion fleet well before it gets close. But even if we don’t, if for some reason
we don’t think we can target the aliens with a nuke or don’t have time, we can still
target ourselves with a full global thermonuclear exchange and go out in a blaze of glory and
poison the planet for the invaders. Such a thing could be arranged very quickly
on this world, minutes, on the orders of only a handful of world leaders. 1. Earth Itself Could Be Deadly Poisonous to
Biological Aliens The biggest improbability in sci fi regarding
alien invasions is that aliens could stand around on earth without a spacesuit. You can’t do that anywhere in this solar
system other than earth. Same for any exoplanet we yet know of. Stand on Mars wearing little but a tee shirt
you are soon dead. The surface of Venus is way worse. In fact, you can’t even breathe in Earth’s
own oceans without technology and fish likewise can’t usually breathe the atmosphere. And even if you could breathe Mars’ atmosphere,
you’re still dead from the sun’s unbridled radiation pretty quickly. And then there is the much lower atmospheric
pressure. Point is, the universe is mostly deadly to
you anywhere except your home planet and the same is likely true for aliens. But it gets worse. Your own planet in the past has been hospitable
to life itself, but deadly for you. Go into the far future and it will be deadly
again. You can only exist on your home planet under
natural circumstances for so long. While it’s hard to envision intelligent
life existing on anything but oxygen, there are few chemical alternatives to run large
brains, the oxygen levels of atmospheres could vary wildly, along with the other gases present. In short, Earth probably wouldn’t have the
right mix for an alien to breathe, which would make this planet virtually useless for conquest
and colonization. So that’s ten reasons why real world extraterrestrials
would not invade earth. So you can sleep well tonight knowing that
tomorrow you probably won’t wake up to your new alien overlords. Unfortunately, there is another side to this
coin, so expect a future video detailing ten reasons aliens might invade. Thanks for listening! I am futurist and science fiction author John
Michael Godier and if you would like to help support the channel, check out my patreon
page, link in the description below, or check out my books at your favorite online book
retailer and subscribe to my channel for regular, in-depth explorations into the interesting,
weird and unknown aspects of this amazing universe in which we live.
