Future Starships May Be More Like “Noah's Ark” Than Star Trek's Enterprise

This fall we will have two new television shows that perpetuate the ideas about interstellar travel that we saw in the Star Trek movies and television series. The first is a comedy-drama TV show called The Orville starring Seth MacFarlane, which has been described as a Star Trek clone. The second is a new CBS series called Star Trek: Discovery, which is yet another incarnation of Star Trek, following in the footsteps of the original TV series, Star Trek: The New Generation, Star Trek: Voyager, Star Trek: Enterprise, and Star Trek: Deep Space Nine.

So far I have enjoyed The Orville, which seems to be striking a nice balance between drama and comedy. As someone who has spent endless hours watching three previous Star Trek television series, I was greatly anticipating the first episode of Star Trek: Discovery. But the episode slightly disappointed me, despite impressive production values. Besides the distracting uniforms (with golden sides that reflect light in a glaring way), there was the issue of the trigger-happy first officer (Burnham). In the show she recommends an unprovoked attack against the Klingons, on the weak grounds that long ago some of them killed some Vulcans.  The show may be trying to make the female first officer look like a real macho man-lady, but so far the show has failed to create a character we can morally respect.

By now the Star Trek series and the Star Wars series of movies have firmly planted various ideas about how interstellar travel will work. These ideas include the following notions:

1. Interstellar travel will be very fast, because ships will be able to use warp drives that allow spaceships to travel between stars in a matter of days, or hyperspace jumps that allow spaceships to instantaneously travel between stars.
2. When an interstellar spaceship gets to a planet revolving around another star, the main activity of the crew will be to interact with or study the life forms that exist on the planet.
3. Interstellar spaceships will be very heavily loaded with weapon systems and defensive shielding systems, to protect themselves against hostile spaceships that may be encountered in a star system.
4. Pretty much the only earthly life forms on the spaceship will be humans. There will be no real vegetation, and no horses, birds or dogs anywhere (except those that appear in a holographic illusion system called the holodeck).
5. The spaceships that travel between stars will be rather cramped, and living on them will be rather like living in a submarine, except for those lucky enough to enjoy the holographic illusion system called the holodeck.

But there are reasons for thinking that such assumptions are totally wrong, and that interstellar spaceships and their activities will be completely different from what we see in Star Trek and Star Wars.

The first reason has to do with the speed of interstellar travel. The nearest star is about 4 light-years away. A light-year is the time it takes for light to travel a year. Einstein's Special Theory of Relativity tells us that the speed of light is an absolute speed limit that cannot be violated. It is barely possible that there are currently undiscovered laws of nature or facets of nature that might allow us to side-step such a limitation, and travel to a distant star much faster, perhaps instantly. But such a possibility is a mere speculation, and there is currently no evidence for it. Given the speed limit of the speed of light, an average distance between stars of about 4 light years, and the engineering difficulties of even reaching half of the speed of light (and the need to slowly accelerate and slowly decelerate), the average interstellar voyage will probably take decades.

There is also strong reason to suspect that once a spaceship reaches another solar system, it will be nothing like what happens on Star Trek or Star Wars. This is because there is strong reason to suspect that life in the universe may be rare, in the sense that the vast majority of planets do not have life, even if the planets are a suitable distance from the star they orbit. The problem is that even the simplest form of life apparently needs to be an incredibly complex system, one that seems to be fantastically improbable to appear by chance.  See here for some of the reasons for thinking that life originating by chance is harder than water-tight log cabins accidentally forming by falling trees. 

I've watched as many Star Trek episodes as anyone, but I can never recall an episode with an exchange like this:

Captain Kirk: Mister Sulu, put us in orbit around the planet. Spock, what do your sensors pick up in regard to life forms?

Spock: Nothing, Captain. Nothing at all. The planet is completely sterile.

Captain Kirk: You mean we came all the way over here for nothing?

But there are strong reasons for suspecting that this is just what would be likely to happen to an interstellar mission arriving in a distant solar system. Unless there is something special going on to increase the odds (some cosmic teleology or some cosmic life-force), the odds are stacked very strongly against us finding life in a particular solar system that we might explore.

These odds may be recognized by the designers of an interstellar spacecraft. So instead of being a ship like the starships we see in Star Trek, the first interstellar spaceship may be completely different. It may have these characteristics:

1. No weapons systems, and no defensive systems, because the odds of encountering a threatening presence may be too small.
2. The ship may be a miniature worldlet, capable of supporting a complex ecosystem. The ship may be designed for multiple generations to live in. There will be huge areas filled with plant life and various forms of life.
3. The ship may be something like a Noah's Ark, containing hundreds or thousands of examples of earthly life, including animals such as dogs, horses, cows, birds, lions, bears, dolphins, and fish.

When the interstellar spaceship arrives at a planet arriving around a distant star, the plan may be to terraform a planet that will probably be lifeless. This will be a slow process that may take centuries. First, microorganisms would be introduced on the planet, microbes that would be designed to give off oxygen. After many decades the planet would have a breathable atmosphere. Then various plant forms could be introduced. Finally various forms of animal life could be introduced, starting with small animals, and gradually working up to larger animals.

The interstellar spaceship would need to be a multi-generation ship because the terraforming process might take centuries. For the crew members, it might be frustrating. The initial crew members who left Earth on the interstellar voyage might live the rest of their lives on the spaceship, dying of old age before the ship ever reached another star. Or, if a crew member lived to see the arrival of the ship at a distant solar system, the crew member might never walk on a planet of that solar system. If it took centuries to terraform the planet, that crew member might have to be satisfied with watching the planet in orbit, as it slowly got a little bit greener every year.

If it turns out that interstellar missions work completely different from what we saw in Star Trek, we should hardly be surprised. Star Trek was a great show, but it did have its realism problems. I've seen all episodes of the original series several different times, and can never recall one time when the crew members either wore a jacket or rolled up their sleeves when exploring distant planets. But such planets would have had random conditions, with some being much colder than Earth, and some being much hotter. While I was writing this post, I watched an old episode of Star Trek in which Mr. Scott tells Captain Kirk that pressing a red button on a panel will blow up the spaceship they are on. But the red button didn't even have any marking next to it indicating what it did. So Star Trek had realism problems from its beginning, and we shouldn't use it as a realistic model for interstellar exploration. 

It may be like this for the first interstellar voyage

The 5 Main Fallacies of Galactic Colonization Arguments

Arguments involving galactic colonization are often made when discussing how much intelligent life exists in our galaxy and our universe. One all-too-common line of reasoning goes like this: if intelligent life had arisen elsewhere in the galaxy, it would have already colonized the entire galaxy, and we would see signs of such intelligent life right now on our planet (or we would never have appeared because Earth would have been colonized first); therefore, man is the only intelligent species in the galaxy. This is a very weak argument that involves multiple fallacies that I will now discuss.

Fallacy #1: The Fallacy of Not Realizing the Implications of Slow Interstellar Travel

According to Einstein's Special Theory of Relativity, nothing can travel faster than the speed of light. So this means travel between stars is going to take a long time. In fact, there are practical engineering reasons for thinking that a spaceship could not travel more than roughly about one fifth of the speed of light. This means that a trip between stars will probably take decades.

This slowness of travel has two main implications. First it means that we should not imagine a galaxy being colonized in less than a period of millions of years. But it also means much more. It means that any unified coherent program of colonization is doubtful. The whole idea of any civilization setting out on a million year project may be entirely dubious. The slowness of interstellar travel also probably means that the galaxy can never really be colonized in the sense of being controlled in a unified way by a single culture.

Imagine if Earth were to create colonies on planets revolving around other stars. The nearest colony would be about 4 light years away. The colonists would know that if they went their own way and declared their independence, it would take 4 years for the news of such an announcement to reach Earth. It would then take at least another 4 years before a spaceship came from Earth to punish them for their disobedience (and probably more like twenty years, because of the near-impossibility of traveling at anything close to the speed of light). Such a colony would therefore not feel that it was under very strong political control by Earth.

Colonies that were farther away from Earth would feel even more free to do whatever they wanted. If an expedition from Earth established a colony on a planet revolving around a star that was fifty light years from Earth, then the inhabitants of that planet would know that they could declare their independence, and it would be at least 100 years before they would suffer any punishment – fifty years for the news to get to Earth, and at least fifty years for a punitive expedition to travel from Earth to the colony (but probably more like hundreds of years).

The farther the colony was from Earth, the more its inhabitants would feel that they could do whatever they wanted without suffering any ill effects. If a colony was established 500 light years from Earth, and then declared its independence, it would have no worries at all about some punishment from Earth that could not arrive in less than 1000 years (500 years for the independence announcement to reach Earth, and more than 500 years – and probably thousands of years – for a punitive expedition to travel from Earth). 

This point is illustrated in the diagram below, in which the yellow dot at the center represents a planet attempting to colonize other stars.  

It would seem, therefore, that in terms of any type of system whereby one planet controls the galaxy, galactic colonization cannot even occur in a meaningful sense. Because of the slowness of interstellar travel, the zones of control of any planet would be relatively short, extending no more than a few hundred light years at most (only a tiny fraction of the size of the galaxy). Planets would realize that, and this realization would make them less likely to even attempt anything such as a colonization of the entire galaxy.

Fallacy #2: The Fallacy of Ignoring Loss of Colonies and Loss of Interest

The typical argument regarding galactic colonization assumes a scenario like this:

1. Some planet starts out as the source of galactic colonization, sending a spaceship to colonize a planet around another star.
   
2. After that planet has been colonized, and has set up an elaborate technical civilization, the colonized planet then itself sends out a spaceship to colonize another star.
   
3. The process continues over and over, until eventually the entire galaxy is colonized.
   

One great weakness in such an idea is the fallacy of assuming that once each planet was colonized, it would continue to contribute to the overall program of galactic colonization, and also the fallacy of assuming that planets that had been colonized would stay colonized indefinitely. It's kind of like the fallacy of assuming that if you built a house on each continent, that those houses would still be around 1000 years later.

In fact, there are all kinds of reasons why different planets that had been colonized would either “drop out” of a colonization program, or would revert to a non-colonized state because of the failure of colonies or the end of civilizations. One reason might just be an act of political independence. Some planets would just say, “To hell with it, we have no interest in sending out interstellar spaceships.” Then other colonies would simply just simply dissolve for the same reason that civilizations have dissolved or might dissolve – resource issues, wars, runaway technology, and so forth. Some planets might be conquered by neighboring planets. When colonies failed, a few million years of geological activity might be sufficient to remove all traces of them.

The point is that you cannot assume that during the million years or more needed to colonize the entire galaxy, that each previously colonized planet would stay colonized. During that long million years, some fraction of the previously colonized planets would revert to being not colonized as colonies failed, civilizations fell, war took its toll, and so forth. We have no idea of what that fraction would be. It be could 10% or 20% or perhaps 90%. 
 
Fallacy #3: The Fallacy of Assuming That Colonizers Would Colonize All Colonization Targets

The fallacious argument discussed at the beginning of this blog post assumes that some galactic civilization would go throughout the galaxy and colonize all available colonization targets (all planets like our planet). But why make such an assumption? It is contrary to what we know about how humans act.

In fact, every large country declares a significant fraction of the available land in its country to be “off limits” to development. Such land is put in natural reserves. The natural reserves in the United States include the national park system and the national forests, which together make up a significant fraction of United States territory. China has a similar system. So why should we assume that interstellar colonizers would colonize every available planet in the galaxy without declaring some planets and some parts of the galaxy to be “off limits” to colonizers? We shouldn't. This possibility makes the whole “if they existed, they would have colonized us already” argument fall apart like a house of cards. It is entirely possible that our planet is part of a little section of the galaxy that some superior civilization has preserved as a reserve area not to be colonized.

The fallacy discussed here is kind of a “fallacy of assuming unlimited utilization” similar to the fallacy of assuming that if you give a boy some crayons and one of those books with blank white pages, then necessarily if you return a year later all of the pages will have drawings or scribbles on them.

Fallacy #4: The Fallacy of Assuming That Very Distant Robotic Squatters Would Have Some Great Net Value

One version of the argument made at the beginning of this blog post is based on the idea of self-reproducing robotic colonizers. The argument goes like this: any civilization could send out a spaceship filled with robots to the nearest star, and when that spaceship arrived, those robots could use resources at that star system to create more robots, which could then travel to another star in their own expedition. The same thing could happen over and over again, and eventually these self-reproducing robots would “take over the galaxy.” But this hasn't happened, so therefore, the argument goes, we must be alone in the galaxy.

The problem with this argument is the underlying assumption that such a galaxy-wide proliferation would actually be “taking over the galaxy,” or that it would be something that would actually have much of a net value. Because the effective zones of control of any planet would be relatively short (actually extending no more than 100 light years), sending out robots to inhabit planets across the galaxy would not really be “taking over the galaxy,” but really just “sending out squatters to the distant corners of the galaxy.” Having robots 20,000 light years away wouldn't actually give a planet any control over distant corners of the galaxy, because you don't have any real control when it takes 40,000 years to send a round trip message from a planet to those distant corners.

Such robotic squatters proliferating throughout every planet of the galaxy would actually have a very strong negative value. By proliferating all over the place and taking up every planet, they would prevent the natural evolution of diverse species and civilizations across the galaxy, and would thereby be a kind of massive “crime against diversity.”

Fallacy #5: The Fallacy of Ignoring the Possibility of Counter-Colonizers

According to the naïve calculations of some thinkers, we need merely calculate how long it would take colonizers from one planet to spread throughout the galaxy unimpeded. But such calculations ignore the important consideration that the efforts of any one planet to colonize the galaxy would probably be resisted by other planets. If intelligent life arose roughly the same time on hundreds or thousands of planets in the galaxy, we would not expect any one to take over the galaxy, because of opposition from other civilized planets that arose at roughly the same time.

This is true even if one imagines robotic colonizers. One interesting point is that self-replicating counter-colonizers are just as easy to create as self-replicating colonizers. So imagine one civilization sends out an interstellar spaceship filled with self-reproducing robots instructed to build colonies, make more robots, and build more spaceships for more interstellar expeditions. The same technique can be used by some other planet to destroy the colonization efforts of the first planet. The second planet might launch such a “counter-colonization” interstellar spaceship filled with self-reproducing robots instructed to find resources, make more robots, and build more spaceships for more interstellar expeditions – not for the purpose of colonization, but simply for the purpose of destroying the robotic colonies created by the first planet. A planet might launch such a “counter-colonization” program if it noticed that some other planet was putting its robots all over the galaxy, and the first planet thought that such a program was a cancer that must be wiped out. 

Conclusion

Typical arguments involving galactic colonization are fallacious, and from such arguments we should not draw any conclusions about how common intelligence is in our galaxy. It is entirely plausible that there exist very large numbers of extraterrestrial civilizations in our galaxy, although it is still too early to assume with confidence that intelligent life is abundant in our galaxy.

The Rare Colonization Hypothesis

Here is a stock argument for the rareness or uniqueness of mankind in our galaxy: if an extraterrestrial civilization were to arise on another planet, it might destroy itself soon after developing atomic weapons; but if it were to survive long enough to develop interstellar travel, it would then spread throughout the galaxy. But no such civilization has come and taken over our planet. So extraterrestrial civilizations must be very rare in our galaxy. Perhaps we are the only civilization in our galaxy.

This argument involves a great fallacy. The fallacy is assuming that a successful extraterrestrial civilization would be likely to spread throughout the galaxy once it was advanced enough to do interstellar travel. There is no reason to think that such a thing would occur. In fact, it may be more likely that any extraterrestrial civilization would either confine itself to its own solar system or only colonize a few nearby stars.

I will call this thesis the Rare Colonization Hypothesis.  I may state the hypothesis as follows: the average extraterrestrial civilization capable of interstellar travel is likely to colonize no more than a small number of other solar systems.

Alien Rejecting Interstellar Colonization Plan

The Difficulty of Interstellar Travel

The main reason for adopting the Rare Colonization Hypothesis is the fact that judging from what we currently know about the laws of nature, interstellar travel is incredibly slow  and difficult.  According to Einstein's Special Theory of Relativity (which is currently regarded as established fact), it is quite impossible to travel faster than the speed of light.  Outside of dense star clusters (where the heavy metals needed for life are not very common), the average distance between stars is about five light years.  This means that even if you built the fastest space ship capable of traveling to another star, it would take you at least five years to get there.

In fact, there are astronautical and engineering reasons why it may well be impossible for any spaceship with living creatures to travel at more than 10% or 20% of the speed of light.  One reason is the need to gradually accelerate a spaceship without creating too high a g-force for the spaceship crew. Another reason is the need to gradually decelerate the spaceship so that it would not zoom too fast into any solar system it was visiting.  Another reason is that the more fuel you take along in the spaceship, the more energy it requires to accelerate the spaceship to a high speed. While there are proposals for starships that scoop up hydrogen between the stars, they don't result in speeds that are a high fraction of the speed of light.

There are all kinds of exotic proposals for faster-than-light travel involving wormholes and space warps, but they all assume that nature has a giant gift waiting for us to discover, a gift that will allow us to cheat on the law of nature saying nothing can travel faster than light. Since we haven't found that gift yet, we should assume that it probably isn't there.  Your mother may have hidden $10,000 in bearer bonds under your mattress, but until you see them, you should assume they aren't there.

It is certainly possible that interstellar colonization could by done by using robots or suspended animation of a human crew or a multi-generational world ship. But, unless there is some surprising twist in the laws of physics that makes interstellar travel easy, any mission of interstellar colonization is going to take decades or centuries.

The Comparative Ease of Interstellar Radio Communication

Compared to interstellar travel, interstellar radio communication is very easy. Rather than spending trillions to launch a mission between the stars, a civilization could achieve radio and television communication across the stars for a millionth of the cost.  Any interstellar rocket expedition would not produce any results known to a home planet until decades or centuries in the future, but by building some powerful radio telescopes a civilization might get results immediately.

The relative ease of interstellar radio communication makes it much less likely that civilizations would engage in extensive interstellar colonization. Why spend trillions on dangerous, risky missions between the stars, when you can get knowledge about other civilizations more quickly at a millionth of the cost?

Would There be Some Natural Tendency Leading Extraterrestrials to Colonize Many Stars?

Despite the considerations mentioned above, it is sometimes argued that there is some natural tendency that would lead a civilization to expand aggressively across the stars. It is sometimes said that humans have a natural tendency to spread their genes to as many distant places as they can.  Some others argue that there is a natural human tendency to conquer everything that we can conquer. Therefore, it is argued, we should assume that alien civilizations should have a similar tendency.

But these imagined characteristics of humanity don't really exist to any extent sufficient to justify such assumptions about alien civilizations.

Do human being beings have any natural tendency to spread their genes to as many distant places as possible? Very few people actually show any such tendency.  Many millions of  young men have the opportunity in today's world to travel around the world, impregnating women around the globe, and spreading their genes all over the planet. Very few men do any such thing. For example, it is very rare to read about a man who has one daughter in Africa, another daughter in China, a son in South America, and another son in the United States.  It is therefore false to imply that we have a natural tendency to spread our genes to as many distant places as we can.

What about the supposed human lust for territorial conquest? Very few humans have actually shown any interest in controlling very distant territories. Even if one looks at the most aggressive conquerors in history, one virtually always sees only people interested in conquering neighboring countries. Even Adolf Hitler seems to have shown no serious interest in conquering anything outside of Europe.

Do we see much in the way of human lust for conquering or colonizing worlds beyond our planet? Consider these facts:

    Time when humans first landed on the moon: 44 years ago
    Number of humans currently on the moon: 0

We actually see fairly little desire in humans for colonizing other worlds or spreading our genes to every distant place we can put them. So there is no reason to assume that extraterrestrials would have such a tendency.

Colonization Not Needed for Worlds to Explore

Here is another reason for thinking that interstellar colonization may be rare:  any civilization capable of colonizing another star would have computer technology and virtual reality technology so advanced that it could create a huge number of breathtaking virtual worlds offering endless opportunities for virtual adventure and exploration. Imagine something like a video game, but with images as good as you see in the sharpest high-production movie, and with flawless computer-generated AI everywhere. It might be hard to get anyone to sign up for a long, risky interstellar expedition, when a person could satisfy all his lust for exploration and adventure and beauty in virtual worlds in his living room.  

Diminishing Returns from Interstellar Colonization

When colonization has occurred in human history, it has usually been because the country launching the colonies was gaining clear benefits that made the colonization worthwhile. For example, the Spanish got a steady stream of gold, silver, and crops from their New World colonies which made the colonies worthwhile to the Spanish.

It seems, however, that there would be very little trade benefit to be got from interstellar colonization. The distances are simply too far for trade to be economically viable. Any civilization capable of colonizing other solar systems would have incredibly sophisticated molecular assembly technologies. The cost of sending materials or treasures from another solar system back to another solar system would be many times greater than the cost of synthesizing such products on the home planet.

What type of benefit would come from interstellar colonization? There would be a kind of “insurance policy” benefit that would come when a planet created one or two interstellar colonies. The benefit would be that the civilization that created the colony in another solar system would no longer have “all of its eggs in one basket,” and would no longer be in a situation where the destruction of its home planet would mean its extinction.

However, such an “insurance policy” benefit would diminish greatly when a planet established its second or third interstellar colony, and this benefit would diminish still further when it created its fifth or sixth interstellar colony. Once any planet existed in two solar systems, it would no longer have a risk of extinction, and would no longer have “all its eggs in one basket.”  There wouldn't be any point in creating a fifth or sixth interstellar colony for an “insurance policy” benefit.

There would also be a diminishing “thrill return” from establishing interstellar colonies beyond the first or second colony in another solar system. It might be terribly exciting to create the first colony on another world, but the home planet would get a much smaller thrill from the creation of additional colonies. I'm reminded of what happened during the first few moon landings:

 Viewer of Televised Apollo 11 Moonwalk: Oh my God! They're walking on the moon!
 Viewer of Televised Apollo 17 Moonwalk: Not another stupid moonwalk! They're  interrupting my regular quiz shows and soap operas!

In short, after a planet created one or two interstellar colonies, there would be a much smaller benefit from creating additional colonies.

The Implausibility of Colonizing Von Neumann Probes

Some people argue that extraterrestrial civilizations would create robotic machines that would go from one solar system to another, always creating mass copies of the original machine. Such machines might then fill up all habitable planets in the galaxy with copies of themselves.

I am tempted to call such a proposal the Dumbest Idea Ever.  Colonizing self-reproducing robot expeditions would be like a cancer on the galaxy. Perhaps the greatest thing about a galaxy such as ours is its diversity, the fact that it presumably allows countless divergent civilizations and life forms and cultures to arise.  The idea of gobbling up all the available planets and filling them with copies of one particular robotic expedition would be like replacing every canvas in the world's museums with copies of one painting.  Any species capable of doing such a thing would presumably be wise enough not to do it.

Conclusion

The theory advanced here (the Rare Colonization Hypothesis) is a plausible hypothesis to help explain why we do not see extraterrestrials in our vicinity. There are other ways of explaining our current non-observation of extraterrestrials. It is quite possible that extraterrestrial colonization occurs very frequently, that there is some huge society of aliens, and that the Earth has been declared a kind of reserve area that is “hands off” for interference or colonization. Such an idea (sometimes called the Zoo Hypothesis) is fairly plausible, but it seems to require that there be some “controlling power” in our galactic vicinity (perhaps some empire or league of planets). The Rare Colonization Hypothesis is simpler and more plausible than this Zoo Hypothesis, because the Rare Colonization Hypothesis does not require any belief in some arrangement or law of conduct that is being followed by our galactic neighbors.  The Rare Colonization Hypothesis simply requires us to believe that extraterrestrial civilizations don't do very often something that is very, very difficult to do: to establish a colony many trillions of miles away.