Political Correctness Goes Galactic

Aeon magazine (an online "mainstream" magazine) sometimes publishes nonsensical articles, such as its current article claiming that the mind does not exist.  When currently popular academia ideas cause people to make such claims, it is the strongest possible signal that those who advance such ideas are people marching in the wrong direction.  A little less inane is a recent article in Aeon magazine entitled "Do we send the goo?" in which an assistant professor  ponders whether we should send "life-generating goo" to planets revolving around other stars. 

The author makes the doubly misleading statement below:

"Each planet or moon is its own world, with its own history and story to tell, and its own potential (however one might define this) for the future. Though mostly barren of life, they are far from empty; many are chock-full of the materials that would go into life-generating goo: sugars, amino acids, carboxylic acids and powerful molecules that drive reactions away from equilibrium."

The claim about many planets or moons being "chock-full" of amino acids and sugars like those used in life is extremely erroneous. There has never been any well-established replicated observations of amino acids or sugars existing on any other planets or moons. Not counting the very tiny traces of amino acids reported in lunar samples (believed to have come from earthly or astronaut contamination), the only claims of detecting an amino acid on another planet or moon is a dubious claim of detecting the simplest amino acid (glycine) in a very tiny trace amount (1 part in a billion) in the atmosphere of Venus.  Made by one paper, the claim has not been replicated by another paper. Since a claim last year of phosphine in the atmosphere of Venus in the trace amount of 20 parts per billion was disputed by several other scientific papers (here, here and here), we can have little confidence in the claim of a much smaller 1 part per billion abundance of glycine in the atmosphere of Venus. 

No amino acids or sugars have been found on Mars or on Saturn's large moon Titan (where about 20 other chemicals have been detected) or an Enceladus (another large moon of Saturn where some chemicals have been detected, but not amino acids or sugars).  A claim has been made that some amino acids existed in a meteorite (Nakhla) reputed to have come from Mars, but the paper making that claim says, "The amino acids in Nakhla appear to be derived from terrestrial organic matter that infiltrated the meteorite soon after its fall to Earth." 

No one has claimed to have detected a ribose or deoxyribose sugar (the types of sugars used by life) on some other planet or moon. Some scientists claimed to have found a ribose sugar in a meteorite, but only in the trace amounts of a few parts per billion; and we can't be sure whether such an amount arose from earthly contamination. No one has generated a ribose or deoxyribose sugar (the types of sugars used by life) in any experiment realistically simulating conditions on the early Earth on some other planet.  

Claims such as the claim that "the stuff of life is all over the place in space" or that "the building blocks of life are common in our galaxy" have been commonly made ever since the often-misspeaking astronomer Carl Sagan started making them about 50 years ago. Such claims have no basis in fact.   

The building blocks of multicellular life are cells, which have never been detected in space outside of spaceships and space stations. The main building blocks of one-celled life are functional proteins, which have never been detected in space outside of spaceships and space stations. The building blocks of the building blocks of one-celled life are the twenty amino acids used by living things, and nucleotides.  No nucleotides have been detected in space, and only two of the twenty amino acids used by living things have been found in space, but only in the tiniest trace amounts. 

No experiment done by scientists provides any warrant for any guess that amino acids or the type of sugars used by life are common on other planets or moons.  The famous Miller-Urey experiment produced some amino acids, but it was never a realistic simulation of conditions on Earth or any other planet.  The experiment consisted of a small closed glass apparatus only 5 liters in size that was subjected to weeks of semi-continuous electrical bombardment of 30,000 volts (with 12 hours a day of such electrical bombardment). There is no reason to believe that any similar-sized enclosed space on any other planet has ever been subjected to anywhere near as strong a daily electrical exposure.  So there is no observational or experimental warrant for the claim that any other planets are "chock-full" of amino acids or the type of sugars used by life.    Other experiments similar to the Miller-Urey experiment have had the same lack of realism because they used chambers subjected to near continuous bombardment of high energy, such as would not exist in nature. Any experiment realistically simulating planetary conditions will not produce amino acids or the type of sugars used by life. 

The second misleading part of the statement quoted above is its reference to "life-generating goo." Such a phantasmagorical concept has no basis in fact, and is like the idea of "car-generating tar." Even the simplest life is a state of extremely great organization and information. There is no reason to believe that any non-living information-free "goo" consisting of unorganized chemicals such as amino acids and sugars would ever give rise to life. No one has ever observed any type of life arise from any type of chemical "goo."  Moreover, no one has ever observed any of the real "building blocks" of one-celled life arise from some mere "goo" of chemicals such as amino acids and sugars. The main building blocks of one-celled life are functional protein molecules. No one has ever observed even a protein molecule appear from some mere "goo" of chemicals such as amino acids and sugars. 

By using the phrase "life-generating goo," the author has given us more "crumbs into castles" nonsense.  Such talk is fantasy, not science. The concept of abiogenesis (that life can naturally arise from non-life) has no basis in scientific observations or relevant scientific experiments. It would be much easier to build a castle than to build a one-celled living thing from low-level chemicals such as sugars and amino acids. 

The scientist author misspeaks when stating this: "Life is a molecular memory written in genes describing a basic chemical architecture." No, life is not genes, and is not a memory; instead DNA and its genes are one of many co-dependent complex components of living things. Multicellular life is something almost infinitely more complicated and organized than "a molecular memory written in genes describing a basic chemical architecture." Even the simplest known types of life (one-celled life) is a  state of organization so high that it is  misleading to describe such a thing as "a basic chemical architecture." There is nothing "basic" about the architecture needed for even a single self-reproducing cell. Such a thing would require more than 50 different types of protein molecules, each a very complex invention.  Most of these protein molecules would have hundreds of parts (amino acids) arranged in just the right way to achieve a particular functional end.  Neither a self-reproducing cell nor any of its a protein molecules has a "basic chemical architecture"; they have very complex and extremely organized architectures. Genes don't even specify the structure of cells. A much more accurate description of life would be this: "Biological life is when you have enormously organized and information-rich organisms that make copies of themselves." 

The author's shrink-speaking definition of life is just the latest example of the same error that many modern scientists very frequently commit: the sin of misrepresenting life, trying to make it look vastly simpler and less organized than it is.  Kind of the opposite type of error occurs when scientists attempt to describe DNA as if it were something much more than it is.   The author commits this error by stating, "DNA is at least a 4-billion-year-old encyclopaedia with information about the extant world, and the world that once was." No, the DNA in an organism is a repository of low-level chemical information, telling us which amino acids make up the proteins in that organism. An encyclopedia is a book or set of books containing alphabetically sorted essays about an extremely broad range of topics. DNA bears no resemblance to an encyclopedia, and does not have any description of the extant world or a previous world. 

Our scientist author then ponders a very strange proposal I have never heard anyone else propose:  that maybe we should create missions to send "life-generating goo" to other planets that do not have life.  The idea is not to plant actual living things on other planets, but some kind of chemical goo from which life might supposedly arise. The author seems to have interstellar ambitions for this very strange proposal, and rather seems to have got the idea that some very rapid progress is being made in interstellar rocketry (something humans have no actual competence in). We read the following:

"Destinations in our galaxy that once seemed ‘impossible to reach’ are now just ‘prohibitively expensive’. These destinations are, as I write, moving quickly into an even lesser category of ‘logistically difficult.’ "

But if you want to spread life around the galaxy, why not just directly plant life,  after some terraforming process that might make a planet habitable to life? Why plant chemical goo that would never actually give rise to life, and that even in the fondest dreams of materialists would only give rise to visible multicellular life maybe a billion years after the chemical goo was planted?  The author seems to be thinking that it would be more politically correct to just send lifeless chemical goo. We read this: "By sending a biogenic capacity and not a strictly predetermined molecular architecture, we would circumvent some of the uglier, more domineering aspects involved with pushing an alien (ie, Terran) physiology on other unsuspecting worlds through in situ missions or terraforming."

So the idea seems to be kind of: let's wait an extra billion years, because we don't want to be politically incorrect and domineering and colonialist when bringing life to other planets.  I don't know which is more ridiculous, this idea or the idea that incredibly organized information-rich self-reproducing cells can arise from lifeless disorganized goo containing no information.  

This "spread goo to the stars" proposal very much clashes with the writer's groundless previous claim that many planets and moons are "chock-full of the materials that would go into life-generating goo: sugars, amino acids, carboxylic acids and powerful molecules that drive reactions away from equilibrium."  If many planets and moons were "chock-full" of such materials, there would be no need for humans to go around planting chemical goo on other planets. 

There's another reason the "spread goo to the stars" idea is nonsensical: the fact that goo is biodegradable.  Some chemical goo planted on another planet would decay away fairly quickly, just as a spoon full of jelly won't last more than a year if you dump it on a rock in your back yard.  There would be essentially zero chance of anything living arising from some chemical goo before it dissolved. 

Postscript: On September 16 we had the latest example of a scientist trying to create unwarranted ideas about amino acids and sugars in outer space. We have a press release discussing some observations in space of three chemicals that are not any of the building blocks of life  and also not any of the building blocks of the building blocks of life. The paper presenting these observations does not refer to amino acids, sugars or nucleotides.  But one of the scientists misleadingly refers to "sugars, amino acids, and even the components of ribonucleic acid (RNA)" that he did not actually observe: "Laboratory and theoretical studies have suggested that these molecules are the ‘raw ingredients’ for building molecules that are essential components in biological chemistry on Earth, creating sugars, amino acids, and even the components of ribonucleic acid (RNA) under the right conditions."  This is rather like some boulder observer who did not observe interstellar spaceships trying to plant in your mind kind of the impression that he sort of observed interstellar spaceships, on the grounds that boulders have the kind of ingredients that would be used by interstellar spaceships. 

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

If Interstellar Travel Movies Were Realistic

If you have got your astronomical education from watching science fiction movies, you probably think that travel between stars is a pretty fast experience. You just jump into your interstellar spaceship like Han Solo's Millennium Falcon, turn on the warp drive, and whoosh, you jump through hyperspace arriving at a distant planet. Even more recent movies (like the movie Interstellar) depict the same type of rapid interstellar travel.

But this is fiction, not science fact. There is no known evidence for anything like hyperspace that can be used to enable rapid interstellar travel. Nor is there solid evidence that you can instantaneously transport anything by using a space warp. Scientists have not been able to transport even a grain of sand from one place to another using a space warp.

It seems, regrettably, that interstellar travel will be a very slow affair. According to Einstein's special theory of relativity, the speed of light is the fastest speed that can ever be reached. If you could somehow build a spaceship capable of traveling at the speed of light, it would take you about five years to get to the nearest star. But there are engineering reasons for thinking that a spaceship will never be able to accelerate to more than a small fraction of the speed of light. This means that it would take many years to get from one star to another.

I wonder: what if Hollywood were to make a realistic movie about interstellar travel – a movie that was as realistic as possible about the difficulties of interstellar travel, and also the low chance of finding life in some particular target of an interstellar mission? Let's imagine what such a movie might be like.

You might think that such a movie might involve a plot in which the starship crew was put into suspended animation, so that astronauts slept through the interstellar voyage of many years. But that wouldn't be particularly realistic, since the prospects of people being put into artificial hibernation for many years are pretty dim.

One realistic plot for an interstellar voyage would involve astronauts who left Earth on an interstellar voyage while they were young men in their twenties. By the time the starship got to the distant star, the astronauts would be so old that they would not have energy to do much exploring. That might work as a comedy.

Another realistic possibility would be to depict a multi-generation starship. This is the most plausible scenario for interstellar travel. The ship would be large enough for someone to live his entire life on the ship. The original astronauts would have children while the ship was traveling between the stars. By the time the ship finally arrived, the starship would be manned not by the original astronauts, but by the children of such astronauts – or perhaps the grandchildren or the great-grandchildren of the original astronauts.

Recruiting poster for a multi-generation starship

Clearly this movie would need an ensemble cast, and it would need to be one of those movies that spans many years. But what would happen when the spaceship reached the distant planet revolving around another star? Would the astronauts find a lush world teeming with life?

The current thought exercise is to imagine a movie about interstellar travel that is as “realistic as possible.” It seems that such a movie should therefore not find the astronauts discovering life on the distant planet the ship finally reached. The origin of life on our planet still seems like quite the little miracle. We have no idea of how self-replicating molecules could have formed from mere chemicals billions of years ago. We have no idea of how the genetic code that life depends on could have arisen through mere chance. The genetic code is what programmers call a lookup table, and we have no known cases of any lookup tables in nature that ever arose through chance processes.

It seems, therefore, that if we are making our interstellar travel movie as realistic as possible, our astronauts should arrive at the planet revolving around a distant star, and find nothing but a dead rock planet. This might make a nice tragic ending, but it wouldn't have the dramatic oomph that makes a good tragic ending. Perhaps our astronauts could perish on the lifeless planet in a kind of “die in the desolate wilderness” ending resembling the ending of the opera Manon Lescaut.

A more hopeful ending might involve terraforming, an engineering effort to make a rocky, lifeless planet more like Earth. The astronauts on the starship could launch an engineering effort to bring earthly life to the lifeless planet. They might have to stay on their multi-generation starship for many years, orbiting the planet, while lifeforms slowly spread around the planet. Finally landing craft from the starship could land on a planet that had grassy fields. This event might occur hundreds of years after the multi-generation starship had arrived in orbit around the distant planet.

So the movie might depict a scenario like this:

Generation 1: Leaves Earth in the multi-generation starship, and dies aboard the starship.

Generations 2, 3, 4, and 5: Lives their entire lives in interstellar space, never seeing a planet.

Generation 6: Lives to see the starship orbit the lifeless planet revolving around another star.

Generations 6, 7, and 8: Lives aboard the starship, in orbit around the planet, waiting for the terraforming process to finish.

Generation 9: Finally gets to land on the planet, which by now has life and grassy fields.

Although highly realistic, such a movie would probably make much less money than absurdly unrealistic sci-fi epics in which traveling to another star is as easy as riding from one subway stop to another.

Postscript: After this post was published, Hollywood finally released a more realistic movie about interstellar travel, the movie Passengers, which depicts a very long interstellar voyage requiring decades of suspended animation. 

Will Man Last for an Eon?

“Sit down,” said the doctor to the patient. “I have some bad news. Your time left is limited. You've only got ten.”

“Ten years?” asked the patient.

“No,” said the doctor.

“You mean, ten months?” asked the patient.

“No,” said the doctor.”

“You mean ten WEEKS?” said the patient.

“No,” said the doctor. “I mean...ten, nine, eight, seven...”

We can make jokes like this about the topic of our future lifespans, but a more serious topic is that of humanity's lifespan. The only joke I know on that topic is the Voluntary Human Extinction Movement, an organization which most sane people will regard as a joke.

One interesting question is the question of whether man will last for longer than man has existed. Scientists estimate that our species Homo sapiens has existed for perhaps 150,000 years. Will man last longer than this? Some people think that man will last for more than another 100,000 years, but others reject this opinion.

Let's imagine a dialog between two men, Tim and Tom. Tim thinks that man will be around for eons, but Tom thinks that man won't last longer than a few thousand years. Let's hear from both of them.

The Case for Thinking Man Will Last for an Eon

Tim: Nuclear weapons threaten man. But there will probably never be a major nuclear war, because no leader would be stupid enough to start one. Even if there was a full-scale nuclear war, it would not cause the destruction of man. It would probably just set back our civilization by a few centuries, and from a geological perspective a few centuries is a relatively short time.

Despite the threat of nuclear war, space travel will probably make man almost immortal. Soon man will establish colonies in space. Once these colonies are established, man will no longer have all his eggs in one basket, so to speak. Even if the earth is destroyed, there will be self-sufficient space colonies capable of independent survival.

Within a few centuries, man will learn how to travel to other planets revolving around other stars. By the year 3000, man will have colonized planets in other solar systems. Once this happens, man will be essentially immortal. No matter what type of war or natural disaster occurred, it could not wipe out man if man had spread to a number of different planets revolving around different stars. Because man will colonize many different locations in space, man will probably last for eons. A million years from now there will probably still be men living somewhere in the universe.

From a purely mathematical standpoint, it makes sense to think that man will last for a huge length of time. Scientists say that modern man has been around for perhaps 150,000. If we imagine that man will last for eons, we can believe that there is nothing special about our age -- we're somewhere in the middle of man's lifespan. That seems like a more plausible assumption than thinking that man's history is 99.9% finished.

The Case for Thinking Man Will Not Last Much Longer

Tom:  Man has existed for about 150,000 years, but there are reasons for believing that man will not last for more than a few thousand years. First, there is a large chance that a nuclear war will destroy man. Or perhaps global warming will make the planet uninhabitable for man. Or perhaps robots will take over the planet, leading to a long, slow twilight for man, one that results in our eventual extinction.

But let us consider what will happen if none of these things happen. In such a case man's science will continue to grow. Within a thousand years scientists will discover genetic engineering techniques that allow parents to have super-intelligent children. Once such techniques are available, parents will choose to have super-intelligent children. After all, why would parents want to have a child with an IQ of only 100, when they could have a child with an IQ of 500 or 600? By the year 3000, almost all normal parents will be using genetic engineering techniques to have super-intelligent children. The result will be that within a few thousand years Homo sapiens will evolve into another species far more intelligent than man. If man is not destroyed by a nuclear war, within a few thousand years the race of men will evolve into a race of supermen. Once this begins to happen, man will fade away, and will be replaced by a successor species. By the year 4000 the earth will either be a nuclear wasteland devoid of human life, or it will be the home of a species of supermen: Homo futuris, the successor of Homo sapiens.

Homo Futuris Inspects his Domain

Eras of Tomorrow: Ages of the Future

Historians like to divide human history up into different eras, such as the Bronze Age, the Ancient Era, the Medieval Era, the Renaissance Era, the Age of Reason, and the Industrial Age. But what type of era delineations will be made by future historians? Below are some speculative answers that admittedly involve a great big dose of guesswork. We will start by looking at some current eras that may well end in the future, and then go on to look at eras that will begin in the future.

The Age of Crude Oil, 1901 to 2050

Large scale oil production began around 1901, and between the years 1900 and 1960 our civilization pretty much built itself all around this liquid that was cheap and plentiful throughout the 20^th century. The problem is that there is only so much crude oil in the ground, and experts predict that the easy-to-get stuff (called crude oil) will be pretty much used up by the middle of this century. Production of other types of oil such as shale oil may continue for a much longer time.

The Age of Coal, 1750 to 2075

Coal has been a big player on the industrial scene much longer than oil, and reserves of coal are greater than the reserves of oil. But experts such as David Rutledge at Cal Tech predict that coal prediction will peak in this century and begin to sharply decline by late in the century. There are environmental reasons why we need to end the Age of Coal as soon as possible, as coal plants are some of the worst agents of global warming. So we can predict the end of the Age of Coal by 2075, and hope that it ends much earlier.

The Age of Nuclear Weapons, 1945 to 2045

The total number of nuclear weapons in the world reached a peak around 1980 with a peak of around 65,000 weapons. The number has now dropped to about 17,000 weapons. If we optimistically project that disarmament will proceed at the same rate it has followed since 1980, we can project that nuclear weapons will be all but eliminated by the time of the hundredth anniversary of the detonation of the first nuclear weapon in 1945.

The Age of Hydrogen, 2040 Onward

Although we may soon experience difficulties in our supply of crude oil, there is a replacement technology waiting in the wings: hydrogen, which can power cars through fuel cells. Cars powered through hydrogen fuel cells may be very convenient, allowing you to drive 5000 miles before going back to a service station. However, a great deal of infrastructure investment must be made before there is anything like a hydrogen car infrastructure remotely comparable to our current oil and gas infrastructure. So even though prototype hydrogen cars may soon be available, we shouldn't list the Age of Hydrogen as beginning before about 2040.

The Age of Superintelligence, 2090 Onward

By superintelligence I mean some type of intelligence significantly greater than the mind power of the smartest human. There are three ways to get to the end result of superintelligence: creating computers smarter than humans, enhancing human intelligence electronically, or somehow just breeding people who are smarter (possibly with the help of genetic engineering). Somehow I think this is going to be a much harder nut to crack than a lot of people think. Ray Kurzweil predicts superintelligent computers by the year 2045, but I think he has greatly underestimated the software difficulties of creating such a thing. I think a more realistic prediction for the creation of true superintelligence is late in this century.

The Age of Global Warming, 1980 Onward (or 1980 to About 2080)

We are already in an Age of Global Warming – but how long will it last? On this matter I will hedge my bets and predict two possibilities. The first is that global warming just continues indefinitely through this century. The second is that sometime later in the century man finds some way to stop or reverse global warming, through the use of geoengineering techniques.

The Age of China, 2020 Onward

The economy of China is growing so rapidly that by the year 2020 the total gross domestic product of China will probably surpass that of the United States. The USA is hampered by ever growing amounts of debt, with a debt per capita of 52,000 dollars. China by comparison has a debt per capita of only 396 dollars. I can therefore predict a future Age of China marked by an economic domination of the superpower to the East.

The Interplanetary Age, 2040 Onward

By the Interplanetary Age I mean an age in which humans are traveling frequently between different planets in the solar system, mainly Earth and Mars. It seems for the past 40 years forecasters have predicted that we are about 15 years away from sending humans to Mars. Not wishing to commit the same “we'll send people to Mars in 15 years” error of past forecasters, I predict that there won't be much traffic between Mars and Earth for another four decades, and that the Interplanetary Age won't begin until roughly the middle of the century.

Credit: NASA

 
The Age of Leisure, 2045 Onward

An Age of Leisure is way overdue. It was predicted way back in 1930 by the leading economist John Maynard Keynes, who wrote: "Thus for the first time since his creation man will be faced with his real, his permanent problem-how to use his freedom from pressing economic cares, how to occupy the leisure, which science and compound interest will have won for him, to live wisely and agreeably and well.” Eventually advances in automation and robotics seem likely to produce an Age of Leisure, in which the average person has to work much less than 40 hours a week, and may work no longer than 20 hours a week. Rather than regarding this as a curse, we should regard it as a blessing, as it will give people more time to pursue things such as art, reading, education, self-fulfillment and spiritual pursuits.

Credit: NASA

The Age of Homo Sapiens, 300,000 BC to 2300 AD

By predicting that the Age of Homo Sapiens will only last until about 2300 AD, I am not predicting the extinction of the human species by 2300. I am merely predicting that by that date some intelligence will exist on our planet that surpasses our current species, and dominates it. That intelligence may be robots smarter than we are, or it may be a new, improved version of the human species, made possible through things such as genetic engineering or a blending of men and machines.

The Interstellar Age, 2400 Onward

By the Interstellar Age I mean an age in which humans are traveling frequently between different stars. Traveling from one star to another is more than a thousand times more difficult than traveling between planets in our solar system. Some space enthusiasts like to think about launching spaceships as early as the next century, but I think they are underestimating the fantastic difficulties of launching a manned interstellar mission. A more reasonable date for the beginning of the Interstellar Age is 2400 or 2500. Of course, there is always the chance that we might be visited by creatures from another planet before that time, and if that happens an Interstellar Age might suddenly be thrust upon us.

The Age of Stars, 12 Billion BC to 100,000,000,000,000 AD

We are still in the Age of Stars, which means a phase of the universe's history in which stars are abundant. This age has lasted for about 12 billion years, and is expected to last for another 100 trillion years, about 20,000 times longer than the remaining lifespan of our sun.

Credit: NASA

The Age of Black Holes, 100,000,000,000,000 AD Onward


By about 100,000,000,000,000 AD the Age of Stars will gradually change over to an Age of Black Holes. More and more matter in the universe will be gobbled up by black holes, with most of the universe's matter existing in these mysterious sinkholes from which nothing can escape.

It will be the ultimate triumph of entropy. Looking from a perspective of the history of the universe, we can put it this way: the Second Law of Themodynamics always laughs last.

The Revelations of the Immortals: A Science Fiction Story

“Traveling at 90 percent of the speed of light is not good enough,” said the Research Director. “We want to make a spaceship that will travel at 99.9999 percent of the speed of light.”

“Aren't you being greedy?” asked the Chief Scientist. “Why does it have to go so close to the speed of light?”

“Because of time dilation,” explained the Research Director. “Don't you remember the facts of Einstein's Theory of Special Relativity? Let me refresh your memory. If a spaceship travels at very close to the speed of light, then time slows inside the spaceship. They've known that since the 20^th century.”

“Ah yes, I remember,” said the Chief Scientist. “The famous Twin Paradox. You could have one 25-year old twin go on a space voyage near the speed of light, and then come back to Earth in a year. That twin would then only be 26, but he might meet his twin who stayed on Earth, and that twin might be 90 years old.”

“Yes, it all depends on how close you come to the speed of light,” said the Research Director. “The closer you come to the speed of light, the more time dilation there is; the more time slows down for the astronauts. Now if we can make a spaceship that travels at 99.9999 percent of the speed of light, the time dilation factor will be 707. That means our astronauts can make a journey of 700 light years, but it will only seem like a single year to them.”

“But I still don't understand why we need our spaceship to go such a long distance,” said the Chief Scientist.

“Very well, I'll tell you something top secret,” said the Research Director. “They've discovered unmistakable signs of intelligent life on a planet named Aquarius 45G. It's about 700 light years from Earth. We've detected signs of some technology there far more advanced than ours. That's why we want our spaceship to go close to the speed of light – so that it can get to Aquarius 45G in what will seem only a single year to the astronauts.”

After years of trial and error, the grand research team finally developed a spaceship capable of traveling at 99.9999 percent of the speed of light. A team of seven astronauts was selected for the dangerous mission to Aquarius 45G. The hardest part was finding astronauts who would have no problem with the idea that when they finally returned to Earth, it would be 1400 years in the future (even though the mission would only seemed to have lasted two years to the astronauts). The spaceship was named Ultimate Dream.

The Ultimate Dream left the solar system in the year 2175. The time dilation effect worked exactly as Einstein had predicted. Because the ship was traveling at 99.9999 percent of the speed of light, a voyage of about 700 light years was made in what seemed like only a single year to the astronauts on board the ship.

The Ultimate Dream finally reached orbit around the planet Aquarius 45G. A landing craft from the spaceship landed on the planet, and five astronauts began exploring the strange planet.

“We saw huge space stations in orbit around this planet,” said astronaut Joe Freeman. “It shouldn't take us long to find some intelligent life here.”

The astronauts explored for a while. Eventually they came to a lake in the middle of some rocky terrain. At one end of the lake, Joe spotted a strange looking alien building. “There!” Joe cried, pointing his finger. “That's one of their buildings!”

The astronauts entered the building, and were greeted by intelligent life forms with thick necks and huge brains. The astronauts stayed at the building for weeks. It took the extraterrestrials only a few weeks to learn the language the astronauts spoke.

Once communication was established, the astronauts had many questions. The extraterrestrials gave many answers. It was the grandest question and answer session any humans had ever engaged in. The extraterrestrials seemed to have the answer to every question the astronauts could ask.

The astronauts asked: what caused the Big Bang? The extraterrestrials gave the correct answer. The astronauts asked: is there a God? The extraterrestrials gave the correct answer. The astronauts asked: is there life after death? The extraterrestrials gave the correct answer. The astronauts asked: why does there even exist a universe? The extraterrestrials gave the correct answer. The astronauts asked: what are the greatest civilizations in the galaxy? The extraterrestrials gave the correct answer.

The astronauts final question to the extraterrestrials was: how is it you know so much? The extraterrestrials answered: because we are immortals who have had many, many thousands of years to find all these answers.

Finally the astronauts returned to their landing craft, and lifted off from the planet. The landing craft docked with their interstellar spaceship Ultimate Dream.

“We have been given the most astonishing gift of knowledge that the human race has ever received,” said Joe Freeman. “Let's get back to Earth as soon as possible so we can give these revelations of the immortals to the human race. When we get back and tell what we have learned, it will be like the ancient Greek legend of Prometheus giving fire to mankind.”

The ship hurtled through interstellar space, traveling about 700 light years at 99.9999 percent of the speed of light. Halfway through the voyage, some of the crew began to get sick. They developed cancer.

“This is what I was afraid of,” said Sue Hendrix, the mission's doctor. “It's all these cosmic rays we are getting from traveling through space.” Like all astronauts since the twentieth century, the astronauts knew that space is filled with cosmic rays, a hazardous form of radiation that can cause cancer.

By the time the Ultimate Dream reached orbit around planet Earth, all of the crew had died of cancer except for one. Only Joe Freeman remained, and even he had developed advanced cancer. For Joe it had been just as if only two years had passed, because of time dilation.

But Joe was determined that he would return to Earth to give the revelations of the immortals to mankind. He told himself that nothing must stop him from telling the human race about the astonishing cosmic truths that had been revealed to his crew on the planet Aquarius 45G.

Joe got in the landing craft of the spaceship, the same one he had landed on Aquarius 45G. He landed the landing craft near New York City.

A crowd of people surrounded the landing craft. Struggling painfully with his very sick, cancer-filled body, Joe exited the landing craft. Joe looked at the crowd, who were dressed in some clothes unlike any he had ever seen. Of course, thought Joe; because of time dilation it is now 1400 years later on Earth.

He went up to one of the people in the crowd.

“I am one of the astronauts who left Earth 1400 years ago,” said Joe. “And I have the most important knowledge imaginable to transmit to you-- the answer to all of mankind's most profound questions. The answers were all given to us by the extraterrestrials.”

“Shropa nika soyn drog shroopy slong friz,” said the person.

Joe thought to himself: he must be a foreigner; there are lots of those around New York City.

“We made it to Aquarius 45G,” said Joe to another person in the crowd. “Let me tell you all about what we found out from the immortals on that planet. They gave us the most important truths ever discovered by humans.”

“Zyna tring vun syma yoop krong dysterbonitz,” said the person.

Coughing violently, and beginning to bleed internally, Joe tried several other spectators in the crowd. The result was the same. No one could understand a word of what he was saying.

Joe finally realized what had happened. In the 1400 years that had passed on Earth, the English language had changed dramatically. The people now used a language that Joe couldn't understand. None of them could understand the language Joe spoke.

But there was in New York City one scholar who could speak Joe's language. He was a professor who specialized in analyzing old texts from the twenty-second century. His knowledge of twenty-second century English was so good that he could understand most of what Joe spoke.

The scholar was rushed to the place where Joe's landing craft had landed. Pushing through the crowd, the scholar came up to Joe, and began slowly speaking in a heavy accent.

“Hello, my name is David, and I can speak the language you call English, the same language you speak,” said the scholar. “Do you have something to tell me?”

Though his cancer-filled body gave him great pain, Joe was overjoyed. Now at last he could reveal the greatest truths a human had ever discovered! Now at last he could tell someone on Earth the answers to all of man's age-old questions, the answers the immortal extraterrestrials had revealed to him!

Hemorrhaging heavily, Joe struggled to speak. “We found...they told us...” he said.

But then his internal bleeding got the best of him, and Joe died before he could say another word.

12 Reasons Why Fermi's Paradox Does Not Show We Are Alone

The prima facie case for intelligent life on other planets seems very strong, as we live in a galaxy of more than 100 billion stars,  and in a universe consisting of billions of galaxies; and we now know (thanks to the Kepler Space Telescope) that planets of all sizes are very abundant. But there is one thing  used by those who don't want to believe in extraterrestrial intelligence: Fermi's Paradox. Fermi's Paradox is the paradox that despite the huge number of stars and planets in the universe, we have no observations of intelligent life outside of our planet. This paradox is sometimes evoked by simply asking: where is everybody?  Fermi's Paradox has often been used by people who wish to believe that extraterrestrial life is rare or nonexistent. Such people make arguments such as this: if extraterrestrial intelligence existed, it would have arisen long, long ago, and would already have come to our planet, leaving many traces of its existence.  A similar argument goes along these lines: if an extraterrestrial civilizations existed, we would have seen some evidence of it in outer space, or would have received radio signals from it.

City on an alien planet. Art by M. Mahin.

I will now give some reasons why Fermi's Paradox is not a valid argument against the abundant existence of intelligent life in our galaxy and other galaxies.

 (1)    Interstellar travel is in all likelihood very, very slow.  While science fiction stories talk about spaceships whizzing around quickly through the galaxy, they are indulging in wishful thinking. Einstein's Special Theory of Relativity tells us that the speed of light is an absolute speed limit to the universe.  The average distance between stars in our galaxy is roughly the same as the distance to the nearest star, about five light years. This means a starship could not travel from one star to another in less than about five years. In fact, there are practical engineering reasons for suspecting that it would typically take decades to travel from one star to the nearest star. One of these reasons has to do with the difficulty of accumulating enough fuel to last for an entire interstellar voyage, and another reason pertains to the need to start decelerating long, long before reaching a star you are traveling to, to avoid overshooting it.  There is currently no evidence that anything like space warps can be used for quick interstellar travel (although one cannot rule out such a possibility).  The slowness of interstellar travel means that even if civilizations arose long ago in many different places in our galaxy, it is not at all evident that spaceships from such civilizations (or colonies arising from them) would have reached our planet by now.
 (2)    If extraterrestrials had previously reached Earth, there is a large chance they would have been unable to colonize it because it was biologically or physically unsuitable for them. The “if they existed, they would be here already” argument is undermined by the fact that there is a large chance that colonizers from another planet might come to a planet like Earth and decide not to colonize it (or fail at colonizing it) because it wasn't what they were hoping to find.  The arriving extraterrestrials might have been spindly thin-legged organisms adapted to live on  a planet with a gravity much lower than ours. Or they might have been organisms used to living on a planet with a gravity much greater than ours. Or they might have been organisms adapted to live on a planet much hotter or much colder than ours. Or they might have required a planet with a different composition of atmospheric gases than our planet has. Or there could have been some biochemical reason or biological reason why they couldn't live here. Perhaps their chemistry wasn't compatible with our soil, or perhaps common microbes on our planet were lethal to them. There are any number of reasons why a colonization mission from another planet to Earth might have failed without establishing a long-lasting colony, and there are also any number of reasons why colonizers from another planet might choose to head for another planet after reaching here and investigating Earth's conditions.
 (3)    The current non-existence of an extraterrestrial colony on Earth does not rule out that there might have been such a colony in the past, possibly existing for a very long time. We have no experience at all with any civilization lasting longer than a few thousand years. Nothing that we know about the development of advanced technology should convince us that if an extraterrestrial colony had been established it would be able to survive for millions of years. We also know that Earth is a geologically dynamic planet, and that things that existed on the planet long ago became buried or destroyed by geological processes. For all we know an extraterrestrial colony could have been created in the past, and existed for a long time. It could then have passed away and been covered up by geological processes, like those that buried so many layers under the Grand Canyon. So we cannot at all say that we have never been colonized in the past.
 (4)    Extraterrestrial civilizations would be more likely to concentrate on using radio and television signals to find out about other planets, rather than the infinitely more difficult route of interstellar travel.  Imagine you are in charge of an advanced extraterrestrial civilization. You can probably get all kinds of information about other planets (probably including images and video) if you build yourself a really good set of radio antennae vastly better than anything we now have. Or you can build starships to try and get the same information. The first technique is 10,000 times cheaper and may give you results this year. The second technique is infinitely more expensive, and probably won't give you knowledge until many decades in the future (given the slowness of interstellar travel). Which are you more likely to concentrate on? Presumably it would be radio communication. This may help to explain why we don't get many interstellar visitors, and may not have gotten any.
 (5)    Super-intelligent extraterrestrials might not have any of the “lust for control” that might fuel a drive for interstellar colonization.  We have no idea what type of mental attitudes extraterrestrials would have. Human beings have repeatedly shown a kind of “lust for control” that may drive imperialistic expansion. We may want to get as many countries as possible under our control, and we may get a thrill out of planting our flag on places such as the moon. But to  super-intelligent extraterrestrials vastly smarter than us, such impulses may seem utterly childish.  For every extraterrestrial civilization that sends out colony ships in all directions, there may be 100 that do not, because they see little benefit in creating distant outposts, given the slowness of interstellar communication. We may be projecting on our superiors a “lust for control” drive of our own they are unlikely to have (just as a 2-year old boy might try to imagine what his father does at work, and imagines him playing with stuffed animals all day, just like the 2-year old boy).
 (6)    As interstellar colonies could not really be controlled from another star (and can only be communicated with after a delay of many years),  other planets would have little incentive to create colonies outside of their solar system.  According to the laws of physics as we currently understand them, traveling faster than the speed of light is impossible. So the idea of a galactic emperor issuing commands that are quickly obeyed over many light years is not realistic.  Once a colonization mission left for some other star, it would be the master of its destiny, and it would be beyond the practical control of the planet that launched it. So what incentive would that planet have for creating such colonies? Would it be worthwhile for the sake of getting transmissions from a colony established on a distant world? But it would be much cheaper just to build radio antennae and listen to radio signals from all over the galaxy.
 (7)    Colonization missions by extraterrestrial civilizations could commonly be wiped out when they encounter defensive technology.  Those who use Fermi's Paradox to argue that man is unique commonly speak as if some extraterrestrial civilization could send colony ships out and colonize countless other planets without difficulty, like a mailman dumping letters in a hundred mail boxes. But it could be that many extraterrestrial civilizations employ defensive technology in their solar systems, designed to destroy any incoming visiting spacecraft capable of colonization. If that happens, then any attempt by one planet to colonize many other planets would be a risky undertaking, facing a much larger chance of eventual failure before it gets very far. 
 (8)     We might currently be receiving visitors from other planets.  I refer here to the possibility that one or more UFO sightings here on Earth may actually be caused by extraterrestrial spacecraft. Now, of course, one can argue that there is no conclusive proof for that; and I would agree. But the mere fact that there are frequent UFO sightings (many of them strange and hard to explain) weakens any argument (based on Fermi's Paradox) that we are alone in the galaxy. It means the first premise of such an argument (the premise that “they are not here”) is not even beyond dispute.
 (9)      We may already have received one radio signal from an extraterrestrial civilization.  I refer here to the famous “Wow signal” of 1977.  See http://news.discovery.com/space/alien-life-exoplanets/the-wow-signal-130524.htm for a good recent explanation. The signal was exactly the type of signal astronomers expected to get from an extraterrestrial transmission. The fact that we are not sure the signal was artificial does not change the fact that it weakens the first premise of any argument (based on Fermi's Paradox) saying “since we have no sign of them, they don't exist.”
 (10)    Extraterrestrials may communicate through some advanced technology more advanced than radio waves.  Other than the possible success listed above (the “Wow signal”), our attempts to pick up radio signals from extraterrestrials have not succeeded.  But that may be because extraterrestrials commonly communicate through some technique more advanced than radio transmissions. There are all kinds of possibilities including laser communication and “subspace” communication. So our failure to pick up signals from them may simply mean we're not trying the right technique.
 (11)    Since intergalactic travel is presumably impossible, we have no reason for not assuming that most spiral galaxies have at least one civilization.  Our galaxy of more than 100 billion stars is a spiral galaxy, and there are billions of spiral galaxies. But the distance between spiral galaxies is about 100,000 times greater than the incredibly vast distance between stars. The distance between galaxies is so great that we should assume intergalactic travel is basically impossible. Traveling between two spiral galaxies would require a journey on the order of a million years, making it unlikely that any civilization (no matter how advanced) could achieve it. Therefore any type of “if they existed, they would be here already” reasoning totally falls apart when we consider civilizations in other galaxies. No,  no matter how old they might be, if they existed in another galaxy they would not at all be here, no matter how eager they might be to get here.  There is no reason to think that any civilization, no matter how old, could achieve a million year journey between galaxies.
 (12)    The extraterrestrials may not be here because they have so many other places to go (real or virtual), and so many other things to do.  Let us imagine a colony of ants in a forest using reasoning similar to arguments based on Fermi's Paradox.  They might argue like this: “If there existed any beings in the world greater than we ants, they would be here already. They would be here at our anthill, trying to control or investigate us. But we see no such creatures. Therefore we ants are the most advanced creatures in the world.” The argument is a fallacy because we humans exist, but we don't go into the forest and peer into the anthill of these ants, because we have a vast number of other more important places to go to, and have a vast number of other more important activities to busy ourselves with. The same thing may be true of extraterrestrials: they may have limitless virtual computer-generated worlds to play in, and a billion places in our galaxy to travel to (not to mention billions of unimaginable and unfathomable activities far more worthy of their time than colonizing our planet). Their non-presence here now proves nothing. 


 These reasons are enough to rebut the most general form of an argument for man's uniqueness based on Fermi's Paradox. There is a very specific (and more elaborate) version of such an argument, built around the possibility of self-reproducing robotic von Neumann probes spreading exponentially throughout the galaxy. I will rebut that argument in a later post to this blog.  My rebuttal will be based on reasons such as these: (1) self-replicating von Neumann probes are an example of runaway, cancerous technology that we would not expect extraterrestrials more intelligent than us to build; (2) if such technology had entered the solar system in the past, it is as likely as not that it would not have left any signs we could now detect; (3) rather than letting such planet-altering probes run amok uninhibited throughout the galaxy, civilizations on other planet would be expected to release counter-technology designed to find and destroy such self-reproducing probes. 

The Thirty-seventh Marina Terletsky: A Science Fiction Story

Author's note: unlike some of the dark and gloomy tales I have written for this blog, the story below is suitable for reading to a young child. I'll have more dark and gloomy tales at a later date.

Marina Terletsky, age 11, woke up one morning. It was a beautiful morning. Every morning was a beautiful morning, because the weather never changed where Marina lived.

Marina went outside, and looked up at the sky. She did not see any blue, nor did she see any clouds. Looking straight up and squinting, she could just barely see people 200 meters away. All she saw were the tops of their heads.

Marina lived in a spaceship, which was traveling between the stars. The spaceship was a gigantic hollow cylinder, 1000 meters long, and 200 meters wide. On all parts of the inner rim of the gigantic cylinder lived more than 700 people. Even though the spaceship was far away from any planet, there was a gravity just as strong as the earth’s gravity. This was because the hollow cylinder was always spinning. Because of centrifugal force, this spinning caused an artificial gravity, just as a giant spinning wheel used for an amusement park ride creates a gravity-like force for the people on it, pushing away from the center of the wheel.

The gravity always pressed away from the center of the hollow cylinder, to any of the curved land inside the cylinder. So anyone walking along on the inner surface of the gigantic hollow cylinder would feel a gravity, pretty much like the gravity on Earth. Marina could walk along and see grass and trees and ponds. But one thing was very strange about this hollow artificial world. Since she lived inside a curved cylinder, if Marina kept walking in a straight line, she would come back to exactly the same place that she started walking.


One day Marina’s mother was showing her some pictures. “This was me when I was your age,” she said. Marina looked at the photograph. The girl in the picture looked exactly like her. It was like looking in a mirror.

“Do all daughters look exactly like their mothers?” Marina asked. “I mean except for the difference in age?”

“Of course not,” Marina’s mother said. “Far away on the planet Earth, most daughters look a little different from their mothers. But you’re not an ordinary daughter, Marina. You’re a clone.”

“Oh yeah,” said Marina. “I remembered hearing about that in biology class. But I’m still a little fuzzy on that. Can you explain that to me again?”

“A clone is an exact genetic copy of another person,” explained Marina's mother. “You were made when they took one of my cells, and started to duplicate it. All of your genes – the things that make you who you are – are exactly the same as mine. That’s not the same as being a regular daughter. A regular daughter starts out as a combination of the genes of her mother and her father.”

“So I don’t have any father?” Marina said.

“Exactly,” said Marina’s mother. “It’s kind of like I’m both your mother and your father.”

“And there are other clones on this spaceship, right?” Marina asked.

“You bet,” said Marina’s mom. “Every single person on this spaceship is a clone. That’s how they organized it, when they set up the great interstellar expedition many, many years ago.”

“Why did they do that?” Marina asked.

Marina’s mother began to tell the strange story of how the long space voyage had began.

“A thousand years ago, the Global Earth Empire organized the first expedition to another star, to Alpha Centauri, the nearest star to the sun. You’ve probably read science fiction books in which spaceships travel quickly from one star to another. But that’s just science fiction. In real life, the distance between stars is incredibly vast, so great that it takes light itself five long years to travel from our sun to the nearest star. The scientists knew that any voyage from our sun to the nearest star would take a long, long time, even with the fastest spaceship they could build. It would take more than a thousand years. The Global Earth Empire decided to build a multi-generational spaceship, one that would travel through outer space for more than 50 generations, for a journey lasting more than a thousand years.”

“But that’s much longer than a lifetime,” Marina noted. “How did they get anyone to agree to go on such a long mission?”

Her mother continued her explanation.

“It was very hard to get people to enlist. All of the first generation that lived on this spaceship knew that they would never see Earth again, and that they would die while traveling through outer space, before the spaceship reached Alpha Centauri. But the mission designers offered a kind of bonus or incentive to the original crew members. They were promised: you will be cloned while you are on the spaceship. And that clone will be cloned. And so it will continue, century after century, until finally a clone descended from you (a person with your name, who looks exactly like you) will eventually be alive on the spaceship, when it finally reaches a planet revolving around the star Alpha Centauri, after a journey of more than a thousand years. That promise encouraged lots of Earth people to sign up for the voyage.”

“Wow,” Marina said. “No wonder I got kind of hazy on that. So I am a clone, and I am also the clone of a clone?”

Marina’s mother made some marks on a paper, and then took a deep breath. “Here is the precise truth: you, Marina Terletsky, are the clone of a clone of a clone of a clone of a clone of a clone of a clone of a clone of a clone of a clone of a clone of a clone of a clone of a clone of a clone of a clone of a clone of a clone of a clone of a clone of a clone of a clone of a clone of a clone of a clone of a clone of a clone of a clone of a clone of a clone of a clone of a clone of a clone of a clone of a clone of a clone.  They all looked exactly like you when they were eleven years old, and they were all named Marina Terletsky. And all of these clones were genetically identical to the original Marina Terletsky, who once walked on the planet Earth. She was the brave one who lived a thousand years ago, and signed up for a spot on the long voyage from Earth to the nearest star. None of the clones of the original Marina Terletsky have ever seen the planet Earth. They have only seen this spaceship, our home.”

“So what version number am I in the Marina Terletsky line?” Marina asked.

“You are the thirty-seventh Marina Terletsky,” said Marina’s mom. “I am the thirty-sixth Marina Terletsky. My mother was the thirty-fifth. And the little girl you will one day raise, who will also be a clone with no father, will be the thirty-eighth Marina Terletsky.”

“Wow,” Marina said. “So I guess the original Marina Terletsky was very important to you and me. Why don’t we have a picture of her somewhere?”

“We don’t need one,” said Marina’s mom. “Just look in the mirror, or at me, and you can see exactly how she looked.”

“Will I ever see the distant star we are journeying toward?” the young Marina asked. “I mean, like, one of the planets that revolves around it?”

Marina had asked this question before, and remembered the answer she had got, but hoped that maybe this time the answer would be different.

“You can see Alpha Centauri through the telescope when we tour the astronomy bay,” said Marina’s mom. “But I’m afraid you will never walk on one of the planets that revolves around that star. Our spaceship is still too far away.”

“Mom,” asked Marina, “which Marina Terletsky will be able to walk on one of the planets that revolves around Alpha Centauri?”

Her mother looked at her rather sadly. “I’m afraid we will not get to Alpha Centauri for about another 500 years. I’ve calculated that it will be about the fifty-fourth Marina Terletsky who will be the first cloned Marina Terletsky to walk on a planet.”

Young Marina looked very sad now, and her mother tried to cheer her up.

“Don’t feel sad, Marina,” said her mother. “We have a nice artificial world to live in, our spaceship. It’s nice and cozy. And we don’t have to worry about things like floods and earthquakes and wars. Although you will never travel beyond this spaceship, you can take comfort in the thought that one day a girl who looks just like you will experience the exciting day when our spaceship finally arrives at Alpha Centauri.”

Five Years Later

Life continued on the spaceship just as it had always been. But one day something astonishing happened. Another spaceship approached from afar, and pulled up right next to the spaceship in which Marina Terletsky lived.

Marina and her mom were very anxious as the silver-colored spaceship approached.

“Maybe they’re aliens here to steal all of our food,” Marina said. “Or who knows, maybe they’re here to eat us!”

Out of the silver-colored spaceship came two figures in space suits. They started to take off their space helmets. Marina was very scared. Would they be monsters with green skin, and yellow, bulging eyes? Or would they be even more hideous?

But when the figures took off their space helmets, Marina was surprised to see that they were handsome young men.

“Hi there!” said  one of the men said, a man named David. “We’ve heard all about your spaceship. You’re the first spaceship sent to travel from our sun to another star. But you know what happened, while your ship was taking centuries to travel 75% of the way to the nearest star? Mankind figured out how to build much faster spaceships! Our spaceship travels at half the speed of light. We were able to travel from Earth to your ship in only 8 years, even though it took you centuries to get this far away from Earth.”

“So we have an offer to make to you,” the other man said. “If anyone wants to transfer to our spaceship, we can take you to the solar system of Alpha Centauri in only 2 years. I think that is better than spending the rest of your life on this slow-moving cylinder world.”

Marina was so excited. It meant that rather than living the rest of her life in the spaceship, she could actually get to the planet near Alpha Centauri, and live on a planet, just as the first Marina Terletsky had done. It meant that the first Marina Terletsky to walk on the distant planet would not be the fifty-fourth Marina Terletsky – it would be her, the thirty-seventh Marina Terletsky.

An old woman Marina knew decided to stay on the spaceship Marina had been living on, as did many others. They said they were used to living there, as they had all their lives. But Marina, her mother, and 200 others transferred to the other, faster spaceship. And off they went, traveling towards Alpha Centauri at half the speed of light.

After two years the silver-colored spaceship arrived at Alpha Centauri. It came to a beautiful, blue-green planet revolving around Alpha Centauri. “It is here that man’s first interstellar colony will be created,” the captain of the ship announced dramatically.

Marina asked, “Will we have to always wear spacesuits if we live down there?”

“No,” a crew member replied. “The atmosphere is just like Earth’s. So we’ll be able to live regular lives down there, just like people live on Earth.”

A shuttle craft took Marina and some others down to the surface of the planet, to start the first colony on another earth-like world.  Marina was now eighteen years old.

The moment Marina would never forget was when she first got a chance to run around on the surface of the planet.  With David and some friends of hers, she ran through a huge meadow of grass. Marina found it so amazing that she could run and run and run, without ending up back at the same place where she started out.  When a gentle fragrant breeze caressed her hair, and she felt the first breeze she had ever felt, she wept a tear of joy.

Looking at David, Marina asked rather nervously: “So that rule followed on the cylinder spaceship I was born on, the rule that every woman has to raise her own clone, rather than mating with someone else – do they still want us to follow that rule on this planet?”

“No,” David answered softly. “The promise made a thousand years ago to the original Marina Terletsky has been fulfilled – her clone reached Alpha Centauri. So there's no need to follow that dusty old rule any more. On this planet we'll make babies the old fashioned way.”

He held Marina's hand, and she smiled.