Will we use metal in the future? What else would we build things out of? Might we use organic technology (machines and buildings made of or from biological organisms) instead?”
In The Graduate, that iconic film from 1967, bewildered 20-something Benjamin Braddock (Dustin Hoffman) gets some career advice from a businessman who leans close and intones “I want to say one word to you. Just one word. Are you listening? Plastics.” Benjamin didn’t follow that advice, but the rest of the world did, and in spades. By 1979, global production of plastic had exceeded that of steel and is still growing, reaching over 200 million tons this year. There’s no doubt that plastic will continue to play a major role in how we make things, but it won’t replace everything.

In some ways, plastic is the material of the future, the latest step in humanity’s long upward trek through the ages of stone, bronze, iron, and steel. The word “plastic” comes from Greek roots meaning “capable of being molded.” Compared to metals and other materials, plastic is infinitely versatile. With its ability to shape-shift and to take on different mechanical and optical properties, it shows up in a huge spectrum of applications from packaging and plumbing to toys, medical supplies, and computers. And unlike iron and steel, plastic doesn’t rust.

But plastic also has problems that will prevent it from replacing metals any time soon. Its very durability can be an issue. Discarded plastic objects can survive for centuries in garbage landfills without degrading, and plastic artifacts have been found polluting the oceans far distant from any land. Also, what doesn’t seem to be widely appreciated, the raw material to make plastic comes from a resource we need to conserve, petroleum.

On top of this, metals do some things better than plastic—just try cutting up an apple with a plastic knife. Copper and other metals are needed to conduct electricity through power grids; all plastic can do is insulate the current-carrying wires. However, plastic is making inroads relative to some materials such as wood, which is being replaced by plastic “lumber” in certain applications.

Plastic also offers a possible way to actually construct things using biotechnology. Unlike metals, which are classified as inorganic, plastics are organic; they’re made of carbon, hydrogen, nitrogen, and oxygen, the same constituents as living things, which links plastic to biological products. For instance, under the right conditions, certain microorganisms can synthesize compounds called polyhydroxyalkanoates (PHAs). These display properties like those of artificial plastics, with the benefits that they’re not petroleum-based and are biodegradable. Researchers are investigating ways to mass-produce these bioplastics, for instance by bioengineering plants to create them.

If you want to speculate even further, way past the idea of growing plastic rather than making it in factories, think about the science-fictionish possibility of bioengineering plants to produce plastic exactly in a desired shape from a drinking cup to a house. Current biotechnology is far short of this possibility, but science fiction has a way of pointing to the future. If bioplastics are the materials breakthrough of the 21st century, houses grown from seeds may be the breakthrough of the 22nd.

DISCOVER: What kind of realistic technology could we use to get to nearby stars? Which stars would be feasibly reachable by such technologies?

Kevin Grazier: It’s a saying plastered on T-shirts and bumper stickers—the kind sold at both science-fiction conventions and physics departments nationwide:

186,000 miles per second:
It’s not just a good idea, it’s the law.

The speed of light, of all electromagnetic energy, in a vacuum is the ultimate speed limit in the universe. Nothing that has mass or carries information can travel faster.

This universal speed limit is a direct fallout from Albert Einstein’s special theory of relativity. Special relativity implies that the speed of light in a vacuum is a universal constant, but values that we tend to think of as constant in our daily experience—mass, length, and the rate of the passage of time—are not. Depending upon the relative velocity of two observers, these values will “adjust” so that both observers see the speed of light as a constant. Two observers travelling at high speeds relative to each other will find themselves in strong disagreement about measurements like the length of each other’s spacecraft and the rate of the passage of time.

Another consequence of special relativity is that, as an object travels increasingly faster, it behaves as if it has increasingly more mass. Therefore the amount of thrust it takes for an incremental change in velocity (known in the space program as a delta-V) is vastly greater at high speeds than at low. This effect is also highly nonlinear: It takes almost an order of magnitude more thrust to accelerate from .9c (nine-tenths of the speed of light) to .99c than it does to accelerate from .5c to .7c. An object travelling at the speed of light would act as if it had an infinite amount of mass and it would, therefore, require an infinite amount of energy (read: an infinite amount of thrust/fuel) to attain it.

This is, of course, a shame for civilizations (like ours) who want to explore planetary systems around other stars first hand. The distances involved are, well, astronomical. Just within the Solar System, it typically takes NASA probes 6 months to a year to reach Mars; it took Cassini 6 years, 9 months to reach Saturn. The (currently) fastest object created by humankind, the Voyager 1 spacecraft, will take 40,000 years, give or take a few thousand years, before it makes its closest encounter with its first star: AC+79 3888—currently located in the constellation Ursa Minor. At that speed few Time Lords, and even fewer humans, would survive the journey to even “nearby” star systems.

Current chemical rockets, and even the more efficient ion drives, cannot propel humanity to the stars at a reasonable speed, but there are concepts for interstellar spacecraft drives that are promising, that could be constructed in a practical sense, and you may be surprised how long the designs have been around. Stanisław Ulam, a Polish mathematician who participated in the Manhattan Project, proposed nuclear pulse propulsion back in 1947.

The idea is simple: explode a series of nuclear bombs behind a spacecraft. The explosions are directed against a thick steel “pusher plate”. The pusher plate is, in turn, connected to the spacecraft by a huge shock absorber to lessen the high G forces from the impulsive accelerations. In the straightforward terminology of Jimmy Johnson, the engineer on the Phaeton:

Basically, we gonna blow us up a bunch of big ass bombs off the ass-end of this here ship. Big ass bombs gonna vaporize some big ass alloy plates, and the translation of all that big ass energy’ll make us go real fast. Real fast. Yippe kai-ay, m…

The practical attempt to design and develop nuclear-pulse propulsion was performed by General Atomics in San Diego in the 1950s and 1960s. Ultimately the Nuclear Test Ban Treaty between the Unites States and Soviet Union made the testing for such a drive illegal, nevertheless over 50 years ago the design seemed practical and could be implemented within the bounds of existing technology. For more information, NASA and Star Trek designer Mike Okuda provided still more details on Project Orion, the U.S. government’s investigation into a nuclear-pulse spacecraft.

An Orion-style drive powered by thermonuclear explosions could theoretically reach speeds of .08c to .10c. That could get a spacecraft to the nearest stars within a human lifetime, but not within Phaeton’s 10-year mission. Virtuality is set in the mid-21st century, and it’s reasonable to assume some technological advances in the intervening time. Phaeton does not use thermonuclear explosions for propulsion, the charges dropped out the back are matter/antimatter charges (yes the thrust for Phaeton is, in essence, provided by photon torpedoes). The obvious assumption is that by the mid-21st Century, science has solved problems regarding the generation and containment of antimatter. One estimate has shown that Orion-style drive propelled by matter/antimatter explosions could attain speeds of .5c to .8c.

If Phaeton’s Orion Drive (named after the real-life nuclear concept) could propel it to 80 percent the speed of light, it could get to Sol’s nearest neighbor, Alpha Centauri (4.4 light-years away) in just 5 years, 6 months. That’s certainly a vast improvement, and shortens the round-trip mission time to several nearby stars to less than a human lifetime.

Only, it gets better.

Special relativity, which bit us in the asteroid when it comes to top-end velocity, does our crew a favor as our spacecraft attains speeds that are a high fraction of the speed of light. Recall that for objects travelling at relativistic speeds, values like mass, time, and length appear to “adjust” to keep the speed of light a constant. At high speeds, distances that we measure at “rest”, or at low speeds compared to c, appear to be shortened. This effect is called Lorentz contraction or Lorentz-Fitzgerald contraction.

Moving at a snappy .5c, the distance to Alpha Centauri is only 3.8 light-years (down from 4.4), and the apparent travel time is a bit over 7 years, 6 months. At 80 percent light speed, the distance is 2.6 light-years, and the travel time is 3 years, 3 months—less elapsed time for the crew than it would take for light to make the same journey.

Travelling at a speed of 0.7c is the “break even” point, where the combination of spacecraft velocity and Lorentz Contraction means you are travelling at “functional light speed” (the distance to Alpha Centauri in that frame would be 3.1 light-years and the travel time 4 years, 5 months). Of course time passes at different rates based upon their relative speeds as well, a phenomena called relativistic time dilation, so if Phaeton were travelling at a speed of .7c, for every year that passes for the crew, a year and five months would pass for The Edge of Never viewers back on Earth. Billie Kashmiri alludes to this in her confessional near the end.

With the phenomena of Lorentz Contraction as an aid, many more star systems become potential targets of a 10-year mission. There are sound scientific arguments why astronomers believe that any star that could potentially have a planet with life, in particular intelligent life, must be similar to our Sol: from mid-F range on the Herzsprung-Russell Diagram to mid-K. There are several stars in that size/temperature range in Sol’s neighborhood. Below is a screen capture of a spreadsheet that the producers of Virtuality used to select the target star for Phaeton’s mission (text color corresponds to the star’s color):

On the spreadsheet are the stars’ distances at rest, and at various fractions of light speed—with the corresponding travel time.

Click image to embiggen.

Epsilon Eridani, the nearby star that the Phaeton is sent to explore, has one, perhaps two planets orbiting it, as well as at least three asteroid/planetesimal belts. If we assume that Phaeton’s Orion Drive can get her up to .8c, or 80 percent the speed of light, then because of Lorentz contraction the journey (normally 10.5 light-years) is only 6.3 light-years, and it takes just under 7 years, 11 months. So if the Orion Drive can reasonably get a spacecraft up to .8c, then Phaeton’s mission is actually closer to 16 years. If, however, the Orion Drive was capable of propelling Phaeton to .9c, or 90 percent the speed of light, then the distance to Epsilon Eridani is only 4.6 light-years, and the one-way flight time is 5.1 years.

So in order for Phaeton to get to Epsilon Eridani and back within the stated 10-year mission duration, we clearly see that the ship’s Orion Drive would have to propel her to over 90 percent the speed of light (.9c). For all the elements of Phaeton’s mission that might be practically attainable by the mid-21st Century, this is where a little science fiction enters the picture.

Thank you to Steve Cooperman, Doug Creel, and John Weiss for their helpful input and comments.

Question: How big an asteroid would be needed to completely destroy a planet?
That’s easy. It would have to be really, really big or moving very, very fast (or both for a real whopper of an impact), but there are some subtleties that are worth explaining.

First off, let’s admit that we’re really concerned with how big an asteroid would destroy planet Earth, especially life on Earth. I’m a bit more worried about my home planet than Mars, Jupiter, or even Pluto and even more worried about all the life we see around us (not to mention ourselves!). Earth is far more important from the human perspective, so let’s tackle that question.

Frighteningly, many large objects have hit Earth. Real whoppers. That’s a bit scary to think about. The good news is that the Earth is still here, so apparently large impacts of the planet-destruction kind rarely happen. We do know that smaller impacts have happened, such as the meteorite that hit the high Arizona desert just east of Flagstaff, at the site known as Meteor Crater. If we could count the impacts, we could gauge how frequently and when the impacts took place.

However, it is hard for us to find evidence of all the impact craters on Earth today. This is mainly due to erosion, which washes away the evidence by slowly filling in the craters, but looking at the Moon, where erosion is for all intents and purposes non-existent, we see that our nearest companion has been pummeled a lot, though mainly in the distant past. It, too, is still here and in one piece. The far side of the Moon, which always points away from the Earth, has a lot more craters than the side facing the Earth, which makes sense because the far side is more likely to be hit—it’s a bit harder for asteroids to sneak by the Earth and hit the shielded side of the Moon (though some have) than to hit the exposed side.

In fact, the Moon itself holds the key to what was probably the largest impact that the Earth has experienced (and hopefully will ever experience). Before I explain what we know about this biggest of all collisions, it is important to understand what we currently know about the formation of the solar system.

Stars form when dense and cold gas and dust that is prevalent in galaxies like the Milky Way slowly collapses under the influence of gravity. Astronomers see these forming stars just about everywhere we look—from regions practically next door, like the Orion Nebula, to the most distant galaxies we can see with the Hubble Space Telescope. As the star forms, a disk of leftover material takes shape through the combined effects of angular momentum and the force of gravity. These disks become fairly violent places as small particles of material slowly accumulate to form specks of dust, then pebbles, boulders, and ultimately planets. Astronomers have seen such disks in various stages of evolution with powerful telescopes.

Current models of planet formation gauge the time to go from a disk of gas and dust to a fully formed planetary system at about a million years, depending on the mass of gas and dust available and some other factors. Astronomers are not entirely sure how the process proceeds, but they have developed telescopes designed to peer through the material surrounding these forming stars to try and pin down the details. A prime example is the Spitzer Space Telescope, which observes in the infrared portion of the spectrum. Radio telescopes like the Very Large Array or the Atacama Large Millimeter Array (now under construction in Northern Chile) can also be used to effectively study the star- and planet-formation process, because the long-radio wavelengths they receive can escape the dense molecular clouds, unlike visible light.

It is now generally accepted that the Moon formed when a large, Mars-sized object crashed into the Earth very soon after the Earth itself formed. This collision dug deep into the Earth’s crust and threw off material from as deep as the Earth’s mantle into orbit where it was pulled together by its own gravity to form the Moon. This explains why rocks brought back from the Moon are composed of fairly lightweight minerals and rocks, containing little to no iron or nickel (metals found at the core of the Earth rather than the mantle). It also explains why the orbital plane of the Moon doesn’t line up with the orbital plane of the Earth itself (the impactor came from a different orbital plane). From dating the ages of rocks, geologists know the Earth is 4.65 billion years old, while the Moon is a bit younger, about 4.6 billion years old, evidently created in a subsequent massive collision.

So, in some sense, Earth wasn’t “destroyed” by an impact of an object the size of Mars that hit the Earth a somewhat glancing blow, but a more direct impact of an even more massive object could easily have had enough energy to seriously disrupt the Earth. Even so, in this case some kind of residual object would have formed, perhaps even two, and if life had taken hold after the planet and its companion cooled down, we might live in a true double planet system. Imagine looking up each night and seeing a blue companion planet in place of the Moon, with its own continents, weather, and oceans. That would be quite a sight.

What about life-ending impacts?
By studying the fossil record, geologists have identified sudden mass extinctions of species. They count the type and number of species in different layers of rock and can see when the number of species changes significantly. Two of the most significant extinction events are called the K-Pg boundary (a.k.a. the Cretaceous-Paleogene event) and the Permian-Triassic event.

The Permian-Triassic event took place about 251 million years ago. Although it is not entirely clear that major impacts caused this extinction, it is clear that the Earth’s life suffered an extreme setback. This extinction event led to the loss of 96% of marine species and 70% of terrestrial vertebrate species. Ponder this for a minute: This means that nearly all marine life was completely wiped out. More than two-thirds of all terrestrial animal species disappeared. Even many insect species—among the best survivors on the planet—were wiped out as well. This event is commonly referred to as the “Great Dying”—suffice to say it would not have been pleasant time to be alive. Although multiple impacts by large asteroids is a likely explanation for the Permian-Triassic event, there are other possibilities and research continues.

The K-Pg event took place 65.5 million years ago and is fairly clearly caused by the impact of a large asteroid. A thin layer of sediment with a high concentration of iridium was laid down around the world in a very short period of time. Iridium is very rare in the Earth’s crust, because it sank along with iron to the Earth’s core, but it’s often found in asteroids. There is also evidence of significant geologic activity around the time of this extinction event, which led to the loss of about 75% of all extant species, but most geologists believe it was caused by a giant impact near today’s Yucatan peninsula, forming the so-called Chicxulub crater. It is still not clear if the impact and its debris cloud (and tsunamis) were the sole cause of the extinctions or if secondary causes (chemical changes in the atmosphere or oceans) had a role to play. Again, research continues.

What can we take away from these extinction events? Life is both pretty tough and pretty disposable. Although life as a whole goes on, your species may not get a golden ticket. Impacts happen that can destroy most life on Earth. The good news is that life managed to survive and ultimately re-conquer the ocean and land, just not in the same forms that existed before. It is one of the amazing things about life on our planet that evolution guides both the long-term survival of life generally and the development (and extinction) of individual species. Life goes on, but any individual species may not.

Astronomers have begun multiple projects to scan the solar system and identify potential asteroids that might impact the Earth. Hopefully by identifying possible life-threatening objects, we could come together worldwide to somehow save ourselves (and all the other life on the planet). Right now, destroying or nudging an asteroid on a collision course would be a tremendous challenge, but it seems that impacts are few and far between, so we probably have enough time to develop the technology necessary for planetary protection.

My heroes are in a first-contact situation, meeting an alien face-to-face for the first time. How could my heroes and the alien learn to communicate with each other?
Both knowingly and unwittingly, humans have been broadcasting their presence to the Universe since the 1920s—when coherent transmissions in the radio portion of the electromagnetic spectrum became widespread. Our radio and television broadcasts do not stop at the edge of Earth’s atmosphere; rather they propagate into space at the speed of light. While these signals attenuate with distance, they are detectable nevertheless: NASA still regularly communicates with the twin Voyager spacecraft despite the fact that they are over 100 times further from the Sun than Earth and that each of which transmit data to Earth with less power than a common household light bulb. This means that an alien civilization as far away as 58 light-years could potentially be trying to make sense of “Lucy, you’ve got some ‘splainin’ to do!” (There are 105 G-type stars—ones like our own lovable Sol—within this I Love Lucy-sphere.)

Thirty-five years ago humans make the first and only significant attempt to say “Hello” to extraterrestrial civilizations. On November 16, 1974 the newly remodeled Arecibo radio telescope beamed a message into space. The signal was beamed into space only once, and it was aimed in the direction of the globular cluster M13, a collection of hundreds of thousands of stars 25,000 light-years away in the constellation Hercules. Because of proper motion, M13 will no longer be in position to receive that message 25,000 years from now, but another star system might.

The Arecibo message was beamed into space less because it was a legitimate attempt to make contact with an extraterrestrial civilization, and more as a test of new capabilities of the telescope. The message was 1679 bits of binary information. Presumably any alien species capable of telecommunication would figure out that 1679 is the product of 73 and 23, both of which are prime numbers, hinting at the intended interpretation of the broadcast: that it is actually is a matrix with 73 rows and 23 columns. One assumption behind the message is that any alien race receiving it will orient the matrix vertically instead of horizontally (23 by 73), which produces gibberish—or at least that they’ll examine both representations before giving up on it.

Contained in the Arecibo transmission are representations of the numbers one through ten in binary; the atomic numbers of the elements that form organic compounds which, in turn, form human beings; formulae of a few basic organic compounds; and graphical representations of a human, the Solar System, and the Arecibo antenna. All of the depictions were crude, at best. Even the binary digits one through ten were represented in such a way as to be non-obvious even to human beings familiar with binary. If an alien race actually receives that transmission, it will be easy to determine that it is of intelligent origin (omitting the obligatory gag about Earth not having intelligent life), but challenging to determine the actual intent of the message. The Arecibo message was unique: Although our radio and TV broadcasts “leak” into space, nobody is actively broadcasting signals with the idea of contacting extraterrestrial civilizations. Today we simply listen.

What if somebody responded?
What if one day aliens received a signal that we had transmitted into space, intentionally or otherwise? What if they decided to invite themselves over for a visit? What if they decided not to land on the front lawn of the White House, instead landing on the front lawn of your house? Assuming that the aliens did not know your language, how would you attempt communication? Should you attempt communication?

In movies and on television first contact scenarios often seem so… easy. That’s usually, at least in part, because the heroes in science fiction stories have access to some device that functions as a universal translator—that translates between most known (and previously unknown) languages. Even if the translator is of biological origin like a fish (Hitchhiker’s Guide to the Galaxy) or a colony of bacteria (Farscape), it’s still a device—a plot device that we generally accept in sci-fi like FTL travel or artificial gravity. It makes sense from a storytelling standpoint.

In an episode of Star Trek: The Next Generation, Captain Picard must learn to communicate with the captain of an alien vessel who speaks entirely in cultural references. While this can be compelling for a lone episode, in series like Star Trek or Stargate it would be dramatically unfulfilling if we had to wait, week after week, while our heroes attempt to communicate with yet another new alien race.

It’s an obvious understatement to say that language is complex—what is startling is how difficult it is to convey even the most basic of concepts to somebody with no known reference points. Everything that you say is fraught with assumptions. Imagine that you walk up to a random stranger on a street corner and say, “Hello. How are you?” What assumption could lie behind such an innocuous greeting? Perhaps it’s more obvious if we rephrase the question. If you walked up to the very same person and said, “Guten Tag. Wie geht’s?” You have made the obvious assumption that the person speaks German which may or may not be a good one. The assumption that other humans with whom we’d like to communicate have shared experiences is a good one. With an alien race, it is not an assumption you can make.

It gets worse. Most language has cultural colloquialisms that make accurate translation even more difficult. Even though a universal translator might function well on a word-by-word basis, it’s still doubtful that meaningful dialogue between humans and alien races would rapidly ensue when we consider even the most common cultural influences upon language. For example if somebody who spoke German as a native language spoke into a universal translator and said, “Er is sehr blau” in reference to your mutual friend, you may think that your friend is feeling depressed—the literal translation is “He is very blue.” You wouldn’t figure out, other than perhaps by visual observation, that your mutual friend is drunk, which was the actual implication of the statement in German. “Blue” means depressed in English, inebriated in German, and in neither case would the connotation of that sentence be, “He is reflecting short-wavelength visible light.”

When the Pioneer 10 and 11 spacecraft were launched in 1972 and 1973, they carried human greetings to any alien civilization who may find the craft one day. Each craft carries a plaque that has diagrams of, among other things, a human male and female, the Solar System, and the spacecraft’s origin. The man has his hand raised in what is supposed to be a friendly gesture, but even this has a cultural bias. It could equally be interpreted as hostile: “You want a piece of this? Come to my planet and I’m going to slap you senseless.” In fact, one argument against affixing the plaques to the Pioneer spacecraft was that it sends the very clear message, “Here are the directions to the restaurant, and here’s what’s on the menu.”

Which brings us back to the spacecraft sitting in your front yard, and the alien beings who have exited the craft and who are now standing before you. If Earth’s history can be used as a template, first-contact scenarios between cultures possessing drastically different levels of technology often end badly for those in the low-tech population. It would, however, probably be reasonable to assume that if the aliens wanted you for dinner, you’d already be in their oven. Or on their plate. Or in their equivalent of a stomach. If they wanted you as slave labor, given the proximity, it’s probably too late for you on that score as well. Nevertheless, the first goal in any such encounter should be, first and foremost, your survival. It might be a good assumption that the aliens are on a heightened state of alert—that they are wary of what you may do simply out of a fear response. Waving “Hello” like the man on the Pioneer plaque is perhaps not a wise move. Slowly turning your hands so that your open palms face the aliens might be a better choice. Presumably if the aliens can get all the way to Earth from their home, they are intelligent enough to look beyond any cultural insult this gesture may cause, and recognize that what you mean is that you are not carrying a weapon. Making all motions and gestures slow and deliberate would not be a bad idea.

If the aliens did, in fact, wish to achieve any meaningful dialogue, the goal in any interplanetary communications, then, would be to find a common ground with a minimum of assumptions and colloquialisms. Whether or not this is an attainable goal is another question. If the situation were reversed, and it was human beings who had just landed at an alien being’s home, presumably we would have done our homework first—doing either remote or in situ observations to smooth over a first-contact scenario. They may have also have experience, having done this once or twice before. So the best communication strategy might simply be to let the culture with the highest level of technology take the lead while the low-tech participants concentrate on staying alive. In the end, it’s probably best to let the alien initiate communication, even if it is simply, “Take me to your leader.”

What is the most likely form an alien would take?
Life’s architecture is difficult to predict because it depends on many factors involving the interaction of the environment and life through evolution and natural selection. We can, however, make some generalizations based on the vast number of morphological forms that life takes on earth.

Life on earth ranges from microscopic spheres and rods to macroscopic creatures exhibiting wide variations in their morphologies (e.g., spiders to humans). Nevertheless, nearly all life (everything except sponges) exhibits symmetry—either bilateral or radial symmetry. In bilateral symmetry (also called plane symmetry), only one plane, called the sagittal plane, will divide an organism into roughly mirror image halves. An organism with radial symmetry has no left or right sides, only a top and a bottom (dorsal and ventral surface). An alien life form, therefore, would most likely be symmetrical. The type of symmetry would be influenced on the environment in which it lived. From our basic knowledge of survival of macroscopic organisms whether they be aquatic or terrestrial it seems that bilateral symmetry dominates.

The possession of other specific attributes (e.g., ability to hear, see, smell, move, etc.) depends on the environment and competition for resources for survival. For example, when we think of “seeing,” we think of “eyes” first. But if we think of the function (sensing specific wavelengths of light) rather than the specific physical attribute, it opens a plethora of ways in which we can imagine “seeing,” ranging from the photosensors for phototaxis in bacteria to the compound eyes of some insects. The uses to which life puts its sensory perception mechanism of light ranges from finding food to escaping from predators. It would seem logical that an alien would have some type of light sensory perception mechanism if it lived on the surface of a planet. What the physical make-up and appearance of that light sensory perception mechanism would be is difficult to define. The perception of light is not just limited to the type of perception just described, that is, “seeing”, but also to perception by photopigments (e.g., chlorophylls) used for capturing light energy to produce cellular energy for use by the organism (i.e., photosynthesis).

Following this line of logic, the form that an alien would take is the form that makes it survive and reproduce best in its environment. If I had to make a guess it would be that it would have symmetry (probably bilateral symmetry), capable of light perception, and probably motile (increases chances of finding nutrients and escaping predators). To say anything more specific would require knowing the planetary environment in which it lived.

What about the form of an intelligent alien, specifically? Would it even need to have a solid form?
First, what is intelligence? As defined by H. J. Jerison, intelligence is the behavioral consequence of the total neural-information processing capacity in representative adults of a species, adjusted for the capacity to control routine bodily functions. This can be related to encephalization. Encephalization is defined as the amount of brain mass exceeding that related to an animal’s total body mass. Quantifying encephalization has been argued to be directly related to that animal’s level of intelligence. Brain-to-body mass ratio (also known as the encephalization quotient, or EQ) is a rough estimate of the possible intelligence of an organism, and is defined as the ratio of the actual brain mass to the expected brain mass of a typical organism that size. On average, the larger an organism is, the more brain mass is required for basic survival tasks, such as breathing and thermoregulation. Therefore, the larger the brain relative to the body, the more brain mass should be available for more complex cognitive tasks. It has been shown that dolphins, which have the highest brain-to-body mass ratio of all cetaceans, are able to communicate with each other and are thought to be intelligent to some degree. Humans have a higher brain-to-body mass ratio than dolphins.

To this day there is no broadly definition of “life”. The Darwinian, or genetic, definition of life is the most accepted today. It holds that life is self-sustained chemical system capable of undergoing evolution by natural selection. Applying this definition to life suggests that it would be a solid form.

Would/will we recognize an alien transmission right away? Is there a chance we could miss such a transmission, or they ours?

We will recognize the sorts of electromagnetic signals for which we have built good matched filters: nanosecond optical laser pulses, narrowband radio continuous wave or pulsed signals. If signals are of some other type (e.g., a modulation scheme with higher dimensionality, or something other than electromagnetic waves) then we will not detect them, except by serendipity as we build new instruments to study our universe in different ways, or by using increasing computational power to look for more complex types of electromagnetic signals.

If signals are transmitted via a technology that we haven’t yet invented, we will miss them until we manage to invent the appropriate technology (remember that we are a very young technology (~100 years) in a very old galaxy (~10 billion years). I suspect we have a lot more to learn.

We could also miss signals in time. If technological civilizations and their signals are short lived, we might be searching for exactly the right thing, but long after the signals have come and gone. Likewise, if we do not manage to continue as a technological civilization for a very long time, then any transmission project that we might decide to embark on would have little likelihood of being detected by anyone else.

I continually tell groups containing grad students and post-docs (who touch more data than the rest of us) to resist the temptation to edit out anomalies until they have first satisfied themselves that it isn’t a real effect, perhaps the artifact of someone else’s astroengineering or signaling project—but in truth, it’s very hard to train someone to be a Jocelyn Bell [who discovered pulsars as a post-doc].

There’s no way to estimate what we might be missing.

Will we understand alien communication, and vice versa?

People argue that mathematics is essential for a technology that can create and operate some sort of transmitter. Therefore a language based on mathematics should be mutually understandable, and in 1960 Hans Feudenthal created such a language he called Lincos (for “lingua cosmica”). Another suggestion is a language based on the period table of elements that are (we think) the same throughout the universe; this idea has been pursued by Carl L. Devito. If the signal is electromagnetic, the wavelength of the transmitted signal serves as a common unit of measurement between sender and receiver; you might describe yourself as being N wavelengths tall. Of course it is hard for us to think in any way except the way we do—it might be that another intelligent species with the capability of manipulating its environment to create a transmitter that we can detect could still perceive their environment in such a different way that it might be impossible to find a common ground for describing the same thing. But all of this is a problem that I’d like to have, and I don’t doubt that there would be many other individuals around the globe just as eager to help unravel any information from a detected signal. An old Southern cookbook starts a recipe by saying, “To cook a possum, you must first catch a possum.”

That’s my personal approach to SETI—it’s the detection of a signal that we must work on first. Even if there were no information encoded within a detected signal, or even if we can never decode it, the detection of a signal answers the old important question “Are we alone?” Even a cosmic dial tone tells us something else implicitly: It tells us that there’s a high probability that we can have a long technological future, because technologies must, on average, be long lived. Otherwise we would never overlap in time with another technological civilization, and the detection would not have occurred.

Philip Morrison used to put this most poetically—he called SETI “the archaeology of the future.” Because of the finite speed of light, a detected electromagnetic signal will give us information about their past, but it will tell us about our future.

Our first expert-answered Codex question goes to J Storrs Hall, an independent scientist and author who’s also president of the Foresight Institute, a nanotech-oriented think tank. Thanks especially to Jennifer Ouellette, a science writer and the director of SEEx, for connecting us with Hall. Without further ado, here’s the question of the day, asked by an (imagined) big-time Hollywood director/producer who thinks getting the science right might help nail down that elusive Oscar:

“How could nanotechnology transform the world? Most importantly, how could I stop a plague of nanorobots from eating my spaceship/research facility/planet?”

Nanotechnology is going to transform the physical world in much the same way that computers and the Internet have transformed the informational world. In the long run, that means that physical things like cars and houses will see the rates of improvement that we are used to with computers. New capabilities, such as super-light, super-tough materials, will appear.

Existing capabilities that are expensive, such as photovoltaic solar cells, will become cheap enough for everyone to use. In some cases, these both will happen—it might, for example, be possible to surface the roads with photovoltaics that are tough enough to drive on but gather enough energy to power your car as it goes.

The latter half of the 20th Century was one of the most exciting times in the history of science, because it brought the solution to one of the great mysteries: the nature of life. We discovered that the almost magical properties of living things—the abilities to grow, heal, and reproduce—were because they were full of molecular machinery. (The fourth property of life, burning fuel to power useful motion, was captured in the Industrial Revolution.) Nanotechnology research and development is slowly unraveling the principles and techniques by which we will ultimately engineer new molecular machines that will be able to make high-tech products as cheaply and cleanly as biology makes potatoes.

Plagues of nanorobots, under the name of “gray goo,” were first considered in detail by the Nanotechnology Study Group at MIT in the 1980s. Their concern was that these would be mechanical bacteria. Of course, the whole Earth is covered with biological bacteria, just as small, with machinery just as molecular, as anything nanotechnology could ever make. So why was anyone worrying about a few more mechanical ones?

The main worry was that the mechanical version might be more efficient and thus more dangerous. A car can go 10 times as fast as a horse. Perhaps a mechanical bacterium could be faster, tougher, or more efficient than a biological one.

On further analysis, it turned out that the situation wasn’t that simple. Horses eat hay and grain and leaves and other naturally occurring energy sources, while cars need highly refined and expensive fuel. One reason cars are more efficient is that their “digestion” is outsourced to refineries.

Similarly, cars outsource their healing to repair shops and their reproduction to factories. They need roads and other infrastructure to be built for them. Any sensibly designed nanorobot would work the same way, for the same reason: It’s much more efficient. But that leaves the nanorobot, like the car, completely unable to go foraging in the wild and form a “plague.”

Imagine trying to build a car that ran on hay which it harvested itself, graded its own roads, made its own parts with which it repaired itself, and built new cars. Plagues of nanorobots are about as likely as plagues of hay-eating cars. And in the unlikely eventuality someone ever actually did build them, such nanorobots wouldn’t be much more efficient than bacteria, and could be controlled easily by efficient, faster, more powerful, fuel-using, non-reproducing nanomachines.  — J Storrs Hall

In the most recent issue of Nature, there are two papers…that detail the characteristics of sodium and lithium under extreme pressure. Specifically, these two metals adopt semiconductor-like (even superconductor-like) characteristics if you subject them to giga-pressure (literally, 80-200 gigapascals). The sodium actually becomes optically transparent during this squeeze. Reading this reminded me of a Star Trek [movie] that involved a not-so-scientific explanation of “transparent aluminum” …Is the idea of using transparent metal for windows pure science fiction?

The paper you’re talking about, the one on high pressure sodium, sure did make a lot of noise in the science world, and for good reason. Drs. Yanming Ma and Artem Oganov at SUNY Stonybrook showed that  lithium and sodium do goofy things under pressure — like turn transparent. Normally under really high pressure, elements turn into metals, c.f. hydrogen. The science makes intuitive sense because the atoms are getting smooshed together as the pressure increases. The electrons are freed to become conductors, and the element takes a metal-like structure. But in sodium, it turns out, the electrons line up into columns, one on top of the other. This creates gaps between the atoms, and instead of becoming a conductor, it becomes an insulator, and, conicidentally,  becomes transparent.

All of which is cool, but it doesn’t really answer Michael D’s question, because the sodium is under 200 gigapasacals of pressure, the sort of pressure you find if you were journeying from Jupiter’s surface toward its core, not hanging out on the bridge of the Enterprise.

And yet! That formula Scotty gave for transparent aluminum in Star Trek IV: The Voyage Home very nearly exists in the form of aluminum oxynitride  (known as ALONtm). Harder than diamond, ALONtm is far more shock resistant than even bullet resistant glass. In Air Force tests it has resisted multiple rounds from a .50 caliber sniper rifle. That hardness also prevents wear and tear, since neither sand nor rocks nor shrapnel in the night will scratch the stuff.

In practical use, the ALONtm would be the outer layer for windscreens of cockpit covers. It would be backed by a thin layer of glass and a layer of transparent polymer to prevent shattering. All together the ALONtm windscreen would be thinner and lighter than a traditional bullet-resistant windscreen.What’s unclear from my research is whether it would be strong enough to hold back enough water to make the aquarium for all those humpbacks whales on a captured Klingon spaceship, but it’s a start.

The main downside? It’s wicked expensive. Traditional bullet resistant glass goes for $3 per inch-squared, but ALONtm costs between $10-$15, or it did back in 2005.  I can’t seem to find any more current applications for it, but this is the military, it could be classified.

Anyway Michael D., I hope that answers your question.

I want to have a teleporter in my story. How would one work?

The good news is that a working teleportation device already exists. The bad news is that it won’t work for you if you happen to be bigger than a rubidium atom—but scientists are toiling away to fix that. As physicist Michio Kaku noted last year in DISCOVER, we could be teleporting things as big as a virus within a few decades, which means we would be ready teleport a person around the 23rd century, just in time for the predicted construction date of Captain Kirk’s Enterprise.

The key to teleportation is to realize that we don’t want to use it as some kind of “matter transporter.” The kind of everyday matter that makes up you, me, and the planet, is made up of protons, neutrons and electrons. Quantum physics tells us that every proton is identical to every other proton, every neutron is identical to every other neutron, and the same holds for electrons too. What’s important are not the particular particles that make up our bodies, but the way those particles are arranged into atoms, molecules, and cells. Duplicate the arrangement, and you duplicate the person.

The situation is analogous to what happens when a scene is captured by a TV camera and transmitted to a screen somewhere else. We’re not interested in somehow transporting the actual photons that entered the camera’s lens to the eyes of the viewer. Instead, the camera records the pattern the incoming light makes. Information that describes this pattern is transmitted to viewer’s screen, where a brand new set of photons are produced with the desired color and intensity. These convey the image of the scene to the eye. What’s important is preserving and transmitting the pattern of information, not the original photons.

The key to transmitting the information pattern of solid matter, as opposed to an two-dimensional image made of photons, is a spooky phenomenon known as quantum entanglement. It turns out that particles can be in a number of different states, and big part of the weirdness of quantum mechanics is that these states are undefined until they are somehow measured. Imagine tossing a coin and catching it. In the quantum world, not until you peek at the coin does it decide to be heads up or tails up! Entanglement means taking two particles and treating them together in such a way that their states become mingled. The states of the particles are still undefined until measured, but now making a measurement of one particle’s state will instantly determine the state of both particles, not just one. This holds true, even if you took one of the entangled particles and moved it to the other side of the solar system before performing the measurement.

Incidentally, Einstein loathed this idea, and it was one of the things that turned him away from quantum mechanics and towards a more-or-less dead end approach to physics in his later years. But thanks to a piece of quantum theory known as “Bell’s inequalities” along with entanglement experiments conducted in Paris in the 1980’s, Einstein was proved to be wrong.

Entanglement makes teleportation possible like this: first create an entangled pair of particles, say two atoms. We’ll call one atom “the pitcher,” and the other “the catcher” (This is not standard physics terminology). Now move the catcher to wherever you want to teleport to. This must be done very carefully to avoid destroying the entanglement. Now let’s take an atom that we want to teleport. This atom has a particular internal arrangement of electrons, neutron and protons that somehow makes it special to us—we’ll call it the Scotty atom. We put the Scotty atom into a chamber containing the pitcher atom. The states of the Scotty and pitcher atoms are combined and then measured. This combination process scrambles the state of the Scotty and pitcher atoms, putting them into random states.

So far, it looks like all you’ve done is put a perfectly good Scotty particle into a quantum shredder—the arrangement that made it special has been destroyed. But now you take the measurements of those scrambled random states and transmit them (in theory this could be done by radio, or any other method you can think of) to wherever the catcher atom is located. A regular, run-of-the-mill, atom is pushed into a chamber with the catcher atom. We’ll call this new, boring, atom the Tabula Rasa atom. The information about the random states that we measured after the Scotty and pitcher atoms were combined is also fed into the chamber. Presto—the Tabula Rasa atom takes on all the attributes of the Scotty atom. To all intents and purposes it is the Scotty atom.

Scientists are working on scaling up the process so that it works on larger and larger scales, hoping to move up from atoms to molecules, molecules to cells, and maybe one day, entire people. But the basic process is the same as for a single atom.

Note that in some ways the process is similar to what happens on Star Trek—teleporting someone requires disintegrating their body. There’s no way to teleport someone and leave their original body intact—the person can’t exist at the pitcher and catcher ends at the same time. Teleportation cannot be used to make copies of a person. In quantum mechanics this restriction is known as the “no cloning theorem.” In some ways however, teleportation is quite different to Star Trek—it requires quite a bit of preparation and equipment at both ends of the process—you can’t just appear on the surface of a planet you’ve never visited before.

But you could imagine this being used as a way to travel to distant solar systems—a robot probe with a supply of entangled particles could be sent out on the decades, or centuries long, journey required to travel between stars. Once it arrived at it destination, explorers would step into a teleportation chamber on Earth containing the entangled pairs of the particles sent with the probe. Their bodies would be destroyed, but information about them would be transmitted by radio at the speed of light to the probe. The probe would receive the information, and reconstitute the explorers. Of course, if anything happened to break the chain of transmission, or to disturb the entangled particles before the right time, the explorers would be killed. But if everything worked, to them it would feel like going from Earth to an alien world in the blink of an eye.

We’re here to help. In the comments below, fire away with your science questions about any sci fi book, TV show, movie, radio play, comic, or whatever that you can think of, and we’ll set about answering as many as we can in upcoming posts as part of our Codex Futurius project.

Bear in mind, we yearn to answer science questions. We’re relatively useless for fielding pop entertainment rumors or speculating on why Starbuck keeps having weird visions. But the science of Sci Fi? Bring it on.

I want Superheroes in my story, all with amazing powers. I also want a good explanation for their origin: could genetic mutation or manipulation create a superhuman?

The short answer is yes, within limits. Billions of years of evolution have produced a vast number of abilities in different animals that are beyond the gift of any normal human. Dogs have noses stuffed with olfactory receptors that make them 100 to 1,000 times as sensitive as humans to scents. Fish that swim in the Antarctic Ocean have natural anti-freeze molecules in their cells that allow them to thrive in water that is so cold it would kill a human within minutes. Many insects can see ultraviolet frequencies of light that are invisible to us, giving them a very different view of nature.

Because all life on Earth uses the same genetic code, in theory anything that you can find in nature is up for grabs. For example, the blood cells of crocodiles contain a type of hemoglobin that is so efficient at oxygenating a crocodile’s body that the crocodile can lurk underwater for an hour without coming up for air. Researchers have been able to tweak the DNA responsible for producing human hemoglobin to incorporate some of the genetic instructions found in crocodiles, thereby creating more efficient human hemoglobin. This superhuman hemoglobin is currently only produced by bacteria in vats and is intended for medical applications, but in principle it could be engineered into human being, giving them Aquaman-like powers.

There are certain physiological limits to what you can borrow, (for example, angel-sized wings on a human being would still be too underpowered to allow him or her to fly. If you really want a character to have working wings, a more radical rearrangement of the superhero’s body plan would be required) but nonetheless scientists have been taking useful traits from one organism and engineering them other organisms for decades now—a famous example is a gene found in the crystal jellyfish that produces a protein that fluoresces, giving off green light. This gene has been used to create “glow-in-the-dark” rabbits, fish, cats, mice and more. You’re not limited to transferring genes between animals either—you can mix and match between bacteria, animals and plants.

This technology is known as transgenics, and it was first demonstrated in 1973. It—along with other advances in genetic engineering—so freaked scientists out at the time that they agreed to a voluntary moratorium on any related experiments until an international conference—the Asilomar Conference on Recombinant DNA—was held in 1975 to establish the rules under which research would be conducted. These rules included a list of prohibited experiments that were deemed to be too dangerous as they might result in horrible scenarios, such as the release of deadly new diseases into the wild.

The big technical problem with transgenics is getting the desired new genetic material into an organism’s cells. With adult creatures, the techniques of “somatic gene therapy” could be used. In a nutshell, this involves taking a infectious agent, such as a virus, and modifying it to transport the desired new DNA into the subject’s cells. With some agents, known as retroviruses, the new DNA is integrated into the cell’s genome, along with the rest of the cell’s native DNA. This means that as long as the cell is alive, the altered DNA will continue to function, and if the cell divides, the new DNA will be passed onto to its daughter cells. Other methods of delivery do not integrate the new DNA into the cell’s genome, meaning that the effectiveness of the therapy can decline over time, as the host body makes new cells without the modified instructions.

Gene therapy is promising in theory, and there have been some early successes in treating genetic diseases, but there also have been some disasters. Cancer is a possible side effect. There is also always the risk of triggering a massive immune response, which is what killed the most famous victim of gene therapy-gone-bad, 18-year-old Jesse Gelsinger. He died of multiple organ failure within four days of receiving an experimental gene therapy intended to treat his liver disease.

If you are willing to ignore a lot of laws, you could do away with gene therapy and start with a human egg. Developing an egg fertilized with altered DNA into a baby would automatically mean that every cell in the subject’s body would have the new genetic material, and could pass those genes on to his or her descendants. This situation is analogous to what occurs when a natural mutation arises, and can also give rise to extraordinary abilities. For example, in 2005, DISCOVER reported on a six-year-old boy, dubbed “Superboy” who was born with bulging muscles. By age six, he could easily lift two seven-pound weights with arms held out horizontally. Researchers identified the cause of his super strength as being due to a mutated gene for myostatin, a growth factor that tells muscles when to stop growing.

Why not give all our children the gene for superstrength? Or a gene related to higher intelligence? The problem is that when we go beyond treating a disease and trying to enhance humans in this way, we would lose a vast amount of genetic diversity, which would sooner or later come back to bite us in the ass. Genetic diversity is so important to the survival of higher life forms that it prompted the evolution of sex, despite all of the drawbacks and effort involved in trying to find a mate.

Sex is a great way to let a species constantly shuffle and recombine DNA from a pool of genes. This helps us keep one step ahead of all sorts of challenges, including pathogens. If we selected a handful of favored genes, and spread them throughout the population at the expense of other genes, we would be at risk of creating a human genetic monoculture. Monocultures are notoriously prone to falling prey to epidemics of disease, as occurred in Ireland in the 19th century when the dominant strain of potatoes turned out to be very susceptible to blight. The resulting famine killed a million people.

But what about giving your superhero powers beyond those found in nature, like the ability to shoot a freeze-ray from their hands or telekinesis? There we must step beyond the bounds of pure genetic engineering and start using nanotechnology or cybernetic modifications, both of which will be the subject of future Codex Futurius entries.