Nemesis

Nemesis

Isaac Asimov

Remaining

Marlene smiled hesitantly at Siever Genarr. She had grown used to invading his office at will.

“Am I interrupting you at a busy time, Uncle Siever?”

“No, dear, this is not really a busy job. It was devised so that Pitt could get of me, and I took it and kept it son that I could be rid of Pitt. It's not something I would admit to everyone, but I'm compelled to tell you the truth since you always spot the lie.”

“Does that frighten you, Uncle Siever? It frightened Commissioner Pitt, and it would have frightened Aurinel – if I had ever let him see what I could do.”

“It doesn't frighten me, Marlene, because I've given up, you see. I've just made up my mind that I'm made of glass as far as you're concerned. Actually, it's restful. Lying is hard work when you stop to think about it. If people were really lazy, they'd never lie.”

Marlene smiled again. “Is that why like me? Because I make it possible for you to be lazy?”

“Can't you tell?”

“No. I can tell you like me, but I can't tell why you like me. The way you hold yourself shows you like me, but the reason is hidden inside your mind and all I can get about that are vague feelings sometimes. I can't quite reach in there.” She thought for a while. “Sometimes I wish I could.”

“Be glad you can't. Minds are dirty, dank, uncomfortable places.”

“Why do you say that, Uncle Siever?”

“Experience. I don't have your natural ability, but I've been around people for much longer than you have. Do you like the inside of your own mind, Marlene?”

Marlene looked surprised. “I don't know. Why shouldn't I?”

“Do you like everything you think? Everything you imagine? Every impulse you have? Be honest, now. Even though I can't read you, be honest.”

“Well, sometimes I think silly things, or mean things. Sometimes I get angry and think of doing things I wouldn't really do. But not often, really.”

“Not often? Don't forget that you're used to your own mind. You hardly sense it. It's like the clothes you wear. You don't feel the touch of them because you're so used to their being there. Your hair curls down the back of your neck, but you don't notice. If someone else's hair touched the back of your neck, it would itch and be unbearable. Someone else's mind might think thoughts no worse than yours, but they would be someone else's might not like my liking you – if you knew why I lied you. It is much better and more peaceful to accept my liking you as something that exists, and not scour my mind for reasons.”

And inevitable, Marlene said, “Why? Where are the reasons?”

“Well, I like you because once I was you.”

“What do you mean?”

“ I don't mean I was a young lady with beautiful eyes and the gift of perception. I mean I was young and thought I was plain and that everyone disliked me for being plain. And I knew I was intelligent, and I couldn't understand why everyone didn't like me for being intelligent. It seemed unfair to be scorned for a bad property while a good property was ignored.”

Training. Photo by Elena.

Language of Dreams

The Language of Dreams

(By Ray Kurzweil, excerpt from How to Create a Mind)

Dreams are examples of undirected thoughts. They make a certain amount of sense because the phenomenon of one thought's triggering another is based on the actual linkages of patterns in our neocortex. To the extent that a dream does not make sense, we attempt to fix it through our ability to confabulate. Split-brain patients (whose corpus callosum, which connects the two hemispheres of the brain, is severed or damaged) will confabulate (make up) explanations with their left brain – which controls the speech center – to explain what the right brain just did with input that the left brain did not have access to. We confabulate all the time in explaining the outcome of events. If you want a good example of this, just tune in to the daily commentary on the movement of financial markets. No matter how the markets perform, it's always possible to come up with a good explanation for why it happened, and such after-the-fact commentary is plentiful. Of course, if these commentators really understood the markets, they wouldn't have to waste their time doing commentary.

The act of confabulating is of course also done in the neocortex, which is good at coming up with stories and explanations that meet certain constraints. We do that whenever we retell a story. We will fill in details that may not be available or that we may have forgotten so that the story makes more sense. That is why stories change over time as they are told over and over again by new storytellers with perhaps different agendas. As spoken languages led to written language, however, we had a technology that could record a definitive version of a story and prevent this sort of drift.

The actual content of a dream, to the extent that we remember it, is again a sequence of patterns. These patterns represent constraints in a story; we then confabulate a story that fits these constraints. The version of the dream that we retell (even if only to ourselves silently) is this confabulation. As we recount a dream we trigger cascades of patterns that fill in the actual dream as we originally experienced it.

Because important things go in a case, you've got a skill for your brain, a plastic sleeve for your comb, and a wallet for your money (George Costanza in The Reverse Peephole, episode of Seinfeld. Photo by Elena. Push, the cat.

There is one key difference between dream thoughts and our thinking while awake. One of the lessons we learn in life is that certain actions, even thoughts, are not permissible in the real world. For example, we learn that we cannot immediately fulfill our desires. There are rules against grabbing the money in the cash register at a store, and constraints on interacting with a person to whom we may be physically attracted. We also learn that certain thoughts are not permissible because they are culturally forbidden. As we learn professional skills, we learn the ways of thinking that are recognized and rewarded in our professions, and thereby avoid patterns of thought that might betray the methods and norms of the profession. Many of these taboos are worthwhile, as they enforce social order and consolidate progress. However, they can also prevent progress by enforcing an unproductive orthodoxy. Such orthodoxy is precisely what Einstein left behind when he tried to ride a light beam with his thought experiments.

Cultural rules are enforced in the neocortex with help from the old brain, especially the amygdala. Every thought we have triggers other thoughts, and some of them will relate to associated dangers. We learn, for example, that breaking a cultural norm even in our private thoughts can lead to ostracism. Which the neocortex realizes threatens our well-being. If we entertain such thoughts, the amygdala is triggered, and that generates fear, which generally leads to terminating that thought.

In dreams, however, these taboos are relaxed, and we will often dream about matters that are culturally, sexually, or professionally forbidden. It is as if our brain realizes that we are not an actual actor in the world while dreaming. Freud wrote about this phenomenon but also noted that we will disguise such dangerous thoughts, at least when we attempt to recall them, so that the awake brain continues to be protected from them.

Relaxing professional taboos turns out to be useful for creative problem solving. We may use a mental technique each night in which we may think about a particular problem before we go to sleep. This triggers sequences of thoughts that will continue into our dreams. One we are dreaming, we can think – dream – about solutions to the problem without the burden of the professional restraints we carry during the day. We can then access these dream thoughts in the morning while in an in-between state of dreaming and being awake, sometimes referred to as “lucid dreaming”.

Freud also famously wrote about the ability to gain insight into a person's psychology by interpreting dreams. There is of course a vast literature on all aspects of this theory, but the fundamental notion of gaining insight into ourselves through examination of our dreams makes sense. Our dreams are created by our neocortex, and thus their substance can be revealing of the content and connections found there. The relaxation of the constraints on our thinking that exist while we are awake is also useful in revealing neocortical content that we otherwise would be unable to access directly. It is also reasonable to conclude that the patterns that end up in our dreams represent important matters to us and thereby clues in understanding our unresolved desires and fears.

I have an old brain but a terrific memory (Al Lewis).  Illustration by Elena.

Extraterrestrials: Where Are They?

Where Are They?

Enrico Fermi was a brilliant Italian physicist who is known to the public as the man who led the team that first harnessed nuclear power under Stagg Field in Chicago on December 2, 1942. His impact in physics was actually much broader than that, and he has been honored (among many other tributes) by posthumously lending his name to the Fermi National Accelerator Laboratory. America's preeminent laboratory for studying the basic building blocks of the universe. In addition to sheer brilliance, Fermi had a gift for trying to ge at the bottom line, using simple estimators. Physicists call “a Fermi Problem” a question that is easy to ask, hard to know definitively, but able to be estimated by thinking it through. The most repeated example of a Fermi Problem is “How many piano tuners are there in Chicago?” By knowing the number of people in the city and then estimating how many households have a piano, how long a piano holds its tune, how long it takes to tune a piano, and the length of a work week, you can come up with a reasonable estimated answer (current estimate, about 125).

Fermi lived in an elite academic world – an active mind surrounded by others of similar caliber. They would talk about all manner of things, looking at them from every angle, trying to get at the truth. From a casual lunchtime conversation, one of the most famous questions involving extraterrestrials was asked. The story goes something like this.

One summer day in 1950, Enrico Fermi was visiting the Los Alamos Laboratory, which had been the secret government facility at which much of the first nuclear weapons had been developed. He and three companions one of who was Edward Teller, were on their way to lunch. They were talking about a cartoon seen in the May 20 issue of The New Yorker, which explained a recent spate of thefts and trash cans in New York City as being perpetrated by Aliens taking them into their flying saucers. (The UFO mania of the late 1940s was still fresh in the public's mind). The conversation then meandered to Teller and Fermi bantering back and forth over the chances of mankind exceeding the speed of light in the next decade, with Teller suggesting a chance in a million and Fermi guessing 10%. During the stroll, the numbers changed as they intellectually fenced.

After sitting down to lunch, the conversation went in a different direction, with Fermi sitting there quietly. Fermi then suddenly burst out, saying “Where is everybody?” to general laughter, as they all instantly understood that he was talking about extraterrestrials.

The premise of Fermi's paradox is the following. The Milky Way is about 13 billion years old and contains between 200 and 400 billion stars. Our own sun is only a little over 4 billion years old, suggesting that there have been stars around for a very long time. If Aliens are common in the galaxy, there has been plenty of time for them to have evolved – perhaps hundreds of millions of years or more before humanity – and have visited Earth. So where are they?

To figure out what sorts of data are needed, it is helpful to have a guiding paradigm. Photo by Elena.

While Fermi's outburst in the origin of the paradox, the question was revisited in 1975 by Michael Hart (leading some to call this the Fermi-Hart Paradox). Hart published “An Explanation for the Absence of Extraterrestrial Life on Earth” in the Quarterly Journal of the Royal Astronomical Society. In this article, he explored some of the reasons why we hadn't contacted yet, from reasons of simple disinterest of the Aliens to either colonize the galaxy or to contact us to the idea that the Earth is being treated as a nature preserve. Perhaps some form of Star Trek's Prime Directive applies, whereby civilizations are not contacted until they develop the capability for interstellar travel. These kinds of explanations were offered in The Day the Earth Stood Still and, of course, Star Trek. What Hart was able to show was that technology wasn't the problem. Taking some simple assumptions, Hart showed that a civilization that sent out two craft traveling at 10% of the speed of light to nearby stars and then spent a few hundred years developing infrastructure to build another pair of slow-moving starships could completely populate the Milky Way in just a couple of millions years.

If intelligent extraterrestrial life is even slightly common in the galaxy and only a few species have mankind's curiosity and exploratory nature, it seems that we would know by now that we are not alone. Hard concluded that it was a distinct possibility that mankind might well be one of the earliest-developing intelligent species in the galaxy. In short, The X-Files tagline “We are not alone” could well be gravely incorrect.

Of course, the answer to the question is unknown and hence the reason why the term “paradox” is applied to it. Another Steven Webb explored the question in his delightful 2002 book If the Universe Is Teeming with Aliens, Where Is Everybody? Fifty Solutions to Fermi's Paradox and the Problem of Extraterrestrial Life. Peter Ward and Donald Brownlee's 2003 book Rare Earth: Why Complex Life Is Uncommon in the Universe is equally enjoyable, and this book takes the position that it is difficult for a planet to develop intelligent life. The book describes the many ways in which planetary disaster can interrupt the development of sentient life on a planet.

No matter how carefully thought out, arguments of the sorts advanced in these books and others like them must defer to data.

Given the fact that there are stars that are billion of years older than the sun, it seems impossible that we should not not have been visited before. Photo by Elena.

Extremophiles

Extremophiles

Extremophiles are organisms that live under conditions injurious to many forms of life. Mankind has used extreme environments for a long time to preserve food. We now know that this is because these techniques kill or suppress the bacteria that would otherwise cause spoilage. A few techniques are to heat (i.e. cook) the food, refrigerate it, salt it, or even irradiate it.

And we all know this works. We have refrigerators and freezers. We have been admonished to cook rare roast beef to an internal temperature of about 140F or as much as 180F for well done beef or all poultry. The reason is to both cook the meat – to convert it from something raw to something yummy – and to kill the bacteria living in the raw meat. 

There are other methods for preserving food that you have encountered in your local grocery store. There are dried vegetables, fruits, and meats, which have been starved of water, inhibiting bacterial growth. Nuts and other foods come vacuum packed to reduce the oxygen available in the package. Processing food by using high pressure can kill microbes. This is used for many products, including guacamole and orange juice.

Meat is cured by salting, as in the familiar bacon and ham. Alcohol is also used to preserve some fruits. This is usually done in conjunction with using sugar as a preservative.

Changing the acidity or alkalinity of the food is another way to lengthen its lifetime. Atmosphere modification is also a useful technique. Food, such as grains, can be put in a container and the air replaced with high-purity nitrogen or carbon dioxide. This removes the oxygen and destroys insects, microbes and other unwanted intruders.

The real point is that mankind has known about various ways to preserve food for millenia. Spoilage of food originates from undesirable creatures (typically microbes of some sort) “eating” the food and releasing wast products. Through some combination of the techniques mentioned above, we have learned to kill the undesirable bacteria that would otherwise ruin our food.

Our experience has led us to some understanding of the range of conditions under which Earth-like life can exist. However research revealed that life is actually hardier than we thought.

Life can be born in the most harsh conditions. Photo by Elena.

Biologists have given the name “extremophile” (meaning “lover of extreme conditions”) to organisms that thrive in environments that would kill familiar forms of life. While the study of extremophiles is still a fairly young science, we can discuss some of the range of conditions under which exotic life has been found.

At the bottom of the oceans, sometimes at extraordinary depths, there are spots where magma has worked its way from the interior of the Earth to the ocean floor. At these points, called hydrothermal vents, superheated water streams away from the magma. This water can be heated to well above the familiar boiling temperature of 212 F, but the huge pressure at the bottom of the ocean causes the water to stay in its liquid form. Water inside these hydrothermal vents can be nearly 700 F, certainly high enough to kill any form of ordinary life.

Only a few feet away from these vents, the temperature of ocean water can be very close to freezing, about 35 F. In this temperature gradient grows an unusual ecosystem.

Heat-resistant, sulfur-breathing life is not the only type that exists in extreme environments On the other end of the spectrum are the cold-loving cryophiles. Life-forms at the cold end of the spectru, have quite different problems compared with their thermophile cousins. If water freezes, it expands and can rupture cell membranes. Chemical adaptations are needed to mitigate the problems of the cold.

As of our current understanding, we know of no eukaryotic life that can exist at temperatures outside the range of 5 to 140 F. While the lower number is below the freezing point of ordinary water, water with high salinity can remain liquid at these temperatures. Microbial life has been observed over a temperature range of -22 to 250 F. An example of a cryophilic organism is Chlamydomonas nivalis, a form of algue that is responsible for the phenomenon of watermelon snow in which snow has the color and even the slight scent of watermelon.

Chemical considerations can give us insights into the ultimate constraints on the temperature of carbon-based life. Due to the bond strength involving carbon atoms, it's hard to imagine life at standard pressure much higher than 620 F; about as hot as the hottest your oven can bake. Of course, pressure can affect the rate at which molecules break apart and the decomposition of molecules can be slower at high pressure. It's probably safe to say that carbon-based life is not possible above about 1000 F at any pressure.

Water is critical to life, however it may be that there are extremophiles that don't need much of it. There are also forms of life that are halophiles (salt loving). In the Dead Sea region of the Middle East, most life couldn't survive. However, there are lichens and cellular life that have adapted their chemistry to maintain their inner environment in such a way as to thrive. Some of these forms of life actually need the high salt environment to live at all.

As with the other food-preserving extremes, life has been found in highly acidic and basic environments and even in the presence of radioactivity a thousand time higher than would kill the hardiest normal forms of life. These observations have certainly broadened scientists' expectations of the range of environments that life can successfully inhabit.

With the discovery of these extremophiles, scientists have intensified their search for the niches that life can occupy on Earth. We have pulled life out of well cores taken from a couple of miles under the surface of the Earth. Life has been found floating in the rarified air of the stratosphere. Microbes have been found as high as 10 miles above the ground. This environment is extremely harsh. The temperature and pressure is very low, the flux of ultraviolet light is very high, and there is nearly no water. Survival in this hostile environment inevitably raises questions of “panspermia”, which is the premise that life might have arrived on Earth from some other body... perhaps Mars. While this seems improbable, it is not ruled out. But life had to start somewhere, so the questions are still relevant, even if life started elsewhere. Of interest to us here is the understanding that some primitive forms of life can exist in an environment that would kill creatures that live closer to the Earth's surface. However, this primitive form of life wouldn't be an Alien. But it does give us some additional information on precisely how resilient Earth-based life, with our carbon and water-based biochemistry, can be.

(Source: Alien Universe, extraterrestrial Life in Our Minds and the Cosmos, by Don Lincoln).

Presence of water and oceans are one of the conditions which create life on the Earth. Photo by Elena.

What Is Life

What Is Life?

This question is seemingly so simple, and yet it has vexed some of the most knowledgeable scientists and philosophers for decades. While hardly the first writing on the subject, physicist Erwin Shrödinger's (of Shrödinger's cat fame) 1944 book What Is Life? Is one such example. It is an interesting early attempt to use the ideas of modern physics to address the question. Both James Watson and Francis Crick, codiscoverers of DNA, credited this book as being an inspiration for their subsequent research.

The definition of life is not settled even today. Modern scientists have managed to list a series of critical features that seems to identify life. A living being should have most, if not all, of the following features:

• It must be able to regulate the internal environment of the organism;
• It must be able to metabolize or convert energy in order accomplish the tasks necessary for the organism's existence;
• It must grow by converting energy into body components;
• It must be able to adapt in response to changes in the environment;
• It must be able to respond to stimuli;
• It must be able to reproduce.

These features distinguish it from inanimate matter.

Life is able to respond to stimuli. Photo by Elena.

While these properties can help one identify life when one encounters it, they don't really give us a sense of the limitations imposed by the universe on what life might be like. We can ask ourselves if a would-be science fiction writer is being ludicrous when he or she bases a story around an Alien with bones made of gold and liquid sodium for blood. So what does our current best understanding tell us that life requires? A combination of theory and experimentation suggests that there are four crucial requirements for life. They are (in decreasing order of certainty):

• A thermodynamic disequilibrium;
• An environment capable of maintaining covalent interatomic bonds over long periods of time;
• A liquid environment;
• A structured system that can support Darwinian evolution.

The first is essentially mandatory. Energy doesn't drive change, rather energy differences are the source of change. “Thermodynamic disequilibrium” simply means that there are places of higher energy and lower energy. This difference sets up an energy flow, which organisms can exploit for their needs. It's not fundamentally different from how a hydroelectric power plant works: there is a place where the water is deep (high energy) and a place where the water is shallow (low energy). Just as the flow of water from one side of the dam to the other can turn a turbine to create electricity or a mill to grind grain, an organism will exploit an energy difference to make those changes it needs to survive.

The second requirement is essentially nothing more than saying that life is made of atoms, bound together into more complex molecules. These molecules must be bound together tightly enough to be stable. If the molecules are constantly falling apart, it is hard to imagine this resulting in a sustainable life-form. It is this requirement that sets some constraints on which atoms play an important role in the makeup of any life. Hopefully after this discussion, you'll understand the reason for the oft-repeated phrase in science fiction “carbon-based life-form.”

Requirement number three is less crucial; however it's hard to imagine life evolving in an environment that isn't liquid. Atoms do not move easily in a solid environment and a gaseous environment involves much lower densities and can carry a far smaller amount of the atoms needs for building blocks and nutrition. Liquids can both dissolve substances and move them around easily.

Finally, the fourth requirement might not be necessary for alien life, but it is crucial for Aliens. Certainly multicellular life of the equivalent not be the first form of life that develops. The first form that develops will be of a form analogous to Earth's single-celled organisms (actually, most likely simpler... after all, modern single cell organisms  are already quite complex). In order to form species with increasing complexity, small changes in the organism will be necessary. Darwinian evolution is the process whereby a creature is created with differences from its parents. The first thing that is necessary is that the organism survives the change. After all, if the change kills it, it's the end of the road for that individual. Once there are changes that both allow the daughter organism to survive and possibly confer different properties, selection processes become important. Creatures who subsequently reproduce more effectively will gradually grow in population until they dominate their ecological niche.

Many forms of life exist. Photo by Elena.