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.

The Sea Gypsies

The Sea Gypsies

The Sea Gypsies are nomadic people who live in a cluster of tropical islands in the Burmese archipelago and off the west coast of Thailand. A wandering water tribe, they learn to swim before they learn to walk, and live over half their lives in boats on the open sea, where they are often born and die. They survive by harvesting clams and sea chambers. Their children dive down, often thirty feet beneath the water's surface, and pluck up their food, including small morsels of marine life, and have done so for centuries. By learning to lower their heart rate, they can stay under water twice as long as most swimmers. They do this without any diving equipment. One tribe, the Sulu, dive over seventy-five feet for pearls.

But what distinguishes these children, for our purposes, is that they can see clearly at these great depths, without goggles. Most human beings cannot see clearly under water because as sunlight passes through water, it is bent, or “refracted,” so that light doesn't land where it should on the retina.

Anna Gislén, a Swedish researcher, studied the Sea Gypsies' ability to read placard under water and found that they were more than twice as skillful as European children. The Gypsies learned to control the shape of their lenses and, more significantly, to control the size of their pupils, constricting from 22 percent. This is a remarkable finding, because human pupils reflexively get larger under water, and pupil adjustment has been thought to be a fixed, innate reflex, controlled by the brain and nervous system.

This ability of the Sea Gypsies to see under water isn't the product of a unique genetic endowment. Gislén has since taught Swedish children to constrict their pupils to see under water – one more instance of the brain and nervous system showing unexpected training effects that alter what was thought to be a hardwired, unchangeable circuit.

The Sea Gypsies have survived using a combination of their experience of the sea and holistic perception. Illustration by Elena.

Cultural activities change brain structure

The Sea Gypsies's underwater sight is just one example of how cultural activities can change brain circuits, in this case leading to a new and seemingly impossible change in perception. Though the Gypsies' brain have yet to be scanned, we do have studies that show cultural activities changing brain structure. Music makes extraordinary demands on the brain. A pianist performing the eleventh variation of the Sixth Paganini Etude by Franz Liszt must play a staggering eighteen hundred notes per minute. Studies by Taub and others of musicians who play stringed instruments have shown that the more these musicians practice, the larger the brain maps for their active left hands become, and the neurons and maps that respond string timbers increase; in trumpeters the neurons and maps that respond to “brassy” sound enlarge. Brain imaging shows that musicians have several areas of their brains – the motor cortex and the cerebellum, among others – that differ from those of nonmusicians. Imaging also shows that musicians who begin playing before the age of seven have larger brain areas connecting the two hemispheres. 

Giorgio Vasari, the art historian, tells us that when Michelangelo painted the Sistine Chapel, he built a scaffold almost to the ceiling and painted for twenty months. As Vasari writes,“The work was executed in great discomfort, as Michelangelo had to stand with his head thrown back, and he so injured his eyesight that for several months he could only read and look at designs in that posture.” This may have been a case of his brain rewiring itself, to see only in the odd position that it had adapted itself to. Vasari's idea might seem incredible, but studies show that when people wear prism inversion glasses, which turn the world upside down, they find that, after a short while, their brain changes and their perceptual centers “flip”, so that they perceive the world right side up and even read books held upside down. When they take the glasses off, they see the world as though it were upside down, until they readapt, as Michelangelo did.

It is not just :highly cultured” activities that rewire the brain. Brain scans of London taxi drivers show that the more years a cabbie spends navigating London streets, the larger the volume of his hippocampus, that part of the brain that stores spatial representations. Even leisure activities change our brain; mediators and meditation teachers have a thicker insula, a part of the cortex activated by paying close attention.

The Sea Gypsies are an entire culture of hunter-gatherers on the open sea, all of whom share underwater sight. For Sea Gypsies it is seeing under water. For those of us living in the information age, signature activities include reading, writing, computer literacy, and using electronic media.

In all cultures members tend to share certain common activities, the “signature activities of a culture.” Signature activities differ from such universal human activities as seeing, hearing, and walking, which develop with minimal prompting and are shared by all humanity, even those rare people who have been raised outside culture. Signature activities requires training and cultural experience and lead to the development of a new, specially wired brain. Human beings did not evolve to see clearly under water = we left our “aquatic eyes” behind with scales and fins, when our ancestors emerged from the sea and evolved to see on land. Underwater sight is not the gift of evolution; the gift is brain plasticity, which allows us to adapt to a vast range of environments.

(The Brain That Changes Itself by Norman Doidge, M.D., excerpt).

The implosion of the media into us, affecting our brains, is not so obvious, but we have seen many examples in our lives. Photo by Elena.

Intelligence and Judgement

Intelligence is not information alone but also judgement

Please, be polite

You, people, live on a moving platform, the Earth, a lovely and more or less placid place. Most of you respect the Humans and treat them as your equals or almost.  But some of the immigrants on the Earth prefer insult every native-earth-born-creature hey meet and position themselves and superior beings.

But why do you disrespect the Earthlings? In fact, human beings are rather good in understanding the world. It may seem to you that their logic is deficient (and in part it may be true, I grant you this), but they were able to hunt game and build fires to survive. And they figured out how to build a wheel. And they always watched the stars and the flowers.

Remember that in the great Cosmic Ocean there are countless stars and planets, inhabited by millions of civilisations both younger and older than this one, the Human civilisation which has developed in this solar system. 

Yeas, there is a million worlds in the Milky Way Galaxy alone that at this same moment is inhabited by beings who are very different from each other (and many of them much more advanced than the Earth).

But all these worlds have one characteristic in common: they change. And almost all of them change for the better. If you lived on a planet where nothing ever changed, there would be little to do. So if you don’t like Humans because they are ignorant and they do not know a lot about the Universe, you are wrong!

Remember that knowing a great deal is not the same as being smart. Intelligence is not information alone but also judgement, so be polite and respect the Humans! Help them to overcome their difficulties so one day in a very distant future they might be able to help your home world…

Thank you and be polite!

You’ll find below some advice about how to explain to the Humans the external World. If you are a new resident on the Earth, you may find these advice useful.

Don’t forget to register as Newcomer at the Milky Way Galaxy Office for Aliens on the Earth (MWGOAE). Some fees apply.

Signed: Megan Jorgensen, expat on the Earth, born on the star R-1876642-12, Large Magellanic Cloud, representative of the MWGOAE in this Solar system).

Over the dying embers of the campfire, on a moonless night, Humans watched the stars and the flowers. Image : © Megan Jorgensen.

Astronomy for the Astrologer

Astronomy and Astrology

Astronomy for the Astrologer

Are the zodiacal signs real heavenly bodies? Are there other bodies in our solar system that we should know about?

One of the most common and constant complains from the astrological fraternity is that astronomers simply will not even try to understand them. The astrologers assert that the astronomers refuse to examine their evidence. For the most part, astronomers refuse to reply, though in the past some of them have shucked their cloak of dignified silence and made boobs of themselves by trying to disprove statistically “astrological tenets” that no reasonable astrologer ever held in the first place. Thus Dr. J. Allen Hynek, associated with UFO research in the press, upon hearing that astrologers linked Mercury with intellectual activity, set to work with scientific thoroughness and showed there was no significant correlation between a high I.Q. and a strong Mercury position in the horoscope. But then, on the other hand, what astrological theorist ever claimed that there was?

The contention by astrologers that astronomers refuse to review their claims is, to a great extent, true. But there is something to be said for the astronomers, too. To them, the universe contemplated by the astrologer is as much out of date as the physiology known to Hippocrates and Galen. There can be no real objection to looking at the Earth as the center of the solar system, considering the fact that Albert Einstein postulated that what is seen by an observer is, in a relative sense, true for him. But astrologers must ever remember that their view-point is no more than relative and that astronomers are quite justified in asserting that practically no astrologer knows even the rudiments of astronomy.

In these times, advanced astrologers and cosmobiologists are accumulating more and more evidence to support most of the claims made for their ancient science. One particularly important discovery is the one suggesting that forces originating outside of the solar system can have an effect upon chemical substances found in human cellular issue. Evidence such as this is lost upon the astrologer who has no understanding of the cosmos as viewed by an astronomer. This article intended for the astrologer who wants to get up-to-date of what science knows about the physical universe he uses as the basis for his interpretations.

Although the Earth creates an elliptical path around the Sun as far as our solar system is concerned, in relation to the galaxy its actual path is something like that of a corkscrew. This means that at certain seasons of the year, the Sun tends to be between the Earth and the sources of Energy which arise in the galaxy.  Since the blocking effect of the Sun is constant from one year to another, it means that the rate of chemical reactions of the type referred to will vary according to different seasons of the year. It is thought that this may be the fundamental basis for astrology.

If the Sun has such an effect, it is quite likely that the planets do also, perhaps by creating a turbulence in whatever field of energy is being emitted in the Milky Way. That such turbulence exists is evidenced by the fact that RCA Communications has for years been using planetary positions to compute the effect upon their international network.

Most serious astrologers long ago gave up the idea that the planets exert any direct influence on mundane events, but the exact rationale of astrology has remained somewhat of a mystery. For some time, consideration was given to Jung’s theory of synchronism, that is that two events may be related by time instead of causality. With the discoveries now being made, however, it seems that the nature of astrological forces resembles a field effect. By this is meant a situation where two bodies have an effect upon one another, not by virtue of their inherent qualities, but because of the nature of the field in which they exist. In the gravitational theory proposed by Einstein, for instance, two bodies are attracted to one another, not because of their own natures, but because their time-space field makes attraction the path of least resistance for them.

Astrologers used to play big role throughout the history of mankind. Photo by Elena.

To see how this works, take a sheet of cloth and suspend it by its four corners so it is approximately flat. Now put two steel marbles on it. No matter where you place them they will be attracted towards one another. This attraction is due to the depression which they make in the sheet, not because of any direct effect of the marbles upon one another.

Field effect astrology – if we may coin a term – would depend upon an analogous phenomenon. Assume a field of energy originating in our galaxy that has a profound effect upon certain chemicals in the human system. From time to time during the year, the Earth is exposed to varying strengths of that energy due to the shielding effect of the Sun. At the same time, the field is further modified by the presence of planetary bodies orbiting the Sun. In total, the astrological effect is caused not by the action of the planets upon the Earth but by field turbulences of which they serve as signals.

Aside from the astrological effect, there are also astronomical effects, and these can be attributed to the influence of other bodies in the solar system. A well-known instance of this is the sunspot cycle with its period of eleven years. Sunspots are fields of turbulence on the surface of the Sun. Their appearance is accompanied by the emission of large quantities of radiation. It has been shown time and time again the as the level of that energy increases, the Earth’s population as a whole begins to get more and more anxious.

During periods of radiation increase, there is a correlative increase in the number of riots, homicides, and wars. Communications are disturbed. The rate of plant and animal growth is altered. The sunspots increase to their maximum in 11 years. At the end of that time they suddenly subside and begin once more to increase again. There is some evidence that the sunspot cycle may be associated with Jupiter’s period of revolution around the Sun. If this is true, there is another direct effect to be considered.

There is a direct influence of the Moon upon the Earth. It is common knowledge that it causes tides in the oceans. What is not so well known is that it also causes tides on land surfaces as well. The point on Earth directly under the Moon is pulled upwards to a distance of two feet.

Though research at Northwestern University has shown that there is a correlation between the Moon’s phases and certain events in the life cycles of lower animals, there is still considerable debate about its direct effect upon humans. There is a body of empiric knowledge based upon reports of police and fire departments as well as mental hospitals and saloon managers that the Full Moon coincides with a period of aberrant sociological phenomena. So far there is disagreement among researchers who have conducted scientific inquiries into this. There has been at least one report that female admissions to mental hospitals reach their peak on the Full Moon; male admissions peak on the New Moon.

It would appear that phenomena correlating with human behaviour fall into two distinct groups. In the one, there is a direct astronomical influence as in the case of the Sun and Moon. In the other, there is the field effect in an energy stream which is occasioned by planetary positions and the position of the Earth with reference to the source of that energy in the galaxy.

The vernal equinox point, that is where the Sun crosses the equator on its way north is the point at which the zodiac begins. For this reason it is known as the first point of Aries. From this point the zodiac is divided into 12 signs of 30 degrees each.

As you probably know, the constellation that identified the original signs of the zodiac have shifted out of the positions that the held back during the days when astrology was becoming formalized, a period around the second century B.C. This is sometimes advanced as an argument against traditional astrology. Actually it is not. It is quite apparent that it is the division of the ecliptic into 12 equal signs that is important. The fact that certain constellations served to identify those signs a couple of thousand years ago was merely a matter of labelling. As a matter of fact, , we are not even certain at what time the constellation of Aries actually coincided with the segment  of ecliptic now known by that name. Estimates of the exact time made by both astronomers and astrologers range from 317 B.C to 321 A.D. Probably the figure determined by Cyril Fagan – 220 A.D. – is most nearly correct for the time at which the first point of the constellation coincided with the first point of Aries on the fixed or ecliptic zodiac. Since the first point moves backwards, this would mark the time that it was on the verge of moving into Pisces. It will, according to this calculation, move into Aquarius in about 300 years.

Can Astrologers predict the future? Illustration by Elena.

Measuring Positions in the Sky

The Earth turns on its axis at a regular rate, on revolution per day. For convenience geographers divided the Earth into 360 divisions along the equator. Those are called degrees of longitude pass by given point in 24 hours. This is at the rate of 15 degrees per hour or one degree every four minutes.

The particular degree on which you are situated is called your meridian. It is also the highest point that the Sun will reach any day. This is the location of the medium coeli (M.C) or Midheaven. The meridian passes through the zenith or the point in the sky directly over your head. The zenith is always the same number of degrees above the equator which gives them their ship’s latitude.

Sometimes astrologers become confused over the difference between celestial latitude – the distance the body is above or below the ecliptic – and declination. Declination is the number of degrees a body is above or below the celestial equator. The celestial equator is an imaginary line that runs across the heavens directly above the Earth’s equator. If you stand on the Earth’s equator, your zenith is located on the celestial equator.

Another method of measuring positions in the sky is by their hour angle. We saw that the Earth moved at the rate of one degree every four minutes. For us, that means that the heavenly bodies seem to move over our heads at the same rate. We can locate a body by saying how long it will take to reach our meridian or by how long it has been since it passed our meridian.

For instance, let us say that a body is located 15 degrees to the east of our meridian. We know that at the rate of four minutes for each degree, it will take 4 times 15 minutes or one hour to come to our meridian. Thus we say that the body has an hour angle of one hour east. If it had passed the meridian and was 15 degrees away, we would say it was one hour west.

Still one more way of locating celestial bodies is by their right ascension. This term, obscure to most astrologers, means no more than the number of degrees measured east from the first point of Aries to the meridian on which a body lies. This measurement is taken along the celestial equator, however, and not the zodiac or ecliptic. Thus is does not always agree with zodiacal measurement. For instance, a body at 15 degrees of Taurus would be 45 degrees away from the first point of Aries if measured on the ecliptic, but its right ascension, along the celestial equator, would vary with the time of year. Some astrologers use tables of the Sun’s apparent right ascension in progressing horoscopes; they feel that the Sun’s movement in right ascension for one day gives a better correlation with a year of life than does the standard “one-degree” method.

Has astrology anything to do with the real world? Illustration: Megan Jorgensen.

Credit Bureau Phone Numbers

Credit Bureau Phone Numbers and Aliens

If there are intelligent beings on the planets of fairly nearby stars, could they know about us?

On another planet, the chances of finding another form of intelligence is rather high. However , the chances of finding beings who are physically very similar to us is near zero, because a different sequence of random processes applies making hereditary diversity and a different environment to select particular combinations of genes, very different from ours’.

They may have switching elements analogous to our neurons. But the neurons which operate their process of thinking may be very different. There may be planets where the intelligent beings have about the same neural connections, as we do. Perhaps they act as superconductors that work at very low temperatures rather than organic devices that work at room temperature, in which case their speed of thought will be thousands of times faster than ours and they will develop therefore faster.

Or let’s imagine a situation that may seem incredible, but can be very real:  perhaps the equivalent of neurons in their brains would not be in direct physical contact but in radio communication so that a single intelligent being could be distributed among many different organisms, or even many different planets, each with a part of the intelligence of the whole, each contributing by radio to an intelligence much greater than itself.

In this case they will need neither phones, nor credit bureau phone numbers, as we need here on Earth.

In some sense such a radio integration of separate individuals is already beginning to happen on the planet Earth, with our system of communication

Places where the neural connections are immensely high… I wonder what they would know.

One conclusion is however evident: Because we inhabit the same universe, we and they must share some substantial information in common. If we could make contact, there is much in their brains that would be of great interest to ours. But the opposite is also true. Extraterrestrial intelligence – even beings substantially further evolved than we – will be interested in us, in what we know, how we think, what our brains are like, the course of our evolution, the prospects for our future.

Might they somehow have an inkling of the long evolutionary progression from genes to brains to libraries that has occurred on the obscure planet Earth?

They might not use our system of communications, their phones may be quite a mystery for us and their system of credit of phone numbers might seem bizarre, but if there are intelligent beings on the planets of fairly nearby stars, they are interested in us. But what they already know about the Earth?

Anyway, if the extraterrestrials stay at home, there are at least one way in which they might find out about us.

This way would be to listen with large radio telescopes. For billions of years they would have heard only weak and intermittent radio static caused by lighting and the trapped electrons and protons whistling within the Earth’s magnetic field. Then, less than a century ago, the radio waves leaving the Earth would become stronger, louder, less like noise and more like signals. The inhabitants of Earth had finally stumbled upon radio communication. Today there is a vast international telephone, radio, television, radar communications traffic. At some radio frequencies the Earth has become the brightest objet, the most powerful radio source, in the solar system – brighter than Jupiter, brighter than the Sun.

An extraterrestrial civilization monitoring the radio emission from Earth and receiving such signals could not fail to conclude that something interesting had been happening here lately.

Our inkling to acquire more and more phone numbers leads us to an eventually contact with alien civilisation! And we can’t change this psychology inherent to the human beings.

“The smartphone revolution is under-hyped, more people have access to phones than access to running water. We've never had anything like this before since the beginning of the planet.” (Marc Lowell Andreessen, an American entrepreneur, founder of Netscape). Illustration by Megan Jorgensen.

Telepathy

Telepathy

Tell me, guys, do you believe in telepathy? To tell the truth, I’ve never given it much thought, but the evidence seems rather convincing. But is someone else capable of reading our mind?

I don’t know if you’ve read any of the evidence suggesting that telepathy is somehow independent of time.

Can you imagine a room without walls, where there’s no entrance or exit?

Well, it’s not as simple as that, but it seems that we can really read other people’s mind while we are dreaming or even slightly drink. Yes, you may say that invalidates the evidence, but I don’t think so. It seems it’s the only way we could break through the barrier that separates us from the others minds.

Try and imagine the effect of that discovery: the effect of learning that every act, every thought or desire that flitted through your mind is being watched and shared by another being. It’ll mean, of course, the end of all normal life for everyone.

The real life would become a nightmare as every man and every woman would be a kind of telepathic Peeping Tom – no longer content with mere watching.

The will be a constant but sudden invasion of your mind. People will be always there, sharing your emotions, gloating over the passions they can’t experience in their bodies.

To make matters worse, some people will came chasing after me, and they wouldn’t leave you alone, and bombard you with e-mail letters and phone calls. It’ll be hell, you’ll be unable to fight them, so you’ll have to run away (and you’ll think on a small calm village in Costa Rica, of all places, where no one would bother you.

Have you ever wondered what the human race will do when science has discovered everything, when there are no more worlds to be explored, when all the stars have given up their secrets? Telepathy is one of the answers.

Indeed, I don’t know if you’ve read any of the evidence suggesting that telepathy is somehow independent of time. If it is people will send back their minds to an earlier, more virile age, and become parasites on the emotions of their predecessors.

Perhaps this explains all cases of what we call possession. How the future Telepath must have ransacked the past to assuage their hunger! Can’t you picture them, flocking like carrion crows around the decaying  Afro-Canadian  Empire, jostling one another for the minds of the Emperor Tremblay? (But perhaps they haven’t much choice and must take whatever mind they can contact in any age, transforming from that to the next whenever he has the chance).

However, perhaps telepathy is a symbol of conscience, a personification of guilt, remarkably detailed hallucination, that is yet another example of the tricks the human mind can play in its efforts to deceive itself. And when we realized this, we would cease to be haunted by our past in times of emotional crises. Just trying to fight an increasing sense of futility and uselessness during these moments might be enough.

Telepathy - a room without walls, where there is no exit. Illustration : Megan Jorgensen.

Space Tourism

A Reality of Space Tourism

Space is truly the final frontier for mankind. As future space tourists, we should keep our eyes on the fast-developing space industry, as it will shape our civilization for decades to come.

Imagine yourself heading out with your family on your annual vacation. Except, this time you aren’t going to a harbour for a Caribbean cruise or to an airport for a Chilean skiing tour. Instead you thrill to the idea that in a couple of hours you’ll be in a spaceport, waiting in line to take your places in a spaceship for this much-anticipated trip to the Moon. This scenario is a likely picture of what might be encountered in the next few decades.

This isn’t to say that space tourism isn’t available now; in fact, Russia has previously allowed some space tourists to travel alongside their cosmonauts to the International Space Station (ISS) for anywhere between 20 and 40 million US dollars (an insignificant sum for some of us, the Earthlings).

The goal, however, for the burgeoning space tourism sector is to make these trips more affordable for the average citizen and to provide infrastructure needed to make spaceflights possible. Today, most of the spacecraft can no longer be used after completing their mission and are discarded, which can prove to be extremely costly. Thus, companies wishing to invest in space tourism are currently researching methods of reusable space transportation.

SpaceX, for instance, has a prototype spaceship called Dragon that can transport up to 7 crew members. It is currently working with NASA to find a way to transport people headed to the orbit to work there, but it also hopes to provide commercial spaceflights to ordinary citizens.

Reaction Engines Ltd has proposed a “space-plane” named SKYLON that produces thrust by burning liquid hydrogen fuel with the oxygen from the air, significantly reducing the amount of liquid oxygen needed on board the ship to burn the fuel. Its SABRE engines will accelerate the ship to Mach 5 – that’s 6125 km/hour up until 25 kilometers above sea level, at which point the engines will switch to rocket mode and carry it the rest of the way to space.

The design received endorsement from the European Space Agency (ESA) in November 2012, and they were looking for funding to build there SABRE engines.

Another well-known company, Virgin Galactics, already had more than 500 ticket holders in 2014 waiting to catch a ride on board SpaceShipTwo, a spaceship that can hold two crew members and six passengers. The Virgin Galactics plans for this spacecraft to be the first ship that sends  tourists to space on a regular basis. The ticket price is currently reported to be $200,000 with a $20,000 down payment, a price much more lower that what the Russians charge. One of the first few planned trips are supposed to take passengers 110 kilometers above sea level marking the beginning of open space, for a total weightlessness duration of 6 minutes.

It is important to keep in mind that these ships will need dedicated ports to house them and to accommodate them for takeoff and landing. Several of these have already been open, like Spaceport America in New Mexico, open for business since 2011 and a few others are being built.

In addition to transportation, future space travelers will need tourist destinations to visit and accommodations to live in for the duration of their journey. A couple of companies are looking into providing housing for these individuals during their stay before the takeoff.

Bigelow Aerospace Company plans to send housing modules into space alongside spacecraft. These modules are compact rooms that can inflate upon command to form livable areas that are shielded from the radiation of the Sun. Theoretically Bigelow Aerospace could build an entire hotel room by room just by interconnecting these modules, effectively creating new destinations in space for tourists. One of these modules is destined to connect to the International Space Station in 2015 or later, providing Bigelow Aerospace with a chance to demonstrate their concept.

Space Island Group, another contender in the space tourism business, intends to build ring-like structures that can spin at variable speeds to create an artificial gravity that is equal to a third of the gravity of Earth. This could be highly beneficial, as it may potentially eliminate many of the negative effects that come from prolonged exposure to low-gravity environments, such as muscle atrophy or loss of bone density.

Naturally, all these accommodations will need to regularly stock oxygen, food, water and other supplies for the guests. While some of these necessities could be grown or recycled on the stations themselves, most supplies would still need to be sent directly from Earth. One candidate for these missions is SpaceX’s Falcon 9, which is capable of carrying a total of 10T of cargo, more than enough to resupply future space hotels. As a matter of fact, in 2008 already NASA employed Falcon 9 to send supplies to the International Space Station, thus illustrating its potential as a reliable cargo carrier.

Safety will be one of the main factors that will make or break the future of space tourism. Before governments can allow their citizens to leave the planet, companies must prove that their shuttles and living quarters will protect their customers throughout their journey.

The US government has already begun to draft some guidelines to ensure safety of their citizens who wish to travel to space. In 2004, the Commercial Space Launch Amendments Act, H.R. 5382, was signed into law. It provides rules and regulations that space companies must follow to legally send people to space, such as getting a license from the Federal Aviation Administration’s Office of Commercial Space Transportation (FAA/AST).

… After all, we might soon find ourselves staring at a tiny blue dot outside our windows and reminiscing of a time when this was all but an impossible dream…

Sources:

• Roupen Djinbachian, Space Tourism close to becoming a reality Technophilic, Winter 2013, page 22).
• Space Tourist Back From “Paradise”, Lands on Steppes”, by Patrick E. Tyler.
• Elysium, movie 2013.
• Clark, Stephen (September 2010), “Boeing allies with Space Adventures for tourist flights”.
• “Anywhere on Earth in four hours? Top-secret Skylon space plane could replace jets and rockets, company claims”. National Post, 29 November 2012.
• “Branson Dedicates Space Terminal”, Wall Street Journal, 18 October 2011.
• “International space station to receive inflatable module”, Washington Post, 16 January 2013.
• “Private-spaceflight bill signed into law”, NBC News, 23 December 2004.

What will we discover in Outer Space, is nothing compared with our beloved planet (Quotations from Megan Jorgensen). Image : © Megan Jorgensen.

Human History

Human History

Human history can be viewed as a slowly dawning awareness that we are members of a larger group. Initially our loyalties were to ourselves and our immediate family, next, to bands of wandering hunter-gatherers, then to tribes, small settlements, city-states, nations. We have broadened the circle of those we love. We have now organized what are modestly described as superpowers, which include groups of people from divergent ethnic and cultural background working in some sense together – surely a humanizing and character-building experience.

If we are to survive, our loyalties must be broadened further, to include the whole human community, the entire planet Earth. Many of those who run the nations will find this idea unpleasant. They will fear the loss of power. We will hear much about treason and disloyalty. Rich nations will have to share their wealth with poor ones. But the choice, as H. G. Wells once said in a different context, is clearly the universe or nothing.

A reasonable – even an ambitious – program of unmanned exploration of the planets is inexpensive. The budget for space sciences is not very expensive. Comparable expenditures in many countries are more or less the same. Together these sums represent the equivalent of two or three nuclear submarines per decade, or the cost overruns on one of the many weapon systems in a single year. In the last quarter of 1979, the program cost of the U.S. F/A-18 aircraft increased by $5,1 billion, and the F-16 by $3,4 billion. Since their inceptions, significantly less has been spent on the unmanned planetary programs of both the United States and the Soviet Union than has been wasted shamefully – for example, between 1970 and 1975, in the U.S. bombing of Cambodia, an application of national policy that cost $7 billion. The total cost of a mission such as Viking to Mars, or Voyager to the outer solar system, is less than that of the 1979-80 Soviet invasion of Afghanistan. Through technical employment and the stimulation of high technology, money spent on space exploration has an economic multiplier effect. One study suggests that for every dollar spent on the planets, seven dollars are returned to the national economy. And yet there are many important and entirely feasible missions that have not been attempted because of lack of funds – including roving vehicles to wander across the surface of Mars, a comet rendezvous, Titan entry probes and a full-scale research for radio signals from other civilizations in space.

Carl Sagan, Cosmos.

Even an ambitious program of unmanned space exploration in inexpensive. Image: Space Travel by © Megan Jorgensen.

X Ray Tech Salary

X Ray Tech Salary

Any society with a marked population explosion will be forced to devote all its energies and technological skills to feeding and caring for the population on its home planet. Technicians will be busy and tech salaries will go up. On any planet, no matter what its biology or social system, an exponential increase in population will swallow every resource.

We can predict thus that no civilization can possibly survive to an interstellar spacefaring phase unless it limits its numbers.

Of course, this is a very powerful conclusion and is in no way based on the idiosyncrasies of a particular civilization.

Conversely any civilization that engages in serious interstellar exploration and colonization must have exercised zero population growth or something very close to it for many generations.

The famous astronomer Carl Sagan and his colleague William Newman have calculated that if a million years ago a spacefaring civilization with a low population growth rate emerged two hundred light-years away and spread outward, colonizing suitable worlds along the way, their survey starships would be entering our solar system only about now.

But a million years is a very long period of time. If the nearest civilization is younger than this, they would not have reached us yet. A sphere two hundred light-years in radius contains 200,000 suns and perhaps a comparable number of worlds suitable for colonization. It is only after 200,000 other worlds have been colonized that, in the usual course of things, our solar system would be accidentally discovered to harbor indigenous civilization.

What does it mean for a civilization to be a million years old? We have had X rays, radio telescopes and spaceships for a few decades; our technical civilization is young, scientific ideas of a modern cast a few thousand, civilization in general a few tens of thousands of years; human beings evolved on this planet only a few million years ago. At anything like our present rate of technical progress, an advanced civilization millions of years old is as much beyond us as we are beyond a bush baby a macaque.

Will a civilization with a low population growth reach some lush Eden? Illustration by Elena.

Used Transmissions for Sale

Used Transmissions for Sale

The two Voyager spacecraft are bound for the Galaxy. Affixed to each is a gold-plated copper phonograph record with a cartridge and stylus and, on the aluminum record jacket, instructions for use. The humans sent data about their genes, something about their brains, and something about their libraries to other beings who might sail the sea of interstellar space. Although the recipients do not know any languages of the Earth, included are greetings in sixty human tongues, as well as the hellos of the humpback whales.

Photographs of humans from all over the world are attached, caring for one another, learning, fabricating tools and art and responding to challenges.

There is an hour and a half of exquisite music from many cultures, some of it expressing the sense of cosmic loneliness, the wish to end this isolation, the longing to make contact with other beings in the Cosmos. Recordings were sent of the sounds that would have been heard on this planet from the earliest days before the origin of life to the evolution of the human species and our most recent burgeoning technology. It is a love song cast upon the vastness of the deep.

But the Earth did not want to send primarily scientific information. Any civilization able to intercept Voyager in the depths of interstellar space, its transmitters long dead, would know far more science than the terrestrial science does.

Instead the Voyagers tell those other beings something about what seems unique about the Earthlings.

The interests of the cerebral cortex and limbic system are well represented; the R-complex less so.

In this spirit the people who launched the Voyagers included on the spacecraft the thoughts and feelings of one person, the electrical activity of the brain, heart, eyes and muscles, which were recorded for an hour, transcribed into sound, compressed in time and incorporated into the record.

In one sense the Humans have launched into the Cosmos a direct transcription of the thoughts and feelings of a single human being in the month of June in the year 1977 on the planet Earth.

Perhaps the recipients will make nothing of it, or think it is a recording of a pulsar, which in some superficial sense it resembles.

Many, perhaps most, of recorded messages will be indecipherable. But the Earth sent them because it is important to try.

Or perhaps a civilization unimaginably more advanced than the Humanity will be able to decipher such recorded thoughts and feelings and appreciate these efforts to share all these thought with them.

We have sent our messages because it is important to try, not because we’d like to sell used transmission. Image: © Megan Jorgensen.

How Do Lasers Work?

How do lasers work?

If you knew what the letter stood for you might be able to guess from the name itself that a laser, which stands for Light Amplification by the Stimulated Emission of Radiation, is a device used to create a very special kind of light beam.

Ordinary light – the kind we flip on with a wall switch – in incoherent. All we mean by this is that the light waves are emitted in a random, disorganized way, going in different directions and out of phase – that is not in step with one another. For example, when we turn of a fluorescent lamp, a current of electrons is sent through the fluorescent tube, bombarding the atoms inside. This excites the atoms to a state of energy higher than normal. When they return to their normal energy state, that is when they give off their light. But since each atom is bombarded, excited and gives off its light energy at random directions and times, the light waves which come from the fluorescent tube are still mixed together, like a troop of drummers who refuse to keep time with one another.

In a laser, though, the atoms all keep time together, and the light waves they give off are pointed in the same direction, with their crests and troughs aligned with one another. This is why we say laser light is coherent. Coherence is what makes laser beams so special.

To create a laser beam, we first of all need to have material whose atoms can be excited and remain excited long enough so that a collection of them can be made to radiate together. One of the early kinds of lasers used a synthetic ruby crystal to accomplish this.

The crystal was machined into the shape of a small cylinder. Its ends were made parallel, polished flat and smooth, and coated with silver to make them act as mirrors. Using this apparatus, here is what happens: when the first of the group of simulated falls to its normal state, and, in so doing, radiates light, that light comes in contact with another of the excited atoms, and it too radiates light. And, what is more, the light waves from both atoms will be in step – that is, in phase. When the light waves from these two atoms hit other excited atoms, they too will be stimulated to emit light in step.

Any light waves which are emitted in the wrong direction – that is, in any direction but parallel to the walls of the cylinder – will bounce through the walls and escape. But the light waves which do travel parallel to the walls will continue to be reflected back and forth by the mirrors at each end, at the same time stimulating other excited atoms to do the same. In this way the light increases in intensity, just as the drummers would sound louder and louder if, one by one, they started keeping time together.

Is one of the mirrors is built so that it will allow a small amount of light to escape, the beam which results will come out straight ahead, the crests and trough of each light wave aligned in unison. It will be coherent. And it will have very little “spread” – unlike a flashlight beam, for example, which in just a few feet spreads out from its initial small diameter to a large circle.

Many other kinds of materials – solid, liquid and gaseous – have been used to create lasers. Some emit different colors – that is, different wavelengths – other than the red of the ruby laser. Other requires less power to operate.  At TRW, for example, where were laser research began in 1961, they developed a portable laser the size of a flashlight. An argon ion gas laser uses a TRW-developed high-current cold cathode (electron emitter) which greatly reduces the power requirements (because of their large power requirements most lasers must remain stationary).

Lasers have many practical as well as scientific uses. A ruby laser, for example, which puts forth its radiation in a thousandth of a second, is used to surgically weld a torn of detached retina of the eye.

Because it is highly directional, that is, it has very little spread - a laser beam will carry over great distances. A dramatic example of this is seen when a laser is used to illuminate a mile-wide spot on the Moon.

One laser beam has an extremely high frequency – a thousand million cycles per second. This gives it more information-carrying capacity than any radio, tv, or any other communication channel now in existence.

Another application of laser technology is holography, a remarkable kind of three-dimensional photography. What makes a hologram so unusual is that it really is three-dimensional. You can move to the side of a hologram and actually see behind the objects in the foreground, as though you were looking through a window.

These pictures are photographs of holograms developed during research at TRW, they are different aspects of the same scene. They were made by viewing a single hologram from three different angles. The three-dimensional aspects of holography make it extremely useful for studying particles of droplets in a dispersion pattern. For this reason holography is a valuable tool for evaluating many kinds of nozzles and vaporizing devices, including paint spray guns, oil burners, fuel injectors and carburetors. The photographs show the dispersion of droplets in two impinging water jets.

At TRW, holography research began in 1963, when they studied the behaviour of electrostatically charged droplet streams in air and vacuum for the Air Force. Later, they work in the field expanded to holography of moving subjects at high-speed events, holographic microscopy and spectroscopy, optical gauging by holography, and acoustic holography.

Engineers of the NASA Goddard Space flight Center send a message by laser beam to a satellite in orbit.

Life in the Cosmos

Life in the Cosmos

There must be many different environments suitable for life in a given planetary system. Once life originates, it tends to be very adaptable and tenacious.

In the Solar system there are several bodies that may be suitable for life of some art: the Earth certainly (if we all live in a real world and not in a computer simulation), and perhaps Mars, Titan and Jupiter.

There is evidence that planets are a frequent accompaniment of star formation. We can see this evidence in the satellite systems of Jupiter, Saturn and Uranus, which are like miniature solar systems. Theories of the origin of the planets are based on this premise and studies of double stars confirm it. We can also observe accretion disks around stars and find the evidence in some preliminary investigations of gravitational perturbations of nearby stars.

Thus many, perhaps even most stars in our universe must have planets.

But what about life? All experiments show that under the most common cosmic conditions the molecular basis of life is readily made, the building blocks of molecules able to make copies of themselves.

We step now on less certain ground: there may be impediments in the evolution of the genetic code, although we think this unlikely over billions of years of primeval chemistry.

On the one hand, many individually unlikely steps had to occur in biological evolution and human history for our present intelligence and technology to develop. There must be many quite different pathways to an advanced civilization of specified capabilities.

On the Earth we must consider the apparent difficulty in the evolution of large organisms represented by the Cambrian explosion. Thus let us suggest that only one percent of planets on which life arises eventually produce a technical civilization.

The conclusion in interesting enough: the total number of planets in the Milky Way only on which life has arisen at least once may be a hundred billion inhabited worlds. And we repeat that we speak about the Milky Way only. That in itself is a remarkable conclusion. But we are not yet finished. One percent of plants where a technical civilization has developed, give us the total number of one billion “civilized” worlds.

Obviously, this estimate represents some middle ground among the varying scientific opinions.  Some think that the equivalent of the step from the emergence of trilobites to the domestication of fire goes like a shot in all planetary systems. Some other think that even given ten of fifteen billion years, the evolution of even ten technical civilizations in the Milky Way Galaxy is unlikely.

Anyway, this is not a subject on which we can do much experimentation as long as our investigations are limited to a single planet. Our estimation about a billion planets on which technical civilizations have arisen at least once is rather speculative. It is very different from saying that there are a billion planets on which technical civilizations now exist. For this, we must know much more about Cosmos.

How many technical civilizations exist in the Universe? We know for sure about only one by now. Image : Megan Jorgensen.

Erosion on the Earth

Erosion on the Earth

Because of erosion on the Earth, our monuments and artifacts will not, in the natural course of things, survive to the distant future. But the spaceships Voyager launched in the XX Century carry human records on their way out of the Solar system.

Indeed, brains and genes and books encode information differently and persist through time at different rates. But the persistence of the memory of the human species will be far longer in the impressed metal grooves on the Voyager interstellar record. It happens because the erosion in interstellar space – chiefly impacting dust grains and cosmic rays – is so slow that the information on these recordings will last a billion years.

But the Voyager message is traveling with agonizing slowness. The fastest object ever launched by the human species, this probe will still take tens of thousands of years to go the distance to the nearest star.

Any television program will traverse in hours the distance that Voyager has covered in years. A television transmission that has just finished being aired will, in only a few hours, overtake the Voyager spacecraft in the region of Saturn and beyond and speed outward to the stars. If it is headed that way, the signal will reach Alpha Centauri in a little more than four years. If, some decades or centuries hence, anyone out there in space hears our television broadcasts, I hope they will think well of us, a product of fifteen billion years of cosmic evolution, the local transmogrification of matter into consciousness.

Our intelligence is providing us with awesome powers, but it is not yet clear yet if we have the wisdom to avoid our own self-destruction.

However, many of us are trying very hard. We hope that very soon in the perspective of our cosmic time we will have unified our planet peacefully into an organisation cherishing the life of every living creature on it and will be ready to take that next great step, to become part of a galactic society of communicating civilizations.

Will we ever become part of a galactic society? Image : © Megan Jorgensen.

Why Do We Go to the Stars?

Why Do We Go to the Stars?

If our Sun or a nearby star were about to go supernova, a major program of interstellar spaceflight might suddenly become attractive, In fact, the discovery that the galactic core was imminently to explode might generate very serious interest in transgalactic or intergalactic spaceflight. Such cosmic violence occurs sufficiently often that nomadic spacefaring civilizations may not be uncommon.

However there may be many other motivations to go to the stars: an emerging technical civilization, after exploring its home planetary system and developing interstellar spaceflight, would tentatively begin exploring the nearby stars.

Some of these stars would have no suitable planets – perhaps they would all tiny asteroids or giant gas worlds. Others would carry an entourage of suitable planets, but some would be already inhabited, or the atmosphere would be poisonous or the climate uncomfortable.

In many cases the colonists might have to change –or as we would parochially say, terraform – a world to make it adequately clement.

The re-engineering of a planet will take time, but suitable world would be found and colonized. 

The utilization of planetary resources so that new interstellar spacecraft could be constructed locally would be a slow process. Eventually a second-generation mission of exploration and colonization would take off toward stars where no one had yet been. And in this way a civilization might slowly wend its way like a vine among the worlds.

It is possible that at some later time with third and higher orders of colonies developing new worlds, another independent expanding civilization would be discovered.

Very likely mutual contact would already have been made by radio or other remote means. The new arrivals might be a different sort of colonial society.

Conceivable two expanding civilizations with different planetary requirements would ignore each other, their filigree patterns of expansion intertwining, but not conflicting. They might cooperate in the exploration of a province of the Galaxy. Even nearby civilizations could spend millions of years in such separate or joint colonial ventures without ever stumbling upon our obscure solar system.

A million years is a very long period of time, but we could manage… (Cosmos by Carl Sagan). Image: © Megan Jorgensen.