TO QUOTE: Astronomy Society of Planetarium Alfa. November 14, 2004. Monterrey, N. L., MX. Conference: Exobiology. Lecturer: Nasif Nahle.
Exobiology is the branch of biological sciences that studies the existence of living forms on other places of the universe out from Earth.
Exobiology has many synonyms, such as Astrobiology, Xenobiology, Extraterrestrial Biology, Space Biology, Biocosmology, etc.
Exobiology is a multidisciplinary science built on Biology, Ecology, Astronomy, Cosmology, Physics, Chemistry, Paleontology, Climatology, Meteorology and Mathematics.
THE SCIENTIFIC METHOD
In general terms, we should follow a systematization to get a valid deduction about something. This systematization is summarized in the steps of the Scientific Method.
Steps of Scientific Method:
I should say that this explanation is a general description of the scientific method. However, the Scientific method is an obligatory tool to know the reality from nature. Any assertion that cannot be submitted to the Scientific Method can be considered as a fictitious thought.
The first step in any investigation is OBSERVATION. Observation consists of setting our attention in a portion of the Universe. Through observation we are able to identify specific realities or events from the cosmos by means of our senses.
Once the observation is executed, the researcher elaborates one or more questions, generally ingenerated by the curiosity of the observer. These questions constitute a PROBLEM. The questions MUST MATCH with the remarked phenomenon and they must adhere to objectivity.
The investigator should always take into account that the questions that begin with a "why" are very difficult - if not impossible - to answer. The objective investigator prefers start with questions like "what", "how", "where", or "when". The question could be also "what is for".
Then, the observer, through INDUCTIVE REASONING, tries to give one or more logical answers to such question. Each answer is a tentative introduction that can serve like a guide for the remainder of the investigation. These preliminary solutions to a question are HYPOTHESES.
HYPOTHESIS is a statement that can be false or true and that should be submitted to experimentation.
After he has enunciated one or more hypothesis or proposed explanations, the researcher elaborates one or more PREDICTIONS, which must to be consistent with the observations and hypotheses. To do this, the researcher uses the DEDUCTIVE REASONING.
Each hypothesis should be submitted to an exhaustive test called EXPERIMENTATION. The results of experimentation will determine the final character (false or true) of the hypothesis.
The experimentation can be performed in diverse ways, but the controlled experimentation is a characteristic of the scientific method, of such way that other simpler systems are not viable for the purpose of science.
In controlled experimentation we should have two groups to test: a group called control group or witness group, and other called experimental group.
Both, the control group and the experimental group, are submitted to the same conditions, excluding the variable that has been chosen for the study. The control group is not submitted to the change, but the experimental group is submitted.
The results are observed and the differences between both groups are registered.
If the investigator notes a difference between both groups, then an answer can be deduced.
As the investigation advances, the false hypotheses are rejected one to one, until the plausible verification of the hypotheses that were presented intially.
When a hypothesis is proved, a final statement is processed, which in science is called THEORY.
Theory is a partially or totally true statement, proved by means of experimentation or natural and observable evidences, only for one time and one place.
If the theory is verified like true for all times and places, then it would be considered a LAW.
A theory is subject to changes, a law is permanent and immutable. A law is comprobable at any time and place of the Cosmos. However, a theory is truth only for a certain place and a given time.
But, we should make clear that there are differences between the meanings of hypothesis, theory and law in sciences.
A HYPOTHESIS is a provisional solution for a question generated through the observation of an event. The hypothesis could be false or true, by this, every hypothesis must be tested through experimentation. For example, all reports on the origin of AIDS are hypotheses.
On the other hand, a scientific THEORY is a statement that must contain a setting of real evidence. A theory would be right only if it has been submitted to a rigorous testing, and it only will be true if it is in concordance with facts. A theory could be reworked, as new evidence be accumulated, but the background of truth of the theory will never be altered. Scientific theories are true only for a given time and space. It could not be true for other spots in the Universe. Evolution is a good example of a scientific theory.
A scientific LAW is a statement that is true and valid for all times and all places in the known Universe. A law is true and valid everywhere, for all times. For example, the Laws of Thermodynamics, Laws of Gravity and Axiom of Biogenesis are good examples of scientific laws. The last is one of three Biological Laws. Other Biological Laws are the Intransference of Life and the Irreversibility of Life.
I have seen a semantic problem in many non-scientific dissertations. It refers to a generalized mistreatment of the term "theory". Perhaps the confusion is attributable to the popular idea that the term "theory" applies to all non-verified perceptions, be scientific or not.
But for science, there is an enormous difference between hypothesis and theory. For the scientific community, a theory is a true statement applicable for one time and one place because it is based on evidence and it has been confirmed by testing.
Cell theory, for example, which says that all living beings are constituted by cells. Evolution is a theory because it applies for all known beings living on earth (for one place) and it applies for all current living beings (for one time). If Evolution were not kept up on observed facts, then we would say "hypothesis of Evolution" instead "theory of Evolution".
CONDITIONS FOR THE GENERATION AND SUBSISTENCE OF LIVING BEINGS ANYWHERE
A THREE-DIMENSIONAL SPACE- Living systems require of a field in the Universe containing a space with three dimensions, longitude, width and deepness.
TIME- Living systems require of a field in the Universe that includes time.
A SUN- The planet that gives shelter to living beings must receive a stable and continuous flow of energy from a star. Earth receives a continuous and stable flow of energy from a medium size star (the Sun); besides, Earth is positioned at an appropriate distance from Sun (Earth occupies the third place from Sun), not too close as to be scorched by the intense solar radiation (as Mercury and Venus), neither excessively far as to be frozen in the cold sidereal space (as the other planets beyond Earth, Mars, Jupiter, Saturn, etc.).
A STEADY AXIS OF ROTATION- The planet must have a stable axis of rotation. Earth has a big Moon that controls its spinning movement. Sun and Moon control the rotary motion and orbital trajectory of Earth.
A MAGNETIC FIELD- The planet that would hold living beings must have a protective field shield against massive particle's radiance during solar electromagnetic storms. Earth has effective magnetic field shields.
A PROTECTIVE ATMOSPHERE- The planet which would give shelter to living forms must have a protective atmosphere against cosmic radiation. Earth has an ozone layer, but it could be also dense dusty clouds of vapor of water.
WATER- The living beings have to be produced in environments rich on water. This is certain because water presents unique physicochemical qualities.
For example water molecules are disintegrated during the photosynthesis process, freeing oxygen atoms.
Water acts as a thermoregulator for climate and living systems:
Thanks to the water the climate of the Earth is maintained stable. Water works also as a thermoregulator in living systems, especially in endothermic animals.
It is possible due to the specific heat of water (specific heat is the heat in calories necessary to elevate the temperature of one gram of a substance in one degree Celsius), which for water is one calorie. In biological terms it means that before an elevation of the temperature in the surrounding environment, the temperature of a mass of water will rise with greater slowness than the temperature of other materials. Equally, if the surrounding temperature diminishes, the temperature of that mass of water will diminish with more slowness than that of other materials. Thus, this property of water permits that aquatic organisms live relatively placidly in an environment with stable temperature.
Evaporation is the change of the physical state of a substance from a liquid physical state to a gaseous physical state. We need 540 calories to evaporate a gram of water. At this point water boils (point of boiling). This means that we have to rise the temperature at 100°C to do water boils. When evaporates from the surface of the skin, or from the surface of leaves of a plant, water molecules drag large quantities of heat with it. This works in the organisms like a cooling system.
Another benefit of water is its melting point. With the intention that a liquid substance change from a physical state liquid to a physical state solid, it should be extracted heat from that substance. The temperature at which a substance change from a physical liquid state to the physical solid state is called melting point. To change the water physical state from liquid to solid we have to diminish the surrounding temperature at 0°C.To revert melting, this is to say to change one gram of ice to liquid water, it requires a supply of 79.7 calories. When water melts, the same amount of heat is liberated to the surrounding environment. This allows in winter that the environmental temperature does not decrease to the point of annihilate all the life on the planet.
Besides, water owns the property of being the universal solvent. Almost all substances, essential to bring about the life, can be dissolved in water. Thus, besides of being accessible for the organisms, water acts as the best vehicle for food transporting in both, external and internal environment of the organisms.
CARBON- Carbon is available for living beings in form of carbon dioxide in the air. It can be found also as carbonates in soil. The Carbon has six electrons in its first level of energy and four in the second level of energy, sharing electrons with other elements in four covalent bonds (tetravalence), which makes it the most flexible element to form compounds (organic compounds, because they have Carbon in their skeletons) For example, Silicon atoms have also four electrons in its outer shell, but Silicon is heavier than Carbon (Silicon's atomic weight is 28.0855, instead, Carbon's atomic weight is 12); because of it, Silicon cannot offer the versatility presented by Carbon. The skeletons formed by Carbon atoms can vary in length and array (linear and ring structures of the same compound).
There is no evidence of extraterrestrial life, and the probabilities (based on the results of Drake's equation) are not accurate because the factors considered are not real observable facts. WE SCIENTISTS DO NOT KNOW IF EXTRATERRESTRIAL LIFE EXISTS.
Mathematically, but not plausibly, a calculus (more by guesswork than by certainty) permits us to speculate on many planets out from Earth which hold up living beings. Unfortunately, we know it may not be true in nature. To affirm that there are living beings in other worlds, we should have factual proofs of their existence. A similar thing happens with the universal laws of physics. Many times there are big mathematical possibilities for the occurrence of an event in the Universe, but, unmistakably, the models are not real in the known Universe.
We are near to produce living beings in our labs. Some scientists have made protobionts in vitro. I am conscious that it has been a tiny pace, but it does not mean that we will not be able of doing it in future times. From a personal viewpoint, with a strict scientific thought, the existence of organisms on other planets out from Earth is practically unknown for us, especially if we consider that life is not a kind of energy, but a "porthole" in the normal flow of entropy in the Universe and that it started as a casual result of diverse temporary events through the evolution of the Universe.
As Biologists, we should be realistic and always in step to the Theory of Truth. The statistics on other planets similar to Earth with the necessary conditions to bear living beings do not allow us to know that necessarily living beings were produced on there. Considering it as a possibility does not mean that it will be an indisputable truth.
SUGAR IN DEEP SPACE
June 19, 2000:
Jan M. Hollis of the NASA Goddard Space Flight Center, Frank J. Lovas of the University of Illinois and Philip R. Jewell of the National Radio Astronomy Observatory (NRAO), have written a paper where they reported the discovery of glyceraldehydes in a big nebula near the center of the Milky Way. Their discovery is the first detection out of Earth of a simple sugar molecule.
This discovery accounts on favor of my theory about the origin of biomolecules in the interstellar media, just where the stellar activity did favor bonds between elements to build more complex chemical compounds.
The abovementioned cloud of gas and dust is in the region of the 26,000 light-years away. That is to say, that this sugar was there 26 000 years ago, and it will help us to know the early history of Earth and the start of life on Earth through the studies in relation to the self-construction of the first prebiotic molecules.
We have detected a profusion of organic matter at Interstellar Nebulas (IN), like methane, ammonia, sulfurs, Carbon Dioxide, amino acids, etc., but the most important inorganic compound found in the IN is water.
If you want to know more about organic complex substances observed at the interstellar medium (ISM), please visit NASA's site.
HOW TO FIND LIVING BEINGS OUT THERE
The question about the existence of life out of Earth is crossing now by an important confusion as for a pragmatic system of analysis consistent with scientific thought.
Frequently we take notice of space agencies that search for water on other planets, which should be interpreted as the detection of a system that could be able to allow the existence of living beings. We should never think that if there were water forcibly there would be living beings.
1. The main error found in those reports is that the pronouncements on the existence of extraterrestrial living beings are based on statistics supported by conjectural data.
This error is continuously made by many experts interviewed in TV bulletins about the quest on the existence of living beings out from Earth. Nevertheless, we cannot assure until now if there are planets similar to Earth, or if those planets contain life simply because we do not know it.
OBVIOUSLY, WE CANNOT FORMULATE ASSUMPTIONS ON SOMETHING ABOUT WHICH WE DO NOT HAVE THE MOST MINIMUM EVIDENCE. UNTIL NOW, EXOBIOLOGY IS IN ESSENCE HYPOTHETICAL; HOWEVER, EXOBIOLOGY IS ESTABLISHED ON SCIENTIFIC OBSERVATIONS OF NATURE’S LAWS AND BEHAVIOUR.
2. Astrobiologists are spending a great deal of resources on searching of extraterrestrial Radio signals (SETI), arguing that extraterrestrials have developed a technology more advanced by millions of years than the terrestrial hi-tech systems.
Again, we cannot assure that there are intelligent beings out there, much less intelligent talkative living beings. However, there is a possibility that there be a civilization like ours at any point of the Universe, so SETI must continue looking for signals from extraterrestrial civilizations; whether they use the same communication systems like ours or not.
When some people talk about extraterrestrial beings, they anticipate "a happy communication with them", "see them face to face", "hear their voices", "shake their hands", " talk with them in their own language", "ask them if they believe in God", etc. Someone has said "it would be TOUCHING by asking them (to aliens) if they know the value of 'pi' (3.14159265), IT IS EVIDENT that they ALREADY know it", etc.
We have on Earth thousands of animals and plants that do not speak our language. Almost none of them even speak. We know that they have a kind of communication, but until now, we have not been able to establish a real communication with other species. The major paradox is that those species have been living with us from the time when humans evolved on Earth. Wow! If we are unskilled to communicate with our own species on Earth, how do they know that extraterrestrials can hear the human voice
Do extraterrestrials have ears? How do they know that extraterrestrials can see? Do extraterrestrial beings have eyes? How do they know those beings have hands? How do they know that extraterrestrial beings will be able to shake our hands? How do they know if those beings rationalize alike humans? Do they need to believe in God? Are there extraterrestrial beings?
As you can see, all disclosed data about extraterrestrial life (exposed by scientists and non-scientists) is pure imaginative supposition. Simply, it is non-science, pseudoscience and/or dogmatism. We challenge them to support their beliefs on the existence of extraterrestrial life with facts (detectable, testable and searchable by other scientists).
3. Origin of Life is an irreversible process. If life did not occur on other parts of the Universe besides Earth, then we will not be able to restore the whole generation of the Universe to enhance our belief on the existence of living organisms on other worlds besides Earth.
Probably all the conditions have occurred on other worlds - as well as protobionts could be formed on those planets; however, we do not have the smallest track of their existence. We have found water on Moon, Mars, Titan, Europe, comets, etc. However, we have not been able to construct a feasible technique to detect living beings on those worlds. It is not a question about the existence or non existence of living beings on those worlds, but a matter on our lack of adequate technical capacity for finding living beings on other worlds without ambiguities, this is to say, plausibly.
This engenders a very high degree of uncertainty that makes unacceptable any statistical probability until now proposed. It obligates us to conclude, as prudent scientists, that life out from Earth is a very hard-to-detect fact. It is harder for us to find living beings that had evolved to intelligent organisms.
4. The origin of Life is an irreversible process. If life did not take place on other parts of the Universe besides Earth, then, it is very improbable that in the future we can find living beings in those places, where living organisms were never formed. However, if the conditions in those places were favorable for the terrestrial life, the human beings can populate them with terrestrial living beings of every class, from Archaeobacteria, to Mammals.
We cannot do either that the living beings that had been synthesized on other planets and later had been extinguished (by any reason) could be recuperated from the catastrophe only because we do not wish to be alone in the Universe. We would not be able to draw the trajectory of just one ancient generation of those extinct beings in those locations of the Universe. If we cannot do it at home, we will not do it at other worlds.
Then, if living beings only were generated on Earth since the beginning to the end of the evolution of the Universe, we would not be able to do one thing by only guessing the existence of life forms on other worlds, neither by means of forging the existence of life forms on other planets. In any case, we would be alone; that is so simple. This does not mean that we do not accept the existence of other living beings out from Earth; I am trying only to portray some possible settings about the presence or absence on other worlds of a state one energy known as "life".
We accept these facts as factual evidence against the existence of Aliens getting Earth from other worlds; but also, against the falsehood of an “obvious evidence” on the existence of life forms on other worlds of our Universe. We do not have "obvious evidence" about the existence of life forms on other worlds in our Universe. We have merely "obvious dreams" of not being alone in the Universe, and the last maxim includes religions.
If living beings were present on other worlds out from Earth, it would not affect our knowledge about the laws that rule our Universe, or our knowledge about the generation of living beings on Earth, but it would affect profoundly our religious sensitivity. In addition, it would not affect our scientific progress if they were not there. Are we going wrong on the road? Let us examine one of some exobiologists’ preferred elements for them to get an idea about the existence of extraterrestrial living beings:
FRANK DRAKE'S EQUATION: N = Ns fp ne fl fi fc fL
Ns = 200 billion = approximate number of stars in the Milky Way galaxy.
fp = 10% = fraction of stars I think have planets around them (<2x10-10 assumed)
ne = 0.33 = number of planets per star I guess are ecologically able to sustain life
fl = 0.000001% (1 of 1,000,000) = fraction of those planets where I think life evolves
fi = 0.000001% (1 of 1,000,000) = fraction of fl where I think intelligent life evolves
fc = 0.0000001% (1 of 10,000,000) = fraction of fi I think can communicate
fL = 1/100,000th (100.000 y) = fraction of time during which I think culture survive.
N = 6.6 x 10-24 = probabilities on existence of communicating civilizations in Milky Way galaxy.
Do not forget that it is a guesswork. Considering the inserted series are tentative, you can substitute the numbers as you wish (in proportion to the command of your imagination).
Something breaks my thoughts upon the possibility of extraterrestrial life: The amazing distances between our solar system and the other stars. They are so large that we could be observing stars that no longer exist today. Perhaps, we are receiving the light from worlds that no longer exist, since we see them until their light reaches us. For the nearest star, the light's round trip would take eight years.
However, we note that most of premises released by alienists, panspermists, creationists, etc. have not a scientific foundation. Up till now, all their premises lack of basis from observable nature. As scientists, we think that there is disrespect against science and reason. It does not matter if the respectable Carl Sagan (he never declared one thing that assured the existence of extraterrestrial living beings; actually, he struggled against the non sense of the Alienists' lies) and Giordano Bruno believed in extraterrestrial living beings.
We must to be curious and, at the same time, skeptical. If a scientist accepts a version just because an authority on sciences said it, without substantiation on a specific issue, at this moment that scientist turns into a perfect pseudoscientist.
We consider Real Science should level its road, getting free of false arguments and imaginaries. We believe we have been enough permissive with the persons that do not have a real sense of scientific thought.
AGAIN, I AM NOT ASSURING THAT THERE ARE NOT LIVING BEINGS OUT FROM EARTH: BUT, I ASSURE THAT WE HAVE NOT EVIDENCE ON THE EXISTENCE OF LIVING BEINGS OUT FROM EARTH.
LET US SEE ONE OF MY PROPOSALS FOR LOOKING FOR LIVING BEINGS ON OTHER WORLDS OUT FROM EARTH MORE PROFESSIONALLY:
THE PROTON MOTILE FORCE (PMF)
One of the most serious difficulties that we have faced in the search of living beings out of Earth has been the recognition of living beings similar to terrestrial organisms. Given that the Physical Laws are the same everywhere in the known Universe, and that all the matter contained by the known Universe is formed by the same particles, we can assume precise methods for the unmistakable recognition of non terrestrial living forms.
Life is a quantum energy state experimented by some quasi-stable thermodynamic systems, which permits them to establish, no-spontaneously, a series of intervals that delay the diffusion or dispersion of their local energy to more available microstates. This is physically perceptible as a Proton Motile Force. Thus, we should try to find the Proton Motile Force, in action, wherever we are looking for living beings.
To be sure that anything found on other planets is or not a living being, we can try to detect the Proton Motile Force (PMF). PMF is a sequence of alterations in the membrane potential that happen across the transference of energy, since it is captured until it is stored in a complex molecule, for example, a molecule of Glucose. PMF occurs when electrons are transported by ATP molecules impelling protons to leap towards the membranes’ outer surface of some cell organelles, as chloroplasts or mitochondria, or towards the outer surface of the cell membranes in bacteria.
After some of my conferences on Exobiology, some persons have asked for a plausible method for detecting the Proton Motile Force.
One of the easiest forms to recognize living beings on extraterrestrial environments would reside on the detection of Adenosine Monophosphate (AMP), Adenosine Diphosphate (ADP), Adenosine triphosphate (ATP), Nicotinamide Adenine Dinucleotide Phosphate (NADP), or NADPH by means of radioactive markers in culture media and its detection by ultra-finely tuned photometers built in robotic probes on planetary soils. It would be obvious that any system possessing those complex compounds would be by running through PMF, and consequently, that system would be alive.
Another way, still simpler than the previous one, would be by producing bubbles of Oxygen in a viscous cell culture media, which had been enriched with soil of the explored planet. If that soil were the habitat of aerobic bacteria, then these would accumulate around the bubbles of Oxygen, which we could monitor by means of a strategic and exhaustive microscopic observation.
A CLICHÉD WRONG REASONING
October 23, 2003
It is common to see some exobiologists saying at Discovery Channel that "For each grain of sand on Earth, there are one million stars in our galaxy"; and that "Each of those stars would have a planet like Earth". They complement their speech with "It is impossible to think that there would not be life in one of those planets, in one of those stars".
The way of sophism is as follows:
1. We have a planet with all the ideal conditions for the development of living beings called "Earth" (assertion de facto).
2. There are trillions of suns in our galaxy identical to the sun that sustains all living beings on Earth (the first factual statement has changed to an abstraction).
3. We still have not detected them, but it is possible that each sun have at least one planet with identical Earth's conditions (blurred deduction).
4. As there are trillions of solar systems with planets analogous to Earth, it is absurd to think that there is not life out of Earth (constructivist presumption obtained from a series of abstract propositions).
5. Consequently, I affirm that there are living beings in the entire universe (inexact conclusion).
Is this a suitable scientific reasoning? I want you to think about a very simple thing:
1. We have trillions of granules of sand on Earth.
2. We have not observed two identical granules of sand on Earth.
UNTIL NOW, WE ARE ALONE AT THIS SIDE OF THE UNIVERSE, BUT PERHAPS WE ARE NOT THE UNIQUE BIOSYSTEMS IN THE UNIVERSE.