Philosophy: Neurology: Astronomy:
An Essay on Continuity and an Awareness of Realities:
Responsibilities of Science
By Tetsuo Kaneko
Vacuum is not simply empty.† It is the source of everything, i.e., the source of the universe.† In the present, this is an important image being the nearest to the reality of vacuum. †All the objects of which no one is aware are always equivalent to nothing.† No one can count how many realities of objects of which no one is aware exist.† Thus, an awareness of how we can be aware must always be necessary for enlarging awareness.† Although humans (Homo sapiens) have not needed to be aware of any realities of the Earth and have been allowed to simply obey human DNA for 0.15 million years, now, enlarging an awareness of its realities is inevitable for continuous future of Homo sapiens.†
In the current global society, there are so many
issues that cannot be easily resolved by working neuronal network systems,
which are formed
Real objects that correspond to images controlling consciousness do not exist in the neural tissues constituting the brain.† In order to continue to enjoy our civilization, cerebral activity must contribute to creating suitable images being the nearest to realities of the objects.† Dinosaurs were capable of continuing to live on the Earth for 0.15 billion years while simply obeying their DNA.† Humans (Homo sapiens) are capable of continuing to enjoy the civilization, while making the brain work independently of primitive images created by fundamental neural tissues originated a priori by human DNA.† While becoming free from the will to try to avoid respecting a universal meaning that the second law of thermodynamics holds, the brain is capable of thinking about the dynamics of mind and a hopeful direction of the evolution of its dynamics.† While the brain is becoming free from cerebral functions characterized structurally by human DNA, the brain is capable of working neuronal network systems in an evolutionary manner aided by the growth of neurons.† While utilizing the brain evolutionarily with accompanying nonlinear responses of neuronal network systems, we are capable of finding suitable ways to continue to enjoy our civilization.†
A characteristic thinking that is produced as an output by neuronal network systems preserving the present connections must correspond to a linear response permitted by the neuronal network systems.† Neuronal networks can be allowed to change by the aid of a specific function of nerve cells, i.e., they have a freedom to change.† An output produced by neuronal network systems involving modification of neuronal networks is different from an output produced without the modification.† The output produced accompanying the modification can be characterized as a nonlinear response.†
Continuing to have an interest in knowing images
being the nearest to the realities of objects raises potentialities for finding
more suitable images.† Continuing to find
more suitable images can correspond to continuing to modify neuronal
networks.† Efforts to continue finding
them raise the possibility of forming neuronal networks contributing to finding
something new that enables any difficulties to be overcome, and these efforts
contribute to protecting the equality between the current generation and far
future generations.† Efforts to find a
way to make the planetary environment and the planetary ecological system
harmonize with extremely advanced technological civilization and a way to
continue to live while avoiding unpleasant nonlinear responses of the planetary
system to human behavior must be aided by efforts to recognize
Potentiality of Neuronal Growth
When new ideas and new consciousnesses are needed for resolving encountered issues, we must not deny that new neuronal networks are necessary for doing something that the present neuronal networks are not capable of doing.† Certainly, nerve growth factor -- which is a small secreted protein molecule synthesized in each nerve cell -- causes axonal growth and causes axonal branching, so that nerve cells can additionally connect with each other through axons.† Brain-derived neurotrophic factor -- which is a protein molecule -- can also cause growth, and it has activity in the hippocampus, cortex, cerebellum, and basal forebrain that corresponds to areas vital to learning, memory, and higher thinking.† The function of these growth factors helps to form neuronal networks including new connections between nerve cells in the brain, enabling neuronal networks to be modified.
Attempts to think accompany the formation of new connections between nerve cells, and these new neuronal connections allow cerebral activity to produce nonlinear responses to inputs.† Owing to the nonlinear responses, a possibility of leading to any faults due to thinking cannot be neglected.† However, new connections between nerve cells are allowed to become free from cerebral activity dominated by former connections, and raise the possibility of being aware of something new.†
Everyone knows that there are current scientific activities being done for helping everyone to ask whether awareness about extending the duration of advanced technological civilization is sufficient or not.† A specific cerebral condition in which understanding originated by daily experiences is firmly dominated often increases difficulties when approaching the realities.† Scientific experience continues to be accumulated toward the cerebral condition allowing awareness of all of the unknowns on which interpretations are prevented from being made. Philosophical efforts continue to be made for becoming aware of the relationships between all the thinking matters and for encouraging everyone to become aware of these relationships.† The consequences coming from both the scientific activities and the philosophical efforts must correspond to two bases aiding the attempt to continue to enjoy our civilization.† The accumulation of the consequences and improvement in the consequences must proceed while being linked with the current existence of everyone and the current situation of everything on the planet.† Moreover, what everyone shares the consequences helps have an opportunity to stimulate nerve cells to grow, thus allowing us to continue to enjoy our civilization and the world around us.† Sharing the consequences allows freedom to be given to cerebral activity dominated by daily experiences, thus aiding the consciousness that allows daily experiences to become objective.†
Advanced Technological Civilization
In general, consciousness has a tendency to be easily subjected to the expectation that both the predicted attractive effects occurring from the use of various materials and devices and the predicted advantages accompanied by the use of advanced technical treatments remain allowable and meaningful.† It is not rare to encounter a situation where consciousness is simply focused on the expectation that unexpected effects appearing as nonlinear responses to attempts to induce the predicted attractive effects and the predicted advantages are negligible.† Despite this fact, examples of unexpected effects that have occurred as unpleasant nonlinear responses so far are not negligible.†
The possibility that nonlinear responses remaining unknown are induced is not negligible, so that attempts to confirm the acceptability, i.e., the reason that materials and technical treatments are acceptable for use should be continued.†† Then, the acceptability should be found as an appropriate situation where the use of the materials and the use of the technical treatments continue to allow the healthy human condition to be preserved with the ecological condition.† Hence, confirming the acceptability must be linked with recognizing the realities of the Earth involving the ecological system, and it involves attempts to recognize the psychological or subjective reason and the scientific or objective reason that persuade the materials and the technical treatments to remain acceptable for being used.† Confirming these reasons must depend on both efforts that are made by science for revealing the realities and other efforts that are made philosophically for considering the meanings of the realities linked with currently human consciousness.†
A role for deeply understanding unknown phenomena occurring as unexpected nonlinear responses to the use of technology must be played by science, which must continue to make efforts to repeat corrections for being allowed to become quantitative.† Certainly, a role for revealing influential phenomena that everyone neglects unconsciously or consciously should be played by science.† Consequences coming from executing the role must contribute to suitably developing either ethics or philosophy for maintaining our civilization.† The act of understanding unexpected nonlinear responses is linked with deepening thinking on the continuation of the civilization.†
The use of technology, to which scientific consequences are applied, itself often make us encounter a situation where consciousness and ways of thinking should be changed reasonably.† Unless predictions based on scientific activities have potentialities for helping to develop ways of recognizing and for helping to change ways of thinking, the scientific activities cannot become valuable for helping the continuation of civilization.† Unless science makes efforts to reveal realities corresponding to unknowns of which no one is aware, the meaning of scientific activities will gradually become feeble.†
Assuring the continuation of civilization must be more important than encouraging the continuous civilization to be utilized.† Thus, unless science contributes to the civilizationís continuance, scientific activities and scientific consequences will, in the end, be meaningless.† Unless science contributes to people who make efforts to develop human consciousness for minimizing additional entropy dependent on unexpected and unpleasant nonlinear responses to the use of technology, scientific activities and scientific consequences will not be respected.
NASAís SETI project is designed to detect traces of living creatures that have established technological civilizations on planets located far from our solar system.† †According to NASA, candidates of planets and confirmed planets, which the Kepler space telescope has detected so far, are more than 5600.† The observations of the Kepler and the other observations show that approximately fifty of confirmed planets and a few hundred planet candidates have their orbits within the habitable zone.† In the whole of the Milky Way galaxy, the number of planets that may have environments allowing creatures to live is estimated at more than ten billion.† This is an expected value estimated from observational data.† Despite this fact, any signals demonstrating the existence of living creatures that have advanced technology have never been received so far.† The Drake equation indicates that the probability of detecting a trace of living creatures is proportional to the number of planets having environments similar to the Earthís environment and also is proportional to the lifetime of an advanced technological civilization. †The current situation where no signals have been received makes us wonder if the lifetime of advanced technological civilization is too short in relation to the SETI project.† Science persuades several billion human brains to become interested in consequences resulting from SETI in order to confirm what is a currently reasonably essential aim of civilization and the meaning of that: What is the aim that is perceived deductively or inductively through the whole of the existence belonging to the Earth?
Potentialities of Cerebral Activity Against Encountering Limited Conditions
Present neuronal networks preserve memories that are accumulated through daily experiences. The memories help ways of thinking, which result in recognition remaining in a category characterized by the daily experiences.† As a result, the present neuronal networks contribute to reaching common recognition.† This allows the neuronal networks to cause the necessity to resist the modification of neuronal networks that enables the expansion of awareness, which aids the brain to understand anomalous unknowns disagreeing with the daily experiences.† Establishing freedom of thinking from the present neuronal networks is not easy, so that establishing this freedom should be helped by either science or philosophy.†
Establishing freedom of thinking aids the ability to
criticize recognition caused a priori
by activities of the present neuronal networks, and aids in enlarging
awareness.† Establishing the freedom of
thinking enables the modification of neuronal networks.† Then, the cerebral condition
Neuronal networks cultivated by daily experiences persuade linear responses to input to be produced as output belonging to both the category of knowledge accumulated through some portions of the daily experiences and the category of sensibility cultivated through some portions of the daily experiences.† The occurrence of rare events that do not belong to these categories must be denied, so that the rare events must be equivalent to nothing.† Thus, the expansion of awareness is necessary.† Its expansion must contribute to elongating the lifetime of an advanced technological civilization.† At the very least, scientific journalism, science, and philosophy should contribute to the expansion.
Common things that are very frequently seen in daily
life do not stimulate the understanding that something essential makes the
common things exist.† The existence of
the air surrounding us
Making unknowns remain equivalent to nothing can allow images created by cerebral activity to be isolated from realities of the unknowns.† Everyone knows that there exist roles that should be played by science and roles that should be played by philosophy.† At least a portion of their roles is to help generate an interest in the unknowns and to help the consciousness that allows continuing to enjoy living in this world and enjoy living in the universe.†
The brain, consisting of over 100 billion nerve
cells, can allow various breakthroughs to be achieved by the aid of a great
function of nerve cells that allows new connections to be formed with each
other through axons.† The industrial
civilization encourages everyone to have an interest in rapidly achieving more
advanced technological breakthroughs that deliver comfort, convenience, and
benefit to everyone.† Then, it should be
inevitable to raise an interest in developing ethics in linear proportion to
the strength of an interest in achieving technological breakthroughs.† Although it is not easy to develop the ethics
that help both the acceptable use of technological breakthroughs and the
development of suitable treatments for avoiding the occurrence of unexpected
nonlinear responses, it is crucial to make it possible.† Certainly, the brainís 100 billion+ nerve
cells have a potentiality that raises an interest in developing the
ethics.† Even if no awareness about the
nonlinear responses can be caused by a characteristic function of neural
tissues originated by human DNA, it is possible to go beyond limitations
attributed to neuronal network systems supporting no awareness.† The great function of nerve cells that allows
new connections to be formed between nerve cells can aid in going beyond it.† The fact that the aid of the great function
of nerve cells contributes to the achievement of various breakthroughs encourages
everyone to continue to make efforts to go beyond the mindís limitations and toward
advanced consciousness that allows to continue to enjoy life
Ancient people lacked the ability to understand the role of neurons participating in cerebral activity.† Moreover, they had no ability to understand what makes stars form and what makes them move. They also lacked the ability to understand what makes stars emit light.† However, they realized the regularity of the starsí movements in the night sky by continuing to observe in an extremely careful way.†
For the attempts to understand unknowns and anomalous phenomena that daily experiences did not aid in imagining, cerebral activity performed by ancient people must have accompanied great difficulties.† The degree of difficulties that were encountered for the will to continue to make the attempts to proceed cannot be compared with the degree of difficulties encountered for the will of the current people.† Performing cerebral activity that avoids giving up in a situation where an essentially limited condition (without the use of a telescope or the knowledge of Newtonian mechanics) caused great difficulties for ancient people.† This demonstrates that the brain is capable of performing cerebral activity without giving up, no matter how difficult a situation is.
Three characteristic examples mentioned below are products of cerebral activity found in ancient civilizations:
†・Precise astronomical observations achieved by the Maya civilization, and their prediction of the fact that the moment when the sun, Venus, and the Earth are aligned in a straight line for the movements of the three astronomical objects appears in a specific year corresponding to 2012
†・Techniques for constructing huge architectural projects in the ancient Egyptian civilization
†・Earthquake engineering established by the ancient Peruvian civilization around 4800 years ago for protecting structures against earthquakes of up to magnitude 8.0.
These are three examples suggesting attractive cerebral activity that proceeded without giving up despite dealing with great difficulties. Cerebral activity within essentially limited situations encountered by ancient people encourages us to utilize the brainís 100-billion+ neurons actively over wide ranges of neural tissues to overcome todayís difficulties.†
The first step of science in the 20th century was to understand anomalous phenomena that belonged to the category of no awareness.† Then, the fact that suggestions obtained from Newtonian mechanics are partially acceptable was known.† However, it was crucial to make efforts to make cerebral activity become free from the classical assumption that the Newtonian mechanics is the complete knowledge.† These efforts allowed the anomalous phenomena to be understood accurately and precisely.† Making cerebral activity become free from the classical assumption induced the transitions from the Newtonian ways to new ways characterized by the Theory of Relativity and Quantum Mechanics.† Then, efforts both to understand the relationships between the Newtonian mechanics and the Theory of Relativity and to understand the relationships between the Newtonian mechanics and Quantum Mechanics revealed the fact that cerebral activity can be strongly influenced by daily experiences.† Even if the limitation of thinking due to neuronal network systems cultivated by daily experiences is inevitable, the aid of both the Theory of Relativity and Quantum Mechanics enables the evolution of the universe from the Big Bang Theory to be recognized as a reality of the universe revealed by observations.† While realizing that it is worthwhile to focus consciousness on great possibilities that are accurately specified by established pieces of knowledge, the brain is capable of perceiving that it can be worthwhile to make the consciousness become independent of the possibilities in an attempt to enlarge awareness.† While consciousness can be concentrated on a limited reality served by a particular object, the brain is capable of keeping other consciousnesses that are freely interested in various realities of infinite objects.†
According to current understanding, observations reveal the fact that more than one hundred billion galaxies exist in the observable universe and more than one hundred billion stars exist in each galaxy.† Other observations reveal the fact that dark energy, with which the universe is filled, accelerates the expansion of the universe.† Dark matter has helped to form stars and to form galaxies.† The brightness of each star is emitted by reactions that proceed in matter condensed by gravitation.† The matter consists of electrons and nuclei; nuclei consist of protons and neutrons; a proton consists of one d-quark and two u-quarks; a neutron consists of two d-quarks and one u-quark.† The quarks and the electrons gain their proper masses for a great nonlinear property of vacuum explained as the Higgs mechanism.† In 2013, the Higgs mechanism was proven experimentally; specifically, it was proven that vacuum has a great nonlinear property.†
The matter constituting the sun is composed of electrons and quarks.† The matter constituting the Earth and the matter constituting our bodies are composed of electrons and quarks.† The whole of the properties of matter is explained by the fact that the matter consist of electrons and quarks, †of which both are fermions.† The reality of matter is simple.† However, accompanying nonlinear responses allows this simplicity to cause the diversity of matter, i.e., to cause various characteristics of †matter and various behaviors of matter.† An awareness of the simplicity forming the realities of matter allows everyone to have confidence in cerebral activity for allowing the brain to become free from the demand for an attempt to select an interpretation made by combining several daily experiences together.† This awareness allows everyone to have confidence in cerebral activity that allows the brain to become free from losing the will to find suitable images which are the nearest to the realities of objects.†
Images obtained from approaching the reality of each unknown object of which no one is aware present an opportunity to allow the brain to be free from thinking dependent on images formed on the basis of daily experiences.† Approaching the reality can even present an opportunity to obtain surprising images that allow everyone to be amused.† Moreover, images obtained from approaching the reality stimulate interest in unknowns that allow us to know of ourselves.
Living as Astronomical Existence
If exposure to brightness being two times as much as the current luminosity of the sun is prolonged for 30 seconds, for this period, everyone so exposed feels anomalous brightness and anomalous warming.† However, it is difficult to imagine an extremely strong luminosity one-hundred-billion times by one-hundred-billion times that of the current luminosity of the sun.† A trace of such strong luminosity remained visible to human eyes for approximately 30 seconds in March 2008.† The astronomical object that emitted the strong luminosity is called GRB080319B, and it is located at a position 7.5-billion light years away from the Earth; this suggests that an extremely energetic event occurred 7.5-billion years ago.† Moreover, a surprised awareness comes when reminded of the fact that distances of most stars visible from the Earth are a few tens of light years away.† GRB080319B that was observed with the naked eye for approximately 30 seconds is extremely much farther than the visible stars.†
The astronomical event that occurred at GRB080319B is a gamma-ray burst that releases most of †its energy in gamma rays lasting only a short time. †This gamma-ray burst was detected by the Swift satellite on March 19, 2008.† The gamma-ray burst is similar to other gamma-ray bursts lasting from ten milliseconds to several minutes., so that it has a luminous optical counterpart as well.† The optical counterpart peaked at a visible magnitude comparable to that of the dimmest naked-eye stars.
Gamma-ray bursts are flashes of gamma rays and are the brightest electromagnetic events in the universe.† They are associated with extremely energetic explosions.† Gamma-ray bursts that are completed in a short time can originate from the merger between binary neutron stars or the merger between a neutron star and a black hole.† In each merger process, attractive elements including gold, silver, platinum, and so on are synthesized and are scattered into the space. †After each merger process, a black hole remains.† All observed gamma-ray bursts, being extremely energetic explosions lasting a few seconds, have originated outside the Milky Way galaxy.† Moreover, extremely energetic gamma-ray burst explosions are rare events, and the sources of most gamma-ray bursts are billions of light years away from the Earth, being events that occurred billion years ago.
Many hard observations for revealing the structure of the Milky Way demonstrate that the Milky Way galaxy has a spiral structure similar to the Andromeda galaxyís structure.† The fact that the structure of the Milky Way has spiral arms reminds us of the fact that an extremely long period of climate change can be linked with the structure.† The Milky Way is much more than just a silver brightness of beautiful clouds in the night sky, but is also the existence that influences life of all creatures living on the Earth.† A scientific consequence that harmonizes with both spiral arms of the Milky Way and climate changes over a long period helps us realize the fact that we exist on the Earth, moving within the Milky Way galaxy.†
The Earth belongs to the Solar System and is located at a distance of 0.1496 billion km from the sun, and is moving around the sun at a speed of 29.78 km/s.† The Solar System itself is located 27-thousand light years away from the center of the Milky Way. †The Solar System is moving at a speed of 240km/s around the center of the Milky Way, and now, the Solar System is moving outside of a galactic spiral arm, i.e., is located between a galactic spiral arm and another galactic spiral arm.† This movement of the Solar System allows it to repeat a passage through each galactic spiral arm at intervals of about 143-million years.† The inside of each galactic spiral arm is an active domain where star formation activity and the occurrence of supernova explosions are most frequently found.† Such astronomical phenomena in each galactic spiral arm can accompany the emission of cosmic rays.† During the passage of the Solar System through a galactic spiral arm, the Earth can be exposed to a higher cosmic ray flux.† The galactic cosmic ray flux reaching the Solar System should periodically increase with each crossing of a galactic spiral arm.† The magnitude of the galactic cosmic ray flux can be recorded by iron meteorites exposed to it .† Certainly, the iron meteorites record the increase in the galactic cosmic ray flux while crossing the galactic spiral arms.
On the other hand, a global icy epoch occurs with a cycle of around 135 million years.† This recurrence of the global icy epoch is revealed by examining the ratio of oxygen atoms of a mass number 18 to oxygen atoms of a mass number 16 .† The ratio resulted from the determination of traces of oxygen isotopes in fossil shells over various epochs.† A series of research projects has revealed the fact that the appearance of ice ages on the Earth varies synchronously with the appearance of cosmic ray exposure ages being recorded in iron meteorites.†
A supernova can occur accompanying a high galactic cosmic ray flux.† Collision of a high galactic cosmic ray flux with atmospheric molecules causes dust particles to be created in the atmosphere.† The dust particles can contribute to the formation of clouds.† If the Earth is covered with clouds more widely beyond the threshold, the reflection of sunlight back into space is more enhanced owing to the clouds.† As a result, the environment of the Earth can become colder.† The increase in the galactic cosmic ray flux witnessed during crossing the galactic spiral arms can cause a reduced temperature, thereby facilitating the occurrences of ice ages characterized as the maximum reduction of the mean temperature 3.5℃ .
The will to try consistently to connect the three factors, i.e., the spiral structure of the Milky Way, a specific record of iron meteorites, and oxygen isotopesí ratio in fossil shells on the Earth is capable of reminding us of the fact that all the creatures on the Earth live in the Milky Way galaxy.† Realizing that the Earth exists in the Solar System, along with many other solar systems in the Milky Way galaxy is equivalent to realizing that a continent exists with the other continents on the Earth.† The brain, consisting of over 100 billion neurons, allows itself to be amused at being an astronomical existence in the Milky Way, which has a diameter of 100,000Ė120,000 light-years and consists of 100Ė400 billion stars.† The reality of the Milky Way galaxy is not independent of our existence.† Every human (Homo sapiens) is an astronomical existence along with every other creature.† Efforts to consistently connect the spiral structure of the Milky Way, iron meteoritesí indication, and fossil shellsí indication lead to an astronomical awareness.† Moreover, this awareness allows us to be confident that the brain is capable of cerebral activity proceeding toward a more harmonized and advanced mind, while forming new connections between nerve cells through an attempt to consistently connect various factors with each other.
Cerebral Activity Accompanying Changes in Local Blood Flows
The attempt to connect the three factors with each other encourages us to think about each issue while simultaneously considering various subjects linked with it.† Then, widely various portions of neural tissues, in which nerve cells are simultaneously activated, participate in cerebral activity dealing uniformly with the different subjects.† Moreover, this simultaneous activation can transpire even though these tissues may be located far away from each other within the brain.†
When cerebral activity involves more widely various portions of neural tissues in the brain, the cerebral activity requires more energy.† For activated nerve cells, an increase in arterial blood flow has to occur in these portions of neural tissues.† This increase can be detected by using a technique called functional magnetic resonance imaging, i.e., functional MRI.†
The use of functional MRI makes it possible to detect whether or not consciousness encourages nerve cells in many different areas located far away from each other in the brain to cooperatively participate in cerebral activity.† A technique of functional MRI allows the indirect detection of nerve cells that are activated and are sending out impulses.† This technique enables the distribution of activated nerve cells to be revealed over the brain.
A role of science and philosophy is to assist us to feel confident forming objectively suitable connections between more various subjects that do not connect with each other (or connect very faintly with each other).† This role is equivalent to aiding the formation of new connections between nerve cells in neuronal network systems.† Fortunately, it is possible to confirm a specific reality of the achievement of the role: the technique of functional MRI enables the reality to be detected.†
In arterial blood flow, red blood cells containing oxygenated hemoglobin molecules are plentiful, and in venous blood flow, red blood cells containing deoxygenated hemoglobin molecules are plentiful.† The magnetism of deoxygenated hemoglobin molecules is paramagnetic so that an ensemble of the molecules induces magnetization in a magnetic field.† The magnetism of oxygenated hemoglobin molecules is diamagnetic so that an ensemble of the molecules induces virtually resistant magnetization.† Thus, in a magnetic field, magnetization of a local region depends on blood flow in capillary vessels.† Within the capillary vessels in the local region, if arterial blood flow becomes more dominant for neuronal activity than venous blood flow, the magnetization of the local region will be reduced.†
Neuronal activation and cerebral blood flow in capillary vessels are coupled.† When neurons in a small local region of a neural tissue become active and begin sending out impulses, local blood flow coming into the active region increases.† The aid of nitric oxide causes vascular arterial capillaries to expand, and allows the active region to draw in more blood, and a rapid delivery of blood to the active region is achieved.† An expansion of arterial blood vessels and a higher rate of arterial blood flow allow the amount of arterial blood flow to become more dominant transiently within the active region.† In the active region, the number of red blood cells containing oxygenated hemoglobin molecules begins dominating the number of red blood cells containing deoxygenated hemoglobin molecules around 2 seconds after triggering the neuronal activity.† The ratio of oxygenated hemoglobin molecules to deoxygenated hemoglobin molecules rises to a peak at 4 to 6 seconds.† Then, the amount of oxygen carried in the active region can be more than the amount of oxygen consumed for synthesizing adenosine triphosphate (ATP) from glucose.† Finally, the ratio of oxygenated hemoglobin molecules to deoxygenated hemoglobin molecules falls back toward a lower level located somewhat below the original level when the neuronal activity stops.
After sending out an impulse, a nerve cell makes its cellular state return to the initial state, in which it is capable of generating the next impulse; the nerve cell needs to use energy supplied with the molecular form of ATP.† In a process corresponding to cellular respiration, i.e., the overall process of oxidizing glucose to carbon dioxide, about 30 molecules of ATP can be produced from a single molecule of glucose.† Oxygen is carried by oxygenated hemoglobin molecules in red blood cells.† Glucose is the primary source of energy for cerebral activity.† Delivering oxygen and glucose to the active region of the neural tissue through arterial blood flow is the inevitable response to the neuronal activity.† In the small region where the neuronal activity is induced, a net decrease in the number of deoxygenated hemoglobin molecules occurs transiently, and oppositely, a net increase in the number of oxygenated hemoglobin molecules occur transiently.†
Because the nucleus of each hydrogen atom is a proton, it has the nuclear magnetic moment proportional to the spin angular momentum of the proton; the proton spins that are attributed to the hydrogen atoms contained in neural tissues take the orientation of the static magnetic field applied to the neural tissues.† The proton spins have a tendency to be aligned in the direction of the magnetic field as they accompany precessional rotation around the axis parallel to the field.† Protons in the neural tissues can absorb energy, supplied as the electromagnetic wave having the appropriate resonant frequency.† Each proton, having absorbed the energy, changes its spin state from the lower energy level to the upper energy level.† Each proton occupying the spin state of the upper energy level can emit an electromagnetic wave as a radio frequency signal, which is measured by a receiver coil.† According to the functional MRI concept, radio frequency signals emitted by protons occupying the spin state of the upper energy level are measured after the energy supply is stopped, but before the emissions from the protons are completely decayed.†
The magnetic field applied by an MRI scanner is weakened in a microscopic area surrounding each deoxygenated hemoglobin molecule owing to the magnetic property of the molecule.† In each local region of neural tissue containing more deoxygenated hemoglobin molecules, the above effect causes the emission from protons to be weakened faster.† Hence, fewer radio frequency signals are emitted from each portion of neural tissue where deoxygenated hemoglobin molecules in the blood are plentiful.† In contrast, since oxygenated hemoglobin molecules do not weaken the magnetic field, more radio frequency signals are emitted from each portion of neural tissue where oxygenated hemoglobin molecules in the blood are plentiful.†††
Being aided by these phenomena, a technique of functional MRI can detect neuronal activity that is occurring within each partial neural tissue having a three-dimensional size characterized by the extent of a few millimeters.† In such a small unit of neural tissue, a few million neurons can be contained; this technique of functional MRI allows the activation of a few million neurons in each small unit to be detected.†
The brain does not have the sensitivity to feel the activation of each individual neuron.† The brain can, however, feel images that are generated by activation of many neurons.† Moreover, the technique of functional MRI allows the brain -- that is generating the images -- to know which areas in the brain are working simultaneously.†
An experiment in which a stuffed cat is used demonstrates an interesting suggestion.† In the brain, active areas when recognizing the entire image of the stuffed cat are more abundant and larger than active areas when recognizing a partial image of the stuffed cat.† In order to create an image closer to the reality of an object, more areas in the brain must be made active.† In order to overcome a more difficult issue, efforts to work in more various areas with wider ranges in the brain are inevitable.† A change in the blood flow in a localized area of activation of neural tissue causes a local density of deoxygenated hemoglobin molecules to transiently differ from a local density of oxygenated hemoglobin molecules.† This fact allows us to know ourselves, i.e., to know how many regions in the brain are working cooperatively; to know this cerebral activity that is performed to achieve a greater societal and ecological harmonization, which aids the continuation of our civilization.
Editorís Note: This concludes Part I of this three-part paper.
Part II will follow in the upcoming July-August issue of this Journal. - JP
The author wishes to think Dr. J. L. Bernhart for having valuable discussions about roles of science and giving valuable suggestions on the manuscript, and Dr. A. Kharrazi for having valuable discussions about climate change and sustainability.††
 Nir J. Shaviv, Physical Review Letters, 89, 051102 (2002). Cosmic ray diffusion from the galactic spiral arms, iron meteorites, and a possible climatic connection?
 JŠn Veizer,et al., Nature 408, 698-701 ,2000. Evidence for decoupling of atmospheric CO2 and global climate during the Phanerozoic eon.
 Tom Clarke, Nature 408, 698-701 ,2003. Nature News: Galactic dust cooling Earth?
Nir J. Shaviv and JŠn Veizer, GSA Today, 13, 4 - 10, (2003). Celestial driver of Phanerozoic climate?
[ BWW Society Home Page ]
© 2015 The Bibliotheque: World Wide Society