Ionizing Radiation

Ionizing radiation

Radiation hazard symbol.
Ionizing radiation has many practical uses, but it is also dangerous to human health. Both aspects are discussed below.
Ionizing radiation is either particle radiation or electromagnetic radiation in which an individual particle/photon carries enough energy to ionize an atom or molecule by completely removing an electron from its orbit. If the individual particles do not carry this amount of energy, it is impossible for even a large flood of particles to cause ionization. These ionizations, if enough occur, can be very destructive to living tissue, and can cause DNA damage and mutations. Examples of particle radiation that are ionizing may be energetic electrons, neutrons, atomic ions or photons. Electromagnetic radiation can cause ionization if the energy per photon, or frequency, is high enough, and thus the wavelength is short enough. The amount of energy required varies between molecules being ionized. X-rays, and gamma rays will ionize almost any molecule or atom; Far ultraviolet, near ultraviolet and visible light are ionizing to some molecules; microwaves and radio waves are non-ionizing radiation.
However, visible light is so common that molecules that are ionized by it will often react nearly spontaneously unless protected by materials that block the visible spectrum. Examples include photographic film and some molecules involved in photosynthesis
Types of radiation
Alpha radiation consists of helium-4 nuclei and is readily stopped by a sheet of paper. Beta radiation, consisting of electrons, is halted by an aluminium plate. Gamma radiation is eventually absorbed as it penetrates a dense material.
Ionizing radiation is produced by radioactive decay, nuclear fission and nuclear fusion, by extremely hot objects (the hot sun, e.g., produces ultraviolet), and by particle accelerators that may produce, e.g., fast electrons or protons or bremsstrahlung or synchrotron radiation.
In order for radiation to be ionizing, the particles must both have a high enough energy and interact with electrons. Photons interact strongly with charged particles, so photons of sufficiently high energy are ionizing. The energy at which this begins to happen is in the ultraviolet region; sunburn is one of the effects of this ionization. Charged particles such as electrons, positrons, and alpha particles also interact strongly with electrons. Neutrons, on the other hand, do not interact strongly with electrons, and so they cannot directly ionize atoms. They can interact with atomic nuclei, depending on the nucleus and their velocity, these reactions happen with fast neutrons and slow neutrons, depending on the situation. Neutron radiation often produces radioactive nuclei, which produce ionizing radiation when they decay.
In the picture at left, gamma quanta are represented by wavy lines, charged particles and neutrons by straight lines. The little circles show where ionization processes occur.
An ionization event normally produces a positive atomic ion and an electron. High energy beta particles may produce bremsstrahlung when passing through matter, or secondary electrons (δ-electrons); both can ionize in turn.
Gamma quanta do not ionize all along their path like alpha or beta particles (see particle radiation. They interact by one of three effects: photoelectric effect, Compton effect, or pair production. By way of example, the figure shows Compton effect: two Compton scatterings that happen sequentially. In every scattering event, the gamma quantum transfers energy to an electron, and it continues on its path in a different direction with reduced energy.
In the figure, the neutron collides with a proton of the material which then becomes a fast recoil proton that ionizes in turn. At the end of its path, the neutron is captured by some nucleus in an (n,γ)-reaction that leads to a neutron capture photon.
The negatively charged electrons and positively charged ions created by ionizing radiation may cause damage in living tissue. If the dose is sufficient, the effect may be seen almost immediately, in the form of radiation poisoning. Lower doses may cause cancer or other long-term problems. The effect of the very low doses encountered in normal circumstances (from both natural and artificial sources, like cosmic rays, medical X-rays and nuclear power plants) is a subject of current debate. A 2005 report released by the National Research Council (the BEIR VII report, summarized in [1]) indicated that the overall cancer risk associated with background sources of radiation was relatively low.
Radioactive materials usually release alpha particles which are the nuclei of helium, beta particles, which are quickly moving electrons or positrons, or gamma rays. Alpha and beta rays can often be shielded by a piece of paper or a sheet of aluminium, respectively. They cause most damage when they are emitted inside the human body. Gamma rays are less ionizing than either alpha or beta rays, but protection against them requires thicker shielding. They produce damage similar to that caused by X-rays such as burns, and cancer through mutations. Human biology resists germline mutation by either correcting the changes in the DNA or inducing apoptosis in the mutated cell.
Non-ionizing radiation is thought to be essentially harmless below the levels that cause heating. Ionizing radiation is dangerous in direct exposure, although the degree of danger is a subject of debate. Humans and animals can also be exposed to ionizing radiation internally: if radioactive isotopes are present in the environment, they may be taken into the body. For example, radioactive iodine is treated as normal iodine by the body and used by the thyroid; its accumulation there often leads to thyroid cancer. Some radioactive elements also bioaccumulate.
[Reaction)
Ionizing radiation has many uses. An X-ray is ionizing radiation, and ionizing radiation can be used in medicine to kill cancerous cells. However, although ionizing radiation has many uses the overuse of it can be hazardous to human health. Shop assistants in shoe shops used to use an X-ray machine to check a child's shoe size, which would be a big treat for the child. But when it was discovered that ionizing radiation was dangerous these machines were promptly removed. Since they are able to penetrate matter, ionizing radiations are can be used by means of gamma or x-rays. This are usually used in industrial production. In biology, one uses mainly the fact that radiation sterilizes, and that it enhances mutations. For example, mutations may be induced by radiation to produce new or improved species. A very promising field is the sterile insect technique, where male insects are sterilized and liberated in the chosen field, so that they have no descendants, and the population is reduced.
Radiation is also useful in sterilizing medical hardware or food. The advantage for medical hardware is that the object may be sealed in plastic before sterilization. For food, there are strict regulations to prevent the occurrence of induced radioactivity. The growth of a seedling may be enhanced by radiation, but excessive radiation will hinder growth.
Electrons, x rays, gamma rays or atomic ions may be used in radiation therapy to treat malignant tumors (cancer).but it is very useful in helping those people who are suffering cancer.
.
[
Radiation hazard symbol.
Ionizing radiation has many practical uses, but it is also dangerous to human health. Both aspects are discussed below.
Ionizing radiation is either particle radiation or electromagnetic radiation in which an individual particle/photon carries enough energy to ionize an atom or molecule by completely removing an electron from its orbit. If the individual particles do not carry this amount of energy, it is impossible for even a large flood of particles to cause ionization. These ionizations, if enough occur, can be very destructive to living tissue, and can cause DNA damage and mutations. Examples of particle radiation that are ionizing may be energetic electrons, neutrons, atomic ions or photons. Electromagnetic radiation can cause ionization if the energy per photon, or frequency, is high enough, and thus the wavelength is short enough. The amount of energy required varies between molecules being ionized. X-rays, and gamma rays will ionize almost any molecule or atom; Far ultraviolet, near ultraviolet and visible light are ionizing to some molecules; microwaves and radio waves are non-ionizing radiation.
However, visible light is so common that molecules that are ionized by it will often react nearly spontaneously unless protected by materials that block the visible spectrum. Examples include photographic film and some molecules involved in photosynthesis
Types of radiation
Alpha radiation consists of helium-4 nuclei and is readily stopped by a sheet of paper. Beta radiation, consisting of electrons, is halted by an aluminium plate. Gamma radiation is eventually absorbed as it penetrates a dense material.
Ionizing radiation is produced by radioactive decay, nuclear fission and nuclear fusion, by extremely hot objects (the hot sun, e.g., produces ultraviolet), and by particle accelerators that may produce, e.g., fast electrons or protons or bremsstrahlung or synchrotron radiation.
In order for radiation to be ionizing, the particles must both have a high enough energy and interact with electrons. Photons interact strongly with charged particles, so photons of sufficiently high energy are ionizing. The energy at which this begins to happen is in the ultraviolet region; sunburn is one of the effects of this ionization. Charged particles such as electrons, positrons, and alpha particles also interact strongly with electrons. Neutrons, on the other hand, do not interact strongly with electrons, and so they cannot directly ionize atoms. They can interact with atomic nuclei, depending on the nucleus and their velocity, these reactions happen with fast neutrons and slow neutrons, depending on the situation. Neutron radiation often produces radioactive nuclei, which produce ionizing radiation when they decay.
In the picture at left, gamma quanta are represented by wavy lines, charged particles and neutrons by straight lines. The little circles show where ionization processes occur.
An ionization event normally produces a positive atomic ion and an electron. High energy beta particles may produce bremsstrahlung when passing through matter, or secondary electrons (δ-electrons); both can ionize in turn.
Gamma quanta do not ionize all along their path like alpha or beta particles (see particle radiation. They interact by one of three effects: photoelectric effect, Compton effect, or pair production. By way of example, the figure shows Compton effect: two Compton scatterings that happen sequentially. In every scattering event, the gamma quantum transfers energy to an electron, and it continues on its path in a different direction with reduced energy.
In the figure, the neutron collides with a proton of the material which then becomes a fast recoil proton that ionizes in turn. At the end of its path, the neutron is captured by some nucleus in an (n,γ)-reaction that leads to a neutron capture photon.
The negatively charged electrons and positively charged ions created by ionizing radiation may cause damage in living tissue. If the dose is sufficient, the effect may be seen almost immediately, in the form of radiation poisoning. Lower doses may cause cancer or other long-term problems. The effect of the very low doses encountered in normal circumstances (from both natural and artificial sources, like cosmic rays, medical X-rays and nuclear power plants) is a subject of current debate. A 2005 report released by the National Research Council (the BEIR VII report, summarized in [1]) indicated that the overall cancer risk associated with background sources of radiation was relatively low.
Radioactive materials usually release alpha particles which are the nuclei of helium, beta particles, which are quickly moving electrons or positrons, or gamma rays. Alpha and beta rays can often be shielded by a piece of paper or a sheet of aluminium, respectively. They cause most damage when they are emitted inside the human body. Gamma rays are less ionizing than either alpha or beta rays, but protection against them requires thicker shielding. They produce damage similar to that caused by X-rays such as burns, and cancer through mutations. Human biology resists germline mutation by either correcting the changes in the DNA or inducing apoptosis in the mutated cell.
Non-ionizing radiation is thought to be essentially harmless below the levels that cause heating. Ionizing radiation is dangerous in direct exposure, although the degree of danger is a subject of debate. Humans and animals can also be exposed to ionizing radiation internally: if radioactive isotopes are present in the environment, they may be taken into the body. For example, radioactive iodine is treated as normal iodine by the body and used by the thyroid; its accumulation there often leads to thyroid cancer. Some radioactive elements also bioaccumulate.

[Reaction)
Ionizing radiation has many uses. An X-ray is ionizing radiation, and ionizing radiation can be used in medicine to kill cancerous cells. However, although ionizing radiation has many uses the overuse of it can be hazardous to human health. Shop assistants in shoe shops used to use an X-ray machine to check a child's shoe size, which would be a big treat for the child. But when it was discovered that ionizing radiation was dangerous these machines were promptly removed. Since they are able to penetrate matter, ionizing radiations are can be used by means of gamma or x-rays. This are usually used in industrial production. In biology, one uses mainly the fact that radiation sterilizes, and that it enhances mutations. For example, mutations may be induced by radiation to produce new or improved species. A very promising field is the sterile insect technique, where male insects are sterilized and liberated in the chosen field, so that they have no descendants, and the population is reduced.
Radiation is also useful in sterilizing medical hardware or food. The advantage for medical hardware is that the object may be sealed in plastic before sterilization. For food, there are strict regulations to prevent the occurrence of induced radioactivity. The growth of a seedling may be enhanced by radiation, but excessive radiation will hinder growth.
Electrons, x rays, gamma rays or atomic ions may be used in radiation therapy to treat malignant tumors (cancer).but it is very useful in helping those people who are suffering cancer.
.
[

ACHY BREAKY HEART

Achy Breaky Heart
Spiral Waves Break Hearts
New Research Stresses the Importance of Communication between Cardiac Cells
MONTREAL, CANADA (February 5, 2002)--Who says physicists don't have heart? In an effort to study the factors that lead to fatal cardiac rhythms, a team of Canadian physicists has shown that the importance of communication applies not only to people, but also to their heart cells. The researchers report their results in today's issue of the journal Physical Review Letters.
Sudden cardiac death kills more than 250,000 people each year in the US alone. Physicists have been studying the important role that electricity plays in the heart's health-and how it may be a culprit in disease..
Electrical impulses regularly circulate through cardiac tissue and cause the heart's muscle fibers to contract. In a healthy heart, these electrical impulses travel smoothly and unobstructed, like a water wave that ripples gently in a pond. However, for reasons that have not been perfectly understood, these waves can sometimes develop into troublesome, whirlpool-like spirals of electrical activity that can circulate through the heart.
Investigating these “spiral waves,” scientists at McGill University in Montreal studied chick-embryo cardiac cells grown as a sheet of tissue. For the first two days after this arrangement of cells is created, spiral waves often form in the tissue. When the researchers sprinkled the sheet of cardiac tissue with a drug that impairs communication between the cells, rotating spiral waves broke up into multiple rotating spirals.
This spiral wave breakup is believed to be similar to the processes that lead to ventricular fibrillation, a potentially fatal cardiac rhythm that often occurs when communication between cells is impaired. In a real-world situation, reduced intercellular communication may be caused by a heart attack or by other cardiac diseases, which can produce diseased or damaged heart tissue.
Developing a theory to explain their experimental findings, the researchers gave credence to another poetic notion: electrical activity in cardiac tissue can spread like a fire in the heart. In a simplified computer model of the experimental results, the cells are irregularly distributed in space. In their model, electrical activity in cardiac tissue proliferates like a fire in a forest. Like trees, cells “light up,” or become electrically active, if enough neighboring cells display a sufficient level of electrical activity.
The model explores several scenarios, corresponding to different amounts of communication between cells. When neighboring cells are able to interact or communicate strongly with one another, electrical waves quickly pass through the tissue, unobstructed. When the interactions between cells are weak, wave propagation is completely blocked. At intermediate levels of interaction, electrical waves break up into multiple spiral waves.

Reaction:

About the said invention, my stand as a student nurse, usually electrical impulses in terms of physics, really helps a lot in everyday life because there are certain things that electrical impulses really works like for example in appliances in all machinery works, in hospital, and used in operating any things, that it is very useful. About the said electrical impulses that was invented and discussed by the scientist, in other ways it is effective in
Helping the heart if there is cardiac problems, but there are certain things that must consider, usually a heart must have no obstruction and healthy, because when it’s not it could easily produce ventricular fibrillation, or cold have abnormal heart beating that could alter his circulation and could end his life. Understanding the effects of communication between cells provides insights into the electrical malfunctions that are suspected to lead to heart disorders, and may ultimately suggest strategies for avoiding them. In addition, spiral wave patterns, electrical and otherwise, appear in many other places in nature. The researchers' observations can help to explain the appearance of multiple spiral waves in the corrosion on metal surfaces, the aggregation of slime molds, and visually striking chemical reactions that display ever-changing patterns.

HaHaHa! The Acoustics of Laughter:

HaHaHa!

The Acoustics of Laughter:
New Insights into this Mysterious Form of Expression

Humans have many ways to express themselves, but one of the most enjoyable - and mysterious - is laughter. More than a frivolous emotional outburst, laughter has many important functions in human communication, playing major roles in social situations ranging from dates to diplomatic negotiations.

Web Resource: Laughter's Influence Vanderbilt University

While scientists have thoroughly researched many other human sounds, such as singing and talking, remarkably little is known about the acoustics of laughter. Seeking to rectify this, Vanderbilt psychologist Jo-Anne Bachorowski and Cornell psychologist Michael Owren studied 1024 laughter episodes from 97 young adults as they watched funny video clips from films such as “When Harry Met Sally” and “Monty Python and the Holy Grail.” The surprising results were published in the September issue of the Journal of the Acoustical Society of America.

“We tend to think of laughter as being tee-hee or ho-ho, sorts of sounds,” said Bachorowski. But their results showed otherwise.

First of all, laughers produce many different kinds of sounds, including grunts and snorts. The investigators found interesting sex differences in the use of these sounds, with males tending to grunt and snort more often than females.

The sex differences don't end there. Women produced more song-like laughter than men. These song-like laughs are “voiced,” meaning that they involve the vocal folds, the tissues in the larynx involved in producing vowels and related sounds.

In men and women alike, laughs are surprisingly high-pitched. To determine this, the researchers took each voiced laugh and measured its “fundamental frequency,” which corresponds to the rate at which the vocal folds vibrate, and is heard by listeners as pitch. They found that women's laughter, on the average, was twice as high-pitched as normal speech (had twice the fundamental frequency). Men's laughter was, on the average, 2.5 times more higher-pitched than their normal speech (had 2.5 times the fundamental frequency).

Even more remarkable were the very high frequencies of some voiced laughs. Male fundamentals were sometimes over 1,000 Hertz (Hz)—about the pitch of a high “C” for a soprano singer. Females were sometimes over 2,000 Hz—one octave higher than a soprano's high C. These high fundamentals were unexpected. “I personally didn't imagine that males and females would produce sounds with fundamentals that high in natural circumstances,” Bachorowski said.

Santa Claus may also have to change his tagline, as researchers found that voiced laughter does not consist of articulated vowel-like utterances, like “tee-hee," “ha-ha,” or “ho-ho.” Instead, laughter is predominantly comprised of neutral, “huh-huh” sounds.

Ever think your laugh sounds funny when you're stressed out? The researchers found lots of evidence that laughter can be associated with out-of-the-ordinary vocal physics, such as whirlpools of air or whistles near the larynx. While the researchers don't know with certainty what the origins of such effects are, they may be associated with a high level of emotional arousal on the part of laughers.

The researchers are in the midst of further studies of laughter. For example, they are studying the impact that these sounds have on emotional responses in listeners. They are also looking to uncover what happens in the human brain when listeners hear laughter. Another piece of their work involves studying whether laughter is speech-like in the sense of providing “meaning” or symbolic value to listeners. The investigators instead think that laughter functions largely to sway a listener's emotional response, with any meaning attributed to the sounds inferred or interpreted from the situation in which the laughter is produced.

REACTION:

The researchers discovered that people produce a wide variety of laugh sounds with a remarkable range of vocal pitch. In particular, they determined that individuals vary both the number and kinds of laughs they produce depending on the sex of their social partner and whether their social partner is a friend or stranger.

"We think that laughter is one of a package of subtle yet effective tools, like physical proximity and eye gaze, that people use, albeit unconsciously, to shape the emotional and behavioral responses of others," Bachorowski said.

They found that individual women, for example, produced laughs with markedly high and variable pitch when in the company of male strangers.

Other findings of the study include:

· Men's laughter is linked to the history of their relationship with their social partner. When paired with friends of either sex, men laughed significantly more than men who were tested alone or with a male or female stranger.

· Women's laughter is linked to the sex of their social partner. Females paired with a male friend produced more laughs than females tested alone, with a female friend, or with a male stranger.

· When paired with male strangers, women's laughter tends to be higher pitched, indicative of smaller body size, possibly exploiting men's propensity to be attracted to females with juvenile features.

· People have a rich repertoire of laugh sounds, with some sounding more like bird chirps, pig snorts, frog croaks and chimpanzee pants than normal human utterances.

· Laughs can be separated into three basic categories: (1) High-pitched, song-like laughs, which fit our stereotyped notions of laughter; (2) Snort-like laughs, with sounds produced primarily through the nose; and (3) Grunt-like laughs produced through the mouth.

In a second study, which is in press in the journal Psychological Science, Bachorowski and Owren asked other listeners to rate examples of the different laugh types in terms of their friendliness, sexiness, how interested they would be in meeting the laugher, whether they thought the laugh should be included in a laugh track, and the extent to which it elicited a positive emotional response.

Regardless of the rating scheme, the researchers found that listeners were more likely to rate comparatively stereotypical, song-like laughs more positively than the other types.

"These results support the notion that one important function of laugh acoustics is to influence the emotional responses of listeners," Bachorowski said.

From an evolutionary perspective Owren and Bachorowski speculate that human laughter evolved as a way to form alliances. First came the smile, which communicated a positive disposition to other individuals. Over time, however, smiles became increasingly easy to fake, so a more complex signal was needed. That is where laughter came in. Because laughter uses more neural systems and has greater energy costs, it is more difficult to fake. So, at some point, laughter supplanted smiling as an honest signal of an interest in joining forces.

Physics in Relation to Health Sciences

Physics In relation to Health Sciences

REACTION:

Physicist are fond of saying that physics is the most basic of all sciences. There is truth in this statement, for physics concerns itself with questions that are basic to all natural sciences. The word physics comes from the greek, meaning “of nature” or “natural philosophy “. Until recent times natural philosophy encompassed many fields, including astronomy, chemistry , biology, mathematics, medicine, philosophy and concerns itself with questions of what underlies the interactions of matter, energy, space and time and even with what constitutes reality.

Physics, whether one is aware of it or not, is encountered in many situations like recreational, occupational, and even social. The situations described are few of the many, particularly in health sciences.

Athletics: We do not all have intuitive feeling for how to use our bodies most effectively. Even the greatest athletes learn from their coaches. One important area of study is kinesiology, literally the study of motion. It is based on relationships between distance, time, velocity, and acceleration. In which as we study this, there is a deeper understanding on how our body , and its muscles , and utilization of energy, and power in terms of underlying physics properties. For example: it will be clear why it is harder to carry an object at arm’s length than close to the body. Experience makes it obvious , but physics tells why. Because it has to do with where the muscles are attached to bones in relationship to the joints.

Traction Systems: Some traction systems seems to have wires, pulleys and weights going every way and performing altogether with mysterious tasks. Tractions are very important not only the strength of a force, but also the direction of the force and the point where it is applied. The strength of the force in traction will obviously depend on how large a weight is used. The direction of the force will be the same as thee direction of the wire attached to the subject.

Nutrition and excercises: Few things have caught the attention of the public as have nutrition and exercise over the several years. It turns out that work is the manifestations of energy changing forms. In humans, work changes stored food energy into heat, motion and other forms of energy. Work, energy, power and efficiency are related to food energy and human exercise.

Body temperature: Humans and other warm blooded animals maintain a constant body temperature by converting food energy to heat energy. However, the body continues to produce heat even when surrounding temperatures are higher than body temperature . that excess heat is dissipitated by perspiring. eat is a special form of energy. Perspiration is the only body’s possible method of releasing heat when surrounding temperatures. Are high. It will also be seen why an alcohol rub reduces body temperature, as might be necessary with a high fever the concept of efficiency makes it evident that the body creates even more heat than normal during exercise since a large fraction of food energy use in producing muscle contractions ends up as heat instead efficiency is less 100%. As a consequence the body requires more cooling and perspire more during exercise when at rest.

Physical therapy:Patient undergoing physical therapy usually have weakened or damaged muscles or suffer from nerve disorders that make it difficult for them to move their muscle effectively. A great deal in physical therapy takes place in water because the water helps to support the weight of the person. Being in water greatly reduces the effective weight of the person an of his limbs., making it possible for him to perform excercises that would be imposible out of water.the underying principle is the Archimedes Principle, it is one aspect of the physics of fluids

X-rays: X-Ray are part of EM spectrum. Microwaves and ultraviolet waves has properties are very useful as a diagnostic tool for medicine. Those x-rays are hazardous and cannot be made perfectly safe, that their use involves a calculated risk.

Vision: Most people consider vision to be their most important senses. Vision also applies an application of general physics of optics. Among the aspects of vision physics have explanation in the laws of physics are how the eye forms an image on the retina and the correction of common vision defects.

INTRODUCTION:

Physics attempts to describe the natural world by the application of the scientific method, including modelling by theoreticians. Formerly, physics included the study of natural philosophy, its counterpart which had been called "physics" (earlier physike) from classical times up to the separation of physics from philosophy as a positive science in the 19th century, as the study of the changing world by philosophy. Mixed questions, of which solutions can be attempted through the applications of both disciplines (for example the divisibility of the atom) can involve natural philosophy in physics (the science) and vice versa .

. Branches of physics

Classical mechanics is a model of the physics of forces acting upon bodies. It is often referred to as "Newtonian mechanics" after Newton and his laws of motion. Classical mechanics is subdivided into

statics (which models objects at rest),

kinematics (which models objects in motion), and

dynamics (which models objects subjected to forces).

Electromagnetism, or electromagnetic theory, is the physics of the electromagnetic field: a field, encompassing all of space, which exerts a force on those particles that possess the property of electric charge, and is in turn affected by the presence and motion of such particles. Electromagnetism encompasses various real-world electromagnetic phenomena.

Thermodynamics is the branch of physics that deals with the action of heat and the conversions from one to another of various forms of energy. Thermodynamics is particularly concerned with how these affect temperature, pressure, volume, mechanical action, and work. Historically, it grew out of efforts to construct more efficient heat engines — devices for extracting useful work from expanding hot gases.

Statistical mechanics, a related theory, is the branch of physics that analyzes macroscopic systems by applying statistical principles to their microscopic constituents and, thus, can be used to calculate the thermodynamic properties of bulk materials from the spectroscopic data of individual molecules.

Quantum mechanics is the branch of mathematical physics treating atomic and subatomic systems and their interaction with radiation in terms of observable quantities. It is based on the observation that all forms of energy are released in discrete units or bundles called quanta. Quantum theory typically permits only probable or statistical calculation of the observed features of subatomic particles, understood in terms of wave functions.