Albert Camus

Charm is a way of getting the answer yes without asking a clear question.Albert Camus

An intellectual is someone whose mind watches itself. Albert Camus

Every revolutionary ends up either by becoming an oppressor or a heretic. Albert Camus

I know of only one duty, and that is to love. Albert Camus

The need to be right is the sign of a vulgar mind. Albert Camus

The only real progress lies in learning to be wrong all alone. Albert Camus

The only way to deal with an unfree world is to become so absolutely free that your very existence is an act of rebellion. Albert Camus

The real passion of the twentieth century is servitude. Albert Camus

The society based on production is only productive, not creative. Albert Camus

Virtue cannot separate itself from reality without becoming a principle of evil. Albert Camus

We always deceive ourselves twice about the people we love - first to their advantage, then to their disadvantage. Albert Camus

Albert Camus

Charm is a way of getting the answer yes without asking a clear question. 14 words

The only real progress lies in learning to be wrong all alone. 11 words

An intellectual is someone whose mind watches itself. 8 words

The need to be right is the sign of a vulgar mind. 11 words

The society based on production is only productive, not creative. 9 words

Albert Camus

The only real progress lies in learning to be wrong all alone. 11 words

An intellectual is someone whose mind watches itself. 8 words

The need to be right is the sign of a vulgar mind. 11 words

Oscar Wilde

No great artist ever sees things as they really are. If he did he would cease to be an artist. (The Decay of Lying)

Men always want to be a woman`s first love - women like to be a man’s last romance. 15 words

A cynic is a person who knows the prize of everything and the value of nothing.

Moderation is a fatal thing. Nothing succeeds like excess.

Whenever people agree with me I always feel I must be wrong.

Albert Einstien

It is the theory that decides what we can observe.

Common sense is the collection of prejudices acquired by age eighteen.

The only real valuable thing is intuition.

Intellectuals solve problems; geniuses prevent them.

If the facts don’t fit the theory, change the facts.

It is a miracle that curiosity survives formal education.

Reality is merely an illusion, albeit a very persistent one.

Anyone who has never made a mistake has never tried anything new.

I think that only daring speculation can lead us further and not accumulation of facts. (Albert Einstein, Michele Besso: Correspon-dance 1903-1955)

Albert Einstien

It is the theory that decides what we can observe.

DiscoveriesHis paper on the par t iculate nature of l ight put forward the idea that cer tain exper imental resul ts, notably the photoelectric effect , could be simply understood from the postulate that l ight interacts with matter as discrete “packets” (quanta) of energy, an idea that had been introduced by Max Planck in 1900 as a purely mathemati-cal manipulat ion, and which seemed to contradict contemporary wave theor ies of l ight (Einstein 1905a).

His paper on Brownian mot ion explained the random movement of very smal l objects as direct evidence of molecular act ion, thus support ing the atomic theory. (Einstein 1905c)

His paper on the electrodynamics of moving bodies introduced the radical theory of special re lat iv i t y, which showed that the observed independence of the speed of l ight on the observer ’s state of mot ion required funda-mental changes to the not ion of s imultanei ty. Consequences of th is include the t ime-space frame of a moving body slowing down and contracting (in the direction of motion) relative to the frame of the observer. This paper also argued that the idea of a lumini ferous aether—one of the leading theoret ical ent i t ies in physics at the t ime—was superfluous. (Einstein 1905d)

In his paper on mass–energy equivalence (previously considered to be dist inct concepts), Einstein deduced from his equat ions of special re lat iv i t y what has been cal led the t went ieth century’s most wel l known equat ion: E = mc2.[25][26] This suggests that t iny amounts of mass could be conver ted into huge amounts of energy and

presaged the development of nuclear power. (Einstein 1905e)

E EQUALS MC SQUAREDIn other words, energy equals mass multipl ied by the speed of l ight squared.The formula was derived by Alber t Einstein, who arrived at i t in 1905 in the paper “Does the iner tia of a body depend upon its energy-content?”, one of his Annus Mirabil is (“Miraculous Year”) Papers.[2] While Einstein was not the first to propose a mass–energy relationship, and various similar formulas appeared before Einstein’s theory, Einstein was the first to propose that the equivalence of mass and energy is a general principle, a consequence of the symmetries of space and t ime.In the formula, c2 is the conversion factor required to convert from units of mass to units of energy. The formula does not depend on a specific system of units. In the International System of Units, the unit for energy is the joule, for mass the ki logram, and for speed meters per second. Note that 1 joule equals 1 kg·m2/s2. In unit-specific terms, E ( in joules) = m (in ki lograms) multipl ied by (299,792,458 m/s)2.

So one gram of mass — approximately the mass of a U.S. dollar bi l l — is equivalent to the fol lowing amounts of energy:89.9 terajoules24.9 mil l ion ki lowatt-hours (≈25 GW·h)21.5 bi l l ion ki localories (≈21 Tcal) [5]21.5 ki lotons of TNT-equivalent energy (≈21 kt) [5]85.2 bi l l ion BTUs[5]Any t ime energy is generated, the process can be evaluated from an E = mc2 perspective . For instance, the “Gadget”-style bomb used in the Trinity test and the bombing of Nagasaki had an explosive yield equivalent to 21 kt of TNT. About 1 kg of the approximately 6.15 kg of plutonium in each of these bombs fissioned into l ighter elements total ing almost exactly one gram less, after cooling [The heat, l ight, and electromagnetic radiation released in this explosion carried the missing one gram of mass.][6] This oc-curs because nuclear binding energy is released whenever elements with more than 62 nucleons fission.Another example is hydroelectric generation. The electrical energy produced by Grand Coulee Dam’s turbines every 3.7 hours represents one gram of mass. This mass passes to the electrical devices which are powered by the generators (such as l ights in cit ies), where it appears as a gram of heat and l ight.[7] Turbine designers look at their equations in terms of pressure, torque, and RPM. However, Einstein’s equations show that al l energy has mass, and thus the electrical energy produced by a dam’s generators, and the heat and l ight which result from it , al l retain their mass, which is equivalent to the energy. The potential energy – and equivalent mass – represented by the waters of the Columbia River as it descends to the Pacific Ocean would be converted to heat due to viscous frict ion and the turbulence of white water rapids and waterfal ls were it not for the dam and its generators. This heat would remain as mass on site at the water, were it not for the equipment which converted some of this potential and kinetic energy into electrical energy, which can be moved from place to place (taking mass with i t ) .

Photoelectric EffectThe photons of a l ight beam have a characteristic energy determined by the frequency of the l ight. In the photoemission process, i f an electron within some material absorbs the energy of one photon and thus has more energy than the work function (the electron binding energy) of the material , i t is ejected. I f the photon energy is too low, the electron is unable to escape the material . Increasing the intensity of the l ight beam increases the number of photons in the l ight beam, and thus increases the number of electrons emitted, but does not increase the energy that each electron possesses. Thus the energy of the emitted electrons does not depend on the intensity of the incoming l ight, but only on the energy of the individual photons.Electrons can absorb energy from photons when irradiated, but they fol low an “all or nothing” principle . All of the energy from one photon must be absorbed and used to l iberate one electron from atomic bind-ing, or the energy is re-emitted. I f the photon energy is absorbed, some of the energy l iberates the elec-

tron from the atom, and the rest contributes to the electron’s kinetic energy as a free par ticle .

Photodiodes and phototransistorsSolar cells (used in solar power) and l ight-sensit ive diodes use a variant of the photoelectric effect, but not ejecting electrons out of the material . In semiconductors, l ight of even relatively low energy, such as visible photons, can kick electrons out of the valence band and into the higher-energy conduction band, where they can be harnessed, creating electric current at a voltage related to the bandgap energy.

Photoelectron spectroscopySince the energy of the photoelectrons emitted is exactly the energy of the incident photon minus the material ’s work function or binding energy, the work function of a sample can be determined by bom-barding it with a monochromatic X-ray source or UV source (typically a helium discharge lamp), and measuring the kinetic energy distribution of the electrons emitted.Photoelectron spectroscopy is done in a high-vacuum environment, since the electrons would be scat-tered by significant numbers of gas atoms present (e .g. even in low-pressure air) .The concentric hemispherical analyser (CHA) is a typical electron energy analyzer, and uses an electric field to diver t electrons different amounts depending on their kinetic energies. For every element and core (atomic orbital) there wil l be a different binding energy. The many electrons created from each of these combinations wil l show up as spikes in the analyzer output, and these can be used to determine the elemental composit ion of the sample .

PhotomultipliersThese are extremely light-sensitive vacuum tubes with a photocathode coated onto part (an end or side) of the inside of the envelope. The photocathode contains combinations of materials such as caesium, rubidium and antimony specially selected to provide a low work function, so when illuminated even by very low levels of light, the photocathode readily releases electrons. By means of a series of electrodes (dynodes) at ever-higher potentials, these electrons are acceler-ated and substantially increased in number through secondary emission to provide a readily-detectable output current. Photomultipliers are still commonly used wherever low levels of light must be detected.

Image sensorsVideo camera tubes in the early days of television used the photoelectric effect; newer variants used photoconductive rather than photoemissive materials.Silicon image sensors, such as charge-coupled devices, widely used for photographic imaging, are based on a variant of the photoelectric effect, in which photons knock electrons out of the valence band of energy states in a semiconductor, but not out of the solid itself.

Atomic Theory

In chemistry and physics, atomic theory is a theory of the nature of

matter, which states that matter is composed of discrete units called

atoms, as opposed to the obsolete notion that matter could be di-

vided into any arbitrarily small quantity. It began as a philosophi-

cal concept in ancient Greece and India and entered the scientific

mainstream in the early 19th century when discoveries in the field of

chemistry showed that matter did indeed behave as if it were made

up of particles.

The word “atom” (from the Greek atomos, “indivisible”[1]) was ap-

plied to the basic particle that constituted a chemical element,

because the chemists of the era believed that these were the fun-

damental particles of matter. However, around the turn of the 20th

century, through various experiments with electromagnetism and

radioactivity, physicists discovered that the so-called “indivisible

atom” was actually a conglomerate of various subatomic particles

(chiefly, electrons, protons and neutrons) which can exist separately

from each other. In fact, in certain extreme environments such as

neutron stars, extreme temperature and pressure prevents atoms

from existing at all. Since atoms were found to be actually divisible,

physicists later invented the term “elementary particles” to describe

indivisible particles. The field of science which studies subatomic

particles is particle physics, and it is in this field that physicists

hope to discover the true fundamental nature of matter.

Photoelectric EffectThe cathode ray tube (CRT) is a vacuum tube containing an electron gun (a source of electrons) and a fluorescent screen, with internal or external means to accelerate and deflect the electron beam, used to create images in the form of l ight emitted from the fluorescent screen. The image may represent electri-cal waveforms (oscil loscope), pictures (television, computer monitor), radar targets and others.Color CRTs have three separate electron guns (shadow mask) or electron guns that share some elec-trodes for al l three beams (Sony Trinitron™, and l icensed versions)The CRT uses an evacuated glass envelope which is large, deep, heavy, and relatively fragile . Display technologies without these disadvantages, such as flat plasma screens, l iquid crystal displays, DLP, OLED displays have replaced CRTs in many applications and are becoming increasingly common as costs decline .An exception to the typical bowl-shaped CRT would be the flat CRTs[1][2] used by Sony in their Watch-man series (the FD-210 was introduced in 1982). One of the last flat-CRT models was the FD-120A. The CRT in these units was flat with the electron gun located roughly at right angles below the display sur-face thus requiring sophisticated electronics to create an undistor ted picture free from effects such as

keystoning.

Rare Earth Materials Rare ear th elements are incorporated into many modern technological devices, including superconduc-tors, miniaturized magnets, electronic polishers, refining catalysts and hybrid car components.[4] Rare ear th ions are used as the active ions in luminescent materials used in optoelectronics applications, most notably the Nd:YAG laser. Phosphors with rare ear th dopants are also widely used in cathode ray

tube technology such as television sets.

PhosphorsCathode ray tubesCathode-ray tubes produce signal-generated l ight patterns in a (typically) round or rectangular format. Bulky CRTs were used in the black-and-white household television (“TV”) sets that became popular in the 1950s, as well as first-generation, tube-based color TVs, and most earl ier computer monitors. CRTs have also been widely used in scientific and engineering instrumentation, such as oscil loscopes, usually with a single phosphor color, typically green.White ( in black-and-white): The mix of zinc cadmium sulfide and zinc sulfide si lver, the ZnS:Ag+(Zn,Cd)S:Ag is the white P4 phosphor used in black and white television CRTs.Red: Yttrium oxide-sulfide activated with europium is used as the red phosphor in color CRTs. The de-velopment of color TVs took a long t ime due to the long search for a red phosphor. The first red emitt ing rare ear th phosphor, YVO4,Eu3, was introduced by Levine and Pali l la as a primary color in television in 1964.[4]Yellow: When mixed with cadmium sulfide, the result ing zinc cadmium sulfide (Zn,Cd)S:Ag, provides strong yellow l ight.Green: Combination of zinc sulfide with copper, the P31 phosphor or ZnS:Cu, provides green l ight peak-ing at 531 nm, with long glow.Blue: Combination of zinc sulfide with few ppm of si lver, the ZnS:Ag, when excited by electrons, pro-vides strong blue glow with maximum at 450 nm, with short afterglow with 20 0 nanosecond duration. I t is known as the P22B phosphor. [5] This material , zinc sulfide si lver, is sti l l one of the most efficient phos-

phors in cathode ray tubes. I t is used as a blue phosphor in color CRTs.

Electron gunA DC, electrostatic thermionic electron gun is formed of several par ts: a hot cathode, which is heated to create a stream of electrons via thermionic emission, electrodes generating an electric field which focus the beam—such as a Wehnelt cylinder—and one or more anode electrodes which accelerate and fur ther focus the electrons. A large voltage between the cathode and anode accelerates the electrons. A repul-sive ring placed between them focuses the electrons onto a small spot on the anode at the expense of a lower extraction field strength on the cathode surface. Often at this spot is a hole so that the electrons that pass through the anode form a coll imated beam and finally reach a second anode called a collector. This arrangement is similar to an Einzel lens.An ion gun consists of a cylinder, where gas enters from one end face, undergoes electron bombardment from the side walls, and an is subjected to an extraction voltage from the other end face. The entire cage has the role of the cathode, the extractor acts as the anode, and an unnamed ring takes the role of the Wehnelt cylinder.Most color cathode ray tubes— such as those used in color televisions - are made up of three electron guns, each one producing a different stream of electrons. Each stream travels through a shadow mask where the electrons wil l impinge upon either a red, green or blue phosphor to l ight up a color pixel on

the screen. The resultant color that is seen by the viewer wil l be a combination of these three.