When a single photon is sent through an interferometer, it passes through both paths, interfering with itself, as waves do, yet is detected by a photomultiplier or other sensitive detector only once.

When an electron in an excited molecule or atom descends to a lower energy level, it emits a photon of light equal to the energy difference.

When the emission of the photon is immediate, this phenomenon is called fluorescence, a type of photoluminescence.

When the emission of the photon is delayed, the phenomenon is called phosphorescence.

When the photon is emitted at a distance equal to the Schwarzschild radius, the redshift will be infinitely large.

When such an electron decays without external influence, emitting a photon, that is called " spontaneous emission ".

When an electron meets a hole, it falls into a lower energy level, and releases energy in the form of a photon.

When this happens due to the presence of the electromagnetic field from a photon, a photon is released in the same phase and direction as the " stimulating " photon, and is called stimulated emission.

When it was found in 1900 by Max Planck that the energy of waves could be described as consisting of small packets or " quanta ", Albert Einstein further developed this idea to show that an electromagnetic wave such as light could be described as a particle ( later called the photon ) with a discrete quantum of energy that was dependent on its frequency.

When an X-ray photon collides with an atom, the atom may absorb the energy of the photon and boost an electron to a higher orbital level or if the photon is very energetic, it may knock an electron from the atom altogether, causing the atom to ionize.

When sodium or its compounds are introduced into a flame, they turn it yellow, because the excited 3s electrons of sodium emit a photon when they fall from 3p to 3s ; the wavelength of this photon corresponds to the D line at 589. 3 nm.

When such an electron decays without external influence, emitting a photon, that is called " spontaneous emission ".

When an atom is probed by an external mechanism, such as a photon or a beam of electrons with energies in the range of 2 keV to 50 keV, a core state electron can be removed leaving behind a hole.

When these are absent, however, optical detection is said to be " photon noise limited " as only the shot noise ( also known as " quantum noise " or " photon noise " in this context ) remains.

When a photon of sufficient energy strikes the diode, it excites an electron, thereby creating a free electron ( and a positively charged electron hole ).

When two nanowires acting as photon waveguides cross each other the juncture acts as a quantum dot.

When an electron and a hole recombine, it is possible for a photon to be emitted.

When the molecule relaxes it emits a photon and it returns to a different rotational or vibrational state.

When Heidegger and Sartre speak of a contrast between being and existence, they may be right, I don't know, but their language is too philosophical for me.

When they express themselves it is incandescent hatred that shines forth, the rage of repudiation, the ecstasy of negation.

When I try to work out my reasons for feeling that this passage is of critical significance, I come up with the following ideas, which I shall express very briefly here and revert to in a later essay.

When the proprietor dies, the establishment should become a corporation until it is either acquired by another proprietor or the government decides to drop it.

When the reactionary response is thus bolstered by an intellectual defense, the characteristics of that defense are explicable only in terms of the basic attitudes of unanalyzed reaction.

When I take over Taliesin, the first thing I'll do is fire you ''.

When someone in the audience rose and asked how does it feel to be a celebrity, Carl said, `` A celebrity is a fellow who eats celery with celerity ''.

When decision makers act within this frame they determine whether a claim put forward in the name of religion is to be accepted by the larger community as appropriate to religion.

When we consider the disorganized state of the world community, and the legacy of predispositions adversely directed against all who are identified as Jews, it is obvious that the struggle for the minds and muscles of men needs to be prosecuted with increasing vigor and skill.

When we turn to Aristotle's ideas on the moral measure of literature, it is at once apparent that he is at times equally concerned about the influence of the art.

When their faith in civil liberties is tested against strong pressures of social expediency in specific issues, e.g., suppression of `` dangerous ideas '', many waver and give in.

There is, of course, nothing new about dystopias, for they belong to a literary tradition which, including also the closely related satiric utopias, stretches from at least as far back as the eighteenth century and Swift's Gulliver's Travels to the twentieth century and Zamiatin's We, Capek's War With The Newts, Huxley's Brave New World, E. M. Forster's `` The Machine Stops '', C. S. Lewis's That Hideous Strength, and Orwell's Nineteen Eighty-Four, and which in science fiction is represented before the present deluge as early as Wells's trilogy, The Time Machine, `` A Story Of The Days To Come '', and When The Sleeper Wakes, and as recently as Jack Williamson's `` With Folded Hands '' ( 1947 ), the classic story of men replaced by their own robots.

When I first came across Samuel Johnson's pronouncement, `` the remedy for the ills of life is palliative rather than radical '', it seemed to me to sum up the profoundest of political and social truths.

When all else fails, it is argued that open sessions slow down governmental operations.

When a person has thoughtlessly or deliberately caused us pain or hardship it is not always easy to say, `` Just forget it ''.

When a person meets God's requirements for the experience of forgiveness he is forgiven.

When I hold my son he stiffens his whole body in my arms until he is as straight and stiff as a board.

When different colors are used, she is just as likely to color trees purple, hair green, etc..

When we become firm enough to stand for those ideals which we know to be right, when we become hard enough to refuse to aid nations which do not permit self-determination, when we become strong enough to resist any more drifts towards socialism in our own Nation, when we recognize that our enemy is Communism not war, and when we realize that concessions to Communists do not insure peace or freedom, then, and only then will we no longer be `` soft ''.

When one powerful nation strives to emulate the success of another, it is only natural.

When a man is laid to rest, he is entitled to stay put.

When I talked to Ching about it, he said, Everyone can learn, if he is not a Reactionary or lazy.

When a frog is attacked, a distress or fright call is emitted, often resembling a scream.

When the excited atoms relax back into their ground state, a low-intensity glow is emitted, giving the technique its name.

When the car is moving to the left, each successive wave is emitted from a position further to the left than the previous wave.

When the source of the waves is moving toward the observer, each successive wave crest is emitted from a position closer to the observer than the previous wave.

When held negative with respect to the cathode, the control grid creates an electric field which repels electrons emitted by the cathode, thus reducing or even stopping the current between cathode and anode.

When Arafat's death was announced, the Palestinian people went into a state of mourning, with Qur ' anic mourning prayers emitted from mosque loudspeakers throughout the West Bank and the Gaza Strip, and tires burned in the streets.

When the exposed surface reaches a temperature of about 30, 000 K, there are enough ultraviolet photons being emitted to ionize the ejected atmosphere, making it glow.

When a gamma-ray burst is pointed towards Earth, the focusing of its energy along a relatively narrow beam causes the burst to appear much brighter than it would have been were its energy emitted spherically.

When the electrode is biased more positive than the plasma potential, the emitted electrons are pulled back to the surface so the I-V characteristic is hardly changed.

When light strikes a charged photocathode plate, electrons are emitted through a vacuum tube that strike the microchannel plate that cause the image screen to illuminate with a picture in the same pattern as the light that strikes the photocathode, and is on a frequency that the human eye can see.

When the experiment is performed, the jelly baby bursts into flames and a screaming sound can be heard as rapidly expanding gases are emitted from the test tube in which the experiment is performed.

When ionizing radiation is emitted by or absorbed by an atom, it can liberate a particle ( usually an electron, but sometimes an entire nucleus ) from the atom.

When a red supergiant becomes a blue supergiant, by contracting, the faster wind it produces impacts the already emitted slow wind and causes the outflowing material to condense into a thin shell.

When the electron falls back to its ground level the light is emitted.

When burnt it emitted a fragrant odour, and hence the incense became a symbol of the Divine name ( Malachi 1: 11 ; Song of Solomon 1: 3 ) and an emblem of prayer ( Psalm 141: 2 ; Luke 1: 10 ; Revelation 5: 8, 8: 3 ).

When a very bright point of light ( and therefore very strong electron stream emitted by the photosensitive plate ) is captured, a great preponderance of electrons is ejected from the image target.

When calculating the radiance emitted by a source, A refers to an area on the surface of the source, and Ω to the solid angle into which the light is emitted.

When radiance is conserved, as discussed above, the radiance emitted by a source is the same as that received by a detector observing it.

When a radiant barrier is placed between the roofing material and the insulation on the attic floor, much of the heat radiated from the hot roof is reflected back toward the roof and the low emissivity of the underside of the radiant barrier means very little radiant heat is emitted downwards.

When no beat is played on the boards, it is called " hutsunea " ( rest ), or it can be played once, and if the performer opts to strike all two possible beats, then it is " ttakuna ", named after the two onomatopoeic sounds emitted.

When used in a room also containing 029 keypunch machines, the verifier operators sometimes missed the auditory feedback provided by the loud " thunk " noise emitted by the older 059.