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If the photons are formed by the collision of a particle and an antiparticle, the invariant mass is the same as the total energy of the particle and antiparticle ( their rest energy plus the kinetic energy ), in the center of mass frame, where they will automatically be moving in equal and opposite directions ( since they have equal momentum in this frame ).
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If and photons
If the photons reside mainly in the higher index material, the confinement is due to total internal reflection.
If light ( photons ) of frequency ν < sub > 12 </ sub > pass through the group of atoms, there is a possibility of the light being absorbed by atoms which are in the ground state, which will cause them to be excited to the higher energy state.
If the number of photons being amplified per unit time is greater than the number of photons being absorbed, then the net result is a continuously increasing number of photons being produced ; the laser medium is said to have a gain of greater than unity.
If the ground state has a higher population than the excited state ( N < sub > 1 </ sub > > N < sub > 2 </ sub >), the process of absorption dominates and there is a net attenuation of photons.
If we imagine the beam is made of photons, then every second numerous photons strike the surface and are absorbed.
If the light were totally reflected then the radiation pressure is doubled compared to total absorption, this is because the photons arrive with momentum E / c and depart with momentum-E / c ( the-ve sign indicates traveling in the opposite direction ), so the change of momentum is 2E / c.
If light falling on the device is of high enough frequency, photons absorbed by the semiconductor give bound electrons enough energy to jump into the conduction band.
If the bandgap is too high, most daylight photons cannot be absorbed ; if it is too low, then most photons have much more energy than necessary to excite electrons across the bandgap, and the rest is wasted.
Prior to any measurements being made, the polarizations of the photons are indeterminate ; If a measurement is made on one of the photons using a two-channel polarizer aligned with the axes of the coordinate system, the photon assumes either horizontal or vertical polarization, with 50 % probability for each orientation, and the other two photons immediately assume the identical polarization.
If photons of a particular wavelength are absorbed by matter, then when we observe light reflected from or transmitted through that matter, what we see is the complementary color, made up of the other visible wavelengths remaining.
If the photons are formed by the disintegration of a single particle with a well-defined rest mass, like the neutral pion, the invariant mass of the photons is equal to rest mass of the pion.
If the Universe is dominated by radiation, or by dark energy, though, those potentials do evolve, subtly changing the energy of photons passing through them.
If their main purpose is radiation measurement, they are called radiation detectors, but as photons are also ( massless ) particles, the term particle detector is still correct.
If this is the case, some or all of the photons emitted by the fluorophore may be absorbed again.
If a Dp-brane is embedded in a spacetime of d spatial dimensions, the brane carries ( in addition to its Maxwell field ) a set of d-p massless scalars ( particles which do not have polarizations like the photons making up light ).
If the optical filter passed only that frequency band, then there would be a net transfer of photons, and their energy, from the second system to the first.
If this were true however, the radiometer would spin away from the non-black faces, since the photons bouncing off those faces impart even more momentum than the photons absorbed on the black faces.
If and are
If it were not for an old professor who made me read the classics I would have been stymied on what to do, and now I understand why they are classics ; ;
If I even hint at it do you think it will matter that you are his nephew -- and not even a blood nephew ''??
If the circumstances are faced frankly it is not reasonable to expect this to be true.
If his dancers are sometimes made to look as if they might be creatures from Mars, this is consistent with his intention of placing them in the orbit of another world, a world in which they are freed of their pedestrian identities.
If love reflects the nature of man, as Ortega Y Gasset believes, if the person in love betrays decisively what he is by his behavior in love, then the writers of the beat generation are creating a new literary genre.
If to be innocent is to be helpless, then I had been -- as are we all -- helpless at the start.
Defoe then commented, `` If they Could Draw that young Gentleman into Their Measures They would show themselves quickly, for they are not asham'd to Say They want only a head to Make a beginning ''.
If Jews are identified as a religious body in a controversy that comes before a national or international tribunal, it is obviously compatible with the goal of human dignity to protect freedom of worship.
If they are right, they will prevail of and by themselves.
Without preliminaries, Esther asked him, `` If you are a world citizen, will you take Garry Davis' place in his tent while he goes to the hospital ''??
If we are to believe the list of titles printed in Malraux's latest book, La Metamorphose Des Dieux, Vol. 1 ( ( 1957 ), he is still engaged in writing a large novel under his original title.
If the would-be joiner asks these questions he is not likely to be duped by extremists who are seeking to capitalize on the confusions and the patriotic apprehensions of Americans in a troubled time.
If we break the minister to our bit, we are buying back our own sins.
If the record buyer's tastes are somewhat eclectic or even the slightest bit esoteric, he will find them satisfied on educational records.
If Daddy's books are out of bounds his own picture books are not.
If it will simply delay the debates until the qualifications are closed next spring, and then carry all the candidates on a tour of debates, it can provide a service to the state.
If they are to be commended for foresight in their planning, what then is the judgment of a town council that compounds this problem during the planning stage??
If the Communists are sincere in wanting a united, neutral and disarmed Germany, it might well be advantageous for the German people in this nuclear age.
If only this could be done more often -- with such heartening results -- many of the earth's `` big problems '' would shrink to the insignificances they really are.
If any are left, presently, we may expect to see signs specifically prohibiting the feeding of them too.
If the raw population figures are crucially relevant, then it is idle to think of liberation, as idle as to suppose that Poland might liberate Russia.
If it is not enough that all of our internationalist One Worlders are advocating that we join this market, I refer you to an article in the New York Times' magazine section ( Nov. 12, 1961 ), by Mr. Eric Johnston, entitled `` We Must Join The Common Market ''.
If the UN troops are not mercenaries then the Hessians were not mercenaries either.
If and formed
If a broader Atlantic community is to be formed -- and my own judgment is that it lies within the realm of both our needs and our capacity -- a ready nucleus of machinery is at hand in the NATO alliance.
If tyrosine and a system generating hydrogen peroxide are added to a cell-free homogenate of the thyroid, large quantities of free mono-iodotyrosine can be formed ( Alexander, 1959 ).
* Let Q be a set enclosed between two step regions S and T. A step region is formed from a finite union of adjacent rectangles resting on a common base, i. e. S ⊆ Q ⊆ T. If there is a unique number c such that a ( S ) ≤ c ≤ a ( T ) for all such step regions S and T, then a ( Q )
If Anne formed an attachment to Weightman it does not imply that he was attracted to her.
If so, they may have originally comprised residual Celtic elements in central eastern Europe such as the Cotini, who formed a Celtic enclave in the Germanic-speaking zone and are described by Tacitus as iron-ore miners working as tributaries of the powerful Quadi Germanic people.
If two molecules react, not only molecules of the final reaction products are formed, but also some unstable molecules, having the property of being able to further react with the parent molecules with a far larger probability than the initial reactants.
If the sheet contains regions where the number of atoms in a ring is different from six, while the total number of atoms remains the same, a topological defect has formed.
If this area is excluded then Egypt has no southern-most point, its southern border being formed by the 22nd parallel north.
If X is a set with an equivalence relation denoted by infix, then a groupoid " representing " this equivalence relation can be formed as follows:
If the king had joined, its resolutions would have received the sanction of the law ; but he refused, and approached the newly formed Roman Catholic League of lords, whose members pledged themselves to support the king, the Catholic Church, and the Council.
If a ham has been cut into pieces and molded, it must be labelled " sectioned and formed ", or " chunked and formed " if coarsely ground.
In The Origin of Species, he wrote, " If it could be demonstrated that any complex organ existed, which could not possibly have been formed by numerous, successive, slight modifications, my theory would absolutely break down.
If they formed in their current locations, their orbits must originally have been circular ; otherwise accretion ( the coalescence of smaller bodies into larger ones ) would not have been possible because the large relative velocities between planetesimals would have been too disruptive.
If at least two-thirds of the National Assembly cannot agree to vote for one presidential candidate, a People's Assembly is formed from all National Assembly delegates and regional and municipal representatives who were elected by popular vote in the most recent national election.
If a fault has lineations formed by movement on the plane, e. g. ; slickensides, this is recorded as a lineation, with a rake, and annotated as to the indication of throw on the fault.
Darwin concludes: " If it could be demonstrated that any complex organ existed, which could not possibly have been formed by numerous, successive, slight modifications, my theory would absolutely break down.
If enough stabilization occurs, an inversion layer is formed.
If the mass of the progenitor is above 8 solar masses but below 10. 5 solar masses, the core temperature suffices to fuse carbon but not neon, in which case an oxygen-neon – magnesium white dwarf may be formed.
If one considers the flux of the electric field vector, E, for a tube near a point charge in the field the charge but not containing it with sides formed by lines tangent to the field, the flux for the sides is zero and there is an equal and opposite flux at both ends of the tube.
On 17 December 1783, Fox stated in the House of Commons that " If … a change must take place, and a new ministry is to be formed and supported, not by the confidence of this House or the public, but the sole authority of the Crown, I, for one, shall not envy that hon.
If its leading edge is raked back enough, it will escape the shock wave formed at the nose of the aircraft as transonic speeds are reached, reducing drag considerably, and the center of lift moves less than on conventionally configured aircraft, reducing trim drag.
If a di-isocyanate is treated with a compound containing two or more hydroxyl groups, such as a diol or a polyol, polymer chains are formed, which are known as polyurethanes.
If the beets are to be left for later delivery, they are formed into clamps.
If Earth's moon formed by such an impact, it is likely that other inner planets also would have been subjected to comparable impacts.
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