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If waves are emitted from an extended source, this can lead to incoherence in the transversal direction.
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If the slowing down of certain seismic waves caused by the damp spot helped uncover the underground ocean, the unusual temperature variation with depth measured in 241 inactive oil wells helped locate the subterranean river.
If the width of the slits is small enough ( less than the wavelength of the laser light ), the slits diffract the light into cylindrical waves.
If the waves are propagating through an anisotropic ( i. e., not rotationally symmetric ) medium, for example a crystal, then the phase velocity vector and group velocity vector may point in different directions.
If a spatial extra dimension is of radius R, the invariant mass of such standing waves would be M < sub > n </ sub > = nh / Rc with n an integer, h being Planck's constant and c the speed of light.
If the pump waves and the signal wave are superimposed in a medium with a non-zero χ < sup >( 3 )</ sup >, this produces a nonlinear polarization field:
If the pump beams E < sub > 1 </ sub > and E < sub > 2 </ sub > are plane ( counterpropagating ) waves, then:
If the pump waves are of frequency ω < sub > 1 </ sub >
If two waves of the same wavelength and frequency are in phase, both the wave crests and wave troughs align.
If two interacting waves meet at a point where they are in antiphase, then destructive interference will occur.
If the object is moving either toward or away from the transmitter, there is a slight equivalent change in the frequency of the radio waves, caused by the Doppler effect.
If electromagnetic waves traveling through one material meet another, having a very different dielectric constant or diamagnetic constant from the first,
If the diaphragm is placed on the patient, body sounds vibrate the diaphragm, creating acoustic pressure waves which travel up the tubing to the listener's ears.
If the bell is placed on the patient, the vibrations of the skin directly produce acoustic pressure waves traveling up to the listener's ears.
If a sound absorbing sheet is slid in between the prongs of a vibrating fork, reducing the waves reaching the ear from one prong, the volume heard will actually increase, due to a reduction of this cancellation.
If the waves have the correct frequency ( or wavelength ) and polarization, their energy can be transferred to the charged particles in the plasma, which in turn collide with other plasma particles, thus increasing the temperature of the bulk plasma.
If u is a superposition of such waves with weighting function φ, then
If scatterers are arranged symmetrically with a separation d, these spherical waves will be in sync ( add constructively ) only in directions where their path-length difference 2d sin θ equals an integer multiple of the wavelength λ.
If the distance between musicians is large enough, listeners may perceive waves to be out of phase.
If unobstructed, radio waves will travel in a straight line from the transmitter to the receiver.
If this depends on the polarization states of the waves, then their polarization may also be altered.
If the path length in the birefringent medium is sufficient, plane waves will exit the material with a significantly different propagation direction, due to refraction.
If the radio wave frequency is decreased, a point is reached where all waves ( even vertically incident waves ) are reflected back to the Earth.
If mounted on a finite baffle, and these out of phase waves allowed to interact, dipole peaks and nulls in the frequency response result.
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.
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