Because this range of non-zero amplitude may be very broad or infinite, this definition is typically relaxed so that the bandwidth is defined as the range of frequencies in which the signal's spectral density is above a certain threshold relative to its maximum.

Because waves at different frequencies propagate at differing phase velocities in dispersive media, for a large frequency range ( a narrow envelope in space ) the observed pulse would change shape while traveling, making group velocity an unclear or useless quantity.

Because the microwave predecessor of the laser, the maser, was developed first, devices of this sort operating at microwave and radio frequencies are referred to as " masers " rather than " microwave lasers " or " radio lasers ".

* Because bass sounds have a higher amplitude than high frequency sounds ( for the same perceived loudness ), the space taken in the groove by low frequency sounds needed to be large ( limiting playback time per side of the record ) to accommodate the bass notes, yet the high frequencies required only tiny variations in the groove, which were easily affected by noise from irregularities ( wear, contaminates, etc.

Because of the frequencies used, early models of UMTS phones designated for the United States will likely not be operable elsewhere and vice versa.

Because they convert electricity into laser light with much higher efficiency, diode lasers also run cooler, which in turn allows them to be operated at much higher frequencies.

Because pseudogenes are presumed to change without evolutionary constraint, they can serve as a useful model of the type and frequencies of various spontaneous genetic mutations.

Because it is excited by small changes and tends to hold its prior output values for a long time, it can pass relatively low frequencies.

Because it requires large ( i. e., fast ) changes and tends to quickly forget its prior output values, it can only pass relatively high frequencies, as would be expected with a high-pass filter with a small.

Because each channel is 0. 2 MHz wide, the center frequencies of adjacent channels differ by 0. 2 MHz.

Because channel 9A is not used for television services in or near Sydney, Melbourne, Brisbane, Adelaide or Perth, digital radio in those cities are broadcast on DAB frequencies blocks 9A, 9B and 9C.

Because radio waves in this band can be reflected back to Earth by the ionosphere layer in the atmosphere, called " skip " or skywave propagation, these frequencies can be used for long distance communication, at intercontinental distances.

Because satellites have a limited number of frequencies to use, the ability to re-use a frequency for different geographical locations ( without different data interfering with each other at the receiver ) allows for more local channels to be carried, since the same frequency can be used in several regions.

Because of that, very steep low-pass filters are used on frequencies above 20 kHz ( the theoretical limit of human hearing ) that may introduce slight distortions into the audible-range signal.

Because glass transitions and secondary transitions are seen in both frequency studies and temperature studies, there is interest in multidimensional studies, where temperature sweeps are conducted at a variety of frequencies or frequency sweeps are conducted at a variety of temperatures.

Because period is the inverse of frequency, lower tone frequencies take longer to decode.

Because of the difficulty of building transmitters that can generate such long waves, ELF frequencies have been used in only a very few manmade communication systems.

Because of its electrical conductivity, seawater shields submarines from most higher frequency radio waves, making radio communication with submerged submarines at ordinary frequencies impossible.

Because of this huge size requirement and, to transmit internationally using ELF frequencies, the earth itself must be used as an antenna, with extremely long leads going into the ground.

Because GaN transistors can operate at much higher temperatures and work at much higher voltages than GaAs transistors, they make ideal power amplifiers at microwave frequencies.

Because the cipher doesn't change any of the characters, the ciphertext will have exactly the same letter frequencies as the underlying plaintext.

Because of the structure of the cochlea and the basilar membrane, different frequencies of sound cause the maximum amplitudes of the waves to occur at different places on the basilar membrane along the coil of the cochlea.

Because of the frequencies involved considerable amount of the sound energy ( on the order of ten percent ) actually travels into this would be sound " shadow zone ".

Because the skull conducts lower frequencies better than air, people perceive their own voices to be lower and fuller than others do.

Because of the quantum mechanical nature of the electrons around a nucleus, atomic orbitals can be uniquely defined by a set of integers known as quantum numbers.

Because it demonstrates the fundamental limitation of the observer to predict experimental results, Richard Feynman called it " a phenomenon which is impossible ... to explain in any classical way, and which has in it the heart of quantum mechanics.

Because of this, most physicists expect that quantum gravity effects will preclude this option.

Because of its close relation to the time-evolution of a system, it is of fundamental importance in most formulations of quantum theory.

Because the muon is a lepton, the atomic energy levels of muonium can be calculated with great precision from quantum electrodynamics ( QED ), unlike the case of hydrogen, where the precision is limited by uncertainies related to the internal structure of the proton.

Because of its relatively constant and well-known fluorescence quantum yield, quinine is used in photochemistry as a common fluorescence standard.

Because a wormhole time-machine introduces a type of nonlinearity into quantum theory, this sort of communication between parallel universes is consistent with Joseph Polchinski ’ s discovery of an “ Everett phone ” in Steven Weinberg ’ s formulation of nonlinear quantum mechanics.

Because an arbitrary potential can be approximated as a harmonic potential at the vicinity of a stable equilibrium point, it is one of the most important model systems in quantum mechanics.

Because the complexity of a quantum system is exponential in its number of degrees of freedom, it is difficult to overlap the quantum and classical descriptions to see how the classical approximations are being made.

Because force is the time derivative of momentum, the concept of force is redundant and subordinate to the conservation of momentum, and is not used in fundamental theories ( e. g., quantum mechanics, quantum electrodynamics, general relativity, etc .).

Because numerous experiments agree with the predictions of quantum mechanical theory, and show correlations that are, according to Bell, greater than could be explained by local hidden variables, the experimental results have been taken by many as refuting the concept of local realism as an explanation of the physical phenomena under test.

Because quantum mechanics only reproduces classical mechanics in a statistical interpretation, and because the statistical interpretation only gives the probabilities of different classical outcomes, Bohr has argued that classical physics does not emerge from quantum physics in the same way that classical mechanics emerges as an approximation of special relativity at small velocities.

Because the quantum efficiency of Hubble's detectors is quite low at 300 nm, the noise in observations at this wavelength is primarily due to CCD noise rather than sky background ; thus, these observations could be conducted at times when high background noise would have harmed the efficiency of observations in other passbands.

Because of its more general utility, the remainder of this article will deal primarily with classical information, although quantum information theory does also have some potential applications ( quantum computing, quantum cryptography, quantum teleportation ) that are currently being actively explored by both theorists and experimentalists.

Because of reasons like these, the Aharonov – Bohm effect was chosen by the New Scientist magazine as one of the " seven wonders of the quantum world ".

Because the electrons from different molecules start " fleeing " and avoiding each other, electron density in a molecule becomes redistributed in proximity to another molecule, ( see quantum mechanical theory of dispersion forces ).

Because astrophysics is a very broad subject, astrophysicists typically apply many disciplines of physics, including mechanics, electromagnetism, statistical mechanics, thermodynamics, quantum mechanics, relativity, nuclear and particle physics, and atomic and molecular physics.