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The problem in answering this question is that the term wave itself is so loosely used to define that which we observe. But fundamentally a wave is just an expression of the flow of energy in time and space. It's observable evidence that energy is flowing. It's clear that traveling waves expresses the flow of energy. And the interference or superposition ...


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$f(x-vt)$ isn't the general formulation of a wave, but is the general expression for a travelling wave. Also, a standing wave can be transverse or longitudinal (on a guitar string or inside a laser cavity it is transverse, inside a flute it is longitudinal). The reason you can hear the sound of a flute is because some of the energy coming from the standing ...


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In quantum field theory, particles are simply excitations of fields. And interactions are determined by symmetry in an extremely elegant way, see gauge principle. Symmetry is the central concept in fundamental physics. Except that it determines the interaction, it can be also used to classify particles. For instance the spin of particles is characterized by ...


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Suppose that a system is subjected to an irreversible process between two thermodynamic equilibrium states. To determine the change in entropy of the system $\Delta S$ between these two equilibrium states, you execute the following sequence of steps: Forget about the irreversible process path. It cannot be used to determine the change in entropy. Focus ...


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Let's say you are doing a typical SR experiment and you have Alice and Bob flying around in spaceships and such and you have each ship feeding you data. Things outside look one way to Alice and a different way to Bob because of their inertial frames. Let's say they're observing two supernovas and trying to determine their timing relative to each other, and ...


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Boosting means you are changing a frame of reference; boosting frames doesn't imply any actual motion. When you talk about boosting, you are talking about changing the way you are observing something instantaneously. Acceleration on the other hand, is a type of motion inside a frame of reference. When you talk about acceleration, you are talking about a ...


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I might use "boost" for a short burst (more like an impulse) and "acceleration" for a more prolonged burst - but both imply a force applied for a certain time in order to effect a change in momentum. I recommend you ask your professor for clarification. He/she must have had a particular application in mind. In the case of orbital mechanics, the calculations ...


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This is, as you stated in the title of the question, a problem of definition. In order to be useful for Physics (and most Science), there is a key characteristic of the properties we use: they have to be objectively measurable. As dmckee stated in a comment to the question, the property does not only need to be able to be put in scale (as you said, you ...


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Coherence means a constant phase relationship; the phase difference could be anything, such as $\pi$ or $7 \pi / 4$. Naively, that means that two waves are coherent if and only if they have the same frequency, which makes the idea of coherence sound silly. However, it actually stands in for a lot of real world effects that can destroy interference. For ...


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Waves can be coherent and yet not have the same wavelength. It is sufficient that they have the same frequency - because that is sufficient to imply a constant phase difference. If you make a Michelson interferometer where you split an incoming light beam into two arms, and you send half the light through a column of water and the other half through air, ...



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