The Fourier transform has become one of the most analytical tools, which is used for the sound intensity analysis and acoustic measurement in many industrial areas. But this method has the limitation that sound sources to measure need to be stationary and it does not provide true characteristics of time varying signals. Instead of the Fourier transform, advanced analysis methods such as the short-time Fourier transform, the Wigner-Ville distribution and the wavelet transform were proposed. These instantaneous spectrum analysis methods can be applied for obtaining the instantaneous intensity...

Space-time in a vacuum has generally been viewed as a transparent and ubiquitous empty continuum within which physical events take place. However quantum field theory and quantum electrodynamics views the vacuum as the sum total of all zero-point fluctuations of the vacuum electromagnetic field, arising from the continuous creation and annihilation of virtual particle pairs. It is this latter more contemporary view that is, for the first time, more fully explored in text form with Physics of the Zero Point Field. The scope of applications in this book range from the Casimir effect, the...