I’m afraid that I remain unconvinced that water divining works at all. I believe that the whole issue is psychological—the power of suggestion. A divining rod will twist when something exerts a torque on it but there is no special force between the rod and water that would exert an unusual torque on the rod.
The absence of right-handed neutrinos is simply a feature of our universe and I don’t believe anyone has a good explanation for their absence. Actually, it’s still possible that right-handed neutrinos exist, but if they do exist, then they don’t interact with other matter by way of any known force other than gravity. Even left-handed neutrinos barely interact with matter—they experience only gravity and the weak force, and usually pass through the entire earth without being absorbed. It could be that right-handed neutrinos are also present but that they don’t even experience the weak force.
In the days before digital signal processing, the filters that were available for audio or video systems were very simple. These filters monitored the audio or video signal and produced an output signal that was related to the present input signal and to that signals value’s in the recent past. Such simple filters could enhance or diminish certain ranges of frequencies and were able to perform basic tasks such as adjusting the balance between treble, midrange, and bass in an audio system.
But with computers and digital signal processing now commonplace, filtering has become much more sophisticated. Filters can now study an audio or video input signal over a long period of time and can even use data about future values of the input signal when producing an output signal. The filters that you ask about are all digital filters that produce an output signal that is related to the past, present, and future values of the input signal. A rectangular window filter is one that determines the output signal from a certain range of past, present, and future input signal values, all weighted evenly. A triangular or “Parzen” window filter is one that determines the output signal from a certain range of past, present, and future input signal values, with the weighting of values decreasing linearly with increasing time in the past or future. A Hanning window filter is one that determines the output signal from the complete past and future input signal values, with the weighting of values decreasing as the cosine of the time in the past or future (see for example, “Numerical Recipes” by Press, Flannery, Teukolsky, and Vetterling). All three filtering windows and filters are used to keep filters that extract certain frequency ranges from the input signal from affecting other frequency ranges. For that purpose, the Hanning window is better than the Parzen window and both are better than the rectangular window. As an example of the applications of these filters, a digital audio filter that makes good use of the Hanning window can enhance the treble of an audio signal uniformly without coloring the midrange at all. Earlier filters that only used past information always colored the midrange and didn’t affect the treble uniformly.
Newton’s gravity has been superceded by Einstein’s gravity; the gravity of general relativity. In this understanding of gravity, the accelerations associated with gravity result from a curvature of space/time around concentrations of mass & energy. The gravity of general relativity is responsible for such exotic effects as the bending of light by gravity and the existence of black holes.
But physicists are still not satisfied with the gravity of general relativity. General relativity is what’s known as a “classical” theory of interactions—it does not include quantum physics and is thus considered to be incomplete. All the other classical theories of interactions have given way to quantum theories. For example, the classical theory of electromagnetic interactions, dating from the works of Oersted, Ampere, Maxwell and others in the 1800’s, was replaced in the 1940’s and 50’s by quantum electrodynamics, through the works of Feynman, Schwinger, Tomonaga, and others. Each time that a classical theory is replaced by a quantum theory, the responsibility for the interactions themselves shifts from classical fields (e.g., the electric and magnetic fields) to quantized or particulate fields (e.g., photons). These sorts of quantum field theories, theories in which interactions between particles are mediated by the exchanges of other particles (the particles of the quantized fields) are the bases for all modern interaction theories except gravity itself. People are still trying to quantize gravity but so far without real success. The particles that mediate gravitational interactions have been named gravitons, but the full theory in which these particles operate is still uncertain.
At astronomical distances, there is no way to tell the difference between the two red shifts. An object that is deep in the gravitational potential well of a very massive object experiences time slowly and its light appears shifted toward the red (low frequency and long wavelength) when it reaches us. The light from an object that is moving away from us rapidly also appears red shifted (low frequency and long wavelength), but this time it’s due to the Doppler effect.
Quasars exhibit enormous red shifts and one explanation for those red shifts is that the quasars are located near the other side of the universe. If so, they would be moving away from us rapidly, along with their surroundings in the expanding universe, and their light would appear highly red shifted. Moreover, their light would have been traveling almost since the beginning of the universe so that we would be observing very ancient objects. However, it’s also possible that quasars are much near to us and that their red shifts are caused by gravitational effects rather than relative motion. As far as I know, this possibility can’t be ruled out and remains a concern amount the astronomical community.
As a phonograph record turns, the needle of its playing arm slides through a narrow spiral groove on the record’s surface. This groove is cut with a 90° angle at its bottom and both of its sides have undulations in them. As the needle slides through the groove, it rides up and down on these undulations. The needle’s movement causes currents to flow in two separate pick-ups that are attached to the needle. One pick-up responds to needle motions caused by the right edge of groove and the other pick-up responds to needle motions caused by the left edge of the groove. The physical mechanism for converting needle motion into electric current depends on the needle cartridge—it can involve moving magnets, moving coils of wire, or squeezed piezoelectric crystals. Since the groove undulations represent air pressure fluctuations at the right and left microphones during recording, the currents from the two pick-ups represent those pressure fluctuations during playback. With the help of amplifiers and speakers, these currents are used to reproduce the sounds that were recorded at the two microphones.
Water is drawn into a sponge in part because of an attraction between the water molecules and the sponge’s surface and in part because of water’s tendency to minimize its own surface area. When you put a drop of water on a waxy surface, the water beads up. That’s because water and wax don’t bind well to one another and the water molecules pull toward one another instead. The water droplet tries as best it can for form a sphere, since a sphere has the smallest surface area that a given volume of water can occupy. These forces that pull water’s surface inward are called surface tension.
But when you put a drop of water on real cellophane (a smooth form of cellulose), the water spreads out. That’s because water and cellulose bind strongly to one another and the water will permit its surface area to increase somewhat if that increase allows it to attach to more cellulose. Similarly, water binds well with other forms of cellulose, including paper, cotton, and Rayon. I think that most artificial sponges are either cellulose or a close chemical relative of cellulose.
A sponge absorbs water by allowing that water to cling to an extensive surface that binds well with water. The water spreads out along that surface while trying to minimize the surface area of any water that isn’t touching the sponge. The surface of a natural sponge interacts well with water (the sponge lives in water after all), but a natural sponge can’t compete with modern technology. A company that makes artificial sponges can adjust the chemical structure of the sponge’s plastic so that it binds nicely to water molecules; it can adjust the sizes of the holes in the sponge to attract the water as efficiently as possible with a given mass of plastic; and it can tailor wall thickness to give the sponge the right elasticity. Furthermore, some of the water is brought right into the plastic and that water softens or “plasticizes” the plastic. That’s why a sponge is hard when dry and soft when wet—the water molecules are effectively lubricating the plastic molecules so that they can slide past one another.
Yes, the mass/energy of a suspended object is greater than the mass/energy of that same object at ground level. The extreme example of this result comes with lowering an object slowly toward the surface of a black hole—as the object descends, its mass/energy diminishes until it reaches zero at the surface of the black hole.
In principle, a vacuum is a region of space containing no real particles (no atoms, molecules, electrons, or other subatomic particles). Because the universe is filled with particles that pass easily through lots of matter (neutrinos, for example), it’s very hard to obtain a true vacuum. But let’s suppose that you could actually obtain a region of space with no real particles in it. That region of space would still contain large numbers of virtual particles at any given moment. These virtual particles are temporary quantum fluctuations of the vacuum; brief excursions of the quantum fields associate with various subatomic particles. These excursions are permitted by the Heisenberg uncertainty principle, which allows temporary violations of the conservation of mass/energy as long as those violations are extremely brief. While the presence of these virtual particles can only be detected indirectly, they are not massless. Except for their short lifetimes, these particles have characteristics similar to those of normal particles. In fact, if enough energy is used in the process of looking for a virtual particle, that virtual particle can be converted from virtual to real so that it can be detected directly. The energy of detection serves to “pay” for the mass of the particle so that it can leave the virtual realm and become a real, permanent particle.
A black hole is surrounded by an imaginary surface called the event horizon. Nothing at all can escape from within this surface-not light, not X-rays…nothing! However, as matter falls into the black hole, and before it reaches the event horizon, the matter can emit any type of radiation it likes. The X-rays and radiation emitted “from a black hole” are actually coming from the area surrounding the event horizon, not from within that surface. As matter pours into a black hole, it often heats up so hot that it emits incredible amounts of radiation of all types so that black holes appear as very bright objects.