Epicycle

Planetary or epicyclic Compact transmission with driving and driven shafts in line, large speed reduction when required ... 

The difference between the two types of case cannot, therefore, concern what was or was not known when theory was produced. Instead the crucial difference is the fact that, in the cases of little or no support, certain aspects of the theory concerned were fixed precisely to yield the phenomena at issue. The relative velocities around the deferent and epicyclic circles in Ptolemy s theory had to be read off the phenomena of stations and retrogressions in order for that theory to yield those phenomena. The details of the fossil-accommodating version of creationism had to be read off the already known fossil record—which particular pretty pictures God chose to draw and what particular features the bone-like structures have can only be determined by observation. 

As an example of the insufficiency of present usefulness and self-consistency as grounds for belief in a scientific construct, it may be in order to recall some scientific history. In our own field we have the familiar example of phlogiston and in astronomy the example of epicycles. By the use of epicycle superimposed on epicycle, the geocentric theory was able to give a self-consistent, popular, and accurate description of apparent planetary motions. The epicycle treatment is analogous to a Fourier analysis of the motions and its accuracy did not guarantee the physical reality of epicycles. 

The oxygen cycle is complicated by its ability to take part in a lot of chemical reactions giving a multitude of epicycles. This fact makes the oxygen cycle sufficiently stable but hinders assessment of its stability. 

Also many epicycles are possible one could consider inflation with several scalar fields, which usually produce isocurvature fluctuations, inflation with a non smooth potential, in which case the slow roll conditions may not be satisfied at some epochs, which then translates into features in the perturbation spectrum (step-like, or with a break in the spectra index), etc. 

The larger atomizer machines cited in Table 12-41 represent a range of very large rotary atomizers available to industry. They are equipped with epicyclic-type gearboxes complete with a lubrication system. An extensive monitoring system is integrated in each machine. 

Coincidentally, this has the the same form as the Newtonian azimuthal frequency. Other (usually smaller) frequencies associated with the orbit are the radial epicyclic frequency n (the frequency of a radial perturbation of Eq. (9) about the circular orbit just discussed), and the vertical frequency (of perturbations off the exactly circular planar orbit). The orbit must lie at r > in addition all circular orbits with rh < r < Srn are known to be unstable n —> 0 at r = 3/y, which is thus known as the innermost stable circular orbit (ISCO). Periodic phenomena associated with circular motion must take place outside the ISCO. Thus Eq. (20) implies for the frequency of a periodic phenomena,... 

Bacon probably saw in Galileo s procedure the continuation of the medieval astronomers epicyclic method, which described a planet s path first by the best circle, the deferent, to which are then added epicycles to account for deviations from pure circular motion. Galileo used an analogous procedure in his study of dynamic processes on earth. Perhaps, he did this as a direct consequence of the fact that Copernicus had placed the earth among the planets, thus suggesting that the same methodological procedures are applicable to both. 

Obviously, a t) has inherited minimal period 2ttIuji from the shape equation. Fourier expansion of cr(t) and direct integration of (3.20) implies that z(t) undergoes a 2-frequency bounded meandering epicycle motion, unless the frequencies... 

To prove that the earth was fixed at the centre of the universe Ptolemy used the observation that all falling objects drop to the centre of the earth. He accepted the traditional order of celestial objects, rotating on crystal spheres arormd the earth, but realized that the implied circular motion had to be replaced by auxiliary circular motion along epicycles on circular deferents. Deferents are large circles centred on the earth and epicycles are small circles whose centres moved around the circumferences of the deferents. The sun, moon and planets move around the circumferences of their own epicycles. This model was still insufficient to account in full for the motion of the... 

Whereas the dogma of uniform circular motion demanded that the moving planet traverse equal arcs in equal intervals of time, Kepler discovered the new uniformity of equal areas in equal times to be valid for any elhpse, including the circle. By adding an additional focus to planetary orbits the need of epicycles was eliminated and the wandering planets were shown, for the first time, to follow harmonious paths around the sim. This discovery should have destroyed the Ptolemaic system for good. It failed. Not even Kepler s discovery of a new supernova, that remained visible for 17 months, was sufficient to shake the world s faith in a permanent sphere of fixed stars. 

The wheels are conventionally driven by electric motors, either directly or by belt drives through a worm and worm wheel gearing system (low-capacity wheels) or by helical or epicyclic gearing systems (high-capacity wheels). 

Conical Dryer with Screw Mixer The conical dryer with screw mixer is similar in principle to the double-cone dryer-blender although the vessel is stationary and solids are mixed by epicyclic screw mixer (Figure 33.13). For pressures from 25 to 150 mbar and wall temperatures from 40°C to 60°C, Simon [6] reports evaporation rates of water up to 10 kg/h m. Units up to 5 m are commercially available. The dryer has no dead spaces and is easy to clean. 

FIGURE 33.13 Conical vacuum dryer with epicyclic screw mixer (1, steamjacket 2, hatch 3, feed tube 4, exit port and valve 5, motor 6, drive arm 7, mixing auger). 

As shown in Fig. 1, this unique design enables the performance of DuCCC using five flow channels connected directly to the column without using a rotational seal. When a column with a particular coil orientation is subjected to an epicyclic rotation, it produces a unique hydrodynamic phenomenon in the coiled column in which one phase entirely occupies the head side and the other phase occupies the tail side of the coil column. This unilateral phase distribution enables the performance of DuCCC in an efficient manner. A theoretical calculation of the hydrodynamic forces resulting from such an epicyclic rotation is very complicated and has not been elucidated. 

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