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The History of the Kaleidoscope and David Brewster

The History of the Kaleidoscope and David Brewster The kaleidoscope was invented in 1816 by Scottish scientist, Sir David Brewster (1781–1868), a mathematician and physicist noted for his various contributions to the field of optics.  He patented it in 1817 (GB 4136), but thousands of unauthorized copycats were constructed and sold, resulting in Brewster receiving little financial benefits from his most famous invention. Sir David Brewsters Invention Brewster named his invention after the Greek words kalos (beautiful), eidos  (form), and scopos  (watcher). So kaleidoscope roughly translates to beautiful form watcher. Brewsters kaleidoscope was a tube containing loose pieces of colored glass and other pretty objects, reflected by mirrors or glass lenses set at angles, that created patterns when viewed through the end of the tube. Charles Bushs Improvements In the early 1870s, Charles Bush, a Prussian native living in Massachusetts, improved upon the kaleidoscope and started the kaleidoscope fad. Charles Bush was granted patents in 1873 and 1874 related to improvements in kaleidoscopes, kaleidoscope boxes, objects for kaleidoscopes (US 143,271), and kaleidoscope stands. Charles Bush was the first person to mass manufacture his parlor kaleidoscope in America. His kaleidoscopes were distinguished by the use of liquid-filled glass ampules to create even more visually stunning effects. How Kaleidoscopes Work The kaleidoscope creates reflections of a direct view of the objects at the end of a tube, through the use of angled mirrors set at the end; as the user rotates the tube, the mirrors create new patterns. The image will be symmetrical if the mirror angle is an even divider of 360 degrees. A mirror set at 60 degrees will generate a pattern of six regular sectors. A mirror angle at 45 degrees will make eight equal sectors, and an angle of 30 degrees will make twelve. The lines and colors of simple shapes are multiplied by the mirrors into a visually stimulating vortex.

(Ecology) Plant Competition Lab Report Example | Topics and Well Written Essays - 2000 words

(Ecology) Plant Competition - Lab Report Example Hence, it is logical to think that as the density of the plant increases, the more intense the competition becomes. In fact, this was demonstrated by Kothari et al. (1974) on Dichanthium annulatum, a dominant perennial grass species. It was observed in the study that as the number of plants increased from 17 to 135 individuals per meter-squared of land, the mean dry weight and nitrogen content per D. annulanum significantly decreased as compared to the other set-ups with lower plant densities. Meanwhile, interspecific competition refers to the interaction between two different plant species vying for the same resources (Freedman, 2011). Crops interspersed with weeds would be a good example of interspecific competition. Those species equipped with the least capacity to compete for the same environmental supply has to adapt or die eventually (Went, 1973). One of the earliest experimental investigations which catalogued the existence of competition within the floral community was conduc ted by Clements et al. (1929). Clements and his team planted sunflower, wheat, potatoes, and other plants species in varying distances with each other. Height (cm), leaf area (cm2), and dry weight (g) were then taken 80 days after planting (Clements et al., 1929). Results of the experiment indicated that the closer the plants are to each other, the more apparent growth inhibition becomes. Interestingly, increasing the number of plants per plot resulted to an overall production reaching a maximum value, which did not change even if spacing was decreased (Clements et al., 1929). It was also noted that growth of all plants within the same plot were equally inhibited (Clements et al., 1929). However, a different finding was observed by Wan et al. (2006) with the growth of Leymus chinensis, a C3 grass species and Chloris virgate, a C4 grass in a mixed pot culture. The researchers cultivated L chinensis in a 21 cm-diameter pots with 2 individuals per pot (monoculture) or mixed with C. vir gate. Assimilation rate, quantum efficiency, light-saturated assimilation rate were then recorded for each set-up (Wan et al., 2006). Results revealed that interspecific competition significantly reduced the measured parameters for the C3 species. However, the presence of the C3 plants had no effect on the C4 species (Wan et al., 2006). The result suggested an asymmetric competition between a C3 and C4 species, with the negative effect taking its toll on the C3 plants only. Njambuya et al. (2011) also provided evidence in support of Wan et al. (2006) that indeed, asymmetric competition occurs. But Njambuya and her team discovered a significant finding: the response of the mixed culture of Lemna minuta, an invasive species and Lemna minor, a native species is also affected by the amount of nutrients supplemented into the culture. In the presence of high nutrient availability, the invasive species exhibited higher Relative Growth Rate (RGR) as compared to the native species (Njambuya et al., 2011) However, when under low nutrient conditions, the native species showed higher RGR relative to the invasive spec