Nonexistence of Twins’ Paradox in Polygonal and Circular Paths: The Proof of the Real Solution

Authors : Luís Dias Ferreira

DOI : doi.org/10.47752/sjsr.8.1.15.22

Abstract:
The so-called Twins’ Paradox has been a controversial issue for more than a century, concerning the foundations of modern physics, in this case, the credibility of special relativity itself. In fact, how can a supposed credible theory predict paradoxes, if one assumes that there can be no paradoxes in Nature? Since Einstein’s founding paper, the phenomenon of time dilation has been mistakenly used to construct a seemingly insoluble contradiction at the heart of the theory, calling into question the fundamental equivalence between inertial frames of coordinates. In an early paper on the subject, I proved that, whether on a one-way trip or a linear round trip, there is no paradox at all: twins meet again at the same age, and this despite time-dilation. Regarding the round trip, a new dilation factor emerged, in an equation for the final time that is precisely the same for the reference frame of each twin. In a second paper, by means of a well-founded conjecture, these conclusions were generalized to closed regular polygonal paths and, in the limit, to circular paths. A generalized equation was proposed and thoroughly verified, while various aspects of the problem were addressed and highlighted. However, it was only a conjecture, formal proof was missing. This paper brings that proof, thus turning the conjecture into a theorem, i.e., a scientific fact.

Design and Evaluation of Grapes Crusher De-Stemmer Machine for Small to Medium-Scale Grape Producers

Authors : Honest Method Lyaruu; Godlove Michael Warwa; Benjamin Lyangalo Yuda; Nelson Richard Makange

DOI : doi.org/10.47752/sjsr.8.1.1.14

Abstract:
This research presents the design and evaluation of a grape crusher-destemmer machine specifically developed for small to medium-scale grape producers. The objective was to enhance processing efficiency, reduce production costs, and improve the quality of grape products in the local wine industry. The machine was designed and developed at TEMDO and was rigorously tested for key performance metrics, including crushing efficiency, destemming accuracy, throughput capacity, and juice yield. Results indicated an average crushing efficiency of 92%, destemming accuracy of 96% and SD of 1.14, and a throughput of 800 kg of grapes per hour, all meeting or exceeding established targets. The juice yield averaged 70.35 % and a standard deviation of 0.772, demonstrating the machine’s effectiveness in maximizing extraction while minimizing waste. Economic analysis revealed that the machine, constructed using locally sourced materials, is a viable investment for grapes processors, with an estimated return on investment within two to three years. The study highlights the potential for the machine to enhance the local grape processing sector, promote sustainable practices, and support economic growth in rural areas. Recommendations for future improvements include automation features, further testing with diverse grape varieties, and establishing user training programs. This work contributes to the ongoing efforts to modernize agricultural practices in Tanzania and supports the development of a competitive local grape industry