Although the effect seems impossible at first glance, it has been observed in numerous experiments, has been reported by Aristotle, Francis Bacon, and Descartes, and is well known in the folklore from around the world. Its history is rich and fascinating, culminating in the dramatic story of high school student Erasto Mpemba, who reintroduced the effect to the 20th century scientific community. The phenomenon, although simple to describe, is deceptively complex and illustrates many important issues regarding the scientific method: the role of skepticism in scientific research, the influence of theory on experiment and observation, the need for precision in the statement of a scientific hypothesis. , and the nature of falsifiability. We study the theoretical mechanisms proposed for the Mpemba effect and the results of modern experiments on the phenomenon. Say no to plagiarism. Get a tailor-made essay on “Why Violent Video Games Should Not Be Banned”? Get an Original Essay Studies on the observation that hot water pipes are more likely to burst than cold water pipes are also described. First, I will tell the story of a surprising experience. The experiment is based on an observation made several times and which seems to go against common sense. The observation is that if approximately equal amounts of a hot liquid and a cold liquid are placed together in a freezer, then the hot liquid freezes first. This seems to me to be a great example of what science teachers call a divergent event (cognitive dissonance/cognitive conflict). A divergent event is an event contrary to our current beliefs. Divergent events would be useful to allow learners to reconstruct imperfectly understood concepts. The literature on divergent events is relatively small, with the following being the main easily accessible references (Fensham and Kass, 1988; Hand, 1988; Thompson, 1989). One of the many unsolved mysteries of science, it will remain a mystery to me to achieve satisfactory results. and logical results, the physics teacher advised me to repeat the experiments to prove the results and make sure they are real. So basically what I'm trying to do is explain Mpemba's theory and find out that hot water freezes faster than cold water is the truth? I suggest that the origin of the Mpemba effect (the freezing of hot water before cold) is due to the lowering of the freezing point by solutes, gaseous or solid, whose solubility decreases with increasing temperature. temperature, so they are removed when the water is heated. Solutes are concentrated before the freezing front by zone refining in water that has not been heated, which reduces the temperature of the freezing front and thus reduces the temperature gradient and heat flow, thereby slowing the progression of the freezing front.Method:Appliance used:• Small freezer with internal temperature: to freeze water from -19.1° to -18.8°C• Cylindrical aluminum calorimetric containers measuring 65 mm high by 48 mm in diameter• Electric kettle: for boiling water• Deionized water: water free of any charged atoms or molecules, used mainly in the manufacture of water-based cleaning chemicals.• Digital data logger: for recording data over time.• Temperature probes: to measure the initial temperature.• Paper towel:• Cling film: to cover frozen water• Masking tape: to cover the area where unwanted substances are not necessary• Mains power supply: to power thesmall freezer and electric kettle. To obtain varying initial temperatures, cold deionized water was prepared at different depths in six aluminum containers (bare and open; bare and sealed on top with cling film; insulated and open; or a combination thereof). ci). Boiled water from a kettle was used to supplement the water so that the total volume of water in each container was 100 ml. The digital temperature probes were attached with adhesive tape so that the 8 mm long head of each probe was fully submerged on the water surface and these were connected to a data logger which sampled the temperature. temperature of each probe at 10 intervals. Each container was placed on an insulating layer of folded paper towel to minimize conductive heat loss through the frost layer on the freezer shelf. A schematic of the experimental setup is shown in Figure 1. A number of mechanisms have been hypothesized to explain the Mpemba effect. Monwhea Jeng [2] along with Marek Balazovic and Boris Tomazik [3] have written an excellent overview of the topic summarizing these hypotheses. The first is that the initially warmer container melts the layer of frost on which it rests more completely than the colder container; when it refreezes, it creates better thermal contact which dissipates heat more quickly. By placing the container on insulating layers of folded paper towels, the possibility of this hypothesis being effective was immediately eliminated. Boiling the water first also reduced the presence of dissolved gases. , which would also have contributed to this effect. Supercoiling, when a liquid remains fluid below its freezing point before spontaneously becoming solid, has also been proposed as an explanation. James D. Brownridge states: "Hot water will freeze before colder water only when the colder water supercoils, and then only if the nucleation temperature of the colder water is several degrees lower than that of hot water. Heating water can decrease, increase or does not change the spontaneous freezing temperature. [4]While this may be the case in some circumstances, it is not a satisfactory explanation for the following reasons. First, supercoiling is finicky. Temperature graph for two insulated tanks; the water in the container represented by the blue line starts out only 4.45°C warmer than that in the red line but begins to freeze in 15.5% less time. Graph of time to onset of freezing versus initial temperature. Red triangles: bare containers covered with cling film. Blue squares: isolated and open containers; this graph is similar to that shown in Mpemba and Osborne's 1969 paper. The phenomenon was not observed at temperatures below about -1°C, if at all. Impurities in the water, surface imperfections on the interior sides of the vessel, and even the very presence of the temperature probe head tended to consistently cause nucleation and freezing at or very close to 0°C. Efforts have been made to encourage overcoiling. (using deionized water and, in some experiments, immersing only the tip of the temperature probe), but supercoiling was still difficult to achieve. Second, Mpemba first observed this effect in ice cream, which is very unlikely to supercool; ideally, we would like a general explanation that also explains Mpemba's original observations. Third, the Mpemba effect has been observed repeatedly without.