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This observation was, in principle, rejected by the scientific community, but gained momentum with the work of the German physician Julius von Mayer(1814-1878) and James Joule(1818-1889). Julius von Mayer realized that the venal blood of patients on the island of Java (Indonesia) had a bright red coloring characteristic of arterial blood, which is more oxygenated. This observation led to the conclusion that von Mayer in hot climates, the human body needs less oxidation tokeep warm. It is due to Mayer, the idea that the human body takes energy from food and turns it into mechanical work by the muscles, or heat, the oxidation of blood. The German doctor was also the first to propose the "Principle of Conservation of Energy", according to which the total amount of energy in the universe is constant, due to changes by physical and chemical processes. Mayer tried to demonstrate this principle by establishing a mechanical equivalent of heat, however its results were given little credence by the scientific community of the time. Disbelief in principle in the work of Rumford and Mayer shows how slow and dificultoso may be the process of overcoming a scientific model. The work of Rumford, for example, was ignored by the next fifty years his presentation. In the 1840s, the work of James Joule gave a consistent basis for the theory of molecular agitation, through the establishment of a relationship between mechanical work and heat. Joule studied systems in which heat was produced by means of energy dissipation in viscosity liquid, friction between solids and the passage of electric current by wires (such as a shower), for example. An important idea in the work of Joule comes precisely from what we saw on Mayer, the transformation of one form of energy into another. An example of this can be seen when a glass fell from a table. At the top of the table, the glass has a certain gravitational potential energy, as it falls, this energy is converted into kinetic energy. Upon reaching the ground, it seems that the energy is lost. However what happens is that part of the mechanical energy is transformed into heat in the body and the ground, and the other part is converted into sound energy. The total energy of the process remains constant, we have only a transformation in every moment. ACTIVITY
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Ovo promatranje je, u principu, odbijen od strane znanstvene zajednice, ali je dobio zamah s radom njemački liječnik Julius von Mayer(1814-1878) i James Joule(1818-1889). Julius von Mayer shvatio da je potkupljiv krv bolesnika na otoku Javi (Indonezija) imali svijetle crvene boje obilježje arterijske krvi, što je više kisikom. Ovo promatranje je dovelo do zaključka da je von Mayer u vrućim klimatskim uvjetima, ljudsko tijelo treba manje oksidacijuostati topla. To je zbog Mayer, ideja da je ljudsko tijelo uzima energiju iz hrane i pretvara u mehanički rad od strane mišića, ili topline, oksidaciju krvi. Njemački liječnik je također prvi predložiti "princip očuvanja energije", prema kojoj je ukupna količina energije u svemiru je konstanta, zbog promjena od strane fizičkih i kemijskih procesa. Mayer pokušao pokazati ovaj princip uspostavljanjem mehanički ekvivalent od vrućine, no njegovi rezultati su dobili malo povjerenje od strane znanstvene zajednice vremena. Nevjericu u principu u radu RUMFORD i Mayera pokazuje koliko je spor i dificultoso može biti proces prevladavanja je znanstveni model. Rad Rumford, primjerice, bila ignorirana od strane sljedećih pedeset godina njegova prezentacija. U 1840, rad James Joule dao dosljedan temelj za teoriju molekularne agitacije, kroz uspostavljanje odnosa između mehaničkog rada i topline. Joule studirao sustave u kojima je toplina su uz pomoć energije rasipanja u viskoznosti tekućine, trenje između čvrstih tijela i prolaskom električne struje strane žice (kao što tušem), za primjer. Važan pojam u radu Joule dolazi upravo od onoga što smo vidjeli na Mayer, transformaciji jednog oblika energije u drugi. Primjer za to može se vidjeti kada stakla pala sa stola. Na vrhu tablice, staklo ima određenu gravitacijsku potencijalnu energiju, dok pada, ta energija pretvara u kinetičku energiju. Nakon dolaska u zemlju, čini se da je izgubio energiju. No ono što se događa je da je dio mehaničke energije pretvara u toplinu u tijelu i na tlo, a drugi dio se pretvara u zvučne energije. Ukupna energija procesa ostaje konstantan, imamo samo preobrazbu u svakom trenutku. AKTIVNOST