italysoft/curios/einstein/einstein-e-il-tempo.php A profound criticism of the Newtonian conception of space and time as absolute entities and not related , was later elaborated by Albert Eintein (1879-1955) , the most famous scientist lived in our century. Einstein realized that the perception was involved in the relativity of motion , just as the observation of the movement of objects was necessary that the object was illuminated : the relativity of Galileo had to relate to the light. Einstein reasoned that if the time of perception of objects was instant (T = 0), the speed of light should be infinite , as was exemplified until then , when we open our eyes and look at the world , we see what it is actually and at the same time present around us. But Einstein knew that Michelson and Morley , two American scientists had shown in 1887 that the speed of light was high , but not infinite , and that in fact corresponded to approximately 300,000 km / second ( quantity denoted by c ) . This means that the light of the stars that we see in the sky from the past , we can in fact accidentally see the light emitted by a star , which in effect has not existed for a long time. Then Einstein , following the statement that it is not measurable nothing faster than light , he imagined to ride the light that carries information about the movement , hence the need to change the dimensions for the space / time in which the events are observed . In fact , moving at the speed of light esploreremmo all the past of the universe : since the ratio S / T should be as a maximum limit equal to the speed of light, which in vacuum was measured as universal constant c , and if the speed of light is constant , to be such in all conditions of motion, must vary the numerator and / or denominator of the ratio , which expresses the speed . In addition, Einstein proposed his theory of relativity in 1905 , he formulated the hypothesis that if we consider the total energy ( E) a universal constant , the change of the dimensions of space and time must correspond to a change in the mass of bodies. From here the famous relativity equation , E = mc2 . This formulation means that, in the vicinity of the speed of light , the mass of a body in motion must become energy. With Einstein realized a big change in thinking to space and time : the equation of relativity states that if the mass of bodies in motion varies depending on the speed , then new dimensions of space / time are defined by the interactions of the mass variable with the field of energy. For Einstein space and time are no longer distinct and absolute quantities of primordial value as Newton had supposed , but intrinsically related , so the space is not completely distinguishable by time, are the events of interaction between energy and matter that determine the variable size space / time universe. Unfortunately, these relativistic distortion of space / time depending on the speed at which they are subject the masses of bodies in motion , generate unacceptable logical paradoxes as yet unresolved . The most famous is the so-called twin paradox . This is a mental experiment in which it is supposed that a twin remains on the ground and the other sail in space at a rate that approximates more and more to that of light ; given that c = S / T, if the speed of the ship increases , the value of time on the ship must decrease , ie it must slow the ticking clock of flying twin than the twin was on the ground . In this case, when the twin steering wheel returns home to find his brother much older than him. This kind of paradox is not new : it is often pointed out the paradox of Achilles and the Tortoise of Zeno of Elea (480 ? BC), which prevented the fast Achilles to overtake the tortoise because , before reaching it , he should get half the distance between him and the turtle , but if you are supposed to be able to divide a segment of space to infinity , so Achilles can not have anything other than an infinite time to reach the infinitesimal division of the distance that separates it from the turtle. The twin paradox as that of the turtle unattainable , show how some scientific reasoning , apparently consistent , leading to paradoxical conclusions . Therefore remain a challenge to search for new conceptual models for the revision of previous scientific reasoning , although it seems that in many ways logical , strictly applied , it becomes irrational also to the common sense. An obvious error common to the two paradoxes of Achilles and turtle , as well as in that of the twins , consists in treating entities such as space and time as absolute , and then think of making them relative to each other . Each entity , in fact to be regarded as absolute , should also be absolutely distinct from the other and therefore can not then be relativized . This simple logical thinking is not enough to better understand the mystery of time : a challenge far more important and complex emerges today in science. What is the time in relation to the birth and evolution of life is a question still open to the creativity of young people able to apply to the study of science.
Posted on: Thu, 19 Sep 2013 21:05:02 +0000
Trending Topics
Recently Viewed Topics
© 2015