In cyclical time, a cause A leads to an effect B, and in the future of B one could come back to the past of A: while growing older, one could enter one’s parents’ past and prevent them from meeting one another! Cyclical time is not time, since there are then no distinctions between past and future. And fourth, the Inhibitors,research,lifescience,medical past cannot be modified (it will always be that what occurred in the past did occur). As of the 19th century, the definition of what is a cause became more complex as the science of Seliciclib research buy thermodynamics developed: mathematical distribution functions were used to describe gas molecules in terms of probabilities,

a rather new concept. More recently, at the beginning of the 20th century, a form of causality principle without cause arose from quantum physics: with certain types of phenomena, which are causally related, a chronology is mandatory, but one cannot establish that the first phenomenon causes the second. Inhibitors,research,lifescience,medical Despite these new ideas about the nature of causes, physicists kept the principle of causality as a valid axiom for their work. In conclusion, in the terms of physics, the principle of causality makes it such that time cannot

be cyclical (repeating itself indefinitely), but that cycles in time can exist (phenomena can Inhibitors,research,lifescience,medical repeat themselves). Tempus The other time, Tempus, is time as we experience it subjectively. It does not flow uniformly, Inhibitors,research,lifescience,medical it depends on our emotional status, in the broad sense of activation, vigilance, and mood:

time is elastic, and the phenomenology of this characteristic has been the theme of many studies. Tempus, the subjective or psychological time can not be measured with Chronos, but nevertheless can be compared with it. Tempus rarely flows as we would wish it to: a minute, being bored or an hour of passion cannot be measured using the tools of physics. This is why we carry watches, so that we do not lose track of time. Aristotle had already observed the subjective Inhibitors,research,lifescience,medical isothipendyl nature of time: “but neither does time exist without change; for when the state of our own minds does not change at all, or we have not noticed its changing, we do not realize that time has elapsed.”22 In myths, time is considered as what will occur, the future. Many myths speak of a world before time, a world in which time had yet to come into existence. Amusingly, astrophysicists have a similar argument when they describe the origin of the universe. Recall that in the Bible, after Adam ate the apple, God said: “behold, the man has become like one of us, knowing good and evil; and now, lest he put forth his hand and take also of the tree of life, and eat, and live for ever.”23 Adam was punished for wanting to archieve eternity and he was thrown into temporality.