Time is really important in chemical reactions. Some chemical reactions, such as  explosions, are naturally fast, while others, such as iron rusting in the presence of oxygen and water, are naturally slow. The reaction rate tells us how quickly reactants act on producuts and describes the concentration changes of reactants over time. Therefore, a catalyst is used to accelerate the chemical reaction in industries.
  With regard to time, physics speaks a little more profoundly. Time is the fourth dimension we live in. Also, physics tells us about the possibility of time travel. It does not matter whether time travel is possible or not. In many movies and dramas, time travel is a very good topic. For instance, we envy the Doctor in TV series “Doctor Who”. He has the spaceship called TARDIS (it is bigger on the inside) and can freely travel to the past, present, and future using it.
  Unlike the time we speak about in science, we do not very care about time too much in everyday life. Everybody knows that time is as fast as an arrow and we can not reverse the time that has already passed. A wise man always says “time is gold”, but it is not easy to save time.
  In Greek, there are two words about time. One is the Kairos and the other is the Chronos. The Chronos refers simply to the time that flows throughout the human history. It is a chronological time. It is the time when the sun rises and sets down and it is the time when the earth rotates and resolves. It is also the time of season’s change throughout the year.
  While the Chronos is the time given to anyone, the Kairos is a subjective time. In Greek mythology, the Kairos was the god of opportunity and the youngest son of  Zeus. He was depicted as a youth with a long lock of hair hanging down from his forehead. Therefore, Kairos has an opportunity for a moment. A time of opportunity can not be caught again if we miss it.
  If you accept time as the Chronos, it is easy to live a passive life, being its slave. On the other hand, those who look at time as the Kairos have an attitude of active engagement in time as its masters. Thus, we do not waste 1 minute and 1 second, but we try to find the meaning of life and create a new value of every moment instead.
  Although we already had a new opportunity in the New Year, we now have a chance to make new choices again in the new semester. Take the Kairos time. No matter who you are, those who have the Kairos time will have a meaningful semester and live a Kairos life in the world of the Chronos.