[Profesi Wiki] Know the History of Space and Time | Online Profession

PROFESI-UNM.COM – Current ideas about the motion of bodies can be traced back to Galileo and Newton. Before them, people believed in Aristotle, who said that the natural state of an object is at rest and that it only moves when it is pushed by some force or impulse. So, heavy objects will fall faster than light objects, because heavy objects have a greater pull towards the earth.

Aristotle also said that all the laws that govern the universe can be learned by thinking alone. Proof by observation is not required. However, Galileo proved Aristotle wrong by dropping an object from the leaning tower of Pisa. Galileo’s measurements showed that every object experiences the same increase in velocity (acceleration) regardless of its weight.

Galileo’s measurements were used by Newton as the basis for the laws of motion. In Galileo’s experiments, as an object rolled down a slope, it was always affected by the same equal force (the object’s weight), and the effect was acceleration. It shows that the true effect of a force is always to change the speed of an object, not to make the object move as it was previously thought. It also means that if an object is not affected by a force, it will continue to move in a straight circle at the same speed.

The big difference between Aristotle’s ideas and those of Galileo/Newton is that Aristotle believed that a state of rest is natural, and any object will be at rest if it is not pushed by a force. Aristotle thought that the earth was stationary. However, according to Newton’s laws there is no standard unique state of rest. The absolute absence of a stationary reference means that we cannot be sure whether events that occurred at different times occurred in the same position in space.

Newton was very worried about the absence of absolute position or so-called absolute space, because it did not match his idea of ​​an absolute god, even though his own laws said so. Newton was criticized for his irrational beliefs by many people. Aristotle and Newton both believed in absolute time. That is, they believe that we can measure a period of time that will always be the same regardless of who is measuring it, as long as you wear a good watch. Time is completely separate and disconnected from space. That is what most people consider to be the common sense view. However, that idea does not apply to objects moving at or near the speed of light that travel at a certain speed and very high. The speed of light was first discovered in 1676 by the Danish astronomer Ole Christensen Roemer.

This article is quoted from the book “A Brief History of Time” by Stephen Hawking, Pages 21-27, published by PT Gramedia Pustaka Utama, Jakarta.