“Things move that’s why things change”
These few paragraphs are for anybody who is curious about motion in nature. How do things, people, animals, images and empty space move? The answer leads to many adventures. Carefully observing everyday motion allows us to deduce six essential statements:
Everyday motion is continuous, conserved, relative, reversible, mirror-invariant – and lazy. Yes, nature is indeed lazy: in every motion, it minimizes change.
The mysteries of motion are the mysteries of all of nature as a whole. It is the great observational link between space and time and is what compelled us to coin the words space-time. From ancient times, great thinkers were fascinated by the notion of the motion. The reason for their minds to try and comprehend the obscurity of the question – Why and how things move? Is quite simple, its because many of other grand ideas came from the only door, which was of none other than motion.
Going on an extensive search for any single aspect of a phenomenon, one finds out that most of the major concept are interconnected. In most cases it leads to motion. In electromagnetism the major results are all formed due to the motion of charges or fields in space (yes, fields too move at speed of light).
In Thermodynamics the motion of atoms or molecules gives rise to the concept of heat and entropy. The very basis of Quantum theory is the special equation, Schrodinger which itself uses the terms of distance and time. Creation of different particles is because of these two reasons:
1- Due to instability (mostly because of the high energy)
2- Collision of particles at very high energy (basically kinetic energy in most cases).
We can deduce that the second reason is the more fundamental one because it is the reason for the creation of the high energy particle, thus saying that even particle physics is in the end related to motion, won’t be wrong. As for cosmology, fluid dynamics, optics, nonlinear dynamics, complexity and chaos and still many others may have motion at their heart
Motion is everywhere: friendly and threatening, terrible and beautiful. It is fundamental to our human existence. We need motion for growing, for learning, for thinking and for enjoying life. We use motion for walking through a forest, for listening to its noises and for talking about all this. Like all animals, we rely on motion to get food and to survive dangers. Like all living beings, we need motion to reproduce, to breathe and to digest. Like all objects, motion keeps us warm.
It is not easy to decipher the true nature of motion. Many great thinkers and philosophers have tried answering this question: “What is motion?”.
The scholars studying the nature of motion also argued that motion doesn’t exist at all. The Greek philosopher Parmenides argued that since nothing comes from nothing, change cannot exist. He underscored the permanence of nature and thus consistently maintained that all change and thus all motion is an illusion.
Heraclitus held the opposite view. He expressed it in his famous statement πάντα ῥεῖ ‘panta rhei’ or ‘everything flows’. He saw change as the essence of nature, in contrast to Parmenides. This debate between great philosophers led to the formation of two sections of scholars. They started to investigate in more detail whether in nature there are conserved quantities or whether creation is possible.
The collaborator of Parmenides; Zeno of Elea argued very strongly against motion, in his words – that it is impossible to slap somebody, since the hand first has to travel halfway to the face, then travel through half the distance that remains, then again so, and so on; the hand therefore should never reach the face. His argument was one of the first examples of the mortals encounter with infinity.
He argued that at a single instant of time, there is no difference between a moving and a resting body. He then deduced that if there is no difference at a single time, there cannot be a difference for longer times. Zeno therefore questioned whether motion can clearly be distinguished from its opposite, rest. Interestingly this particular idea inspired Einstein to develop the Theory of Relativity.
(© Christoph Schiller, Motion Mountain)
When we explore quantum theory, we will discover that motion is indeed – to a certain extent – an illusion, as Parmenides claimed. More precisely, we will show that motion is observed only due to the limitations of the human condition. We will find that we experience motion only because,
— we have a finite size,
— we are made of a large but finite number of atoms,
— we have a finite but moderate temperature,
— we move much more slowly than the speed of light,
— we live in three dimensions,
— we are large compared with a black hole of our own mass,
— we are large compared with our quantum mechanical wavelength,
— we are small compared with the universe,
— we have a working but limited memory,
— we are forced by our brain to approximate space and time as continuous entities, and
— we are forced by our brain to approximate nature as made of different parts.
Now just for the fun purpose, see we can’t even distinguish whether the snake is moving or not.Think why is it happening?
(© Akiyoshi KITAOKA)References-(for more details)”http://www.motionmountain.net/index.html”(Motion Mountain) Image-“http://www.ritsumei.ac.jp/~akitaoka/index-e.html”
YASH RAJ SINGH
(PHYSICS AT UTKARSHINI)