What is motion in physics?

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It is not easy to find an adult who has never heard the catch phrase “Movement is life” in his life.

There is another formulation of this statement, which sounds somewhat differently: “Life is movement”. The authorship of this aphorism is usually attributed to Aristotle – an ancient Greek scientist and thinker who is considered the founder of all “Western” philosophy and science.

Today it is difficult to say with complete certainty whether the great ancient Greek philosopher ever uttered such a phrase, and exactly how it sounded in those distant times, but, looking at things with an open mind, it should be admitted that the above definition of movement is, although sonorous, but rather vague and metaphorical. Let’s try to figure out what movement is from a scientific point of view.

The concept of motion in physics

Physics gives concept “movement” a very specific and unambiguous definition. The branch of physics that studies the movement of material bodies and the interaction between them is called mechanics.

The section of mechanics that studies and describes the properties of motion without taking into account its specific causes is called kinematics. From the point of view of mechanics and kinematics, motion is considered to be a change in the position of a physical body relative to other physical bodies that occurs over time.

What is Brownian Motion?

The tasks of physics include observation and study of any manifestations of motion that occur or could occur in nature.

One of the types of motion is the so-called Brownian motion, known to most readers of this article from the school physics course. For those who, for some reason, were not present at the study of this topic or had time to thoroughly forget it, let us explain: Brownian motion is the chaotic motion of the smallest particles of matter.

Brownian motion occurs wherever there is any matter, the temperature of which exceeds absolute zero. Absolute zero is the temperature at which the Brownian motion of particles of matter should stop. On the Celsius scale, which we are used to using in everyday life to determine the temperature of air and water, the temperature of absolute zero is 273.15 ° C with a minus sign.

Scientists have not yet succeeded in creating the conditions that cause such a state of matter; moreover, there is an opinion that absolute zero is a purely theoretical assumption, but in practice it is unattainable, since it is impossible to completely stop the oscillations of matter particles.

Biological Movement

Since biology is closely related to physics and in a broad sense is completely inseparable from it, in this article we will consider motion also from the point of view of biology. In biology, movement is considered as one of the manifestations of the vital activity of the organism. From this point of view, movement is the result of the interaction of forces external to an individual organism, with the internal forces of the organism itself. In other words, external stimuli cause a certain reaction of the body, which manifests itself in movement.

It should be noted that although the formulations of the concept of “motion”, adopted in physics and biology, are somewhat different from each other, in their essence they do not enter the slightest contradiction, being simply different definitions of the same scientific concept.

Thus, we are convinced that the catch phrase, which was discussed at the beginning of this article, is fully consistent with the definition of motion from the point of view of physics, so we just have to repeat the common truth once again: motion is life, and life is motion …