A small point to describe the Universe
Everything is in motion
The motion is the manifestation of life in the Universe and in the world around us.
The movement is the flow of charges in an electric circuit, of the red blood cells in our body, a streaming river, the Ocean waves, a butterfly wing clap, the leopard’s running. Motion is that of celestial bodies, like the rotation and the revolution of our planet, which gives us the day and the night, and the seasons. Motion if the propagation of the sunlight which warms the Earth and feeds the life.
We can observe various types of motion, based on the trend of the moving subject. Let us consider, for example, the rectilinear motion, the circular motion, the parabolic motion, the oscillatory motion. They depend on the medium, the change of direction and the speed variations. All these aspects are the effect of the action of a force, such as gravity that holds the solar system together, the nuclear force inside an atom and the mechanical force that we apply to a top. Studying these phenomena means being able to describe what happens in nature, in our universe, and to ourselves. It means being more aware of what naturally surrounds us.
The point particle
To describe the motion we don’t need complex mathematical formulas or difficult calculations. We just need to start from a point particle.
Let us think, for example, to a ship: its movement can be understood as a variation of its position in a certain time interval. We can describe this change by thinking that the ship is a point moving in the middle of the sea. In fact, in order to locate the ship in a radar, we are not interested in knowing where the stern or the bow is. If the ship is in a port, however, knowing this information is useful for avoiding accidents. This suggests that we can approximate any moving object as a point particle if its dimensions are smaller than the reference system where it is placed.
The reference system
A reference system is a diagram where we orient ourselves when we move or when we observe the movement of others. A natural example of a reference system is the Polar Star that in the past navigators used to identify the North. To study the motion we use the Cartesian plane where the references are the X and Y axes, perpendicular to each other. This system allows us to locate a point particle through its coordinates. If these coordinates vary over time, then the point particle has moved. A point can be identified through a vector, which is a container of information. During the motion the vector indicates the magnitude and the direction of the displacement.
Knowing what surrounds us
In Physics, kinematics describes the motion of bodies with simple mathematical models using points, vectors and functions. Dynamics adds information to these models by specifying the forces that produce the motion. It is therefore a journey to rediscover the world around us through the eyes of science. It is a particular language that explains what happens in our daily life. Sounds exciting, doesn’t it?
Travel buddies
It is a journey in the company of Leo and Mia, always busy chatting about physics, and of Ren and Zoe, who will guide you in the mathematical language and Python programming.
You can meet Leo and Mia in the webcomic Physictionary, while Ren and Zoe await you in the Mathematiworld series! The two series are complementary.
You can find the newborn webcomic Physictionary on Webtoon: https://www.webtoons.com/en/challenge/physictionary/a-small-point-to-describe-the-universe/viewer?title_no=748139&episode_no=1 .
For special content and exercises take a look at my Patreon page: https://www.patreon.com/AstroFederica . And for discussions and questions, I am waiting for you in the chat, on Instagram and Twitter: https://twitter.com/AstroFederica .
Stay tuned for the next updates! See you soon!
AstroFederica
