A movie that explains 'Where are you in the vast universe?' On a ridiculous scale



Many people think of where they are now as 'home room,' 'toilet,' 'neighborhood convenience store,' 'park bench,' etc., but this is just the information that their body can receive. It's just a thing. In reality, the place where humans are is on the round earth, which rotates and revolves at high speed, and the solar system continues to move in outer space. Kurzgesagt, a scientific YouTube channel, explains the mysterious question 'Where am I in the vast universe?'

You Are Not Where You Think You Are --YouTube


When asked 'Where are you now?', Many people say 'in the room' ...



You can expand it further and think of it as a city, a continent, the earth, or one of the stars in the galaxy.



It is difficult to think exactly where you are, but the concept of 'absolute position' was created by humans, and the actual position is only relative.



If all beings, such as stars and black holes, disappear from the universe, only empty space remains behind.



In an empty space, everything is uniform and the meaning of 'specific position' is lost.



In other words, matter is positioned only in 'relationship with something else', and the concepts of up and down and left and right are only relative.



When humans go out and look around, the world looks flat and capable of three-dimensional movement up, down, left and right. This point of view is called a 'frame of

reference ' in physics, and there is no problem at least from the point of view of the person himself.



But in reality, the world is not flat. The earth is spherical, and humans can only see the horizon about 5 km away ...



People who live in the 'down' direction from their own perspective recognize this side as 'down'.



'Bottom' is a concept influenced by gravity, and it is an illusion of a reference frame.



Also, people usually use maps with the north up, so it's easy to think that the north is up ...



Being looking at the Earth from a greater distance may see this in reverse.



Admitting that 'the earth is actually not flat, but spherical' is not the end.



The earth is constantly spinning and revolving around the sun, not just in one place.



Many people may think that rotation and revolution are very orderly movements, but in reality they are more complicated than people think.



In fact, the orbit of the earth

is not a perfect circle but an ellipse, and even during the year, it may be near or far from the sun, and the speed of movement is also changing.



In addition to that, the elliptical orbit is also shifted every 100,000 years, and the revolution orbit is also changing little by little. Will be.



This is affected by the gravity of the Earth's moon, the moon.



The moon is quite huge and has enough gravity to pull the earth. The earth and the moon orbit a common center of gravity, but this is about 4700 km away from the center of the earth, and the earth is drawing a swaying orbit by that amount.



Therefore, the orbit of revolution is slightly shaken by the gravity of the moon.



The 'plane of the solar system' is defined as the plane around which the earth orbits ...



In fact, each planet orbits a slightly offset plane.



Moreover, even the solar system is not immovable. The solar system belongs to the

Milky Way (Milky Way Galaxy) and orbits the center of the galaxy.



The solar system orbits the galaxy in a cycle of about 230 million years ...



The plane of the solar system does not coincide with the

galactic plane where most of the mass of the galaxy exists, and it is said that it is tilted by about 60 degrees.



Seen from the center of the galaxy, the planets of the solar system appear to orbit in a spiral.



Also, the mass of the

galactic disk surrounding the galaxy also affects the orbit of the solar system ...



It is said that the solar system orbits while going up and down with respect to the galactic plane.



It is estimated that it will take about 30 million years for the solar system to move up and down once, but it seems that it is not completely mapped because it is too long.



When we confirm the relative position again, the earth revolves around the sun while drawing a complicated orbit due to gravity with the moon ....



The solar system revolves around the galaxy while moving up and down under the influence of the galactic disk while the plane is tilted 60 degrees with respect to the galactic plane.



It is meaningless to think about the galaxy, 'Which is above and which is below?' Due to the problem of the reference frame.



The galaxy is in the corner of the

Laniakea Supercluster , which contains a total of about 100,000 galaxies ...



The Laniakea Supercluster constitutes the largest structure in the universe called

galaxy filaments . At this point, it is easy to realize that the perspectives of humans living on the earth are only relative.



We will return to the perspective of humans living on the earth.



Considering the scale of the universe, my head may be confused, but ...



In fact, these facts are not a big deal for humans. The fact that humans exist somewhere on the earth has not changed ...



Kunzgesagt states that nothing prevents him from thinking that he is in the center of a small universe.



in Science,   Video, Posted by log1h_ik