The universe we live in is empty mainly in terms of matter density. The protons and neutrons that constitute matter are called baryons, and approximately one proton exists in a space of 19.8 square meters. However, when the universe expands rapidly, the cosmic background radiation, known as a photon, is produced, resulting in two billion more photons in a grain of light. Since this light is a microwave, which has low energy and a long wavelength, it cannot be seen by the human eye. Therefore, humans, who only perceive visible light, consider the universe and the night sky to be dark. If there were aliens capable of seeing microwaves, the universe would be shining very brightly. The truth is that nothing has changed, but if the standards shift, it’s an entirely different story. - Joseph’s “just my thoughts”
In the USA, even in one country, the time difference between the west and the east is 3 hours. People thought that time was a natural thing. But it is not. It's very political. The time that man lives in a unit of minutes is too short. However, since the invention of the steam locomotive, the appearance of faster vehicles made crazy changes to the concept of time. The shift in distance made people realize what time was. Sandford Fleming, an engineer and inventor, asked to unify the time difference caused by long-distance transportation, but people rejected his request. If the boarding time were not fixed, the railroad would be useless. The history of the 24-hour clock was made only about 140 years ago. Even with the invention of high technology, if nothing is consensus, nothing benefits. - Joseph's "just my thoughts"