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”
Human beings don't know the substance of time. The time we know is only a sign expressed mathematically and astronomically by the machine "clock." Human life under the minute-unit system began when human beings lived with a comparatively precise machine. Before the Industrial Revolution, a concept of time naturally followed the ordinary way of life. When a promise was made, the condition was, "Let's meet before dinner." Therefore, there was a rare case of people angrily going outside because the counterparty was 10 minutes late. The framework that the human being makes, makes the human being again. - Joseph's "just my thoughts"