Time-space intersection refers to the interweaving of time and space. Often used to refer to the past and the present, two different worlds have exactly the same things or connections at a certain moment.
In real life, in epidemic prevention and control, we can use the concept of time-space crossing population to find the risk population to the greatest extent, and include more people who may be at risk of infection because of time-space crossing into epidemiological monitoring.
Introduction:
Time is the expression of eternal movement, continuity and changing order of matter, including two concepts: time and time period. Time is a parameter used by human beings to describe the process of material movement or the occurrence of events. The determination of time depends on the law of material circulation that is not affected by the outside world. The time measurement system based on the earth's rotation is called universal time system.
Time measurement of time, day, month, year and century belongs to the calendar category in astronomy. Time is one of the seven basic physical quantities in physics, and the symbol is T. In the International System of Units (SI), the basic unit of time is seconds, and the symbol is S.