The body of an average human being contains trillions of germs living both on it and inside it, not to mention a good number of multicellular parasites that we won’t consider here. These germs are comprised of microorganisms such as bacteria, fungi, protozoa, and archaea, and infectious agents such as viruses. These germs outnumber the cells in the human body by a 10 to 1 ratio, and their combined number is greater than the number of stars in our galaxy. We are not conscious of it, but when we interact with each other physically as in, for example, shaking hands, or even at a distance as in, for example, talking with each other in close proximity, we exchange germs. The vast majority of these germs are either not harmful to us, or can be dealt with by our immune system. However, every now and then a germ comes along that can pose a real threat to us. Such is the case of the current coronavirus (COVID-19) pandemic.
In the video below, YouTuber Mark Rober, uses Glo Germ powder which can be visualized under black light to show how we can transmit germs to each other and pick them up from surfaces. This is especially relevant as it has been shown that the virus that produces the COVID-19 disease can survive on surfaces for intervals ranging from hours to days.
Remember to protect yourself from the virus by following these simple guidelines from the CDC.