To tackle the problem of space debris above earth, does it look practical to use ion gun satellites to shoot ions into orbits so as to electrify small sized space debris, so that they would be slowed down by the earth's magnetic field and eventually burn up above earth?
covid-19 usually infect the lining of the throat first, so testing a proper throat swap would detect the virus pending on the sensitivity of the test. What if a whiff of viruses went straight into the lungs through deep breathing? Then the virus is difficult to detect early on, and these are usually diagnosed through a CT scan (3D sectional photos of the lungs). The precence of the virus in blood is a clear indicator of infection, but the blood does not get infected early on. The virus may also be present in the faeces. Even asymtomatic patients can transmit the virus. So basically, no single simple test can reliably detect an infection early on to ascertain who is not infected.
Therefore, social distancing needs to be maintained to avoid infection.