Can bacteria and viruses be seen under intense light known as "candling"?

The assertion that bacteria and viruses cannot be seen under intense light, or "candling," is correct. Candling is a method generally used to inspect the quality of eggs, where an intense light source allows one to observe the contents of the egg, such as the development of the embryo or any defects. This technique relies on the ability of the light to penetrate the shell, which is not suitable for viewing microscopic organisms like bacteria and viruses.

Bacteria and viruses are extremely small, with bacteria typically measuring in micrometers (millionths of a meter) and viruses even smaller, often in nanometers (billionths of a meter). Neither can be resolved using standard light techniques, including candling, which lacks the necessary magnification and resolution provided by microscopes. Instead, they are visualized using specialized microscopy techniques, such as electron microscopy, which can achieve the necessary power to observe these microorganisms. Thus, stating that bacteria and viruses cannot be seen under candling reflects an understanding of these fundamental scientific principles regarding size and visibility.