Wi-Fi’s ubiquity in modern society has prompted a reactionary response among an increasingly vocal minority who claim Wi-Fi signals are hazardous to their health, a condition they call “electromagnetic hypersensitivity.” Such claims are unsupported by scientific research, according to Kenneth R. Foster, professor emeritus of bioengineering at the University of Pennsylvania, in an article for research journal Education Next published Tuesday.

Claims of adverse health effects from Wi-Fi, and other radio frequency (RF) signals, rely heavily on the colloquial use of scientific terms. Opponents of Wi-Fi quite often bandy about “radiation,” which average people associate with nuclear accidents or overexposure to X-rays. Scientifically, radiation is defined as “energy moving through space,” and Foster notes that “even light from a flashlight is a form of radiation.” The key differentiator is that RF signals are a form of non-ionizing radiation, which is unable to damage cells and tissues.