sentence: Most people hear terms like radiation and immediately think of it as a bad or dangerous thing.
sentences_after: It turns out that only certain types of radiation are ordinarily harmful to humans. For example, ultraviolet radiation can give people sunburns. X-rays and gamma rays can make a person sick, or even die if they are exposed to them for a very long time. Some types of particle radiation can also make people sick and lead to burns. Any type of radiation that causes changes in the world like these is referred to as ionizing radiation.
concept_name: people
headings: Radiation Danger from radiation
categories: Basic physics ideas Wave physics Nuclear physics