red light
- Definition
- Red light is the 625-740 nm wavelengths of the visible light spectrum (approximately 400-700 nm) which appears red to the eye.
- Definition Source
- NAL Thesaurus Staff
- Spanish
- luz roja
An official website of the United States government.
The .gov means it's official.
Federal government websites always use a .gov or .mil domain. Before sharing sensitive information online, make sure you're on a .gov or .mil site by inspecting your browser's address (or "location") bar.
This site is also protected by an SSL (Secure Sockets Layer) certificate that's been signed by the U.S. government. The https:// means all transmitted data is encrypted - in other words, any information or browsing history that you provide is transmitted securely.