The sensor allows the pilot light to be automatically re-ignited if the flame is no longer present. The circuit is a surprisingly simple one, with a PNP transistor being turned on by the flame ...

There has been light from the beginning. There will be light, feebly, at the end. In all its forms—visible and invisible—it saturates the universe. Light is more than a little bit inscrutable.

Perhaps we shouldn’t kid [Justin] given how hard he worked on this project – seventeen prototypes before ... The result is a faint blue glowing flame that’s barely above room temperature ...

The universe tells us its story mainly through light and other wavelengths of electromagnetic radiation. We learn about the planets, stars, and galaxies by their light—visible light, and also ...