When humans see purple, we’re really seeing a blend of red and blue light. Hummingbirds see purple plus ultraviolet—and lots of other nonspectral colors. https://bit.ly/2BsFKUF
For the first time, a commercial craft will bring a crew of civilians to the space station. It’s a harbinger of space tourism’s future—and its inequities. https://bit.ly/3jf25HC
