Skip to main content Accessibility Feedback

Now I Know

If you love learning about lots of random, interesting things, go sign up for Now I Know right now. Every day, Dan Lewis sends out an email about one really interesting topic.

Last week I learned that those white trails planes leave are called contrails, and they may actually help decrease global warming.

Sign up now.

🚀 Make 2018 the year you master JavaScript! My pocket guides and mini courses are short, focused, and made for beginners. You can do this!

Have any questions or comments about this post? Email me at or contact me on Twitter at @ChrisFerdinandi.

Get Daily Developer Tips