- The main objective of the freestarcharts website is to provide quality star charts for use by amateur astronomers under a “Creative Commons License”. What that means is you are basically free to download, use and/or distribute this work for non-commercial purposes with appropriate attribution. A simple credit of “www.freestarcharts.com” is all that’s required as attribution. You can also create and distribute derived works if they follow the same license. https://freestarcharts.com/contact
- The author distributes the charts in PDF format, and I converted to SVG for use on this site. I recommend downloading the original PDF for printing.
- Incredible Moiré Patterns! (youtube.com)
Sir Roger Penrose demonstrates the extraordinary moiré patterns produced by overlaying and rotating two identical, repeating patterns. As the two patterns overlapped and rotated they interfere with each other to produce tertiary patterns.
