Believe it or not gravity is not really a force, it is an acceleration and on Earth it is about 32 feet/sec2. This same science principle applies in decelerating devices like parachutes and parafoils. The parachute decelerates or slows down the fall of the object.
What is a .DS_Store or ._ AppleDouble file? .DS_Store files are created by OS X to store metadata about folders and files including viewing options, icon positions and color labels. ._ AppleDouble files are created by the OS X when an application adds resource data or metadata to a file on a disk whose format doesn't support resources or metadata.
6 Answers 6. Given that Macs support multiple forks to files, the AppleDouble trick (._ files) try to preserve the data in those forks. So they are needed so that Mac OS X can perform operations on them. However, most of the files are created when the same volume is mounted through AFP, not SMB/CIFS or NFS.