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.
In order to get rid of AppleDouble files, you can on a Mac the dot_clean command: dot_clean --keep=dotbar /Volumes/mounted_smb_volume. where mounted_smb_volume would be the name of the mounted volume. You could add it to a crontab entry, or better yet, use something like Lingon X to create a launchd entry.