Ghosts now officially exist, thanks to Sergey Larenkov's computational rephotography

Photographer Sergey Larenkov uses computational rephotography (as shown above and explained here by Wired) to overlay extant WWII-era photographs on their corresponding modern settings. The results are both spooky and stunning:

The shots really do have to be seen large, so check out Larenkov's LJ page for the rest of 'em.
via gizmodo