When the trailer for the upcoming all-female reboot was released, then recut by film director Bevan Bell, both made the rounds of the internet so fast that almost no one noticed the "secret" featurette that appears on a website whose address is hidden inside a shot in the trailer. 

According to Slate: "Tucked inconspicuously into the trailer footage (at around the 1:05 mark) was a short shot of an equation-filled whiteboard. Appearing somewhat mysteriously atop it was a url: ParanormalStudiesLab.com." This website contains the video seen above, which contains an explanation by an actual scientist person, James Maxwell, senior postdoctoral associate at MIT’s Laboratory for Nuclear Science.


Apparently, when the film's director, Paul Feig, wanted to update the famous proton pack (the beam shooting, ghost catching device from the first two films), he turned to Maxwell, who used science to come up with a redesigned prop that could (in theory) function in the real world. 

Check it out, provided you are not afraid of any ghosts. Or easter eggs. 

Source: Slate