bugeye mentioned my statement of why does BF only show up in the woods..
people still have genes that allow thier minds to see patterns and assess dangers real or imagined, its a hold over from the neolithic era, most valuable when people were still considered prey. so, today when we are in the woods, tired and cold or lost, the mind fires and hormones kick in, those left over genes "go to work" so to speak and people see BF in the shadows.. nothing more to it really.
alternate dimensions.. or the multi ( many ) worlds concept of quantum physics, is to this point pure speculation. even top minds like steven hawking is only guessing and no viable data for other dimension exist. however if BF traveled thru a rift here is what we'd actually be referring to a spacial dimesion.
dimesion theories such as the string theory suggest that physical space has 10 dimensions .These dimensions are spatial meaning realtive to each other by a measurement. However, we perceive only three spatial dimensions ( height, width, and length ) along with time, and up to current scientific knowledge no experimental or observed evidence( thru the scientific method ) is available to confirm or even suggest the existence of any extra dimensions..
First, does Bigfoot cross in and out of this other dimension into ours at will?
no because BF as a biological natural creature does not exist in reality.
Does Bigfoot knowingly opens the door and comes thru then exits when it wants to?
no BF cannot control hypathetical dimensional doorway for the above reasons.
Second, does Bigfoot have or may have an extra organ in its body that allows dimensional jumping, etc?
no, because an biological organ could not control hypathetical quantum physics
so, i wont continue to answer these very valid questions in the negative, because my answers will be the same, for the above data suggests if and thats one huge if, dimensions via quantum dynamics exist, there would be no way to study or test it.
i.e. you cannot see a quantum particle , observe its location and see it movement to and from that location..