Take the 2-minute tour ×
Science Fiction & Fantasy Stack Exchange is a question and answer site for science fiction and fantasy enthusiasts. It's 100% free, no registration required.

Caught the end of Ghost last night on Sky Living. It struck me as odd as there is a whole section on how he can't interact with living objects through touch. He goes and gets guidance from the train ghost who teaches him how to touch objects (even though he's dead).

Now, it may be a flaw in the film makers thoughts but if he cannot touch living objects with this his hands, surely that same logic applies to his feet. Why can he walk on floorboards? Surely if you apply the logic of he cant touch objects and his hands go through them when he tries, surely his feet would do the same and he would actually keep falling through the core of the earth and out the other side?

share|improve this question
    
Maybe they don't fall through the floor for the same reason that Wile E. Coyote doesn't immediately fall off the cliff: because they don't know they're supposed to, being in limbo and all. –  FishBasketGordo Apr 25 '12 at 14:44

4 Answers 4

up vote 26 down vote accepted

This is actually a pretty standard film and tv problem. Examples come from all over, including Star Trek: TNG. (In the episode called The Next Phase) As far as I know, the only time this problem has been directly addressed was in the terrible Cosby movie Ghost Dad. In which, Cosby falls into a carpet like the floor wasn't there, but is able to catch himself on the 'edge' of the floor.

This problem is sometimes cavalierly side-stepped with some comment about the metaphor of floors being useful for ghosts to occupy multiple levels of space, just like they are for people. In this case, the idea is that the ghosts are capable of passing through the floor, but typically chose not to, because it is confusing. These ghosts are just flying so that their feet seem to touch the floor.

But in the case of Star Trek, the problem is explicit. They goofed. Or rather, chose to goof in the name of not having an episode where Geordi phases and falls instantly into the vacuum of space, while also suffocating from the lack of air phased along with him. (Since they had already done the let's randomly and brutally kill a main cast member thing.)

Also, there is a more interesting question here: Are ghosts made of dark matter? They react to gravity but don't otherwise interact with traditional matter.

share|improve this answer
5  
+1 for dark matter comment –  Christopher Galpin Mar 14 '11 at 14:54
    
As tempting as it was to downvote for mentioning the abomination that is Ghost Dad, that paragraph on Star Trek needs an upvote. –  Keen Mar 14 '11 at 17:57
    
It's tough being a ghost. To appear to stay in the same place, you have to simultaneously compensate for the earth's spin, the earth's orbit around the sun, the sun's orbit around the galactic center and our galaxy's motion in our expanding universe. –  Ferruccio Mar 16 '11 at 23:18
    
@Ferruccio, maybe not. If Ghosts are dark matter, they are affected by Gravity, which means they follow the curvature of space and so from their relative position, everything else is moving around them, not the other way around. :P –  DampeS8N Mar 16 '11 at 23:26
    
@DampeS8N There was also an episode of Batman Beyond that dealt with phasing in an accurate way. –  OghmaOsiris Sep 26 '11 at 6:26

If a ghost cannot interact with "things" then it stands to reason that things cannot interact with the ghost. This includes gravity, which makes sense, since gravity as a function of mass, and presumably ghosts have no mass. Therefore it is not possible for ghosts to "fall" in any sense, since "falling" is caused by gravity.

The second problem with your question also relates to this. It is not possible to "keep falling through the core of the earth and out the other side." In the (impossible) event of you being able to move through matter unobstructed and still being affected by gravity, you would "fall" to the centre of the earth and no further. Apparently it is quite hot there, so we had better hope that you are also unable to be affected by energy.

So the scenes as depicted in the movie you saw make sense (given the premise.) The ghost would have to "pretend" to be walking, presumably in order not to "freak out" innocent bystanders.

share|improve this answer
    
Wait, so if they're massless but affected by gravity, wouldn't they fall to the middle of the Earth extremely quickly? –  Keen Mar 14 '11 at 17:59
    
@Keen He means massless in the sense that they would not be effected by gravity. Not massless like photons are massless and therefore can move at the speed of light but are still affected by gravity. –  DampeS8N Mar 14 '11 at 18:45
    
I'm asking about his second paragraph's scenario. –  Keen Mar 14 '11 at 19:00
    
I suppose it depends on the definition of "falling." The whole premise is so unscientific that one can conjecture almost anything. That is the fun of fantasy. Make up your own rules. –  user1217 Mar 15 '11 at 2:39
1  
@Piet What about momentum? IF you were falling to the center of the Earth, you would shoot past it very quickly. Falling "up" on the other side, you would slow down, eventually stop, and reverse direction toward the middle. Eventually you would stop at the middle, but that would be after many oscillations. –  CajunLuke Aug 18 '11 at 15:08

This question is adressed in 'Kill the dead' by Tanith Lee as well. Ghosts are an unwanted fact of everyday life. They cannot touch or manipulate things, but they do not fall through floors either. One ghost even manages to catch a musical instrument which was dear to him in life.

The ghost hunter/ destroyer of the story explains that ghosts are creatures of habit. Falling through floors would be really unpractical, they would never stop falling. (and would protect things they have protected in life as well. But ghosts are socialized in the culture they haunt as well. So they can move through walls and such, because when they were alive, they were taught that ghosts move through walls.

share|improve this answer

Perhaps his ability to grab objects, is on the same level as touching objects, and whatever heavenly body forged his being decided that he should subconsciously decide NOT to fall through the floor for obvious reasons.

share|improve this answer

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.