Judy Skatssoon
ABC Science Online
Tuesday, 29 August 2006
Who needs ghostbusters when you’ve got Newton, says a scientist who has used physics and maths to poke holes in the way Hollywood depicts ghosts and vampires.
In a paper, published recently on the physics website arXiv, theoretical physicist Professor Costas Efthimiou of the University of Central Florida shows that when it comes to things supernatural, the figures just don’t add up.
For instance, the ability to walk through walls is a common talent of celluloid ghosts.
But Newton’s laws of physics suggest that if a ghost can walk it shouldn’t be able to pass through walls, say Efthimiou and Cornell University postgraduate student Sohan Gandhi.
Newton says a body at rest will remain at rest until it’s acted on by an external force and for every action there is an equal but opposite reaction.
So in order to walk, we apply a backward force on the floor with our feet, propelling the feet up and us forwards.
But if a ghost can walk through walls, it must be “material-less”, the authors argue, and incapable of exerting force.
By the same token, a ghost that can walk through walls should also sink through the floor, and a ghost that can walk should be bouncing off the walls it tries to pass through.
“The depiction of ghosts walking contradicts the precept that ghosts are material-less,” they write.
Ghostly chills
Sharp drops in temperature are also associated with the arrival of a ghost.
But the paper says physics, which suggests that a sense of cold is correlated more to the rate at which heat is transferred from bodies to the environment than actual temperature, can provide an explanation.
Well to fair to the ghosts….. I think the whole point of believing in them is also believing that they are living in another dimension crossing over into ours. One which defies the laws of physics in this plane/dimension. I was watching an old Carl Sagan “Cosmos” last night, and he mentioned that the laws of physics can change under certain extreme conditions, but hey, too much thought takes all the fun out.
Carl didn’t mention anything about vampires, but I thought EVERYBODY knew that they don’t turn EVERY BODY they feed on into another vampire. Only those they feel are worthy to become one of the undead. Geez, these guys should research more carefully.
The thing is, as far as science is aware the laws of physics don’t change, ever. Under extreme conditions such as inside a black hole or immediately after the big bang current physical laws don’t work, but that’s because not enough is known about the fundamentals that make up these laws, not because of any changes in the laws themselves. They need to be refined to fully explain conditions such as those. And even though unexpected things might occur then, we don’t exist in those conditions.
As for other dimensions, they may very well exist. But they’re very tiny (or alternately, universe dwarfingly large if you’re talking about branes). As I recall, they had to be smaller than 1 millimeter at last measurement (this may have been refined even smaller by now), which is still pretty big but is far from big enough to easily see a ghost peeking in. Certainly not a full human sized ghost.
But if a ghost can walk through walls, it must be “material-less”, the authors argue, and incapable of exerting force.
I was under the impression that that wasn’t true. It’s possible for a human being to walk through a wall, due to the fact that atoms are mostly empty space. However, it’s ridiculously unlikely, due to the large number of atoms in both the wall and the human body. 0% chance. But they could still theoretically all line up so that nothing collides. Maybe ghosts just have a built in infinite improbability drives?
Smerk - 30 August 2006 10:51 AM
“The depiction of ghosts walking contradicts the precept that ghosts are material-less,” they write.
That’s silly. Everyone knows ghosts don’t walk, they float. They just mime walking motions, because that’s how they got around when they were alive.
And everyone knows only some vampires kill and that they have to offer their blood to a human to make them a vampire. A vampire killing is bad, as it draws attention and suspicion, and possibly vampire hunters, so they feed off of willing hosts, instead.
But if a ghost can walk through walls, it must be “material-less”, the authors argue, and incapable of exerting force.
I was under the impression that that wasn’t true. It’s possible for a human being to walk through a wall, due to the fact that atoms are mostly empty space. However, it’s ridiculously unlikely, due to the large number of atoms in both the wall and the human body. 0% chance. But they could still theoretically all line up so that nothing collides.
Well, that’s not quite true. There’s more to an object (such as a person) than just atoms and matter; there are also the various forces that hold the atoms together or keep them from collapsing in on each other. So it’s mainly these forces repelling against each other that keep us from falling through the ground to the centre of the Earth. It’s sort of like your body and the wall being made out of billions of tiny magnets, and while some will attract each other, others will repel. And so overall, you can’t get through.
Or so we hope, or else maybe one day you will fall into the centre of the Earth. . .
Each individual particle is capable of ‘being’ on the other side of the wall at any given point. And it’s theoretically possible that all particles could spontaneously ‘be’ on the other side of the wall as you attempt to walk through it. However, to have even one particle do it is so unlikely that it’s probably never happened in the history of the universe, which gives you an idea of how unlikely it is for a whole body to do it.
Keep in mind that this is an extremely simplified version. I could make it slightly more complicated involving particles spontaneously borrowing energy to move them through the wall, but the gist is the same. For anything more detailed you’d have to ask a quantum physicist.
Sounds very similar to an argument I heard a logic (philosphy) professor make “proving” the non-existence of God or souls or anything else whose definition includes at some level something supernatural (i.e. something beyond or independent of the material world). Basically, you can’t have something that influences matter without being matter (I mean “matter” vs. spiritual—obviously energy and matter are interchangeable. This isn’t a phsyics argument really, but a logical one.) If the defintion of something is “not material” then it can’t have any of the accidents of something material. (It can’t be p and not p.)
Some kind of Platonic dualism makes a strange counter argument. For example, the soul: maybe the soul (being immaterial) can’t influence the person (the material, corporeal person), but it could just follow a parallel track. To me, this just backs up the point of convergence (unless my “soul” is parallelling me just by pure chance) to whatever caused both my soul and me to exist (and to be in parallel).
For me, I don’t think you can prove the non-existence of anything, but it certainly tips the scales for the burden of proof that direction. I haven’t heard any strong argument for the existence of anything supernatural. It’s like saying there’s everything, and then there’s something else.
I was under the impression that that wasn’t true. It’s possible for a human being to walk through a wall, due to the fact that atoms are mostly empty space. However, it’s ridiculously unlikely, due to the large number of atoms in both the wall and the human body. 0% chance. But they could still theoretically all line up so that nothing collides. Maybe ghosts just have a built in infinite improbability drives?
The point is that you couldn’t both walk through walls AND use the floor to walk on.
So, does the good professor explain why Vampires do not show themselves in mirrors?
And everyone knows they do not show up in photos, but would that apply to digital photos?
And if you try to photograph a Vampire, and there is, say, a vase with flowers behind him, so you, the photographer, cannot see the flowers in the view-finder, how do the flowers end up on the photograph?
And on the subject of ghosts, Shakespeare used them in his plays quite often, so isn’t that proof of sorts? And who does all the ghost-writing? Certainly not Vampires! They do not have the patience to produce a good novel, everyone knows that!
And if you try to photograph a Vampire, and there is, say, a vase with flowers behind him, so you, the photographer, cannot see the flowers in the view-finder, how do the flowers end up on the photograph?
