PSA: The unwritten code of ghost physics
Dec. 11th, 2006 12:28 am![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
jackMany science-fiction/fantasy stories have a ghost or two, and it's often unclear what they can do. I've attempted to research the basic laws which govern such beings so everyone can make use of them.
* Ghosts rest on flat surfaces. The most likely explanation for this is subconscious direction from the ghost. In the comic 1/0 (which has caught up Terry Pratchett as the story providing the most handy-metaphors) ghosts naturally assume the shape they had at death (or possibly the most representative point in their life) and hover over the ground, but with concentration can change their shape a bit or a lot and move about.
It also explains a ghost's body, which is invariably quite like a real body, but doesn't actually have (even ghost) chemistry and physics going on inside.
The theory is almost entirely consistent, the only problem being it doesn't feel like a satisfying, physics, explanation, as you can justify almost anything like that.
* Another hypothesis is that ghosts have inertia. If they remained stationary, it would be meaningless because stationary only has meaning relative to something. If they continued in a straight line they'd drift away, within 5m for about 10 minutes, and gone in an hour. If they followed gravity naturally, they'd fall into the earth. However, if they had a tinier attraction to gravity, it'd be basically undetectable, but they'd orbit along with the rotation of the earth.
I don't know how this would interact with artificial gravity, or warp drive -- Geordi La Forge going up in a Turbo-lift in StarTrek isn't particularly explained, nor even going up stairs.
* Or that other things have a normal effect on ghosts, but not ghosts on other things. This breaks "Every action has an equal and opposite reaction", which I'm not sure if it makes sense or not. But then ghosts would feel but not exert gravity. They could be supported by earth and car seats and things, and blown by winds, and hit by people, but not pick things up, nor walk through things.
* There is often some unreliable telepathy, with people picking up thoughts from the ghost. This sometimes has to do with emotional intensity, but basically, is at times unconnected apart from plot need.
* Ghosts can't affect other objects, except possibly as times of strong emotion. Sometimes time of day is important, too. They can generally only blow things about, often small things, but occasionally large things. Some ghosts can actually write, though normally only at the end of the film.
* However, they can't do this in the presence of anyone acquainted with scientific method or scepticism. In front of people who think it's the wind, or who see ghosts in every kitchen, they can do all sorts of things. In front of someone who says "Here are two candles. If you can blow out the one I designate first each time I light the pair, I'll believe in you with 99.9% confidence" they are entirely powerless, and merely gibber invisibly. (To be fair to Piers Anthony, he did treat this sensibly, if misogynistically.)
* There is normally an arbitrary cut off in sapience which decides who can become a ghost, of whom a random selection will. It's often dependent on state of mind, eg. unfinished business, etc.
To me this is evidence that sapient consciousness has a special place in that universe, but sometimes there is an unexplained rationalistic explanation.
In some canons, inanimate objects become ghosts but fade almost instantly (thank you, Terry Pratchett, for having more consistency in comic fantasy than in many 'serious' books :)) In Night's Dawn trilogy, it's interesting: you can have electronic copies of people, who count as separate people for the purposes of making ghosts!
* Go into the light!
* Ghosts rest on flat surfaces. The most likely explanation for this is subconscious direction from the ghost. In the comic 1/0 (which has caught up Terry Pratchett as the story providing the most handy-metaphors) ghosts naturally assume the shape they had at death (or possibly the most representative point in their life) and hover over the ground, but with concentration can change their shape a bit or a lot and move about.
It also explains a ghost's body, which is invariably quite like a real body, but doesn't actually have (even ghost) chemistry and physics going on inside.
The theory is almost entirely consistent, the only problem being it doesn't feel like a satisfying, physics, explanation, as you can justify almost anything like that.
* Another hypothesis is that ghosts have inertia. If they remained stationary, it would be meaningless because stationary only has meaning relative to something. If they continued in a straight line they'd drift away, within 5m for about 10 minutes, and gone in an hour. If they followed gravity naturally, they'd fall into the earth. However, if they had a tinier attraction to gravity, it'd be basically undetectable, but they'd orbit along with the rotation of the earth.
I don't know how this would interact with artificial gravity, or warp drive -- Geordi La Forge going up in a Turbo-lift in StarTrek isn't particularly explained, nor even going up stairs.
* Or that other things have a normal effect on ghosts, but not ghosts on other things. This breaks "Every action has an equal and opposite reaction", which I'm not sure if it makes sense or not. But then ghosts would feel but not exert gravity. They could be supported by earth and car seats and things, and blown by winds, and hit by people, but not pick things up, nor walk through things.
* There is often some unreliable telepathy, with people picking up thoughts from the ghost. This sometimes has to do with emotional intensity, but basically, is at times unconnected apart from plot need.
* Ghosts can't affect other objects, except possibly as times of strong emotion. Sometimes time of day is important, too. They can generally only blow things about, often small things, but occasionally large things. Some ghosts can actually write, though normally only at the end of the film.
* However, they can't do this in the presence of anyone acquainted with scientific method or scepticism. In front of people who think it's the wind, or who see ghosts in every kitchen, they can do all sorts of things. In front of someone who says "Here are two candles. If you can blow out the one I designate first each time I light the pair, I'll believe in you with 99.9% confidence" they are entirely powerless, and merely gibber invisibly. (To be fair to Piers Anthony, he did treat this sensibly, if misogynistically.)
* There is normally an arbitrary cut off in sapience which decides who can become a ghost, of whom a random selection will. It's often dependent on state of mind, eg. unfinished business, etc.
To me this is evidence that sapient consciousness has a special place in that universe, but sometimes there is an unexplained rationalistic explanation.
In some canons, inanimate objects become ghosts but fade almost instantly (thank you, Terry Pratchett, for having more consistency in comic fantasy than in many 'serious' books :)) In Night's Dawn trilogy, it's interesting: you can have electronic copies of people, who count as separate people for the purposes of making ghosts!
* Go into the light!
no subject
Date: 2006-12-11 02:21 pm (UTC)He often tries to inject this sort of rationality; it generally comes across as a bit heavy handed and too arbitrary, but I like the ideas.
However, he is often ridiculed by fantasy fans. He's often loved by young teenagers, but the books have a definite problem with: being too much the same; having a few interesting puns, but too many shit ones being forced down your throat; having horrifically painful gender characterisation; being heavy handed.
It's probably not worth it, however if you want to, try the first two books of the Xanth series, which have a lot of the good ideas and characters and plot, and few of the flaws.