Gravity, sci-fi and wormholes

[clockworksaint]

I've read more than one piece of sci-fi where some sort of wormhole transport technology can only function far away from the gravitational fields of planets, but is revealed also to function anywhere the gravitational potential field has a zero gradient: at Lagrange points or even at the centres of planetary bodies. I wonder, though, is this

Comments

[amont]

It's been a while since Uni, but here goes.
If the feild has to be constant, a Lagrange point wouldn't work, as there would only be a single point in space where the feild would be zero, same as the gradient of y=x^2 (y=x) only equals 0 at a single point. This would mean that part of the structure would experience pull due to gravity, albeit minute.
That said, if the device created a sheet-like hole, a la stargate or event horizon, you could argue that having it angled correctly would bypass this. At least, if you disregard the grvitational effect of all the other planets.
As to whether something can be sensitive to a gravitational gradient, an extreme case would be someone falling towards a black hole. As the gravitational pull at their feet is greater than at their head, you get stretched in an effect called 'spaghettification'. I suppose it would depend how sensitive the process of creating wormhole travel is to this effect.