DdhuAltair

The function seems to describe the variation of the gravity field (unit : m.s-2, just like g) created by an object located at x=0 (probably a planet). x is the radius distance between the planet core and the position where you are.
r0 is probably the radius of the planet which creates this field and h the altitude from the sea level of this planet. So r0+h is the distance from the core of the planet and from the graphic, in this case, it values something around 32 (kilometers i guess). In the exponential term, s is a term that indicates how large is the well. a indicates how deep is the well.
So by choosing ro+h you can set where you want your gravity well to be, choose s to set how large it is and a to set how deep it is. If you want to have anti-gravity (so that the function is negative somewhere), you have to choose a wisely. If you choose a=0, then you have the standard field of gravity (the green curve).
 
I hope it will help some of you to understand but it's mostly maths and does not have much to do whith physics. To sum up, by adding a gaussian function to the standard gravity field you are able to create a given area where g is negative (=anti-gravity). The only trick is that you want it to be on a specific location and that's why you use a gaussian function (it does not have much effect at distances greater than a few s).
 
N.B : english is not my mother tongue so you may have some difficulties to understand what i meant only due to my poor english skills

To be a bit more accurate, NQ's definition of g is g(r0) from your equation. In NQ's equation, r is reffered as x.
 
The point is to make the gravity field being zero in some points. Then in these points you will no longer "feel" the gravity field and if your velocity is null then you will stay on these points and so you are able to have an orbital "floating" station without needing it to have a velocity (as it's supposed to be built using static cores in the game) on the orbit of a planet. But by doing this you have to put your object very accurately otherwise it will oscillate indefinitely around the point (depending how far you placed the object from the equilibrium point supposing that the gravity field is the only force). So i guess they will likely introduce some friction (or anything that dissipates energy) to stabilize the position.

The function seems to describe the variation of the gravity field (unit : m.s-2, just like g) created by an object located at x=0 (probably a planet). x is the radius distance between the planet core and the position where you are.
r0 is probably the radius of the planet which creates this field and h the altitude from the sea level of this planet. So r0+h is the distance from the core of the planet and from the graphic, in this case, it values something around 32 (kilometers i guess). In the exponential term, s is a term that indicates how large is the well. a indicates how deep is the well.
So by choosing ro+h you can set where you want your gravity well to be, choose s to set how large it is and a to set how deep it is. If you want to have anti-gravity (so that the function is negative somewhere), you have to choose a wisely. If you choose a=0, then you have the standard field of gravity (the green curve).
 
I hope it will help some of you to understand but it's mostly maths and does not have much to do whith physics. To sum up, by adding a gaussian function to the standard gravity field you are able to create a given area where g is negative (=anti-gravity). The only trick is that you want it to be on a specific location and that's why you use a gaussian function (it does not have much effect at distances greater than a few s).
 
N.B : english is not my mother tongue so you may have some difficulties to understand what i meant only due to my poor english skills

Well to be exact, mass conservation is not a rule of physics. Nuclear reactions are based on the fact that some mass is lost in the process (it is converted into energy : that's how nuclear plants works). Energy is the only thing which is conservative.
 
But i agree with you. I am against the idea of being able to delete "material" things. It would distord the economy. Even dirt can contribute to the economy because it may cost you (you will have to manage it) or be an income (some people may want to buy it !). Of course, as it has been stated before, i don't think it will have a big effect on the beginning of the game (there will be plenty of land to put it on : the world will seem infinite) but later on as some people may do not want you to trash dirt on their land, it will cost you (either by owning land where you would store dirt or paying people to accept it on their land for exemple).
 
To broaden the topic, i think this possibility need to be linked with waste management. In a game, generally, when something is useless to you (which is what waste is), you can delete it and the problem is solved. But as DU aims to reproduce a civilization development and i think civilizations are human organizations managing all the problems humanity have to face in order to survive and/or achieve goals (waste is one of these problems : just think about nuclear waste), deleting shouldn't be possible for material components ; we can already recycle constructions with a 100% efficiency (if i'm not mistaken) which is already a very convenient feature not accessible in reality.