In my textbook and in many other sources it states that the gravitational field strength is the negative of the field strength. The field strength in a gravitational field is positive in all regions in that field. If you move a mass a positive displacement (from r to r+dr where the displacement vector is pointing outwards from the mass to infinity) then the gravitational potential also increases. Hence dv/dr is positive. This would then mean that the gravitational field strength is negative here since it is defined to be the negative of the potential gradient. But obviously, the field strength is not negative. I have read further into this and the explanation that I have come across mentions that the negative sign arises because the field is in the opposite direction of the displacement. I understand this, but purely in terms of the mathematics, why does this never work. Surely for the maths to work it should be dg=-dv/dr not g=-dv/dr. (d = capital delta, not a derivative in the cases stated above) If you do take the derivative of potential with respect to displacement you do get a positive g. (GM/r^2).
EDIT: Upon further reading, I have noticed that this does work in the case of a hypothetical uniform gravitational field. I think my main question now is where you measure the displacement vector from, because if I measure it against the field as positive it doesn't work. But the graphs of potential and field strength definitely do measure displacement (r) as positive from the surface of the mass to infinity, not the other way around.