Building a wall by precisely stacking randomly shaped boulders could almost be the definition of hard work – both physically and mentally. It's the sort of thing we might want robots to do one day, so it should come as no surprise that one has in fact just done it.
Robotic excavator builds a giant stone wall with no human assistance::undefined
Wonderful. This is actually some technology that some desert countries in the middle east could use. Those loosely-stacked walls are perfect to take water out of the air in the chill of the morning. Walls of this kind have been used for ages in that region for this purpose. Having an autonomous building system would allow to spread this use.
I presume stones get cold during night, when temperature rise they remain colder than air so water in the air condensate on them. Why is this wanted? Well, to get drinkable water in dry areas?
Problem is that does not generate water. It just takes the water away which is then missing somewhere else and fucks up the other areas which would otherwise be in healthy equilibrium.