In this part of the world a lot of flattop roofs are covered with a layer of gravel or small river pebbles. Oldtime (and now posh) driveways are made from the stuff too. horizontal surfaces are not very suitable for advertising to people closeby, but they are very suitable for advertising on things like google earth. Why not use the original covering to spellout your advertising message? Companies would pay a lot to have their office building marked with their logo.

There is a natural variation in the color of the pebbles used. The pebbleprinter sucks up the top layer of pebbles in front of it and sorts these into light and dark (or more greyscales if that turns out feasible). The pebbles are stored in a small cache and from there put on a conveyor belt according to need. along this belt are one or more moveable 'printing heads' that can travel sideways and blow the pebbles with compressed air from the belt into a funnel and onto the surface. this continues until the whole line is 'printed' and the machine travels forward an inch to print the next line. The machine could use separate belts for the different colors, or remember what it put onto the belt and time the printing heads to that.
-- nietsch, Apr 09 2006

roof tops ads are coming.... http://adverlab.blo...-real-business.html
[xandram, Apr 10 2006]

Are these pebbles stuck down? Because I think that they would get mucked up very quickly otherwise.

Also, bird crap would add interesting extensions to the words.
-- dbmag9, Apr 09 2006


It's like lawn care. You just need the driveway re-done every week or so, depending on traffic. Roof-top signage, of course, is longer lasting.
-- lurch, Apr 09 2006


Brilliant! Although separate "tanks" of light and dark stone might be needed.
-- Galbinus_Caeli, Apr 09 2006


@dbmag: can you see birdcrap on satelite imagery now? The reason to use pebbles is because they don't tend to fade or degrade. The resolution is not fantastic (keeping driveways readable would be hard)but the stuff is very good at just lying there.
-- nietsch, Apr 09 2006


Oh, that kind of scale. I was thinking merely person-scale things. That (literally) puts it in perspective.
-- dbmag9, Apr 10 2006


I don't understand why there is one person who cast a negative vote on this! +
-- rrr, Apr 10 2006


Problem is nietsch that Goog earth can just digitally label the tops of buildings.
-- dameyawn, Apr 10 2006


I didn't think that Google earth photos were updated that often...certainly, for my neck of the woods, the photo looks about 2 years old.
-- Ling, Apr 10 2006


[ling] You are very right. At least two years since an update here. I know that as it does not show the giant muddy pit that replaced the seven houses next to mine just under two years ago.
-- Galbinus_Caeli, Apr 10 2006


//The other day I was pondering on the possibility of hiding an enormous obscenity across an entire town, by planting concentrations of daffodil bulbs across parks, gardens and spaces collectively in such a way that it can only be seen from very high altitudes.//

Less impressively, but amusingly, a group of criminals did some community-service flower-planting on the side of a motorway. Turned out they'd planted the bulbs so that when they bloomed, they bloomed into blooming rude words.
-- imaginality, Apr 10 2006


I think someone voted against this simply because the replacement cartridges probably cost more than the printer.
-- Jscotty, Apr 11 2006


or they're stoned.
-- po, Apr 11 2006



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