Cones for street lamps

Tl;dr: Add a reflective "cone" to each street lamp.

Reasons

• Reduce light pollution, such as
  • Light that shines into people's windows at night
  • Light that awkwardly goes into your eyes and makes it harder to see when walking at night. TODO: add a picture example to demonstrate
• Increase the efficiency of street lamps
  • Streets are lit better, because light that would otherwise go sideways is instead reflected downward to where it needs to go.

Investment required

Relatively little compared to replacing street lamps. A simple metal cone will do.

Research needed for this sectionResearch needed for this section

• Should the "cone" really be cone-shaped, or is parabolic better? In either case, need to suggest more details about the shape (i.e. maybe a 120-degree cone?).
• Would simple steel or aluminum be reflective enough, or is some silver needed (and if so, how much)?
• Retrofit details: For each of the most common street lamp models, what would be the best way to attach the cone?^{[new page needed]}
• Cost per capita - quick estimates(...)( could be based on a particular city's population density and streetlight density )
  • In terms of money
  • In terms of energy or labor (consider manufacturing and installation)(...)( If no data is available, just extrapolate from monetary cost. Also consider the standard amounts of energy needed to process metals (per unit mass). )

New wikipages could be made for details of specific implementations.

Considerations

This section has not been filled in yet.