Another problem for highway use is that the radar beam spreads as it travels farther from the truck; once it is more than one lane wide it is useless, mistaking vehicles in other lanes, or even bridge abutments, as hazards.
22.
Then I took advantage of a home page promotion to order 16 GE, 50W, 120V, PAR-38 Halogen Bulbs with 25 ( degree symbol ) Beam Spread and Medium Base ( diameter 4 3 / 4 inches ) for $ 3.49 a piece.
23.
Then I took advantage of a home page promotion to order 16 GE, 50W, 120V, PAR-38 Halogen Bulbs with 25 ( degree symbol ) Beam Spread and Medium Base ( diameter 4 3 / 4 inches ) for $ 3 . 49 a piece.
24.
It isn't that clear to me how long the probe accelerates for before the beam spreads out too much to be caught by the sail, but they seem to describe sails just meters across being beamed at for some appreciable portion of a light year.
