Gene therapy for color blindness near 530 nm, and the S cone absorbs near 420 nm. Contrary to popular belief, the peak absorption frequency for L, M, and S cones do not exactly correspond to red, green, and blue wavelength. Rather, the peak frequency for the L cone is orange, yellowish green in M cones, and blue-violet in S cones. These cones transduce the absorbed light into electrical information to be relayed to neurons in the retina such as retinal bipolar cells and retinal ganglion cells, before reaching the brain. The signals from different cones are added or subtracted from each other to process the
Electrically powered spacecraft propulsion Electrically powered spacecraft propulsion An electrically-powered spacecraft propulsion system uses electrical energy to change the velocity of a spacecraft. Most of these kinds of spacecraft propulsion systems work by electrically expelling propellant (reaction mass) at high speed, but electrodynamic tethers work by interacting with a planet's magnetic field. Electric thrusters typically use much less propellant than chemical rockets because they have a higher exhaust speed (operate at a higher specific impulse) than chemical rockets. Due to limited electric power the thrust is much weaker compared to chemical rockets, but electric propulsion can provide a small thrust for a long time.