Cherenkov radiation permeability and formula_16 is the index of refraction of the material the charge particle moves through. Unlike fluorescence or emission spectra that have characteristic spectral peaks, Cherenkov radiation is continuous. Around the visible spectrum, the relative intensity per unit frequency is approximately proportional to the frequency. That is, higher frequencies (shorter wavelengths) are more intense in Cherenkov radiation. This is why visible Cherenkov radiation is observed to be brilliant blue. In fact, most Cherenkov radiation is in the ultraviolet spectrum—it is only with sufficiently accelerated charges that it even becomes visible; the sensitivity of the human eye peaks at green,
James A. Abrahamson retrieval and repair mission. Abrahamson was appointed by President Ronald Reagan to be the first director of the Strategic Defense Initiative ("SDI") in April 1984. The "Star Wars" program, as SDI's detractors dubbed it, was initiated to develop a sophisticated anti-ballistic missile system that would prevent missile attacks from other countries, particularly the Soviet Union. Some countries opposed to U.S. missile defense efforts raised concerns about the program "contravening" the anti-ballistic missile (ABM) of the Strategic Arms Limitation Talks in years before the program was enacted. Ultimately, concerns about the objectives of SDI and fiscal budgetary constraints forced the Reagan