PPRuNe Forums - View Single Post - Mach Crit for transport aircraft

11th March 2003 | 11:15

#17 (permalink)

Crossunder

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From: Norveg

The SWs are visible because as the density across the SW changes, so does the refractive index. Light is then spread (refracted) in an "uneven" manner, thus making it visible to the naked eye!