[Milis_Iqra] What Supersonic Looks Like

What Supersonic Looks Like

LiveScience.com robert Roy Britt
editorial Director
livescience.com – Tue Jun 30, 9:35 am ET

The breaking of the sound barrier is not just an audible phenomenon. As a new picture from the U.S. military shows, Mach 1 can be quite visual.

This widely circulated new photo shows a Air Force F-22 Raptor aircraft participating in an exercise in the Gulf of Alaska June 22, 2009 as it executes a supersonic flyby over the flight deck of the aircraft carrier USS John C. Stennis.

The visual phenomenon, which sometimes but not always accompanies the breaking of the sound barrier, has also been seen with nuclear blasts and just after space shuttles launches, too. A vapor cone was photographed as the Apollo 11 moon-landing mission rocketed skyward in 1969.

The phenomenon is not well studied. Scientists refer to it as a vapor cone, shock collar, or shock egg, and it's thought to be created by what's called a Prandtl-Glauert singularity.

Here's what scientists think happens:

A layer of water droplets gets trapped between two high-pressure surfaces of air. In humid conditions, condensation can gather in the trough between two crests of the sound waves produced by the jet. This effect does not necessarily coincide with the breaking of the sound barrier, although it can. To learn more, click here.

The aircraft carrier was participating in Northern Edge 2009, an exercise focused on detecting and tracking things at sea, in the air and on land.

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In The Water Cooler, Imaginova's Editorial Director Robert Roy Britt looks at what people are talking about in the world of science and beyond. Find more in the archives and on Twitter.

• Original Story: What Supersonic Looks Like

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Serulah kepada jalan Tuhanmu dengan hikmah dan pelajaran yang baik
dan bantahlah mereka dengan cara yang lebih baik. -Qs. 16 an-Nahl :125

Berilah mereka pelajaran, dan katakanlah kepada mereka perkataan yang berbekas pada jiwa mereka. -Qs. 4 an-Nisa' : 63

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