View Full Version : Sound Barrier

04-05-2006, 08:19 PM
Here is a photo I got from JPL May 2003 of a Navy fighter breaking the sound barrier. In case you are interested.

04-06-2006, 09:15 AM
Cool! That's just like what my dad used to see when he was in the airforce.

04-06-2006, 09:28 AM
An F/A-18 Hornet apparently (bigger image at http://apod.gsfc.nasa.gov/apod/ap010221.html)

04-06-2006, 09:46 PM
DUDE! :whoa: :shock: :whoa: :spin:
That picture owns!
Google "sonic boom" in images, and you get tons of them, sweet!
This one (http://www.sky-flash.com/speed/F4TMAA.JPG) really intrigues me, because I thought they could only break the barrier over the oceans?

Sonic Boom Refraction:

Depending on the aircraft's altitude, sonic booms reach the ground two to 60 seconds after flyover. However, not all booms are heard at ground level. The speed of sound at any altitude is a function of air temperature. A decrease or increase in temperature results in a corresponding decrease or increase in sound speed. Under standard atmospheric conditions, air temperature decreases with increased altitude. For example, when sea-level temperature is 58 degrees Fahrenheit, the temperature at 30,000 feet drops to minus 49 degrees Fahrenheit. This temperature gradient helps bend the sound waves upward. Therefore, for a boom to reach the ground, the aircraft speed relative to the ground must be greater than the speed of sound at the ground. For example, the speed of sound at 30,000 feet is about 670 miles per hour, but an aircraft must travel at least 750 miles per hour (Mach 1.12, where Mach 1 equals the speed of sound) for a boom to be heard on the ground.

the above is from here (http://www.sky-flash.com/boom.htm)

04-15-2006, 09:56 AM
that is insanely cool nice