View Full Version : Discussion: Chandra Detects Sound Waves From ...

2003-Sep-10, 10:30 PM
SUMMARY: The Chandra X-Ray Observatory has "heard" a black hole for the first time. The object is a supermassive black hole at the heart of a galaxy in the Perseus cluster, located 250 million light-years away. Chandra detected deep sound waves eminating from the black hole in the surrounding gas and dust which have traveled hundreds of thousands of light-years. This discovery may help astronomers understand why there is so much hot gas in galaxy clusters when all calculations predict it should cool away - the sound energy is warming it up.

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2003-Sep-12, 03:04 AM
I actually have two questions concerning this article. I'll jump right into it. The first one: Could someone explain to me the physics of seeing sound waves using an X-Ray observatory? That was so weird! I've never heard of such a thing. So if I were to get my jaw x-rayed at the hospital and I was yelling, would I distort the photo?

Okay, on to my second-ish question. I thought that no infomation leaves a black hole. I understand that sound moves in the atmosphere that was created by all of the dust and gas surrounding the black hole, which should have had to of been pulled in all at once for there to be a conncetion between the black hole's surface and the gaseoes material around it long enough for it to transmit sound by ripples in the molecules without creating empty space. Furtermore, I stated earlier that no information (other than its mass) leaves a black hole. Light can't escape it, so how can sound? Especially when the sound is generated from the black hoel itself? Someone please help! The physics just don't add up.

2003-Sep-12, 11:23 AM
I am curious as well. I thought sound needed a medium to propogate. How is this sound energy propogating?