9.1-earthquake 'Shook Gravity'

Chipper Q
Chipper Q
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Topic 191669

I just ran across an interesting article (that was in the NY Times, by Kenneth Chang) where significant changes in the Earth's gravitational field were measured by satellites during a 9.1-earthquake (that caused the tsunami in the Indian Ocean in 12/04). I was wondering, could there be evidence for GWs in that data? Would this properly be referred to as measuring the 'jerk' of the satellites in their orbits, or the time-rate-of-change of acceleration?

DanNeely
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9.1-earthquake 'Shook Gravity'

I suspect not. The signal was probably caused by parts of the earth bouncing up and down several feet, not by distorting spacetime.

Chipper Q
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Yeah, I'm guessing they'd be

Yeah, I'm guessing they'd be too weak, and that the arrangement of satellites was designed to measure a static field... but it seemed like the arrangement of the satellites is similar to the design of the space-based LISA, where the satellites are the test masses. I know the change in the location of mass in the Earth doesn't involve the density of a neutron star, but the detector is much closer to the source...

Ernesto Solis
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Hey Chipper Q Weak or not,

Hey Chipper Q

Weak or not, could there have been a trace of gravitational wave somewhere?

Are their any other sources(short gravitationsal waves) other than just LISA?
Just curious!
Ernie S
Team Art Bell
God Bless

Have a good day Chipper Q

Chipper Q
Chipper Q
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RE: Weak or not, could

Quote:
Weak or not, could there have been a trace of gravitational wave somewhere?


Hi Ernie!
According to theory there would have to be, but considering the mass in question (a small bit of the Earth), I guess the effect would be far weaker than what should already be there, in the stochastic background of gravitational waves. In other words, sources like neutron stars and black holes, having a great deal more mass per unit volume, are the only kinds of objects that will make waves big enough to be detected, even though they're much farther away. Hopefully that's correct.

LISA is the Laser Interferometer Space Antenna, planned to be launched around 2015. One of the neatest things about it is that it wouldn't be affected by any of the noise (like the ground vibrating from passing cars and trucks) that the ground-based detectors have to contend with...

Ernesto Solis
Ernesto Solis
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RE: RE: Weak or not,

Message 43929 in response to message 43928

Quote:
Quote:
Weak or not, could there have been a trace of gravitational wave somewhere?

Hi Ernie!
According to theory there would have to be, but considering the mass in question (a small bit of the Earth), I guess the effect would be far weaker than what should already be there, in the stochastic background of gravitational waves. In other words, sources like neutron stars and black holes, having a great deal more mass per unit volume, are the only kinds of objects that will make waves big enough to be detected, even though they're much farther away. Hopefully that's correct.

LISA is the Laser Interferometer Space Antenna, planned to be launched around 2015. One of the neatest things about it is that it wouldn't be affected by any of the noise (like the ground vibrating from passing cars and trucks) that the ground-based detectors have to contend with...

Thanks Chipper Q

The web page for LISA is interesting. I wonder if something different might
be developing by 2015.

Have a Chipper day
Ernie

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