Questions about the science of
22 Feb 2005 4:28:55 UTC
Topic 187842
(moderation:
Please understand I am not a scientist and I am definitly not a gravitational expert. As a matter of fact I didnt even goto college and barely made it out of high school, but I have some questions.
1) Since these detectors are "hard mounted" to the earth, can/are they being aimed at locations to be scanned or are they just scanning as we travel through space?
2) What about the southern hemisphere? Since all the detectors are north of the equator arent we missing half of the spectrum?
3) Are the detectors only looking at pulsars or other sources of gravitational waves?
4) Has it been "observed" that gravitrons are massless or is it still theory?
5) With the debate over dark-matters existance still ongoing. I wonder if dark-matter supposedly occupying 90-95% of the mass of the universe would cause confusion in the gravitational readings? or using the argument against dark matter of the negative cosmological constant, with gravitational forces becoming stronger over distance, would this confuse readings?
Thanks in advance.
WARNING! DiHydrogen MonOxide kills!
Questions about the science of
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Czar Brent,
I said some things about directionality in this thread.
This is related to the issue of the southern hemisphere. Gravitational waves pass right through the Earth, so the detectors are not blind to half the sky. In fact, that's why gravitational waves are so hard to detect - they tend to pass right through the detectors too!
Detectors are actually most sensitive to waves coming from directly overhead or underfoot. They are least sensitive to waves coming from the horizon, but this blind spot moves around as the Earth moves. And due to the curvature of the Earth, no two detectors have precisely the same blind spot.
This is also related to your question about dark matter. Gravitational waves will pass through it like they do everything else, so there isn't any chance of dark matter obscuring signals from neutron stars for example. Depending on what the dark matter is, it may go bump in the night and generate signals of its own.
The LIGO Science Collaboration is searching for gravitational waves from several types of sources, but Einstein@Home is focused on pulsars. That is the biggest computational challenge.
Gravitons are massless as far as anyone can tell. Ian Jones could fill in the details.
Hope this helps,
Ben