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X-43D
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If the advanced LIGO will not detect gravitational waves then is the theory dead?
ohwilleke said:Theories don't die. They just get remodeled.
X-43D said:If the advanced LIGO will not detect gravitational waves then is the theory dead?
SpaceTiger said:We haven't confidently reached the threshold where we can be sure we should have detected gravitational waves. One of several things could happen:
1) LIGO detects something and everybody believes it. This is looking less and less likely with time.
2) LIGO is a bust, but LISA (a planned space interferometry mission) detects gravitational waves. This is where my money is at the moment.
3) LISA is a bust because of some failed instrumentation and we have to wait for the next generation.
4) LISA registers a non-detection of gravitational waves down to the threshold where theory definitely predicts them.
Rather than "killing" anything, that last option would likely excite the community. The least interesting result would be a complete verification of current theory.
X-43D said:In a chance when both LIGO and LISA will fail, we would have to wait for Constellation-X (after 2016) i guess.
SpaceTiger said:Constellation-X is an X-ray mission...
X-43D said:Do you have any idea what could be remodeled?
ohwilleke said:Well, and to be clear, I'm talking about a situation where the experiment disproves with undisputed accuracy the presence of gravity waves which theory predicts, you have a number of options:
(1) The wave length of gravity waves is different, probably longer, than expected.
(2) Gravity waves are slower than expected.
(3) Contrary to theory, gravity is particle-like and not wave-like.
(4) Contrary to theory, gravity is instananeous.
(5) The instrument is part of the system in an unexpected way which makes it incapable of detecting gravity ways.
(6) It's all the Dolphins' fault.
Gravitational waves are ripples in the fabric of space-time, caused by the acceleration of massive objects. They were first predicted by Albert Einstein's theory of general relativity in 1915.
Gravitational waves are detected using highly sensitive instruments called interferometers, such as the Advanced Laser Interferometer Gravitational-Wave Observatory (LIGO). These instruments measure tiny changes in the distance between two points caused by passing gravitational waves.
Detecting gravitational waves provides evidence for the validity of Einstein's theory of general relativity and opens up a new window for studying the universe. Gravitational waves can also provide insights into the nature of black holes, the early universe, and other astrophysical phenomena.
Advanced LIGO consists of two L-shaped interferometers with arms that are 4 kilometers long. Laser beams are sent down each arm of the interferometer and are reflected back to a central point. When a gravitational wave passes through, it causes the length of the arms to change, which is detected by the interference of the laser beams.
Since its first detection in 2015, gravitational waves have been detected multiple times, providing further evidence for the theory of general relativity. These detections have also confirmed the existence of black holes and neutron stars, and have provided new insights into the properties of these objects. Additionally, gravitational wave detections have allowed us to study the universe in a new way, providing a new avenue for future discoveries and advancements in our understanding of the cosmos.