5 ms·

How strange that "Seeing is believing" still holds even with gravitational waves, which aren't electromagnetic phenomena. Human nature :)

redis_mlc 6y ago
The LIGO concept was thought to be impossible for decades because of how small the signals are, and some would say it's still incredible that it works at all. Whereas we've had a lot of success with optical detection and they're inexpensive experiments. Also, there's a few naysayers continually making public comments, so it's good to have something else to point to for confirmation.
willis936 6y ago
Two point verification always has value. It’s how every instrument we’ve ever made is calibrated.
- number6 6y ago
  Can gravitational waves be verified by optical signals? I thought the whole point of LIGO is that it's a method not relying on electromagnetic signals
  - wolfram74 6y ago
    Depending on the source, we may or may not expect photon's to accompany the gravity waves. The most note worthy one so far was a gravity wave signal that we associate with a neutron star merger[1] that we also managed to catch a lot of photon signals which also matched what we think should come out of such a collision. Most black hole mergers that I know of would be dark. I imagine if they had a large accretion disks associated with them they might generate some light as well as gravity waves? But I'm not sure, I get most of my astronomy over lunch with colleagues. [1] https://www.sciencemag.org/news/2017/10/merging-neutron-stars-generate-gravitational-waves-and-celestial-light-show https://www.sciencemag.org/news/2017/10/merging-neutron-star...
  - willis936 6y ago
    Yes. In fact that this is the exact (very exciting and somewhat recent) experiment that proved that if gravity does propagate in higher dimensions, then the dimensions must be very thin. https://youtu.be/3HYw6vPR9qU https://youtu.be/3HYw6vPR9qU Edit: To be clear: the experiment I’m referring to was the observation of two neutron stars merging. Since there was no event horizon prior to the merger, we’d expect a lot of EM energy to be radiated away. This new observation is neat because we’d expect much less EM energy out of a black hole merger.
  - nickik 6y ago
    I recommend this video of the press conference from the neutron star merger discovery. https://www.youtube.com/watch?v=mtLPKYl4AHs https://www.youtube.com/watch?v=mtLPKYl4AHs Its an amazing example of collaboration where it stars with gravitational waves, that helped locate it and quickly half the world of astronomy was looking at it on every wave length. Its an unbelievable example of cooperation and using different observatories to look at the same event. It also shows how LIGO can be used to find events, and then others can point there to get more information.

redis_mlc 6y ago

The LIGO concept was thought to be impossible for decades because of how small the signals are, and some would say it's still incredible that it works at all. Whereas we've had a lot of success with optical detection and they're inexpensive experiments. Also, there's a few naysayers continually making public comments, so it's good to have something else to point to for confirmation.

willis936 6y ago

Two point verification always has value. It’s how every instrument we’ve ever made is calibrated.

number6 6y ago
Can gravitational waves be verified by optical signals? I thought the whole point of LIGO is that it's a method not relying on electromagnetic signals
- wolfram74 6y ago
  Depending on the source, we may or may not expect photon's to accompany the gravity waves. The most note worthy one so far was a gravity wave signal that we associate with a neutron star merger[1] that we also managed to catch a lot of photon signals which also matched what we think should come out of such a collision. Most black hole mergers that I know of would be dark. I imagine if they had a large accretion disks associated with them they might generate some light as well as gravity waves? But I'm not sure, I get most of my astronomy over lunch with colleagues. [1] https://www.sciencemag.org/news/2017/10/merging-neutron-stars-generate-gravitational-waves-and-celestial-light-show https://www.sciencemag.org/news/2017/10/merging-neutron-star...
- willis936 6y ago
  Yes. In fact that this is the exact (very exciting and somewhat recent) experiment that proved that if gravity does propagate in higher dimensions, then the dimensions must be very thin. https://youtu.be/3HYw6vPR9qU https://youtu.be/3HYw6vPR9qU Edit: To be clear: the experiment I’m referring to was the observation of two neutron stars merging. Since there was no event horizon prior to the merger, we’d expect a lot of EM energy to be radiated away. This new observation is neat because we’d expect much less EM energy out of a black hole merger.
- nickik 6y ago
  I recommend this video of the press conference from the neutron star merger discovery. https://www.youtube.com/watch?v=mtLPKYl4AHs https://www.youtube.com/watch?v=mtLPKYl4AHs Its an amazing example of collaboration where it stars with gravitational waves, that helped locate it and quickly half the world of astronomy was looking at it on every wave length. Its an unbelievable example of cooperation and using different observatories to look at the same event. It also shows how LIGO can be used to find events, and then others can point there to get more information.