New trio of telescopes scans the southern sky for gravitational waves

[Judi Lynn]

By Paul McClure
May 16, 2023



A night view of the three telescopes of the BlackGEM array at ESO’s La Silla Observatory, Chile. The Large and Small Magellanic Clouds can be seen just above the telescopesESO

The new BlackGEM telescopic array at the European Southern Observatory’s (ESO’s) La Silla Observatory in Chile has officially begun scanning the southern skies, searching for the sources of gravitational waves.

Gravitational waves are ripples in space-time caused by violent, energetic space phenomena, such as colliding black holes or neutron stars, or massive stars exploding as supernovae at the end of their lives.

Existing observatories like the Laser Interferometer Gravitational-Wave Observatory (LIGO) and the Virgo Interferometer are specially designed to detect the ripples caused by gravitational waves. Interferometers merge two or more light sources to create an interference pattern, which can be measured and analyzed. However, LIGO and Virgo can’t pinpoint the exact origin of gravitational waves or see the light emanating from colliding neutron stars or black holes.

That’s where BlackGEM is different. It can detect both gravitational waves and visible light from these events and use the information to determine the precise location of the wave source. Using visible light also means BlackGEM can obtain detailed observations of processes such as the formation of heavy elements like gold and platinum from these interstellar collisions.

More:
https://newatlas.com/space/trio-telescopes-southern-scan-sky-gravitational-waves/

[lastlib]

1. I Freakin' LOVE science!

Thanks for posting!

[erronis]

3. I agree with you. Can't understand it all but just trying to is what makes life worthwhile.

[GreenWave]

2. Yikes! Everything we are is held together by gravity,

and I do mean everything.

[erronis]

4. Do the gravitational waves move at the same speed as the light originating from the source?

I'll assume (yes, that makes me one) that gravitational waves move at the speed of light - can't be faster based on Einstein's theory of special relativity. But light can travel more slowly than c (the maximum speed) depending on lensing or travelling through a non-perfect vacuum.

So if the gravitational wave detectors sense an event and tell the visible light telescopes to scan that part of the sky, would there be some possible delay in visible light detection?

I'm going back to bed now.

[Jim__]

5. According to this source gravitational waves are "expected" to travel at the speed of light.

From LSC (my bolding):

Multiple interferometers are needed to confidently detect and locate the sources of gravitational waves (except continuous signals), since directional observations cannot be made with a single detector like LIGO, which is sensitive to large portions of the sky at once. Gravitational waves have a finite speed and are expected to travel at the speed of light. This will induce a detection delay (up to about 10 milliseconds) between the two LIGO detectors. Using this delay and the delay between LIGO and its international partners will help pinpoint the sky location of the gravitational wave source. Multiple detectors also help sort out candidate gravitational wave events that are caused by local sources, like trees falling in the woods or even a technician dropping a hammer on site. These events are clearly not gravitational waves but they might look like a gravitational wave in the collected data. If a candidate gravitational wave is observed at one detector but not the other within the light travel time between detectors, the candidate event is discarded.

[erronis]

7. Thanks for that excerpt. More reading ahead for me!

[erronis]

6. An interesting article in phys.org touching on some of the science behind this effort

https://phys.org/news/2023-05-spacetime-quantum-simulator.html
...

A model system for quantum gravity

The experiments show that the shape of light cones, lensing effects, reflections, and other phenomena can be demonstrated in these atomic clouds precisely as expected in relativistic cosmic systems. This is not only interesting for generating new data for basic theoretical research—solid-state physics and the search for new materials also encounter questions that have a similar structure and can therefore be answered by such experiments.

"We now want to control these atomic clouds better to determine even more far-reaching data. For example, interactions between the particles can still be changed in a very targeted way," explains Jörg Schmiedmayer. In this way, the quantum simulator can recreate physical situations that are so complicated that they cannot be calculated even with supercomputers.

The quantum simulator thus becomes a new, additional source of information for quantum research—in addition to theoretical calculations, computer simulations, and direct experiments. When studying the atomic clouds, the research team hopes to come across new phenomena that may have been entirely unknown up to now, which also take place on a cosmic, relativistic scale—but without a look at tiny particles, they might never have been discovered.