Five new ways to catch gravitational waves – and the secrets they'll reveal

Something already lost in the twisted passages of history is that the first generation of gravitational wave detectors was of an entirely different design than the current interferometers [1]. It never worked and Weber's claim to have detected gravitational waves from SN1987A in 1987, was widely discredited...

[1] https://en.wikipedia.org/wiki/Weber_bar

So, going from a very narrow frequency band (up to 1000Hz) to a much wider range, which can theoretically encode information (e.g. frequency modulation)... Hmm, I'm wondering if comms over gravity is something a sufficiently advanced civilization might consider using, and should we be looking for that 'Hello, world' in some 'natural frequency' like we're doing for EM radiation?

Just a plug that you can tour the LIGO facilities for free! I visited a couple years ago and got a tour of the Hanford facility, included a lecture beforehand as well. Really awesome people and got to tour the entire facility, even going to the control room.

https://www.ligo.caltech.edu/WA/page/lho-public-tours

I’m amazed there was no mention of LISA [0] — a space-based gravitational wave detector using 3 satellites flying in formation 2.5 million Km apart! Seriously cool engineering, planning to launch in 2035.

[0] https://en.m.wikipedia.org/wiki/Laser_Interferometer_Space_A...

I just learned of a new proposal to use an already planned probe, as a gravitational wave detector. Maybe I am missed it, but this does not appear to be covered in TFA.

> Bridging the micro-Hz gravitational wave gap via Doppler tracking with the Uranus Orbiter and Probe Mission: Massive black hole binaries, early universe signals and ultra-light dark matter

https://arxiv.org/abs/2406.02306

> Practically Free Primordial Gravitational Waves Detector

https://www.youtube.com/watch?v=XfOxNJvSvf4

Probably a dumb question, but... is it basically proven then that gravity doesn't exist (it's effects are just a result of spacetime's geometry?). Because it seems like these gravitational waves experiments show that spacetime exists and has measurable geometry. Yet every time quantum mechanics comes up everyone talks about how we haven't found the gravity force carrier yet which doesn't make sense to me if gravity doesn't exist and is a consequence of the geometry of spacetime.

- "Kerr-enhanced optical spring for next-generation gravitational wave detectors" (2024) https://news.ycombinator.com/item?id=39957123

- "Physicists Have Figured Out a Way to Measure Gravity on a Quantum Scale" with a superconducting magnetic trap made out of Tantalum (2024) https://news.ycombinator.com/item?id=39495482

This made (very lay-person) me wonder if you could detect quantum wave function events.

https://physics.stackexchange.com/questions/275556/can-you-d...

I just want to add something about how sensitive LIGO is. The gravity waves it is detecting are equivalent to measuring the distance from Earth to Alpha Centauri with a variation the width of a human hair.

Anyway, these techniques are aimed at detecting different types of gravitational waves, not necessarily about simply increasing sensitivity. I don't know what dictates the frequency of a gravitational wave.

Truth be told, I still don't get what expanding space or gravitational waves really are but then again I'm just an idiot who doesn't understand tractor calculus [1].

[1]: https://www.math.auckland.ac.nz/mathwiki/images/c/cf/Staffor...

A more niche but nonetheless interesting method that I was hoping to see discussed was magnetism. Gravitational waves are expected to decay into photons in intense magnetic fields. Or so I was told by one of my physics professors back in the day. I did understand the math somewhat back then, but it is beyond me now. It does however seem as though some people are still exploring this avenue [0].

[0] https://indico.cern.ch/event/1074510/contributions/4519384/a....

I was surprised that the article doesn't mention LISA at all. I had thought that's the next stage gravitational wave detector on the horizon?

https://www.esa.int/Science_Exploration/Space_Science/LISA_f...

So if you can set black holes to collide if a large gravitational wave passes by, that would be stimulated emission and amplification...

A bit tricky to find something that could reflect a gravitational wave, to make an equivalent of a gravitational wave laser.

Why is there no hope of raising the upper frequency limit of the current detection methods? 1kHz seems pretty low for an interferometer.

Is it limited by the wavelength associated with the 1kHz, which becomes smaller than the length of the light path through the interferometer?

Any physicists in here that could layout a path of going from rudimentary first year level physics knowledge to being able to understand on a deeper level topics such as gravitational waves?

These articles are interesting but are very abstract when you do not have knowledge from first principles.

How does one aim a gravitational wave detector? Or is that not how they work?

It's entirely possible if it's extremely sensitive to detect the waves given off by alcubierrie warp drives crisscrossing the galaxies.

Here's something to get you ready ... https://youtu.be/DRRfhZFyDvg?feature=shared

Now that’s the kind of clickbait title I can get behind!