My understanding is that "gravitational waves" are mechanical waves, like water, not "quantum waves" like light.
This article seems to confuse what wave particle duality means:
just like water waves are waves that are made of particles, we fully expect that gravitational waves are made of particles, too.
When it comes to duality it's the particles that exhibit wave-like properties individually.
Wave/Particle duality of quantum objects (quanta) is a bit like bicycle/car duality when looking at motorcycles. Light isn't a wave or a particle, but it has properties of both. Motorcycles aren't pedal-powered bikes or cars, but have properties of both.
There are no particles, just quanta.
Right - that's what I'm saying. But this article seems to think that if you make a bicycle out of cars then you have a motorcycle.. Unless I'm not understanding it.
AFAIK gravity waves are ripples in actual space (mechanical waves) - not a property of "gravitons".
Gravity waves are completely different from gravitational waves.
https://coco1453.wordpress.com/home/gravity-related-terms/
Gravitational waves are not 'mechanical waves'. It is thought that gravitational radiation is a lot like electromagnetic radiation. Therefore gravitational waves might work like light waves, and have a particle like light does.
Ah! Thanks! I wasn't aware there was a difference!
Common mistake
Gravitons are the name for the quanta of the (hypothetical) quantum gravitational field. They'd be the force carriers of the gravitational force in a theory of quantum gravity, if we had one.
Gravitational waves would still be physical waves like water waves, and they'd be composed of moving gravitons. Spacetime would likely be quantized instead of continuous; this becomes very hard to resolve since quantum mechanics needs to be reformulated to use discrete math instead of calculus, and we don't really know how to do that (non-uniform spacetime breaks QM).
That's why I think the article is confused. They seem to think the gravity waves are a property of gravitons.
Yeah, not disagreeing there!
They seem to think the gravity waves are a property of gravitons.
The article talks about gravitational waves, not gravity waves. It is believed that gravitational radiation is similar to electromagnetic radiation. This would mean that gravitational waves are made up of particles called gravitons. But as the article says, we don't know that for sure because we haven't been able to detect gravitons yet.
maybe space is the graviton field itself(!), but maybe there is a graviton field (or is it the Higgs field?) and gravitons (and Higgs particles?) are excitations of that field; like other particles are excitations of their various postulated quantum fields
When it comes to duality it’s the particles that exhibit wave-like properties individually.
And waves exhibit particle behavior because waves are particles and particles are waves. Light comes in waves. But when we see light it doesn't mean we are seeing a single light photon.
Surely that would require gravity to be quantized.