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Comment by dvt | Hacker News Reader

Awesome experiment, and really cool findings, but I feel that...

> The findings take us a step nearer to measuring gravitational fields that are so weak that they could enter the quantum regime.

...is overstated. There's a long way between 90 milligrams and quantum gravity.

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In terms of mass it takes us halfway there already, from 10^30kg to 10^-3kg, with quantum effects arriving around 10^-15kg.

And in terms of force, the article states that the force involved in that experiment is equivalent to the force of earth gravity on a mass of 10^–15kg, which is probably even closer to the energy of a graviton.

Depending on how you're cutting it, you could also call it 1/1000000000000 of the way there.

That's half (within some tolerance).

Why do you say that quantum effects arise at 10^-15kg? The carbon atom is about 2x10^-26 kg. And I don't think we can put objects much larger than a few atom molecules into a superposition of two locations.

It depends on the nature of the quantization of the gravitational field. If we expect the gravitational field itself to be quantized in a manner somewhat similar to the electromagnetic field, we may be able to detect quantum effects without the objects being particularly small. A good analogue is the photoelectric effect, which involves no superposition at all and can be observed even with macro amounts of energy involved.

Not sure if this has held up, but Google points at this 2010 paper that put a microscopic object into a superposition: https://www.researchgate.net/publication/232755709_Quantum_g...

It's science-journalism. They needed a tag to wrap up the article.

For a lay reader, it would give them an overall concept they can tie the just-read article to, increasing the likelihood of retention.

For an astute reader, yeah, it smells like bullshit.

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