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New theory claims to unite Einstein's gravity with quantum mechanics

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Re: New theory claims to unite Einstein's gravity with quantum mechanics

#171

Post by kristov »

simiones wrote: post #113
kristov wrote: post #101

I wonder: does this theory explain any currently unexplained phenomenon? It may be testable, but that doesn't guarantee it to be correct. There could be another undescovered theory that also passes these tests. It feels weird to make up a theory, and then make up some tests to validate it, without mentioning the actual problem the theory is trying to resolve. It seems physicists just don't like there being two separa…

> It seems physicists just don't like there being two separate models, one for large things and one for small things, but it could be the universe is just like that, right? No, it couldn't be just like that. There could exist a common umbrella theory that uses GR for certain objects and QM for others, but it would have to be a new theory that introduces a very important new info: the nature of the separation between…

Thank you!

Re: New theory claims to unite Einstein's gravity with quantum mechanics

#172

Post by thereddaikon »

snewman wrote: post #154
thereddaikon wrote: post #135

Earlier quoted context omitted.

Usually when people say something is untestable they don't mean like the Higgs Boson. It was testable, they just needed the proper tools. This was always known and was being actively worked towards. An untestable theory is one that cannot be tested regardless of the tools due to the nature of the theory. Multiverse is an example of an untestable theory. There is no way we know of to actually prove or disprove it. And…

Isn't the term for this "unfalsifiable"?

In this case I think multiverse is both. Testability and falsifiability are closely related. But its possible to make a testable statement that can't be falsified in most examples I can think of the test can't be exhaustive.

Re: New theory claims to unite Einstein's gravity with quantum mechanics

#173

Post by leptons »

mr_mitm wrote: post #65
szundi wrote: post #19

Earlier quoted context omitted.

Untestable theories are not theories - I mean, for what purpose and why care?

Some theories are only untestable for practical reasons, like needing a particle accelerator the size of the solar system. That doesn't make them unscientific or "not theories". That is not the kind of falsifiability that Karl Popper had in mind.

Yes, it does. The word "theory" has a specific meaning. What this article is about is really a hypothesis, not a theory. I saw no evidence or data to back up what they think might be happening, thus not a theory.

"In scientific reasoning, a hypothesis is constructed before any applicable research has been done. A theory, on the other hand, is supported by evidence: it's a principle formed as an attempt to explain things that have already been substantiated by data."

Most people in this thread, as well as the writers of the article seem to be confused about the meaning of the word theory.

Re: New theory claims to unite Einstein's gravity with quantum mechanics

#174

Post by sumtechguy »

dataflow wrote: post #97
Widdershin wrote: post #63

Earlier quoted context omitted.

Can you give any examples of times you’ve easily anticipated X when a whole field of subject matter experts have demonstrably overlooked it?

This isn't to agree with the parent comment, but wouldn't this situation itself be an answer to your question (assuming the claim is true)? Laymen like me easily anticipated mass divergence, but purportedly scientists have been surprised by it.

I think that they do not have an exact reason and measured it and seen it happen is the surprising bit. Anything else is a good guess. Of those, people have plenty.

Re: New theory claims to unite Einstein's gravity with quantum mechanics

#175

Post by showlife »

hoseja wrote: post #54
staunton wrote: post #41

Earlier quoted context omitted.

Yes. GR does it and GR gives good descriptions for a lot of observed phenomena.

Except, you know, all the elementary particles. I have this intrusive thought those are just bits of non-smoothly kinked/knotted spacetime but have neither the physics background or sense where to even start to look further into that.

Maybe what you're looking for is a "geon"?

https://en.wikipedia.org/wiki/Geon_(physics)

Re: New theory claims to unite Einstein's gravity with quantum mechanics

#176

Post by jakubmazanec »

nojvek wrote: post #143
hn_throwaway_99 wrote: post #2

> A second paper, published simultaneously in Nature Communications and led by Professor Oppenheim's former Ph.D. students, looks at some of the consequences of the theory, and proposes an experiment to test it: to measure a mass very precisely to see if its weight appears to fluctuate over time. Definitely don't know enough to comment about the overall proposal, but given how many grand physics theories over the pas…

Love that there is a test. Some of the theories like gravity waves and Higgs boson took almost half a century to be confirmed by experimentation. The hard part about this is building tools that can precisely measure mass fluctuations with extremely low error bars at picosecond timescales. Because we need to both validate the theory and that the device is correctly measuring. So much of science became only possible be…

> So much of science became only possible because of better instruments.

I would argue a stronger claim: experimental confirmation of theories and better measurements must always bootstrap each other. The history of temperature has many examples [1].

[1] https://psychology.okstate.edu/faculty/jgrice/psyc4333/Therm...

Re: New theory claims to unite Einstein's gravity with quantum mechanics

#177

Post by mr_mitm »

leptons wrote: post #173
mr_mitm wrote: post #65

Earlier quoted context omitted.

Some theories are only untestable for practical reasons, like needing a particle accelerator the size of the solar system. That doesn't make them unscientific or "not theories". That is not the kind of falsifiability that Karl Popper had in mind.

Yes, it does. The word "theory" has a specific meaning. What this article is about is really a hypothesis , not a theory. I saw no evidence or data to back up what they think might be happening, thus not a theory. "In scientific reasoning, a hypothesis is constructed before any applicable research has been done. A theory, on the other hand, is supported by evidence: it's a principle formed as an attempt to explain th…

Maybe that should give you a hint that professional working scientists don't care much for definitions from wordbooks.

Besides, I was commenting on the topic of falsifiability. To be a scientific hypothesis or theory it must be falsifiable - in principle, not practically. At least that's my claim in the context of Popper. Evidence didn't even enter the discussion.

Re: New theory claims to unite Einstein's gravity with quantum mechanics

#178

Post by codethief »

maho wrote: post #99

After skimming the second paper, I still don't understand how precision mass measurements come into play here. They mention Cavendish-type measurements, but they are used for measuring the gravitational constant. Of course, you can turn the formula around, plug an unknown mass into the apparatus and then call it a mass measurement, but it's going to be a very imprecise measurement. A Penning trap can give you 11 to 1…

Wouldn't it be enough to measure the (fluctuation of the) total gravitation force ( = gravitational constant times mass) exerted on the second particle, in order to draw conclusions about the nature of the gravitational force at small scales?

Re: New theory claims to unite Einstein's gravity with quantum mechanics

#179

Post by amai »

digging wrote: post #170
amai wrote: post #155

I believe gravity can be both quantizable and non quantizable. Gravitons could be like phonons (quantized sound waves) and only exist in the solid state of space time. In the fluid state of space time gravitons don’t exist ( Similar to the fact that phonons can only exist in solids, but not in fluids).

What are the solid and fluid states of spacetime?

One could imagine that for a very low Unruh temperature spacetime changes the phase and becomes „solid“. A low Unruh temperature means very low acceleration/gravitation. This might explain dark matter.

Similar things are discussed in the literature under https://en.wikipedia.org/wiki/Superfluid_vacuum_theory and https://penntoday.upenn.edu/news/physicist-theorizes-dark-ma...

Re: New theory claims to unite Einstein's gravity with quantum mechanics

#180

Post by dang »

rhelz wrote: post #3

The various standard kilograms held by the national bodies, and the prototype standard kilogram in paris, were measured very precisely over the past hundred years, and their weights did seem to diverge mysteriously.

(We detached this subthread from https://news.ycombinator.com/item?id=38527238.)
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