Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

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

phys.org

Post reply on HN
Print view View original

21–30 of 203 posts

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

#21

Post by colordrops »

szundi wrote: post #19
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…

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

Path finding

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

#22

Post by fgoesbrrr »

inasio wrote: post #7

I was really hoping to find concrete details of what the experiment that they proposed to validate or refute their theory is. I hope it's something achievable, or at least not ridiculously far from what we can currently measure

They mention 20 years in the article.

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

#23

Post by irjustin »

dataflow wrote: post #4
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.

What made them mysterious? Aren't there always some fraction of atoms or molecules with sufficiently high energy to escape the object?

> Aren't there always some fraction of atoms or molecules with sufficiently high energy to escape the object?

Can someone help me understand this? I thought that things were supposed to be stable given the elements used for le grand k. That they don't decay on their own and it would have to be another mechanism to explain the divergence?

[0] https://en.wikipedia.org/wiki/International_Prototype_of_the...

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

#24

Post by dotnet00 »

szundi wrote: post #19
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…

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

The other big theories aren't completely untestable, the issue is basically that the models have a lot of parameters which can often be tuned in a way that leaves a possibility for the general theory to still work, and testing them to the point that any corrections seem too unreasonable is even more difficult and expensive.

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

#25

Post by bookmark1231 »

sam0x17 wrote: post #20
mvdtnz wrote: post #6

Earlier quoted context omitted.

The fact that you, a random internet guy, knows this makes me believe that the world's top experts on measuring this exact thing probably thought of it, and if there is a mysterious divergence this probably doesn't account for it.

I find that it saves time to just start by assuming the experts haven't thought of X because of how many times I've seen assuming that they _have_ thought of X turn out to be a poor assumption, across many domains.

That’s incredibly specious reasoning.

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

#26

Post by sroussey »

selecsosi wrote: post #13
lostdog wrote: post #5

Is there a decent explanation of what the conflict is about, that is understandable with a non-physics-major college level maths background?

Being _hyper_ reductionist, the standard model of physics, which describes, to an extremely high degree, the interaction (creation, elimination, and chance of one thing turning into another) of particles that constitute "stuff" (matter / energy) does not account for the interaction of matter via gravitation. Most things interact with each other, they create "particles" to exchange force / energy (actually in the case…

Coming from an engineering background, is there something about this that might prove useful?

Like electron tunneling that made a good amplifier (transistor)?

Could this “snapback” be utilized in interesting ways?

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

#27

Post by pants2 »

irjustin wrote: post #23
dataflow wrote: post #4

Earlier quoted context omitted.

What made them mysterious? Aren't there always some fraction of atoms or molecules with sufficiently high energy to escape the object?

> Aren't there always some fraction of atoms or molecules with sufficiently high energy to escape the object? Can someone help me understand this? I thought that things were supposed to be stable given the elements used for le grand k. That they don't decay on their own and it would have to be another mechanism to explain the divergence? [0] https://en.wikipedia.org/wiki/International_Prototype_of_the...

In a system of particles, due to random Brownian motion and the nature of Gaussian energy distributions, a small number of particles occasionally gain significantly higher energy than average through statistical fluctuations. Maybe enough to escape the binding energy of le grand k. However I would think this is a very very small effect in platinum.

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

#28

Post by maaaaattttt »

This is a question I've been asking myself (probably due to a lack of understanding and knowledge) and this theory seems to hint at something similar: why do we assume spacetime to be homogenous in its nature? Here they seem to say that on some quantum level spacetime could vary drastically. Couldn't then dark matter be explained by some variations on a large scale? Like giant "wrinkles" in spacetime? They would then behave as pseudo black holes, or more like "black trenches", that lead to the structures we see today in the universe. The structures seem to have more mass than what we can actually see, but are in fact just placed in locations that behave differently gravity wise?

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

#29

Post by junon »

selecsosi wrote: post #13
lostdog wrote: post #5

Is there a decent explanation of what the conflict is about, that is understandable with a non-physics-major college level maths background?

Being _hyper_ reductionist, the standard model of physics, which describes, to an extremely high degree, the interaction (creation, elimination, and chance of one thing turning into another) of particles that constitute "stuff" (matter / energy) does not account for the interaction of matter via gravitation. Most things interact with each other, they create "particles" to exchange force / energy (actually in the case…

Wow, thank you for this very clear explanation. :)

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

#30

Post by samus »

maaaaattttt wrote: post #28

This is a question I've been asking myself (probably due to a lack of understanding and knowledge) and this theory seems to hint at something similar: why do we assume spacetime to be homogenous in its nature? Here they seem to say that on some quantum level spacetime could vary drastically. Couldn't then dark matter be explained by some variations on a large scale? Like giant "wrinkles" in spacetime? They would then…

Science had fared quite well so far with the assumption that the laws of physics are largely the same no matter where and when we are. There would have to be very strong evidence to throw that out. And the immediate next problem is that it actually wouldn't explain much. The immediate next question would be "why is spacetime behaving this way".
Post reply on HN