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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

#81

Post by vanderZwan »

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…

If you look at the various ways people have tried to interpret thermodynamics and the observation that our local universe started in a state of low entropy (not exactly spacetime, I know, but it's related to the problem), then you'll see that a variation of your question has been very thoroughly considered already.

Namely, the possibility of the low-entropy start of our observable universe being merely a local statistical fluke on a cosmic scale across infinite time and space.

The problem is that this often leads to weird paradoxes, like the Boltzmann brain universe[0], and from what I understand it's still not entirely clear if that's just a sign we're doing statistics wrong or if there's something missing in the theory of cosmology.

Personally, I'm wondering if the issue isn't that these theories are assuming randomness, but in reality the next "state" of the universe depends on the previous state, so it's actually pseudo-random. But that sounds like too obvious an explanation so that has probably been ruled out somehow.

Anyway, just to be explicit about it again: what I'm talking about relates to thermodynamics and entropy. You're question is about spacetime and the laws of physics, which is something else.

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

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

#82

Post by mikro2nd »

guenthert wrote: post #80
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…

> it's really nice to see the proponents proposing a test. Is it feasible though? I wonder whether that test is not just outside of what can be technically realized today, but Heisenberg's uncertainty principle gets in the way.

Well,... measuring gravity waves was outside of the technically realisable for a long time, but a couple of decades of trial and refinement and it got realised.

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

#83

Post by Cthulhu_ »

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?

Yeah they are, they just cannot be verified - or cannot be verified yet.

The higgs boson theory was theorised in 1964 and it was untestable at the time, but that theory got the funding together to create one of the largest and most expensive scientific instruments built to prove the theory.

Nuclear fusion was theorised in 1915, again untestable at the time, and look how far we've come.

The above comment is an anti-science comment if I've ever seen one.

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

#84

Post by bilekas »

yathaid wrote: post #33

The article mentions the 5000:1 odds bet, but reading the text of the bet itself is hilarious: >>> Whereas Carlo Rovelli and Geoff Penington firmly believe that gravity is better described by a quantum theory. >>> And whereas Jonathan Oppenheim is more sympathetic to other possibilities (i.e. doesn’t have a clue) ... [1] - https://www.ucl.ac.uk/oppenheim/pub/quantum_vs_classical_bet...

> a small amount of olive oil, balsamic vinegar, or wine

I think we can guess who write up the contract!

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

#85

Post by spuz »

hoseja wrote: post #47
vore wrote: post #44

Earlier quoted context omitted.

They're not AI generated, there's literally artist credits in the picture captions.

Perhaps they're post-edited somewhat but there isn't a way you're convincing me those are fully handmade. Look at the nonsensically warped tiles. Look at the rods suspending some of the globes but not others in a random fashion, look at the illegible "writing".

I think you're right. I don't really have a problem with AI generated art being used in articles like this. After all, what kind of alternative visual can you put alongside an article about fundamental theories of nature? If AI art helps to reduce the cost of scientific journalism (without decreasing the quality) then I'm ok with it.

Having said that, to produce art that actually works is clearly not easy. If you've ever used Midjourney or DALL-E, you'll know it's a challenge to get the tool to output exactly what you have in mind. It's also clearly hard to produce images that physically realistic. If mismatched tiles and unrealistic perspectives are noticeable then they'll be a distraction and detract from the reader's experience.

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

#86

Post by ben_w »

hoseja wrote: post #40

What awful AI-generated illustrations. Anyway, is there any justification for treating spacetime as a smooth manifold, except for mathematical tractability?

I'm more annoyed with the captions.

> … Carbon-60, one of the largest known molecules.

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

#87

Post by DrBazza »

bilekas wrote: post #84
yathaid wrote: post #33

The article mentions the 5000:1 odds bet, but reading the text of the bet itself is hilarious: >>> Whereas Carlo Rovelli and Geoff Penington firmly believe that gravity is better described by a quantum theory. >>> And whereas Jonathan Oppenheim is more sympathetic to other possibilities (i.e. doesn’t have a clue) ... [1] - https://www.ucl.ac.uk/oppenheim/pub/quantum_vs_classical_bet...

> a small amount of olive oil, balsamic vinegar, or wine I think we can guess who write up the contract!

Crisps though!

> Should space-time be shown to be quantum, the loser will give to each of the winners, one ITEM* of their choice. If the alternative hypothesis is deemed to be correct, the losers will each give 5,000 ITEMS to the winner.

> * ITEM is defined to be a object of the winner’s choice, worth no more than 20 British pence on January 21st, 2021. Examples include some crisps, a bazinga ball, a small amount of olive oil, balsamic vinegar, or wine

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

#88

Post by aaron695 »

mvdtnz wrote: post #6
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?

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.

[dead]

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

#89

Post by hoseja »

spuz wrote: post #85
hoseja wrote: post #47

Earlier quoted context omitted.

Perhaps they're post-edited somewhat but there isn't a way you're convincing me those are fully handmade. Look at the nonsensically warped tiles. Look at the rods suspending some of the globes but not others in a random fashion, look at the illegible "writing".

I think you're right. I don't really have a problem with AI generated art being used in articles like this. After all, what kind of alternative visual can you put alongside an article about fundamental theories of nature? If AI art helps to reduce the cost of scientific journalism (without decreasing the quality) then I'm ok with it. Having said that, to produce art that actually works is clearly not easy. If you've…

But these add nothing to the article but confusion. That's not how doing interference works. That's not any sort of weighting device. Could have been a generic galaxy-brain stock art and I'd be less annoyed.

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

#90

Post by simiones »

Widdershin wrote: post #63
sam0x17 wrote: post #20

Earlier quoted context omitted.

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.

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

I don't really agree with the OP, but I do think there is at least one, possibly two such examples. The pretty clear one is nutrition: the vast majority of studies and recommendations made over the years are pure bullshit, and quite transparently so. They either study a handful of people in detail, or a huge swathe of population in aggregate, and get so many confounding variables that there is 0 explanatory power in any of them. This is quite obvious to anyone, but the field keeps churning out papers and making official recommendations as if they know anything more about nutrition than "missing certain key nutrients can cause certain disease, like scurvy for missing vitamin C".
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