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

It might be possible to detect gravitons after all

quantamagazine.org

Post reply on HN
Print view View original

121–130 of 167 posts

Re: It might be possible to detect gravitons after all

#121

Post by wasabi991011 »

DemocracyFTW2 wrote: post #57

I choked on this part: > The discussion recalls a messy, largely forgotten episode from the dawn of the quantum era. In 1905, Einstein interpreted experimental data to mean that light is “quantized,” coming in discrete particles now called photons. Others, including Niels Bohr and Max Planck, thought that the classical, wave nature of light might still be saved. [...] Most physicists presume that everything in the wo…

For 1): Yes, the photoelectric effect is frequently told. But that's not what the article is referring to here, it is foreshadowing its discussion on the semiclassical treatment of the photoelectric effect (by Lamb and Scully). This is the "messy, largely forgotten" part which is rarely discussed. I saw it in a graduate quantum optics course, but even at that level I'm not sure it's part of the standard curriculum.

Re: It might be possible to detect gravitons after all

#122

Post by pessimizer »

sroussey wrote: post #109
skhunted wrote: post #94

Earlier quoted context omitted.

Nice. I think it would probably be more effective propaganda to say the "jihad on Christmas" than the "war on Christmas".

The “war on Christmas” was thought up by a think tank and agreed upon by a group of conservative media that meet weekly to decide agenda to push across talk radio, tv, online. Truly an American phenomenon.

Think tanks that create agendas for groups who meet regularly to decide how to push those agendas through the media and through their politicians are not an American phenomenon, and not specifically conservative.

The people who you work for (and who everyone works for) are probably loosely associated with tons of them.

Re: It might be possible to detect gravitons after all

#123

Post by marcosdumay »

DebtDeflation wrote: post #107
marcosdumay wrote: post #100

Earlier quoted context omitted.

So... If gravity is quantized, then black holes must be only a low-energy approximation of whatever phenomenon is really happening there? If there's some proof that they aren't black (AFAIK, the only thing we know empirically), I've missed it. All I see is a point that the current theory would be wrong.

Rather, the existence of black holes demonstrates that gravity is not renormalizable. The last sentence in the paper: "It seems that gravity is a low energy effective field theory description of something else that is not a quantum field theory." QFTs like QED and QCD are renormalizable. This is a technique used to eliminate the infinities that arise in calculations from self-interaction. For a very long time, renorm…

Does it contest anything that we have observed? Because I couldn't find anything there that won't allow objects that behave the same way as the black holes we've seen, and differ only on details we can't see. (But IANAP, and could easily have missed something.)

Re: It might be possible to detect gravitons after all

#124

Post by poornsad »

elashri wrote: post #112
DemocracyFTW2 wrote: post #57

I choked on this part: > The discussion recalls a messy, largely forgotten episode from the dawn of the quantum era. In 1905, Einstein interpreted experimental data to mean that light is “quantized,” coming in discrete particles now called photons. Others, including Niels Bohr and Max Planck, thought that the classical, wave nature of light might still be saved. [...] Most physicists presume that everything in the wo…

I will start by agreeing that usage of "war" seems weired. Although scientific drama in fundamental physics is not uncommon but a word like "debate" would be more appropriate. I don't like your usage of word "Inshallah" as a mock up of the idea that something will never happen. Because it is a complete opposite meaning of when you suppose to use it. It is usually overused by arab moms (I know that people tends to mea…

[dead]

Re: It might be possible to detect gravitons after all

#125

Post by Auracle »

losvedir wrote: post #113
maronato wrote: post #99

Earlier quoted context omitted.

Your response needlessly called out Arabic for using too much “Allah”. English overuses it the same amount, given that Allah is their word for God.

> English overuses it the same amount Not even close! I only have experience in the Gulf but they use "allah" words all the time! "Alhamdulillah" (thank god) is pretty much part of the standard greeting (Pretty much just two people rapid firing a list of phrases at each other simultaneously "peace be with you / and also peace with you / how are you / thank god / how's the family / thank god") and a frequent response…

I had a photoshoot scheduled with a young Somali man. He was late by over an hour, and I had another shoot after so I had to cancel. I rescheduled and told him if he was late for the next shoot I wouldn’t be rescheduling again.

He said he wouldn’t be…inshallah.

I know it’s part of their language but just as with your cab example it can be a bit annoying as an outsider, as it feels like they’re passing off responsibility. I feel the same way about some of the things Christians say too, for what it’s worth.

Anyways, that’s my infuriating inshallah story. He was late again - and he needed to find another photographer after that.

Re: It might be possible to detect gravitons after all

#126

Post by creer »

skhunted wrote: post #78
DemocracyFTW2 wrote: post #57

I choked on this part: > The discussion recalls a messy, largely forgotten episode from the dawn of the quantum era. In 1905, Einstein interpreted experimental data to mean that light is “quantized,” coming in discrete particles now called photons. Others, including Niels Bohr and Max Planck, thought that the classical, wave nature of light might still be saved. [...] Most physicists presume that everything in the wo…

Please spare me that "war" simile, it only shows you're an American who can not write too well. It’s understandable that you don’t like the desensitization of war that comes from our over usage of the word. Perhaps it speaks to a defect in American culture but this is how we communicate in our language. I think Arabic has too much emphasis on allah related phrases. But that’s how they speak. Nothing I can do about it…

> [war] is how we communicate in our language.

Is it? Or is it how marketing communicates? (Which apparently is then spilling into how you communicate?)

Re: It might be possible to detect gravitons after all

#127

Post by ricksunny »

Can we take a metascience / meta-scicomms perspective? Quanta magazine, like all scicomm journos, relies on the receptive access to researchers for source content, especially exclusive results. So scicomms is essentially the same kind of access-journalism evryone comolains about in DC beltway rwporting, but amplified & couched in the 'but science" brand. In Quanta's case, its sources are quantum physicists / particle physicists. So couching everything in terms of quantized particles (bonus points if somehow 'spooky') avails of the continued access. Articles from the likes of Quanta get cited in particle physicists' onward grant proposals. Pwrticle physicists get grant, get results which get reported just so, and the scicomm journo gets invited to show up once again to scribe away. The circle repeats, meanwhile everyone just hopes it's a virtuous one.

Re: It might be possible to detect gravitons after all

#128

Post by btilly »

jcranmer wrote: post #40
btilly wrote: post #27

Earlier quoted context omitted.

Yes. The Standard Model has completely explained all experiments involving them for around 50 years now. In fact the outstanding success of the Standard Model has posed its own problems - the lack of deviations from it makes it hard for experiments to point in a useful direction for better theories to be developed along.

That's not quite accurate. There are a few things that the Standard Model doesn't exactly account for--neutrino oscillation being the most famous. The trouble is that these issues aren't really big enough to suggest new physics, and the experiments aren't good enough to really suggest how much patching actually needs to be done.

Yes, there are some deviations. But minor adjustments to the Standard Model handles those. And don't really point in the direction of a better theory.

More relevantly to the previous question, I'm not aware of any of those which affect interactions with the strong or weak nuclear forces.

Re: It might be possible to detect gravitons after all

#129

Post by gosub100 »

renegade-otter wrote: post #50
ta93754829 wrote: post #10

So I thought gravity was basically the curvature of spacetime. But if there's a "gravity" particle, those two things seem mutually exclusive? Can someone who understands this please explain it to me, thanks!

I just watched this a few days ago on the Space Matters channel about gravitational waves: https://www.youtube.com/watch?v=9bg2NINW8a0 Not just some dumbed down Discovery show - it pushes the limits of what a layperson can understand.

The YT algorithm is so damn bizarre sometimes. I'm subscribed to probably a dozen different astronomy and physics channels, some for 8 years, and never once saw this channel you recommended. It recommends plenty of AI-TTS bunk too. But somehow didn't decide to show me that channel. Thanks for recommending it.

Re: It might be possible to detect gravitons after all

#130

Post by russdill »

whatshisface wrote: post #16
russdill wrote: post #12

Earlier quoted context omitted.

Gravitons impacting and imparting momentum seems like it would have a bunch of observational implications. Does a massive object cast a graviton shadow? Is the momentum positive or negative?

Classical waves do all of those things too.

So gravitons are only emitted by accelerating objects?
Post reply on HN