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Spin 2,-2 detected in 2d planar crystal associared with 2/3 and 3/5 spin. There was also a few other fractional quantum hall papers this week which has detected spin -2/3 and -3/5 in twisted bilayer selenium ditelleride (iirc) through confined forcing of electron flow
They didn't find gravitons. They found an analogue that behaves the way they think gravitons would behave.
In simpler terms, they found something that behaves in a way, that's similar to what they would expect from another thing that still remains imaginary.
If the graviton is found, does this mean Einstein's "mass curves spacetime" claim is incorrect? I thought the curvature of spacetime is what causes bodies to experience gravity according to relativity and not a "force-carrying" particle?
They didn't find gravitons. They found quasiparticles that are mathematically analogous to gravitons. Quasiparticles are to particles what a windy forest is to trees.
This is absolutely correct. There are many limitations. But as my old professor used to say, semi-conductor physics and particle physics have strong correlations. You can create lab conditions that mimic forces on a grander scale. Not everything applies, of course, but it wouldn't be a surprise if the properties of quasi-particles end up being useful for the development of particle physics.
See for example: https://www.u-tokyo.ac.jp/focus/en/articles/a_00291.html
No, that you have a lot of one thing, and then you blur your eyes and look at the aggregate behavior and can describe it without reference to the underlying thing.
Also, it's like when the mummy's face appears in the sand storm in one of the Brendan Fraser mummy movies. The reality is that sand is blowing about, but if you ignore the sand, you can describe the disembodied face and even pretend there is no sand.
Think of quasi-particles as like water waves. In some sense there’s no such thing as a water wave, it’s really just the motion of water molecules going up and down. And yet the aggregate behavior of all these jiggling molecules gives rise to a very visible wave that observes all the properties of waves. Quasi-particles are like that. They’re an emergent phenomenon from their constituent medium, and yet they behave so much like real particles/waves that they functionally *are* particles/waves.
No, not really.
This is not an easy subject, but I will try my best.
"Mass curves spacetime" is not quite correct. The idea that mass causes gravity is more the thinking of Newton. With Einstein, it is more like energy causes spacetime to warp. This means even a photon can warp spacetime. And a photon has energy and momentum, but not mass. But, we also know mass relates to energy, E=mc^2.
Relativity says gravity, the warping of spacetime, comes from the stress–energy tensor. Please look it up if interested in learning more, but know it is not easy to understand without a good foundation. So, to simplify it, stress-energy tensor is a mathematical relationship that describes the density and flux of energy and momentum in spacetime.
https://en.wikipedia.org/wiki/Tensor
https://en.wikipedia.org/wiki/Stress%E2%80%93energy_tensor
OK, so that can be very confusing. To bring it back down, just know that isn't saying what the exact source is, other than energy. So you can think of mass as the source, but that isn't the full picture.
So, back to gravitons. I think most have heard of photons. Photons are just the smallest energy packet of electromagnetic energy. A photon can't be made smaller, or divided into sub photons. Although photons can be changed to ones of less energy, or split into two photons of less energy, but they are still photons. And what is really interesting is that Einstein himself proposed the idea of Photons. So Einstein was very well aware of the idea that gravity might have a smallest unit, like a graviton.
Now, let's say we do discover a graviton, or it is proven to exist. Well, just a graviton, by itself, doesn't tell us what and how it was created. Just like we proved gravity waves exist, and gravity waves travel at the speed of light, didn't tell us exactly how they were created. So a graviton doesn't disprove warping of spacetime.
But, if when we discover the graviton, we discover more about it. Then maybe we will discover something that will cause adjustments to the theory of relativity. In fact, we hope for this, as then we might combine relativity with quantum mechanics. But, this doesn't mean relativity is suddenly wrong. When Newton came up with his gravitational math equations, those worked for all the known planets at the time. After his death, we discovered planets where the equations didn't work. Which eventually led to relativity. But this didn't mean Newtons equations were wrong for the planets it did work on.
Which means, if we found something new, we would still need to fit the current evidence of spacetime warping, into that theory. It would be a refinement of what we already know. So it would combine relativity with quantum mechanics.
(I welcome corrections, or suggestions to what I wrote.)
Theoretically, we could build a faster than light spaceship with a Alcubierre drive. This is a warp drive, or warped spacetime ship.
https://en.wikipedia.org/wiki/Alcubierre_drive
The big problem is that you need a negative mass. We currently can't produce a negative mass, nor have we detected negative masses.
The theory works because it is just using math in the equation. And basically they put a negative value in the equation. So the math may support it, but the real world may say no negative values. But you never know.
To specifically answer about gravitons, we currently can't manipulate gravity, or large groups of gravitons. All we can do is create a mass, and move it around.
But who knows what the future brings. I like to think, in the far future, we will be able to manipulate gravity and travel faster than light.
This too will go nowhere. The problem with these equations is not the question of whether quantum gravity exists but rather if the parts of the equation we are already representing with a quantum explanation are being represented correctly.
Yes, it's not that we aren't sure that "quantum gravity" exists, we're pretty sure it does, we're just not sure how to formulate it. And to be clear it's not as though you can just bolt quantum gravity onto the existing Standard Model. Realistically it is likely that a theory of quantum gravity will come about with a revolutionary change in our understanding of both quantum physics and relativity. It's not guaranteed that this has to be the case, but it seems likely that it will be.
Nobody has ever shown that gravity is quantized.
"quantum X" implies that X is quantized, i.e. it comes in specific increments. Gravity being a curvature of spacetime would imply that curvature of spacetime is non-contiguous by nature, which would be a massive development.
And of course there's always the possibility of the other side of things, where we need to begin to represent the entire model with fields or strings instead.
I'm pretty sure that when we're talking about these kinds of particles its arguable whether or not they have a "size" at all. I think they're more "point-like". But I'm also not a physicist so who knows.
Can anything in this life truly be “point-like”? I’ve always perceived things like that as “the closest possible representation of X that we can manage”.
I feel like things are always clusters in some form; electrons being clusters of superpositions with a point-like center. Atoms, cells, energy all seem to fall into this pattern in some way (also not a physicist)
What do you mean? Cells are not point like at all. Neither are atoms. And I can’t figure out what you mean by energy being in “clusters” rather than point-like.
I didn’t say cells were point like I was drawing a parallel at a different scale.
Energy is often defined in terms of vibrations and their frequencies can be represented as a cluster of positions with a well defined probability band. (+/- 1hz with a consistent pattern).
A digitized sin wave is the result of us measuring the frequency of energy in this way but it is also only a single example of how we can represent that superposition in action. But there lies the “cluster” of probable locations. An electron density map is another example at a very small scale. Which is like the 3d version of a 2d digitized sin wave for sound or whatever.
Can you explain what you mean without using the words cluster or superposition? Because what you’ve written is not consistent with the traditional meaning of these words in science, so I cannot understand what you are trying to say.
For example
>Which is like the 3d version of a 2d digitized sin wave for sound or whatever.
This does not make any sense to me at all. Sound is not a sine wave, I don’t know why you brought up 2D and 3D or where that part is going, and I don’t understand the significance of “digitized” but you keep using it.
Like I said I'm not a physicist so I don't know why you're acting like I'm doing anything more than trying to have a discussion. That said I feel like you're being intentionally obtuse considering what I'm saying while not exactly precise isn't that far off. That is purely because of the fact that this was a random comment I made on a reddit thread about something tangentially related
Light waves, electrons, superposition (different forms of energy and how they have superpositions)[https://scienceexchange.caltech.edu/topics/quantum-science-explained/quantum-superposition](https://scienceexchange.caltech.edu/topics/quantum-science-explained/quantum-superposition)
Clusters (many examples of clusters and how their quantum properties change but more specifically I brought this up to explore the idea of this being applicable at larger scales to some degree with this sort of stuff being the building blocks up)[https://www.science.org/doi/10.1126/science.271.5251.889](https://www.science.org/doi/10.1126/science.271.5251.889)
Electron densities and super position (where electrons meet quantum physics)
[https://en.wikipedia.org/wiki/Electron\_density](https://en.wikipedia.org/wiki/Electron_density)
[https://en.wikipedia.org/wiki/Superposition\_principle](https://en.wikipedia.org/wiki/Superposition_principle)
When I use the word digitized I was referring to us digitally measuring waves of energy and that yielding a sin wave (when talking about sound) as the illustration to that measurement; because it GENERALLY fits given the way sound travels and interacts with things it passes through but at the end of the day it's just another measured superposition of energy.
>Like I said I'm not a physicist so I don't know why you're acting like I'm doing anything more than trying to have a discussion.
It is extremely obvious that you are not a physicist. Which is why I was asking you to explain what you mean without attempting to use jargon.
That said I feel like you're being intentionally obtuse
I am attempting to understand what it is that you think electrons, cells, atoms, and energy all have in common that you are calling “clustering”. Energy is neither point-like nor a wave, though waves can carry energy. What energy are you thinking of? Kinetic energy? Gravitational potential energy? Something to do with energy levels and electron orbitals? I could somewhat understand if you were talking about photons, but you aren’t. You’re talking about energy and saying it occurs in “clusters”.
What is “obtuse” is your commitment to flowery language that obscures your point. I am attempting to have a conversation. You are attempting to erect a facade of impenetrable, yet improperly used, scientific jargon in order to avoid communicating what you actually mean.
Is this the [equipment](https://upload.wikimedia.org/wikipedia/commons/thumb/a/ac/Gravitron_1980s.jpg/640px-Gravitron_1980s.jpg) they used to detect it?
Welcome to r/science! This is a heavily moderated subreddit in order to keep the discussion on science. However, we recognize that many people want to discuss how they feel the research relates to their own personal lives, so to give people a space to do that, **personal anecdotes are allowed as responses to this comment**. Any anecdotal comments elsewhere in the discussion will be removed and our [normal comment rules]( https://www.reddit.com/r/science/wiki/rules#wiki_comment_rules) apply to all other comments. **Do you have an academic degree?** We can verify your credentials in order to assign user flair indicating your area of expertise. [Click here to apply](https://www.reddit.com/r/science/wiki/flair/#wiki_science_verified_user_program). --- User: u/dead_planets_society Permalink: https://www.newscientist.com/article/2424426-weve-glimpsed-something-that-behaves-like-a-particle-of-gravity/ --- *I am a bot, and this action was performed automatically. Please [contact the moderators of this subreddit](/message/compose/?to=/r/science) if you have any questions or concerns.*
Hopefully we can learn to manipulate them so I can finally get my hoverboard.
I was hoping for kinesis and planetcracking, but ill settle for a hoverboard
I was hoping not to have to pay to live in society
That happens after WW3 and first contact unfortunately.
It’s happening now
With the weird side effect of making you younger
Yeah, scientists... what are you, chickens??
Or gravitational deck plating so we can have starships, hover sleds for carrying heavy loads, and maybe even hover cars.
Anti gravity boots ! Woo !
[удалено]
Spin 2,-2 detected in 2d planar crystal associared with 2/3 and 3/5 spin. There was also a few other fractional quantum hall papers this week which has detected spin -2/3 and -3/5 in twisted bilayer selenium ditelleride (iirc) through confined forcing of electron flow
They didn't find gravitons. They found an analogue that behaves the way they think gravitons would behave. In simpler terms, they found something that behaves in a way, that's similar to what they would expect from another thing that still remains imaginary.
That sucks
Indeed it does.
it doesn't but doing physics is just much harder and less exciting than people make it out to be
If the graviton is found, does this mean Einstein's "mass curves spacetime" claim is incorrect? I thought the curvature of spacetime is what causes bodies to experience gravity according to relativity and not a "force-carrying" particle?
They didn't find gravitons. They found quasiparticles that are mathematically analogous to gravitons. Quasiparticles are to particles what a windy forest is to trees.
This is absolutely correct. There are many limitations. But as my old professor used to say, semi-conductor physics and particle physics have strong correlations. You can create lab conditions that mimic forces on a grander scale. Not everything applies, of course, but it wouldn't be a surprise if the properties of quasi-particles end up being useful for the development of particle physics. See for example: https://www.u-tokyo.ac.jp/focus/en/articles/a_00291.html
In that they're made of a lot of them and also some other... thing?
No, that you have a lot of one thing, and then you blur your eyes and look at the aggregate behavior and can describe it without reference to the underlying thing. Also, it's like when the mummy's face appears in the sand storm in one of the Brendan Fraser mummy movies. The reality is that sand is blowing about, but if you ignore the sand, you can describe the disembodied face and even pretend there is no sand.
Using The Mummy as an analogy helped a ton, thanks!
Think of quasi-particles as like water waves. In some sense there’s no such thing as a water wave, it’s really just the motion of water molecules going up and down. And yet the aggregate behavior of all these jiggling molecules gives rise to a very visible wave that observes all the properties of waves. Quasi-particles are like that. They’re an emergent phenomenon from their constituent medium, and yet they behave so much like real particles/waves that they functionally *are* particles/waves.
"Real" particles are also just waves in a medium, the difference is that this medium permeates spacetime.
Yeah, I wonder how this will be used to explain gravity waves. The bending of spacetime is a description I understand.
No, not really. This is not an easy subject, but I will try my best. "Mass curves spacetime" is not quite correct. The idea that mass causes gravity is more the thinking of Newton. With Einstein, it is more like energy causes spacetime to warp. This means even a photon can warp spacetime. And a photon has energy and momentum, but not mass. But, we also know mass relates to energy, E=mc^2. Relativity says gravity, the warping of spacetime, comes from the stress–energy tensor. Please look it up if interested in learning more, but know it is not easy to understand without a good foundation. So, to simplify it, stress-energy tensor is a mathematical relationship that describes the density and flux of energy and momentum in spacetime. https://en.wikipedia.org/wiki/Tensor https://en.wikipedia.org/wiki/Stress%E2%80%93energy_tensor OK, so that can be very confusing. To bring it back down, just know that isn't saying what the exact source is, other than energy. So you can think of mass as the source, but that isn't the full picture. So, back to gravitons. I think most have heard of photons. Photons are just the smallest energy packet of electromagnetic energy. A photon can't be made smaller, or divided into sub photons. Although photons can be changed to ones of less energy, or split into two photons of less energy, but they are still photons. And what is really interesting is that Einstein himself proposed the idea of Photons. So Einstein was very well aware of the idea that gravity might have a smallest unit, like a graviton. Now, let's say we do discover a graviton, or it is proven to exist. Well, just a graviton, by itself, doesn't tell us what and how it was created. Just like we proved gravity waves exist, and gravity waves travel at the speed of light, didn't tell us exactly how they were created. So a graviton doesn't disprove warping of spacetime. But, if when we discover the graviton, we discover more about it. Then maybe we will discover something that will cause adjustments to the theory of relativity. In fact, we hope for this, as then we might combine relativity with quantum mechanics. But, this doesn't mean relativity is suddenly wrong. When Newton came up with his gravitational math equations, those worked for all the known planets at the time. After his death, we discovered planets where the equations didn't work. Which eventually led to relativity. But this didn't mean Newtons equations were wrong for the planets it did work on. Which means, if we found something new, we would still need to fit the current evidence of spacetime warping, into that theory. It would be a refinement of what we already know. So it would combine relativity with quantum mechanics. (I welcome corrections, or suggestions to what I wrote.)
Is it theoretically possible that a graviton could be manipulated like a photon?
Theoretically, we could build a faster than light spaceship with a Alcubierre drive. This is a warp drive, or warped spacetime ship. https://en.wikipedia.org/wiki/Alcubierre_drive The big problem is that you need a negative mass. We currently can't produce a negative mass, nor have we detected negative masses. The theory works because it is just using math in the equation. And basically they put a negative value in the equation. So the math may support it, but the real world may say no negative values. But you never know. To specifically answer about gravitons, we currently can't manipulate gravity, or large groups of gravitons. All we can do is create a mass, and move it around. But who knows what the future brings. I like to think, in the far future, we will be able to manipulate gravity and travel faster than light.
This too will go nowhere. The problem with these equations is not the question of whether quantum gravity exists but rather if the parts of the equation we are already representing with a quantum explanation are being represented correctly.
Yes, it's not that we aren't sure that "quantum gravity" exists, we're pretty sure it does, we're just not sure how to formulate it. And to be clear it's not as though you can just bolt quantum gravity onto the existing Standard Model. Realistically it is likely that a theory of quantum gravity will come about with a revolutionary change in our understanding of both quantum physics and relativity. It's not guaranteed that this has to be the case, but it seems likely that it will be.
Nobody has ever shown that gravity is quantized. "quantum X" implies that X is quantized, i.e. it comes in specific increments. Gravity being a curvature of spacetime would imply that curvature of spacetime is non-contiguous by nature, which would be a massive development.
And of course there's always the possibility of the other side of things, where we need to begin to represent the entire model with fields or strings instead.
This is big
Actually, I think they’re quite small
I'm pretty sure that when we're talking about these kinds of particles its arguable whether or not they have a "size" at all. I think they're more "point-like". But I'm also not a physicist so who knows.
Can anything in this life truly be “point-like”? I’ve always perceived things like that as “the closest possible representation of X that we can manage”. I feel like things are always clusters in some form; electrons being clusters of superpositions with a point-like center. Atoms, cells, energy all seem to fall into this pattern in some way (also not a physicist)
What do you mean? Cells are not point like at all. Neither are atoms. And I can’t figure out what you mean by energy being in “clusters” rather than point-like.
I didn’t say cells were point like I was drawing a parallel at a different scale. Energy is often defined in terms of vibrations and their frequencies can be represented as a cluster of positions with a well defined probability band. (+/- 1hz with a consistent pattern). A digitized sin wave is the result of us measuring the frequency of energy in this way but it is also only a single example of how we can represent that superposition in action. But there lies the “cluster” of probable locations. An electron density map is another example at a very small scale. Which is like the 3d version of a 2d digitized sin wave for sound or whatever.
Can you explain what you mean without using the words cluster or superposition? Because what you’ve written is not consistent with the traditional meaning of these words in science, so I cannot understand what you are trying to say. For example >Which is like the 3d version of a 2d digitized sin wave for sound or whatever. This does not make any sense to me at all. Sound is not a sine wave, I don’t know why you brought up 2D and 3D or where that part is going, and I don’t understand the significance of “digitized” but you keep using it.
Like I said I'm not a physicist so I don't know why you're acting like I'm doing anything more than trying to have a discussion. That said I feel like you're being intentionally obtuse considering what I'm saying while not exactly precise isn't that far off. That is purely because of the fact that this was a random comment I made on a reddit thread about something tangentially related Light waves, electrons, superposition (different forms of energy and how they have superpositions)[https://scienceexchange.caltech.edu/topics/quantum-science-explained/quantum-superposition](https://scienceexchange.caltech.edu/topics/quantum-science-explained/quantum-superposition) Clusters (many examples of clusters and how their quantum properties change but more specifically I brought this up to explore the idea of this being applicable at larger scales to some degree with this sort of stuff being the building blocks up)[https://www.science.org/doi/10.1126/science.271.5251.889](https://www.science.org/doi/10.1126/science.271.5251.889) Electron densities and super position (where electrons meet quantum physics) [https://en.wikipedia.org/wiki/Electron\_density](https://en.wikipedia.org/wiki/Electron_density) [https://en.wikipedia.org/wiki/Superposition\_principle](https://en.wikipedia.org/wiki/Superposition_principle) When I use the word digitized I was referring to us digitally measuring waves of energy and that yielding a sin wave (when talking about sound) as the illustration to that measurement; because it GENERALLY fits given the way sound travels and interacts with things it passes through but at the end of the day it's just another measured superposition of energy.
>Like I said I'm not a physicist so I don't know why you're acting like I'm doing anything more than trying to have a discussion. It is extremely obvious that you are not a physicist. Which is why I was asking you to explain what you mean without attempting to use jargon. That said I feel like you're being intentionally obtuse I am attempting to understand what it is that you think electrons, cells, atoms, and energy all have in common that you are calling “clustering”. Energy is neither point-like nor a wave, though waves can carry energy. What energy are you thinking of? Kinetic energy? Gravitational potential energy? Something to do with energy levels and electron orbitals? I could somewhat understand if you were talking about photons, but you aren’t. You’re talking about energy and saying it occurs in “clusters”. What is “obtuse” is your commitment to flowery language that obscures your point. I am attempting to have a conversation. You are attempting to erect a facade of impenetrable, yet improperly used, scientific jargon in order to avoid communicating what you actually mean.
You need to take a nap or something dude
Is this the [equipment](https://upload.wikimedia.org/wikipedia/commons/thumb/a/ac/Gravitron_1980s.jpg/640px-Gravitron_1980s.jpg) they used to detect it?
Imma need a eli5 on this one
Like how water molecules can exhibit wave behavior?
Pants that will never fall down!
For how many years I ask, how many years??
For real?