New ALPHA-g Detector Poised to Search for Signs of Anti-Gravity(spectrum.ieee.org)
spectrum.ieee.org
New ALPHA-g Detector Poised to Search for Signs of Anti-Gravity
https://spectrum.ieee.org/tech-talk/aerospace/astrophysics/new-alphag-detector-poised-to-search-for-signs-of-antigravity
29 comments
If anti-matter has anti-gravity, then the next question to answer is why do photons obey normal gravity?
Are there anti-photons? (Presumably only anti-matter can make them.) Or is matter special because it matches photons gravitationally and thus answers the question of baryogenesis.
That second option leads to some very interesting implications for stars made of anti-matter. Any photons they make would be "shoved" away from the star - but where does that energy come from?
The first option means there are photons we can not detect (only anti-matter can make them, so only anti-matter can see them). That would imply there is an entire second universe out there overlayed on this one (at least photonically overlayed) that we have never seen, except gravitationally.
But during annihilation events which type of photon would be produced? Both? Randomly one or the other?
Finding that anti-matter has anti-gravity would open an absolutely enormous list of questions. It's not as simple, as OK, anti-gravity - every other part of physics would have to change as well.
Are there anti-photons? (Presumably only anti-matter can make them.) Or is matter special because it matches photons gravitationally and thus answers the question of baryogenesis.
That second option leads to some very interesting implications for stars made of anti-matter. Any photons they make would be "shoved" away from the star - but where does that energy come from?
The first option means there are photons we can not detect (only anti-matter can make them, so only anti-matter can see them). That would imply there is an entire second universe out there overlayed on this one (at least photonically overlayed) that we have never seen, except gravitationally.
But during annihilation events which type of photon would be produced? Both? Randomly one or the other?
Finding that anti-matter has anti-gravity would open an absolutely enormous list of questions. It's not as simple, as OK, anti-gravity - every other part of physics would have to change as well.
Do we know that photons obey normal gravity? I was under the impression that we know that light can be bent by the warping of space-time due to gravity, but not that it interacts with the Higgs field.
Photons don't really have an anti-matter pair that we can observe afaik because anti-particles have the same mass and spin but opposite charge as their counterpart. Since photons have no charge, a photons anti-matter pair is just another photon. Furthermore, we know that anti-hydrogen has the same spectral lines as hydrogen so their electromagnetic interactions are the same.
Finding that anti-matter has anti-gravity would be world changing, though I'm setting my expectations very low. It would mean that we have access to the kind of exotic matter needed for a practical Alcubierre warp drive and could open up an entirely new field of space time engineering. It's just extremely unlikely, given all we know, that anti-matter has such properties.
Photons don't really have an anti-matter pair that we can observe afaik because anti-particles have the same mass and spin but opposite charge as their counterpart. Since photons have no charge, a photons anti-matter pair is just another photon. Furthermore, we know that anti-hydrogen has the same spectral lines as hydrogen so their electromagnetic interactions are the same.
Finding that anti-matter has anti-gravity would be world changing, though I'm setting my expectations very low. It would mean that we have access to the kind of exotic matter needed for a practical Alcubierre warp drive and could open up an entirely new field of space time engineering. It's just extremely unlikely, given all we know, that anti-matter has such properties.
>we know that light can be bent by the warping of space-time due to gravity
That literally is light obeying gravity. Gravity interacts exclusively by the warping of space-time. Gravity and the Higgs field are completely 100% unrelated.
https://profmattstrassler.com/2012/10/15/why-the-higgs-and-g...
That literally is light obeying gravity. Gravity interacts exclusively by the warping of space-time. Gravity and the Higgs field are completely 100% unrelated.
https://profmattstrassler.com/2012/10/15/why-the-higgs-and-g...
Thank you for that link, it clears up a lot!
> Gravity and the Higgs field are completely 100% unrelated.
That is an incredible insight for me -- I never thought of it that way. So the thing that creates inertia (mass) is not the same as the thing that generates gravitational force -- they're just correlated in the types of matter that beings like us can interact with?
That is an incredible insight for me -- I never thought of it that way. So the thing that creates inertia (mass) is not the same as the thing that generates gravitational force -- they're just correlated in the types of matter that beings like us can interact with?
IANAP, but IIRC while the higgs field gives mass to electrons, quarks, the W bosons and a few more particles, the vast majority of the mass of the atom (and thus of what we normally call matter) is due to the binding energy of quarks and gluons and not related to the higgs field.
The Higgs field is not directly related to gravity. Linking gravity with quantum mechanics is still an ongoing research area.
This could be one of the most important experiments that modern physics has attempted.
It's funny that they must adapt their schedule to others, and not the other way around. They're being given just a few days to carry everything out before hitting a cut-off point that may realistically cause the experiment never to get done due to changes in funding or the landscape.
If they obtain a positive result, how many experts will suddenly no longer have a position of expertise?
Suddenly, I wonder if they are having a harder time than other experiments, and whether there are any at CERN who actually don't want the experiment to occur.
It's funny that they must adapt their schedule to others, and not the other way around. They're being given just a few days to carry everything out before hitting a cut-off point that may realistically cause the experiment never to get done due to changes in funding or the landscape.
If they obtain a positive result, how many experts will suddenly no longer have a position of expertise?
Suddenly, I wonder if they are having a harder time than other experiments, and whether there are any at CERN who actually don't want the experiment to occur.
It is silly to suggest conspiracy theories like that. This is not "one of the most important experiments that modern physics has attempted". Most physicist would say "the result is a forgone conclusion, but it is our job to double check". This is why the experiment is not a priority compared to experiments where the result is unknown.
Yes, if it turns out that the result is positive, this would be enormously exciting, especially for these experts that you are worried would lose their expert status. It is just that scientist do not get excited over something that has pretty enormous chances of not happening.
Yes, if it turns out that the result is positive, this would be enormously exciting, especially for these experts that you are worried would lose their expert status. It is just that scientist do not get excited over something that has pretty enormous chances of not happening.
No, I'm not suggesting a conspiracy theory. If you think about it, there is no need for people to conspire to produce the effect. There is simply the clear psychological reaction that people tend to reject what contradicts the things they are deeply involved in and have already accepted. Does that mean all scientists who learn about and believe they understand the Standard Model have closed minds? No. But it does mean that individual scientists' judgement will tend to be influenced to give a lower priority to the things they think are less important. Please don't misrepresent my comment. As a side note if something is true then it has 100% chance of happening. If you don't know it's not true then you don't know about the enormity of its chances.
Your last comment about chances shows misunderstanding of how science and/or statistics work. We have not tested our theories in every possible way, so yes, we know they will need updating here and there. However, there is an immense body of work pointing to no "antigravity", so the chance of a surprising result from this experiment is vanishingly small. If you are interested, check out Feynman's Quantum Field Theory textbook where he quite descriptively puts constraints on tensor interactions (like gravity). I would be happy to suggest more introductory books if you are interested.
> If they obtain a positive result, how many experts will suddenly no longer have a position of expertise?
This is true of most experimentation for novel theories, and it's true of many large experiments e.g. attempting to locate the Higgs Boson (the discovery of which invalidated many theories of physics just through confirming certain unknowns.)
> Suddenly, I wonder if they are having a harder time than other experiments, and whether there are any at CERN who actually don't want the experiment to occur.
Well, possibly, but not for the conspiratorial reasons you're alluding to. It's a powerful device with only so much time to operate; the usage of that time needs to be prioritized, and that prioritization can really only be accomplished by gauging the likelihood of an outcome which produces new knowledge (either validating a theory or invalidating it). No one behind the operation of the ALPHA-g detector is going to block an experiment because they may personally not like the results; if the detector has a hand in a successful discovery, the detector and the team supporting it will be able to claim having a hand in the discovery.
This is true of most experimentation for novel theories, and it's true of many large experiments e.g. attempting to locate the Higgs Boson (the discovery of which invalidated many theories of physics just through confirming certain unknowns.)
> Suddenly, I wonder if they are having a harder time than other experiments, and whether there are any at CERN who actually don't want the experiment to occur.
Well, possibly, but not for the conspiratorial reasons you're alluding to. It's a powerful device with only so much time to operate; the usage of that time needs to be prioritized, and that prioritization can really only be accomplished by gauging the likelihood of an outcome which produces new knowledge (either validating a theory or invalidating it). No one behind the operation of the ALPHA-g detector is going to block an experiment because they may personally not like the results; if the detector has a hand in a successful discovery, the detector and the team supporting it will be able to claim having a hand in the discovery.
> attempting to locate the Higgs Boson
Isn't this a false equivalence? The Higgs boson is predicted by the Standard Model. Antigravitation of antimatter is not. How is an experiment that might have failed to detect something predicted by the Standard Model equivalent to "experimentation for novel theories"?
> Well, possibly, but not for the conspiratorial reasons you're alluding to.
What "conspiratorial" reasons? I never suggested any conspiracy was required whatsoever. Please refer to my other recent comment on this.
> prioritization can really only be accomplished by gauging the likelihood of an outcome which produces new knowledge
I don't know if you'll be receptive but I also happened to touch on this very point in the same other comment.
> No one behind the operation of the ALPHA-g detector is going to block an experiment because they may personally not like the results
That's also not equivalent to what I suggest, which is that it can be deprioritized, not blocked... a notion which you and others are already admitting.
> if the detector has a hand in a successful discovery, the detector and the team supporting it will be able to claim having a hand in the discovery
Is that why we do science?
Isn't this a false equivalence? The Higgs boson is predicted by the Standard Model. Antigravitation of antimatter is not. How is an experiment that might have failed to detect something predicted by the Standard Model equivalent to "experimentation for novel theories"?
> Well, possibly, but not for the conspiratorial reasons you're alluding to.
What "conspiratorial" reasons? I never suggested any conspiracy was required whatsoever. Please refer to my other recent comment on this.
> prioritization can really only be accomplished by gauging the likelihood of an outcome which produces new knowledge
I don't know if you'll be receptive but I also happened to touch on this very point in the same other comment.
> No one behind the operation of the ALPHA-g detector is going to block an experiment because they may personally not like the results
That's also not equivalent to what I suggest, which is that it can be deprioritized, not blocked... a notion which you and others are already admitting.
> if the detector has a hand in a successful discovery, the detector and the team supporting it will be able to claim having a hand in the discovery
Is that why we do science?
> Isn't this a false equivalence? The Higgs boson is predicted by the Standard Model. Antigravitation of antimatter is not. How is an experiment that might have failed to detect something predicted by the Standard Model equivalent to "experimentation for novel theories"?
The comparison you're suggesting isn't the one being made; the comparison being made is that any experiment yielding net-new knowledge risks shifting the accepted expertise in a different direction, and to that end, the Higgs Discovery is representative of this fact simply because it confirmed one set of predictions and refuted others.
> What "conspiratorial" reasons? I never suggested any conspiracy was required whatsoever. Please refer to my other recent comment on this.
Let's not gaslight people in a public forum; it's poor form. You set the tone in your initial comment: "Suddenly, I wonder if they are having a harder time than other experiments, and whether there are any at CERN who actually don't want the experiment to occur." focus is drawn to the sudden change of heart ("suddenly"), the emphasis on how this experiment might be having a "harder time" than other experiments, etc.
> I don't know if you'll be receptive but I also happened to touch on this very point in the same other comment.
You touched on positive outcomes alone. Any net-new knowledge including validation of existing knowledge is fair game. The risk here is that neither validation nor invalidation of existing knowledge will take place, i.e. we'll be no further along after the time is spent.
> That's also not equivalent to what I suggest, which is that it can be deprioritized, not blocked... a notion which you and others are already admitting.
True, we're admitting as such because there are other areas where the maths already suggest there's likely to be something interesting to explore or some existing body of knowledge to strengthen from a novel angle. You also did in fact say "harder time," which is not the same as blocking; I'll give you as much.
> Is that why we do science?
The point conveyed is that there is no personal motive observed by the ALPHA-g detector team to impede the experiment. The most likely motive is simply prioritization because of... again... the likelihood of net-new knowledge.
---
I hope this helps. If not, I hope other commenters are successful in bringing you around, but I now need to invest my time elsewhere. Feel free to have the last word. Or not. It's up to you :)
The comparison you're suggesting isn't the one being made; the comparison being made is that any experiment yielding net-new knowledge risks shifting the accepted expertise in a different direction, and to that end, the Higgs Discovery is representative of this fact simply because it confirmed one set of predictions and refuted others.
> What "conspiratorial" reasons? I never suggested any conspiracy was required whatsoever. Please refer to my other recent comment on this.
Let's not gaslight people in a public forum; it's poor form. You set the tone in your initial comment: "Suddenly, I wonder if they are having a harder time than other experiments, and whether there are any at CERN who actually don't want the experiment to occur." focus is drawn to the sudden change of heart ("suddenly"), the emphasis on how this experiment might be having a "harder time" than other experiments, etc.
> I don't know if you'll be receptive but I also happened to touch on this very point in the same other comment.
You touched on positive outcomes alone. Any net-new knowledge including validation of existing knowledge is fair game. The risk here is that neither validation nor invalidation of existing knowledge will take place, i.e. we'll be no further along after the time is spent.
> That's also not equivalent to what I suggest, which is that it can be deprioritized, not blocked... a notion which you and others are already admitting.
True, we're admitting as such because there are other areas where the maths already suggest there's likely to be something interesting to explore or some existing body of knowledge to strengthen from a novel angle. You also did in fact say "harder time," which is not the same as blocking; I'll give you as much.
> Is that why we do science?
The point conveyed is that there is no personal motive observed by the ALPHA-g detector team to impede the experiment. The most likely motive is simply prioritization because of... again... the likelihood of net-new knowledge.
---
I hope this helps. If not, I hope other commenters are successful in bringing you around, but I now need to invest my time elsewhere. Feel free to have the last word. Or not. It's up to you :)
The real issue is so far all the supporting evidence and theory says antimatter obeys normal rules of gravity. So it really is a long-shot experiment - if it actually differs in a significant way (and let's be clear: experiencing less gravity, going in a slightly different direction - anything - would be major) - then that would be a huge surprise.
Right, and if it turns up nothing, what does it invalidate?
...well, nothing.
The negative conclusion of this experiment doesn't achieve anything, and the aspirational conclusion is a colossal longshot. So more likely than not, time is wasted here (though it'd be cool if there were a Discovery, or even just a 3σ observation).
...well, nothing.
The negative conclusion of this experiment doesn't achieve anything, and the aspirational conclusion is a colossal longshot. So more likely than not, time is wasted here (though it'd be cool if there were a Discovery, or even just a 3σ observation).
What evidence are you referring to which supports antimatter obeying "normal rules of gravity", by which I am presuming you mean gravitating in the same direction as matter?
There is a very large and very convincing body of purely mathematical arguments, and some minor experimental work https://en.m.wikipedia.org/wiki/Gravitational_interaction_of...
For some reason I had a feeling you'd post that. That wikipedia page doesn't show anything except for, at best, an argument that the Standard Model is incompatible with gravitational repulsion plus many statements of unsuccessful attempts to falsify repulsion of antimatter. Did you even read it??
By the way, it's old news by now that Standard Model is incomplete. But let's just go back to passive aggressively condescending to people we don't know on the internet by implying they've never studied so much as modern QFT because we're not prepared to understand their original argument.
By the way, it's old news by now that Standard Model is incomplete. But let's just go back to passive aggressively condescending to people we don't know on the internet by implying they've never studied so much as modern QFT because we're not prepared to understand their original argument.
How was I passive aggressive or condescending? I do believe you are misunderstanding what the math says about all of this, but I am eager to suggest textbooks that explain my point of view. I am suggesting textbooks not because I am condescending, rather because I can not give a meaningful arguments in a comment.
And you are misrepresenting the wiki page. There is a large number of "though experiments" and a few actual experimental observations that make antigravity look implausible. Yes, there are loopholes (like in virtually any statement about fundamental physics) and we should devise experiments to test the loopholes, but when these loopholes are already implausible it is not unreasonable to put the majority of your resources in more interesting experiments.
P.S. None of my comments have anything to do with the Standard Model and I do not see why you are bringing it in this conversation.
And you are misrepresenting the wiki page. There is a large number of "though experiments" and a few actual experimental observations that make antigravity look implausible. Yes, there are loopholes (like in virtually any statement about fundamental physics) and we should devise experiments to test the loopholes, but when these loopholes are already implausible it is not unreasonable to put the majority of your resources in more interesting experiments.
P.S. None of my comments have anything to do with the Standard Model and I do not see why you are bringing it in this conversation.
Misunderstanding what math?
If I'm misrepresenting that wiki page, then how about actually getting specific for once in your comments. It shouldn't be so hard to point out one example with actual details and questions if there such a large number of them.
P.S. If you think your comments about what is considered likely and not likely to CERN have nothing to do with the Standard Model then you really do need to read that wiki page again.
I don't see a single substantial and actually relevant argument in your comments so far. If I'm missing something, again, let's get specific so I have something that tells me you know what we're even talking about here. Are you representing "tensor interactions" as somehow capable of sufficiently explaining gravity and its interactions with antimatter? And are you saying that CERN is using constraints on "tensor interactions" as their reasoning to deprioritize such an experiment?
What are your qualifications in physics, by the way?
If I'm misrepresenting that wiki page, then how about actually getting specific for once in your comments. It shouldn't be so hard to point out one example with actual details and questions if there such a large number of them.
P.S. If you think your comments about what is considered likely and not likely to CERN have nothing to do with the Standard Model then you really do need to read that wiki page again.
I don't see a single substantial and actually relevant argument in your comments so far. If I'm missing something, again, let's get specific so I have something that tells me you know what we're even talking about here. Are you representing "tensor interactions" as somehow capable of sufficiently explaining gravity and its interactions with antimatter? And are you saying that CERN is using constraints on "tensor interactions" as their reasoning to deprioritize such an experiment?
What are your qualifications in physics, by the way?
Specific example: the very first one from the wiki page, namely the equivalence principle, together with (also in that very first example) the fact that particles that are their own antiparticles have been heavily tested to obey ordinary gravity. The whole notion that energy has mass and that antiparticles gain their mass/energy through the same mechanisms that ordinary matter does.
About the Standard Model: None of this has to do with the particularities of the Standard Model. Most quantum field theories have that structure.
Tensor interactions: We have two unrelated arguments for why gravity is a tensor field: one comes from quantum field theory where to have a similar attractive force you need it to be a tensor one; the other one comes from general relativity (the premise of the theory). This is again not a proof, but all of physics is built on such cute "coincidences". (Edit to add: point being, the coincidence is that attraction as we have it requires a tensor force, which happens to be the case for completely unrelated reasons)
Qualifications: Graduate student at the Yale Quantum Institute (through Yale's Physics Department). Hopefully I will be graduating this academic year :) (fingers crossed)
About the Standard Model: None of this has to do with the particularities of the Standard Model. Most quantum field theories have that structure.
Tensor interactions: We have two unrelated arguments for why gravity is a tensor field: one comes from quantum field theory where to have a similar attractive force you need it to be a tensor one; the other one comes from general relativity (the premise of the theory). This is again not a proof, but all of physics is built on such cute "coincidences". (Edit to add: point being, the coincidence is that attraction as we have it requires a tensor force, which happens to be the case for completely unrelated reasons)
Qualifications: Graduate student at the Yale Quantum Institute (through Yale's Physics Department). Hopefully I will be graduating this academic year :) (fingers crossed)
> But let's just go back to passive aggressively condescending to people we don't know on the internet
Please stop accusing people of this; it's being observed as radiating from your own commentary by multiple people, which might explain why others are responding in kind. I called out the gaslighting elsewhere, and the fact that you're persisting with it against multiple parties hampers constructive discussion.
Please stop accusing people of this; it's being observed as radiating from your own commentary by multiple people, which might explain why others are responding in kind. I called out the gaslighting elsewhere, and the fact that you're persisting with it against multiple parties hampers constructive discussion.
Are you not aware of his other comment to me? I've seen it many times before. We don't know each other so perhaps defer belief that you can tell whether that is true or not until you have some evidence. Gaslighting... lol
> how many experts will suddenly no longer have a position of expertise?
None. Math stays the same, and the skills needed to solve the problems stay the same.
In general new discoveries in physics only add detail to what we know and do not invalidate the old knowledge.
None. Math stays the same, and the skills needed to solve the problems stay the same.
In general new discoveries in physics only add detail to what we know and do not invalidate the old knowledge.
> Math stays the same
Not necessarily. How much calculus which is necessary to do modern physics has been built on discrete numbers?
> do not invalidate the old knowledge
Of course what is truly known will never be invalidated.
But it's clear that the (rare?) situation in which something which is widely accepted turns out fundamentally flawed has the potential to make those who have proclaimed their strong confidence in it lose apparent credibility (not to mention many years of their life).
Not necessarily. How much calculus which is necessary to do modern physics has been built on discrete numbers?
> do not invalidate the old knowledge
Of course what is truly known will never be invalidated.
But it's clear that the (rare?) situation in which something which is widely accepted turns out fundamentally flawed has the potential to make those who have proclaimed their strong confidence in it lose apparent credibility (not to mention many years of their life).
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The Economist recently covered the same experiment at CERN: https://news.ycombinator.com/item?id=18110857