Biggest dark matter detector spots a single weird particle
science.org
science.org
So it's certainly interesting!
That said, particle physics history is full of 3 sigma particle "discoveries" that disappeared with more data. They're collecting more, so hopefully we'll learn more in a few more years.
[1] https://lz.lbl.gov/wp-content/uploads/sites/6/2026/08/LZ_Pre...
It was a fascinating experience as a junior member to follow the collaboration internal conversation and investigation on this, because a lot of extremely principled scientists were clearly deeply worried about losing their hard earned reputation. In the end, I am convinced that we were simply unlucky.
It's stories like this that raise my p(we are in a simulation).
Then when it comes out as measurement error, the public is all "Damn these scientists are all hype machine clowns..."
I’m less fine with the time and resources spent on mouse models. They already know you’d get the same utility from a magic 8 ball, but they do it anyway.
Also, you can do nasty stuff to mice that would never be allowed with humans. In that experiment they injected cancer cells in mice with a bad inmune system, so they could get like 90 mice with cancer and run the experiment in a short time. No ethical committee would approve that in humans.
Congratulations. You've just reduced all of medical science to the Tuskegee STD experiment.
I was a bit dismayed at the reaction within the physics community. Experiments absolutely do need to follow procedures like blinding and careful internal review (especially before the data unblinding), but you can only spend so long designing the analysis before you unblind, and there are opportunity costs to cross checking everything. In an optimized community experiments will inevitably make mistakes. And once you unblind, it does no one any good to sit on an anomalous result forever.
I think the final COVID consortium report has something like 30k authors.
The Pierre Auger Observatory certainly is a large collaboration for the astroparticle physics domain though. It's a big international collaboration.
Quick anecdote: my name (S Mueller) is not on that paper's author list because we had a rule that you had to be in the collaboration for a year before getting authorship. You stayed on for a year after leaving. Very reasonable! At the time I was nonetheless a bit bummed about missing out on the big Science paper. I guess I'm on the retraction though ;)
They were pretty model agnostic in what they were looking for. They modeled and simulated a number of different ways a WIMP could interact with normal matter. If this is a discovery, more data will be needed to figure out the nature of that interaction and how it fits into particle physics.
But there's always a chance it's something completely new, or some extremely rare manifestation of things we already know about, but have never seen before. And even if it is WIMP, it may not be the right type of WIMP (wrong mass, or wrong interaction strength) to explain cosmological dark matter.
When doing this kind of thing, the analysts will plot the rate of events as a function of "distance from the outer surface" and confirm that it decreases, and in this case "is 0" inside of the detector used for analysis.
But keep in mind that all statements are made statistically, so it's not that the event _can't_ be an external neutron, but that it is _very_ unlikely to be.
That's not to say it can't be a neutron, but it would be surprising if it were.
would you include all the quoted text in the reply-alls, or is that too much?
Science has too many threads to do it successfully though
Only quote the relevant part and reply to it, just like this very comment.
And Linux has a large mailing archive of various lists and threads that are searchable and available to everyone and get this: free access
(Notwithstanding the absurdity of academic publishing, of course.)
https://www.scientificamerican.com/blog/information-culture/...
Which of course is the point: it is in fact quite similar to a mailing list, just with some extra protocol surounding it to make it manageable.
So the attempted snark about it up thread is stupid.
A paper has a (semi-formal) structure, including TITLE, AUTHORS, and the all-important ABSTRACT.
Email guarantees none of those.
Pre-prints are basically a mailinglist where you post your paper prior to peer review.
The value over a simple mailinglist is:
1. Stable URL and citation to enable other work and discussions to cite and reference it.
2. Versioning of the paper, allowing updates to be made without having mail out the paper, while allowing everyone to find all prior versions
3. Host for a PDF and data that might be quite large
4. Centralized searchable long term archive of scientific papers
5. Scalability, arxiv gets 30,000 submissions a day, no one wants to receive 30,000 PDFs in their inbox everyday
Culturally, an attempt to intentionally distort or misrepresent data to suggest a result like this would not be tolerated. You can imagine a bad actor writing a single-author paper with fakery, but a collaboration at this level is inherently critical of itself and everyone holds each other accountable.
But mistakes do happen. Exciting results or hints of exciting results can appear due to well-intentioned researchers making convenient mistakes which get glossed over for psychological reasons and then add up to appear as something significant. You can read about "blinding" (which is mentioned in the paper) to get a feel for the techniques researchers employ to not only guard against fabricating results intentionally, but even unintentionally.
The point of "blinding," as I mentioned it before, is to guard against biasing the result due to choices made by analysts while figuring out how to compute their final answer. Part of that is just psychological --- if an analyst _knows_ that the data is obscured, for lack of a better term, in a way such that they can't believe a signal that they see (for example --- that's just one way to blind), then they won't feel any emotion or excitement about things they encounter while constructing the analysis, because they know what they're looking at isn't real, and that helps them to maintain objectivity. It's also common to have multiple independent analysis teams for something like this --- they know that they'll have embarrassed themselves if they don't all get the same result both before and after unblinding, which provides pressure to maintain objectivity.
As far as review goes --- there are physicists who believe in dark matter, and there are physicists who don't believe in dark matter. But all particle physicists and nuclear physicists use the same core technical and statistical methods. For a result like this, there will be a few "core analysts" who do the analysis, typically graduate students and postdocs. Their advisors review their work, through the lens of making sure that they are doing so sanely. The collaboration will also establish an internal review committee to comb through the documentation and software which produced the result, not necessarily trying to disprove what they found, but really looking at it critically. Once it gets to a journal, they'll get reviewers who may be biased for or against the result, and who may or may not work directly on dark matter detection, but who can all assess the methodology by which the result was obtained. That's probably the best we can do with humans involved.
However, the context here is that the DOE has already paused funding for the experiment's successor, XLZD, for an unspecified amount of time which realistically, is probably going to depend on the next US presidential election. At the same time, the DOE encouraged the LZ project to develop scenarios for continuing to operating beyond its current end date of 2028.
Now, here's what the NBC Bay Area report I mentioned[0] ended with:
> "All the more reason, they say, to keep these machines running. [...] They'd like to keep the machines running, they wanna keep doing this research, they're applying for funding now, so fingers crossed, we'll have more updates on this [...]"
The media attention this received was not the organic result of some journalist noticing the preprint or the talk at TeVPA in Japan. There was a major wave of synchronized official press releases, coinciding with the TeVPA talk, from Berkeley National Lab[1], Brown University[2], SLAC[3], Brookhaven[4], Stanford[5], University of Sydney[6], and others including UMass Amherst and Imperial College London.
Now, these institutions are all involved in the collaboration somehow, so it makes sense that they would coordinate press releases for a major result. The question is whether this result warrants such treatment. It's a single event at 2.6 sigma global significance. Promoting it in this way was a choice, and I'm pointing out that it seems quite possible - in fact I'd say extremely likely - that that choice was made with the funding situation top of mind.
[0] https://www.youtube.com/watch?v=bf3aW0xTEEc
[1] https://newscenter.lbl.gov/2026/09/01/lz-sees-surprising-res...
[2] https://www.brown.edu/news/2026-09-01/lz-dark-matter-results
[3] https://www6.slac.stanford.edu/news/2026-09-01-lz-sees-surpr...
[4] https://www.bnl.gov/newsroom/news.php?a=123133
[5] https://news.stanford.edu/stories/2026/09/dark-matter-detect...
[6] https://www.sydney.edu.au/news-opinion/news/2026/09/03/lz-ex...
But I don't see anything particularly strange or coordinated is happening. From the collaboration's perspective, it's quite stressful having this event. They've already unblinded, so it would be unethical to do anything other than report what they found. If they publicize it and it's a mistake, then that's a big blow to their credibility. But if they withhold it and it's real, then they miss making the discovery and/or bias their future analyses on larger datasets without disclosing that to the community. So they are in a tough spot, and are safest to just tell the world what they saw.
This is getting media attention because it would be a big deal to the general public if this ends up being a real. Someone in the field wouldn't claim that it's real, but the possibility is catnip to folks looking for a sensational headline. That the press releases are synchronized in time is because the result was just released right now and they're all doing their commentaries right away --- for something like this, each institution independently negotiates a release with the local researchers who are involved. They all promise to wait until the result is officially released, out of respect for the scientific process, like you say, but the different institutions aren't coordinating with each other. They're just all respecting their own researchers.
Is a 2 or 3 sigma fluctuation worth a lot of press? Personally, I don't think so. But we don't know if it's a fluctuation yet, and no institution is going to pass on having made it clear, if this does turn out to be real, that they were involved.
All that being said: I would very much like these folks to continue to receive funding. They are professional and do excellent work, as demonstrated here.
Absolute and utter ridiculous nonsense. Can you not just admit when you're wrong?
It's perfectly ethical for them to give a talk at TeVPA about a paper they've published.
But at least 8 global, coordinated press releases? That's a choice, with consequences.
And one of those consequences is that they reveal themselves as chasing funding above all else. Scientific rigor goes out the window. 2.6 sigma results become amazing new discoveries.
It's not really their fault - it's systemic. But don't try to pretend that this is somehow the normal process of science being conducted with integrity.
> Absolute and utter ridiculous nonsense. Can you not just admit when you're wrong?
Wrong about what? If you think they should _not_ just report their findings, and instead try to change their analysis after already finding this event, then you're free to think that, and you're also free to say so. Personally, I don't think that that would be ethical.
> But at least 8 global, coordinated press releases? That's a choice, with consequences.
You seem to be asserting that there is something of nefarious happening. The collaboration does coordinate otherwise-unrelated releases by individual institutions. The alternative is that PR folks distributed across different institutions, few if any of whom have any training in physics or statistics, would make whatever claims they feel appropriate at whatever time they feel appropriate (relative to each other, and relative to publication of the actual paper). In what way is that preferable?
> 2.6 sigma results become amazing new discoveries.
They are not claiming a new discovery. They are claiming to have observed a single event, which is significant at the level of 2.6 sigma. A naive treatment produces a significance of more than 3 sigma, and the collaboration did what you might call "extra" work to be fair in their statistical analysis, which reduced the appropriate number to quote to be below 3 sigma. They state that clearly, and suggest interpreting the event at 2.6 sigma, the less-flashy option. To me, that shows integrity.
The idea is that because 3 sigma means a ~1/1000 chance of the thing being explained by random chance, 1 in 1000 experiments will produce a bogus 3 sigma result, and we do many thousands of experiments.
Very hard to manage jumping the gun by reporters. Sounds like they saw some new data. No idea what it is.
Looking forward to the follow up.
Glad to see such things getting re-purposed instead of just sealed off and abandoned.
It sounds like this implies they've seen 3x more events but it seems like they would have said that if it were the case. Have they just gathered more data about the single event or is this 4 separate events they're talking about?
The work being done here falls into the category of "low background physics" --- they aren't trying to produce anything, and actually put quite a bit of effort into doing the opposite, by removing all sources of particles (e.g. sourcing materials free of radioactive contaminants, physically cleaning all surfaces and purifying all fluids involved, etc).
So the detector, if built properly, is fairly quiet, and you try to write as much data to disk as you can (e.g., if something even fairly-potentially interesting happens, you save it). Then when you analyze the data like this, you ignore the majority of what you've got --- only a teeny fraction makes it into an analysis of this caliber.
As they better understand the detector, they can use more of that mass. They have data from it, but they just didn't use it. And they're always collecting more data, too, as time passes.
So the 3x is saying they have something like 8.5 tonne-years of data.
Hopefully it the new data may have 3 additional events, or perhaps 2 or perhaps 4 or perhaps 10 or perhaps... Or the reported event may be false event caused by a lucky coincidence, and they may find 0 additional events.
Then, at some point, they freeze their pipeline, "open the box", run the analysis on the real data, and report what they find. But they can only "open the box" once per exposure, after that you can worry that human bias can creep in.
But probably more likely is for this to have been a particularly energetic event in the tail of one of the known sources of neutron recoil detection they did model. More events needed!
I hope this turns into a real discovery about something; but even if it's an equipment malfunction, hopefully it's a lesson that can be turned into improving the detector.
Especially after JWT started looking deeper into the early universe.
This doesn't in any way mean that you can't in principle describe with perfect accuracy with such a system, in a provable way, every aspect of physics. Sure, you might need a theorem that can't be proved and be stuck because of that, but it's not a given. Physics certainly doesn't depend on all possible statements in that formal system to accurately model the real world, and so Goedel's theorem can't prove that the subset that physics needs might not be all probable.
Why couldn't the territory be losslessly compressible?
If reality has irreducible randomness (an open question afaik), and we're talking about theories and explanations (so we're not necessarily trying to describe the actual state of every particle in the universe, but only the rules governing their interactions), couldn't we have a complete, correct theory that was much smaller than the universe and contained terms for the random elements?
There would always be the possibility that it would turn out to be wrong, but it could be complete and correct, so it seems like the original claim must depend heavily on the word 'provable' and not on the impossibility of describing a system via a map smaller than the territory.
edit: but also, surely 'the territory is randomized' is a contingent physical fact, and not a necessary truth of information theory. Until we know for sure that there is irreducible randomness, we can't know that the information content of the universe (including the actual state of all particles at all times) isn't losslessly compressible, right?
We know with a high degree of certainty the universe contains things we can’t predict or observe, see Bell’s Theorem.
“Truth” doesn’t exist outside reality. There’s no substrate to hang it in. Information theory is likewise a subset of the territory, part of the universe, not apart from it. For these things to exist independently, you need something other than or bigger than the universe to put them in. If such a thing existed, sure, from that perspective maybe a lossless compression could exist. But that’s a metaphysical argument.
Additionally, when a particle interacts with the nucleus, the ratio of how much energy ends up as scintillation light versus ionization is different than when a particle interacts with an electron, which is most of the background processes.
Then, whatever is left, they try to model using known processes. After all that, there's one event that they can't account for. And that's what the news is about.
Xe-124, half-life 1.1 * 10^22 years. That's crazy.
I don't remember anything specific about deuterium, and the method that Xe124 uses is not available, and I can't imagine a razonable alternative method, so my guess is that deuterium is as stable as protons.
Also even if something is REALLY REALLY long lasting, you can still check for the halflife by observing enough of it, they've been able to rule out proton halflives under 10^34 years (the universe is on the order of 10^10 years old) but by observing enough protons (like say 50,000 tons of water) you would expect at least some to decay.
Oh, they actually don't. Radioactive decay, AFAIK, is still an open physics mystery. We know it happens, we don't know why, what causes it, or if there even is a cause. We can predict factors that make it more likely.
> to the point they can predict some to be radioactive before it's actually observed to be (like Bismuth-209).
Right, but Xenon 124 wasn't predicted to be radioactive which is what makes it fascinating. It shows holes in what we can predict as being radioactive which is what makes me wonder about everything being radioactive but the timetable is too far out.
Which seems to point even more towards, scientists have a pretty good handle on which ones are radioactive.
I get a little shiver imagining that the dark matter might be something like ordinary atoms. Imagine that other 85% of the universe could have its own parallel atomic table, chemistry, even some kind of life utterly alien to us?
By itself, that does not exclude the possibility of dark matter having other interactions which do not interfere with our detectors.
Since where we see dark matter mass shadows we don't see structure formation, what self interaction it may have must be very, very limited.
Don’t ask me how or why, but this is essentially the universal (pun intended) consensus amongst cosmologists.
https://en.wikipedia.org/wiki/Hidden_sector
The scary thought is that, were it true that there is voluminous richly-interacting dark matter, we would be the actual dark sector.
I can imagine other scary thoughts, though. Ever read any Warhammer lore?
The difference: LUX-ZEPLIN, which is underground, is waiting to detect a dark matter particle itself. On the other hand, NGRST seeks to observe the effects of dark matter.
The reason we haven't mapped the seafloor is because why would we? It's like arguing we know nothing about biology because we've only sequenced the genome of a fraction of humans or something. It's not that we can't do it, the reason we haven't done it is because there's no good compelling reason to do it. What do we expect to learn from mapping 100% of the sea floor?
As for the parents question – "How many years until we've discovered "everything"?"
I think we may be fairly close to knowing everything we can know and it's quite reasonable to assume we're now comfortably on the tail end of the S-curve of physics discoveries. I hope I'm wrong of course.
Just given dark matter and energy, things the standard model doesn't answer, and our evolving tools (e.g. Grace telescope, etc.).
This means that today to make new discoveries we tend to have to invest huge sums of money and build experiments that we'll increasingly struggle to scale significantly beyond. For example, maybe humans could just about build something 10x the size of the LHC if we really wanted, but 100x seems near-impossible. Maybe we can build slightly larger telescopes, but again, this is becoming harder due to the scale we're already working at.
So while I agree there's probably lots of physics out there to discover, the physics we humans are actually likely to be able to discover is rapidly diminishing. And the physics which is likely to revolutionise our daily lives is presumably even smaller more due to scale and energy levels where mysteries remain.
But ultimately who knows, this is just my opinion – an opinion I'm being downvoted for because apparently HN discussions these days are a place for us circlejerk around the consensus view rather than discuss differences in opinion.
Why would we map the seafloor is an insane question that immediately invalidates all other opinions that you may have, unfortunately. The human embodiment of that meme with the pickaxe guy walking away from a diamond strike if only he had swung once more.
It's so hubristic to assume that our generation is the one that will discover the answers to everything.
I think maybe I was assuming the parent was referring specifically to physics discoveries while you were assuming that they were asking more broadly about how many years until we've discovered everything discoverable?
Unless you are actually arguing there's likely lots of physics discoveries to be made because humans have only photographed a fraction of trees on the earth, or mapped a fraction of the seafloor, or sequenced only a fraction of the genomes of known species?
https://users.ece.cmu.edu/~gamvrosi/thelastq.html
tl;dr: likely as long as the lifespan of the universe.
That's more than 3σ.
The LZ collaboration is going to run their machine until at least 2030. They have almost no hope of making a meaningfully larger detector, no will you hear them suggest one. Their detector is already designed at such a scale that it contains a substantial fraction of all the needed xenon isotope available on Earth.
[1] https://news.wisc.edu/dark-matter-detection-receives-10-ton-...
Hopefully, other aparatus elsewhere are big enough too in order to spot similar events.
What I was addressing was whether this detector is big enough for a reliable discovery. In that case what you really want to constrain is the rate, such-and-such events per kilogram of xenon per year (the per-kilogram-of-xenon can be traded for a per-liter rate given the density of the xenon).
"Basic" gravitational equations applied to observed behaviour: clumping and rotation of galaxies, lensing (light bending), etc.
The behaviour implies "something" is exerting force in a mass like way - but there's a shortfall of visible mass.
The observational hole left by the apparent behaviour of "unseen matter" attracts a lot of theory.
* Physics "allows for" various types of particles with various types of properties - these may or may not all exist, some do. eg: Neutrino's from the sun barely interact with anything, consistently capturing them is a challenge. Maybe Dark Matter is a new hard to observe gravity particle.
* Physics has equations formed by "human scale" observation and sometimes tweaked for scales beyond direct human experience. eg: relativistic tweaks related to speeds approaching that of light. Maybe Dark Matter is a warping of observation at galaxy scale.
The opening paragraphs of, say, https://en.wikipedia.org/wiki/Dark_matter cover the ground of speculation.
When your equations are missing a number to work, you announce a new particle.
That's a lot like a blind person saying they can't believe light exists.
It takes only a small amount of knowledge of physics to understand why and how dark matter might be possible, even likely. So small, in fact, that I can describe it in this comment.
The tl;dr is that all the senses you experience - sight, touch, smell, taste, and hearing - depend on the electromagnetic (EM) interaction. Touch, smell, taste, and hearing all depend on how electrons interact, and sight depends on how photons interact with electrons. But EM is only one of four fundamental interactions that we know of. We humans are essentially blind to all the others, without using devices to detect their presence.
But using devices we've invented, we can detect all sorts of things that we can't detect directly with our senses. X-rays and gamma rays, for example. But those are still just high-energy photons, not a different kind of particle altogether. They just help illustrate how limited our senses are.
A better example is the neutrino. They're pretty close to being "dark matter," because they don't interact via electromagnetism. As a result, they can pass right through your body, because there's nothing much to stop them. You're just as invisible to a neutrino as a neutrino is to you. It's estimated that about 100 trillion neutrinos pass through your body each second.
But neutrinos aren't perfectly "dark" - although they don't interact with electromagnetism, they do interact via the weak nuclear interaction, which is mostly something that happens inside the nuclei of atoms. (They also interact via gravity, but they have very small mass, so that doesn't help us detect them.)
We can detect neutrinos by building huge tanks full of very pure substances like water or argon, and burying them deep underground, to shield them from other interference. We can then look for the tell-tale signs that occur when a neutrino just happens to have a direct hit on an atomic nucleus, something that doesn't happen very often because nuclei are very small. That's why we need large tanks - to increase the odds of a hit.
The IceCube neutrino detector in Antarctica (https://icecube.wisc.edu/science/icecube/) extends to 2.5 km underground, and Super-Kamiokande in Japan (https://www-sk.icrr.u-tokyo.ac.jp/en/sk/) is buried 1 km below a mountain. They're able to detect neutrinos with high confidence, because aside from the tell-tale sing we can often even relate the neutrinos they detect to astronomical sources such as supernovae and supermassive black holes.
Neutrinos show that it's possible to have matter that doesn't interact via electromagnetism, which is all but invisible to us. And not just invisible - it can pass right through us. In the case of neutrinos, we're just "lucky" that they participate in the weak nuclear interaction, so we can detect them if we try hard enough. But what if a particle didn't do that? Then you'd have real dark matter - particles that we can't detect at all, except via the energy they carry, which participates in the gravitational interaction. But it's very difficult to detect tiny particles using gravity - which is why the first place we think we've detected dark matter is at large scales, in the motion of galaxies, where the collective mass of dark matter is large enough to be detected.
With all this in mind, a question dark matter skeptics would need to answer is, why wouldn't we expect dark matter to exist? We've identified quite a large zoo of particles, and what distinguishes each of them is that they each participate differently in the different interactions that we know about. Here's a summary of the fundamental particles and their participation in the fundamental interactions - which are gravity, electromagnetism (EM), weak nuclear, and strong nuclear (the latter two are different types of interactions that happen to have very generic names):
Electron: gravity, EM, weak
Neutrino: gravity, weak
Photon: gravity, EM
Quark: gravity, EM, weak, strong
Gluon: gravity, strong
Dark matter: gravity, ?
There's no physical reason we wouldn't expect a particle like dark matter to exist. It doesn't even have to have no interaction other than gravity - it could just have a very small degree of interaction that we can't easily detect, which is what the OP experiment is counting on.
If you accept the existence of X-rays and neutrinos, then it's not very consistent to draw the line at dark matter, once you have some understanding of the physics involved.
It's an open question, right, whether dark matter has no interaction or just very little interaction with normal matter? If there's none, this experiment will detect nothing but noise.
I'm confused why, if dark matter exists and has mass (since it interacts gravitationally), there's no noticeable missing results from high-energy events that create particles. Shouldn't dark matter particles be generated by, say, cosmic ray collisions? Or black hole decay?
Correct. What this experiment (LUX-ZEPLIN) is looking for is the effects of xenon nuclei being "bumped" - recoiling - due to something undetectable. It doesn't matter what interaction mediates the recoil - it could even be a so-far-undiscovered interaction. They're just looking for evidence of the recoil happening. But if the only interaction is gravity, they won't detect anything, since gravity is too weak for us to detect the effects of at that scale.
> I'm confused why, if dark matter exists and has mass (since it interacts gravitationally), there's no noticeable missing results from high-energy events that create particles.
Particle physicists actively look for this, e.g. in reactions in particle accelerators. But not finding evidence of that only places constraints on how strongly dark matter can couple to ordinary matter, it doesn't rule it out.
> Shouldn't dark matter particles be generated by, say, cosmic ray collisions?
Not necessarily. Just being energetic doesn't guarantee anything. There's a bit of a chicken-and-egg issue here: without knowing more about dark matter, we can't predict what reactions might produce it. That's why experiments like LUX-ZEPLIN make as few assumptions as possible - all it requires is that some mechanism for energy transfer from dark matter to matter exists.
> Or black hole decay?
Black hole decay has never been observed. Since it's purely theoretical, no matter how well-justified it is, it doesn't really help in the search for dark matter. There's no reason that Hawking radiation couldn't include dark matter, in fact if dark matter exists it probably would, but we have no way to detect that.
Even if say black hole collisions (which have been indirectly observed) produced dark matter, we wouldn't really have any way of detecting it at the distances in question.
> My intuition
> I really assume
hmmmm
I wouldn't go into a neurological medical thread, and post "I'd guess it doesn't even exist" as a solution for Alzheimer's. But you just did the same, analogously.
Has there ever been an article about particle physics that didnt end with a statement about the "next and bigger" version of the current detector. The field has an addiction. No matter the size/luminocity, they will only ever crave a bigger hit.
One wonders if we should measure detectors as we do nuclear bombs: by the kiloton mass of thier detection medium. The DUNE detector would be a 70 kiloton-class detector. Super-Kamiokande, 50kt. IceCube would be approaching a gigaton.