[HN Gopher] What could explain the gallium anomaly?
___________________________________________________________________
What could explain the gallium anomaly?
Author : ars
Score : 201 points
Date : 2024-07-12 18:35 UTC (1 days ago)
(HTM) web link (www.quantamagazine.org)
(TXT) w3m dump (www.quantamagazine.org)
| CamperBob2 wrote:
| Photo caption: _In the lab that houses the BEST experiment, fish
| serve as an early warning system about any leaking radiation._
|
| Never change, Russia. Never change.
| dylan604 wrote:
| You can't get them all right. To be fair, they used pencils
| while NASA spent time and money to have a pen that writes in
| 0g.
| spankalee wrote:
| That's just a myth, you know:
| https://www.scientificamerican.com/article/fact-or-
| fiction-n...
| dflock wrote:
| Fischer made the space pen as a commercial product, all R+D
| entirely at their own expense. NASA just bought some of the
| pens from them.
| Etheryte wrote:
| This is a myth, using a pencil in space isn't clever or
| thrifty, it's a disaster waiting to happen. The graphite from
| pencils breaks off in small fragments while writing and the
| fragments can create shorts in electronics and to top it off
| they're also flammable. None of those are properties you want
| to bring into a spacecraft.
| sterlind wrote:
| dumb question but how well do sharpies work in space? the
| ink diffuses through the felt tip - that doesn't require
| gravity. wouldn't that work pretty well?
|
| also crayons seem like a better bet than pencils - they're
| still flammable and prone to flaking but at least they're
| not conductive.
| mypalmike wrote:
| Your question piqued my curiosity, so I did some
| googling... Apparently sharpies do work in space, though
| NASA seems to prefer the Duro brand of marker.
|
| https://airandspace.si.edu/stories/editorial/saga-
| writing-sp...
| crazygringo wrote:
| Sharpies and markers generally run out waaay quicker than
| pens or pencils. They also dry out if you're not careful,
| and dry out temporarily if you use them for more than a
| few minutes at a time.
|
| Crayons just aren't dark enough, and are too wide.
| Accurately reading numbers and symbols written in crayon
| at a normal handwritten size is not something I want to
| do. Not to mention the constant sharpening.
| hinkley wrote:
| And we licensed the pens from a dude who spent a fortune
| developing them.
| mrguyorama wrote:
| After Fisher, the pen company, spent their own couple
| millions to develop a pen that could write in zero gravity,
| they convinced NASA to use it, and a few years later the
| Soviets bought 100 of them for their own space program.
|
| NASA was never involved in the development of the space pen,
| though they supposedly had their own effort that was quickly
| abandoned as it got expensive. Before that they also used
| pencils.
|
| The pen is just a better writing implement in space. It cost
| $3 in the 60s, with wide availability.
| sterlind wrote:
| coal miners carried canaries to warn of CO. chemical weapons
| workers brought bunnies in cages to monitor nerve gas leaks.
| it's an old tradition - it's simple, and it works.
|
| though why not Geiger counters for radiation? there must be a
| reason.
| CamperBob2 wrote:
| If there's enough CO to kill a canary, you still have time to
| get to safety.
|
| If there's enough nerve gas to kill a rabbit, you still have
| time to get to safety.
|
| If there's enough radiation to kill a fish, you're a walking
| dead man... and the 'walking' part is temporary.
| dudinax wrote:
| Maybe the fish get less shielding.
| qup wrote:
| Maybe it's concentrated in his water
| postalrat wrote:
| What if you have a potential worrisome alpha emitter
| already in water. Keeping some fish in that water might
| give you heads up when something is going wrong.
| CamperBob2 wrote:
| Then, lacking the availability of an ISO-standard fish,
| you should probably use a scintillator or surface-barrier
| detector. Like everyone else who has to deal with such
| matters.
| labster wrote:
| If you teach a man a fish, he will eat for one lifetime. If
| you give a man a radioactive fish, he will eat for many
| half-lives.
| Terr_ wrote:
| I'm no nuclear physicist, but a theory to try out:
|
| 1. The leak scenario they're concerned about is an alpha
| emitter within water, which-- unlike gamma rays and Geiger
| counters--is harder to detect remotely, since the water
| serves as effective shielding for anything but microscopic
| distances.
|
| 2. Permanent resident fish serve as a kind of long-term
| accumulator for dissolved amounts that would otherwise be too
| hard to detect.
|
| 3. The concern isn't so much immediate risks to human health,
| but rather how any slow leak or discrepancy might compromise
| the experiment.
| TeMPOraL wrote:
| > _though why not Geiger counters for radiation? there must
| be a reason._
|
| If a detector fish moves, it works. With Geiger counter, you
| may not be always able to tell when it malfunctions.
| lossolo wrote:
| Did you know that mussels and clams are sensitive to changes in
| water quality and can absorb pollutants? They are often used as
| bioindicators to detect harmful substances like heavy metals
| and toxins in the water. They are used in United States and in
| Europe to check if water is clean.
| hinkley wrote:
| I remember someone creating a sensing system to see if the
| shells were open or closed. Given enough mussels, the odds of
| them all closing at once due to random chance instead of
| pollution drops to zero.
| LeifCarrotson wrote:
| This Tom Scott video?
|
| https://youtu.be/i0RkEs3Xwf0
|
| Clams at 2:22.
| hinkley wrote:
| I believe Tom is the second time I heard of this, as was
| the experience of a number of his chattier viewers.
| ars wrote:
| Would sterile neutrinos as an oscillation really change anything
| about dark matter? The total mass of neutrinos doesn't change,
| just the lepton number.
| AnimalMuppet wrote:
| It might mean 20% more neutrinos exist than we think. That
| would change the total mass of neutrinos.
|
| _Much_ more interesting (and not touched on by the article as
| far as I noticed): The electron neutrino is the "partner" to
| the electron. The muon neutrino is the partner to the muon, and
| the tau neutrino to the tau. What's the sterile neutrino the
| partner to? (Or doesn't it have one, and that's what makes it
| "sterile"?)
|
| If there is a partner to it, does the partner have mass? Does
| it interact in any way besides gravitationally? If not...
| torrefatto wrote:
| IIRC, there is another quantum number, the chirality. All the
| neutrinos measured are left chiral. The sterile neutrino,
| which does not pair with other lepton, is right chiral.
| AnimalMuppet wrote:
| Is that the only possible sterile neutrino? Because if I
| recall correctly, a right chiral neutrino _cannot_ change
| into one of the other types, because of the chirality.
| (That 's why it's "sterile".)
|
| So either they aren't produced by beta decay, or they are
| but they can't be captured by gallium, or we're seeing a
| sterile neutrino in a different sense. ("Sterile" because
| it can't interact with gallium, but not sterile due to
| chirality.)
|
| If I understand, the conversion of gallium into germanium
| is exactly a beta interaction. (But I may not understand,
| because it seems to me that gallium->germanium should
| _emit_ a neutrino, not _absorb_ one.) So I have a hard time
| seeing how a neutrino could be emitted by the source, but
| not absorbed by gallium. I could more readily see it as
| saying that there 's a fourth type of neutrino that they
| cycle through, and while in that fourth state it can't
| convert gallium. But that wouldn't be "sterile" in the
| chirality sense.
| eigenket wrote:
| > If I understand, the conversion of gallium into
| germanium is exactly a beta interaction
|
| In a "standard" beta decay the neutron turns into a
| proton and emits an electron and an anti-electron
| neutrino. In this reaction its absorbing an electron
| neutrino and emitting an electron (while still turning
| the neutron into a proton). Absorbing an electron
| neutrino is pretty much equivalent to emitting an anti-
| electron neutrino.
| floxy wrote:
| >gallium->germanium should emit a neutrino, not absorb
| one.
|
| Neutron-Neutrino interaction?
|
| https://www.vivaxsolutions.com/physics/feynman-
| diagrams.aspx
| ahartmetz wrote:
| Emitting an antiparticle is (in Feynman diagrams at
| least) the same as absorbing a particle. IIRC, for
| neutrinos the anti aspect isn't _that_ important because
| they don 't quickly annihilate with regular matter and
| they have no electrical charge.
|
| I even seem to remember that the most commonly produced
| neutrinos are antineutrinos (so the anti aspect is more
| fundamental than a convention for each particle type).
| ars wrote:
| > It might mean 20% more neutrinos exist than we think.
|
| Would it though? It's not like we know neutrino mass from
| measurement, rather we estimate it from nuclear reactions
| that have occurred. The estimate would not change if a
| neutrino oscillates into a sterile one.
| ars wrote:
| > What's the sterile neutrino the partner to?
|
| It would be a very unusual partner that has no concerved
| quantum numbers, and only mass.
|
| A sterile neutrino would also imply that the neutrino is a
| Majorana particle (because it would have not quantum numbers
| that could be "anti").
| PaulHoule wrote:
| Sterile neutrinos could also be a lot heavier than regular
| neutrinos, those kind of sterile neutrinos are ideal candidates
| for explaining dark matter and the matter-antimatter asymmetry
|
| https://arxiv.org/abs/1303.6912
|
| Just as I am disappointed that "global warming" changed into
| the more ambiguous "climate change", I'm a little disappointed
| that the "right-handed neutrino" has turned into the "sterile
| neutrino". It's _really strange_ that we only observe left
| handed neutrinos and either the revelation that there is a
| hidden right-handed neutrino or that neutrinos are fully
| Majorana particles without a right-handed form would be
| absolutely groundbreaking.
|
| My take on it is that the neutrino mass term is not "physics
| beyond the standard model" but rather a "missing part of the
| standard model" and that one way or another, neutrinos hold an
| important secret, if not the important secret of the universe.
| (Note potentially three generations of right-handed neutrinos
| could exist at three mass scales and explain the gallium
| anomaly, cold dark matter, and the rarity of antimatter)
| labster wrote:
| As a climatologist, I can tell you that we switched to
| "climate change" because it's more precise. "Global" in
| global warming is not the "universal" sense of global,
| because not everywhere on Earth warms equally, and some
| places may even cool with mean global warming. Global climate
| change implies that the averages and ranges are changing. The
| phenomenon is best measured in statistics.
|
| (Also as a climatologist I have no idea what the handedness
| of neutrinos even means. Something with spin?)
| kadoban wrote:
| > (Also as a climatologist I have no idea what the
| handedness of neutrinos even means. Something with spin?)
|
| Indeed, it's the relation of spin to linear momentum of the
| particle.
| eigenket wrote:
| Its not quite that, the thing you're describing is called
| _helicity_. Helicity and chirality are closely related,
| they 're the same if your particle is massless for
| example, but for massive particles they aren't the same.
|
| Imagine I have a particle which is spinning in the same
| direction as its linear momentum (so positive helicity)
| but then I speed myself up really fast so now I'm going
| faster than it. Its linear momentum (to me) appears to
| have switched sign but its spin hasn't so the helicity
| has flipped.
|
| Chirality is a more complicated thing which avoids this
| "problem" with helicity. Chirality doesn't change when
| the observer changed velocity.
| Terr_ wrote:
| > sterile neutrinos
|
| It's funny when one encounters serious real-world discussion on
| something previously seen as sci-fi technobabble.
|
| In this case, I'm thinking of the Destiny universe, such as this
| apocalyptic alert from a military AI. [0]
|
| > Multiple distributed ISR assets report a TRANSIENT NEAR
| EXTRASOLAR EVENT. Event duration ZERO POINT THREE SECONDS. Event
| footprint includes sterile neutrino scattering and gravity waves.
| Omnibus analysis detects deep structure information content (nine
| sigma) and internal teleonomy. No hypothesis on event mechanism
| (FLAG ACAUSAL). Bootstrap simulation suggests event is DIRECTED
| and INIMICABLE (convergent q-Bayes/Monte Carlo probability
| approaches 1). No hypothesis on deep structure encoding (TCC/NP-
| HARD).
|
| ______
|
| > In the lab that houses the BEST experiment, fish serve as an
| early warning system about any leaking radiation.
|
| I'm curious how this works, it looks as if there's one central
| underwater valve and two above-water valves, perhaps supposedly-
| breathable air is getting bubbled up through the tank?
|
| > SAGE used a tank of 57 metric tons of gallium.
|
| Some napkin-math [egregious mistake corrected] to visualize how
| much that is, and I get "45 oil drums". Line
| item Amt Units Gallium Mass
| 5.70E+01 metric tons Gallium Mass 5.70E+04
| kg Gallium Mass 5.70E+07 grams Liq.
| Gallium Density 6.10E+00 grams/cm3 Gallium Vol
| 9.35E+06 cm3 Oil Drum Volume 5.50E+01
| gallons Vol Ratio 3.79E+03 gallons/cm3
| Oil Drum Volume 2.08E+05 cm3 Gallium Volume
| 4.49E+01 oil drums
|
| ____
|
| [0] https://www.ishtar-collective.net/cards/ghost-fragment-
| darkn...
| auspiv wrote:
| double check that math - olympic pool is 50x25x2 meters, or
| 2500m3. 1 m3 of water is roughly 1 metric ton (1 g/cc = 1 kg/L
| = 1 t/m3) depending on temperature and such.
|
| 57000000g / 5.9 g/cc = 9661017 cc = 9.661m3
| Terr_ wrote:
| Whoops, yeah, made a few mistakes. Next time I'll do the
| usual and open a throwaway spreadsheet. Also, picking
| gallium-density from a slightly higher temperature where it's
| liquid.
| addaon wrote:
| Google is (still) a great tool for this sort of conversion. It
| comes up with just under 58 barrels:
| https://www.google.com/search?q=57+tonnes+%2F+%286.1+g%2Fcm%...
| Terr_ wrote:
| > Google is (still) a great tool for this sort of conversion
|
| Alas, not in this case, since Google is interpreting that as
| a 42-gallon "petrochemical-industry traditional abstract
| measuring unit of crude oil" as opposed to a 55-gallon
| "physical container readers may have seen and everybody
| actually uses." (Including to hold crude oil, in the rare
| cases that it's not in an enormous tank or pipeline.)
|
| Perhaps this is an example of where "intelligent assistant"
| software lands in a dangerous middle-zone of "wrong, but not
| wrong enough that it's obvious."
|
| Anywho, if we reword it a bit and put in a less-rounded
| density, it comes out the same:
|
| https://www.google.com/search?q=57+tonnes+%2F+%286.095+g%2Fc.
| ..
|
| __________
|
| _P.S.:_ The way it parses this small change is also amusing,
| where "in _water_ barrels " isn't a change in the type of
| barrel, but instead introduces a non-SI unit of _pressure_ ,
| making everything murky indeed.
|
| https://www.google.com/search?q=57+tonnes+%2F+%286.1+g%2Fcm%.
| ..
| Hnrobert42 wrote:
| It is remarkable that you spotted the inaccuracy. You make
| a good point about it being wrong but not wrong enough.
|
| OTOH, the correct answer by your reasoning is 44 barrels.
| For my purposes, 58 is right enough. I can't even visualize
| the difference between 44 and 58 barrels.
|
| 44 barrels is about 323 cubic feet (9.1 cubic meters).
| That's about the size of my bathroom.
|
| 57 tons in my tiny bathroom. Gallium is shockingly dense.
| Which makes sense.
| easygenes wrote:
| My preference for this on the web is Wolfram Alpha: https://w
| ww.wolframalpha.com/input?i=57+tonnes+%2F+%286.1+g%...
|
| (note I've slightly changed the prompt to match the "drums"
| OP used instead of barrels. This avoids the issue other child
| mentions of ambiguous units, as it clearly states the volume
| of drum it's using and gives options for others (e.g. the
| international 200L instead of the US 208L/55 GAL).
|
| Another option which I wouldn't inherently trust to get the
| calculation just right, but is good for explaining the
| process if you can fact-check it is ChatGPT-4o: https://chatg
| pt.com/share/ead07fff-8d55-4147-a742-6e19b26f1e...
| jessriedel wrote:
| >> It's funny when one encounters serious real-world discussion
| on something previously seen as sci-fi technobabble.
|
| > In this case, I'm thinking of the Destiny universe, such as
| this apocalyptic alert from a military AI.
|
| To be clear, physicists have been thinking very non-fictionally
| about sterile neutrinos since 1968.
| bawolff wrote:
| > While Russia's invasion of Ukraine "has complicated things,"
| Elliott said, the collaboration between the U.S. and Russia on
| BEST is still ongoing, for now.
|
| Nice to hear in these uncertain times.
| geuis wrote:
| How is that "nice"? The fact that 3 years in we are still
| collaborating with Russia on the ISS and in other scientific
| programs is deeply disturbing. I get that the ISS is a special
| circumstance and a difficult knot to unravel. That's an
| extremely unique situation and it's not worth digging into at
| length for this situation. Life support onboard for all
| occupants relies on a continuing collaboration.
|
| Beyond the ISS situation we should have completely cut all ties
| with Russia. They have killed hundreds of thousands of
| Ukrainians. Stolen children, assaulted women, and killed
| Ukrainian elderly and children. Not even digging into their
| internal recruitment policies, but the way they drag innocent
| Russian civilians into supporting their invasion is worth its
| own war crimes investigation.
|
| Yes, this experiment is interesting and it's intriguing to me.
| But it's not "nice" when a few physicists are getting results
| at the expense of all the collective suffering going on right
| now.
|
| I'm generally pragmatic about things, but in this situation
| cooperation is entirely uncalled for.
|
| Meanwhile the US ignores joint efforts with China. They (China)
| have some interesting things going on right now. For an
| international space station, it's awful that a Chinese crew
| hasn't even been invited to the ISS despite allowing numerous
| rich folks going up for a week long vacation.
|
| To be clear, I'm NOT supporting China. Their government is
| antithetical to a free society and is deeply partnered with
| Russia, N. Korea, and other states hostile to the EU and US.
|
| But they are a major player in humans in space, and it's
| important to engage them at that level. Again, the ISS is a
| unique scenario.
| jpgvm wrote:
| The problem is these joint scientific efforts were and
| continue to be effective tools to diffuse more dangerous
| possibilities.
|
| In case you have forgotten Russia is still the 2nd largest
| nuclear power and their arsenal is enough to eliminate pretty
| much all life on Earth.
|
| The war in Ukraine is terrible but don't underestimate how
| much worse things could get. If things do get worse it's back
| channels like space collaboration/UN/other symbolic things
| that can keep people talking enough to not end up cleansing
| the Earth in nuclear fire. Just because those things are
| ineffective at stopping a proxy war doesn't mean they aren't
| worth doing.
|
| For the same reason I also agree that China should be
| welcomed into the international space community. They are
| flying state of the art rockets and have their own modern
| space station... you couple that with the fact they too are
| an increasingly powerful military nation then more
| collaboration rather than less is the way to go.
| geuis wrote:
| Glad we agree on China at least.
|
| I highly disagree about Russia being a modern nuclear
| power. China and Israel are really the only countries that
| have the modern infrastructure required to maintain
| significant nuclear presences other than the US. Russia
| today is mostly living off of the remnants of pre-1985
| Soviet energy infrastructure investments.
|
| They have some nuclear capability, but it's far, far below
| what the US still maintains. Sadly even a reduced capacity
| is still far above what's needed to mess things up.
| otabdeveloper4 wrote:
| a) This isn't true, quite the opposite.
|
| b) The shilling for "#yolo, let's start nuclear war with
| Russia" is a bad idea. Trust me. You don't want to go
| there.
| timcobb wrote:
| Living in the world as a hostage to nuclear weapon
| yielding crazies is a fate worse than death for some
| free-minded people.
| TeMPOraL wrote:
| Shame about those free-minded people; everyone else
| understands that it's how the world works and why
| everything isn't on fire. MAD is the foundation of
| international politics; everything else is role-playing
| on top of it.
| timcobb wrote:
| > MAD is the foundation of international politics
|
| MAD is a religion-like fiction by-for people who
| emotionally need it. People armed with nuclear weapons
| are coming for us, whether it's emotionally convenient
| for you or not. And it doesn't matter whether we have
| nukes, too.
| timcobb wrote:
| > b) The shilling for "#yolo, let's start nuclear war
| with Russia" is a bad idea. Trust me. You don't want to
| go there.
|
| Russia already went there. We're already there.
| underdeserver wrote:
| Eh, I wouldn't discount India and France so fast.
| lazide wrote:
| They'd have no issues producing a dozen Tsar Bombas even
| today, no question.
|
| Plenty enough to ruin everyone's day.
| justinator wrote:
| Tsar Bombas aren't realistic weapons.
|
| Russia is having trouble producing modern tanks and
| planes. Its ships are being blown up by radio controlled
| boats with explosives on them.
|
| Russia absolutely excels at one thing: the relentless use
| of its human meat grinder. Nothing fundamental has
| changed since Stalingrad.
| lazide wrote:
| Russia also excels at MAD. And suffering.
| justinator wrote:
| Suffering yes -- to an extend that we here in the US have
| little understanding the depths of.
|
| But re: MAD, my point may have been the emperor's new
| clothes.
| sho wrote:
| > I highly disagree about Russia being a modern nuclear
| power
|
| Look, I'm as pissed at Russia as anyone but it doesn't
| change the facts. They are indisputably a modern nuclear
| power, and they have ramped up their spending in recent
| years. It's practically the only thing in their defense
| they _haven 't_ starved of funds.
|
| > They have some nuclear capability
|
| They don't have "some" nuclear capability. They are equal
| first or near enough.
|
| > China and Israel are really the only countries that
| have the modern infrastructure
|
| Israel!?? Now I'm really questioning your source of
| information. Whoever told you tiny Israel was anything
| other than dead last was leading you quite astray, I'm
| afraid. In fact some would say that Israel's nuclear
| capability is behind some other countries who don't even
| possess the weapons.
| meindnoch wrote:
| >their arsenal is enough to eliminate pretty much all life
| on Earth
|
| Lol, not even close.
| bawolff wrote:
| I hate the russian regime and what its doing to ukraine too.
|
| Still there is something comforting about putting aside our
| differences, petty and otherwise, to do science.
|
| After all, its not like the Russian scientists involved
| personally ordered the invasion.
| a3n wrote:
| Everyday Russians, including scientists, should feel
| consequences for their government's murders.
|
| Except for the ISS (complicated, as noted), I'm astounded
| that anything goes in or out of Russia: people, goods,
| services, atoms, electrons.
| namibj wrote:
| For non-restricted goods, it's still the fastest non-air
| transport route from China to Germany.
|
| We'll have to at least pay for the track maintenance and
| electricity usage caused by that, so why should we listen
| to a country that isn't affected? BTW the next best
| option would be to send war ships to the red sea and put
| the shipping corridor under effectively European control,
| would that be preferred?
| jlarocco wrote:
| There aren't many "innocent" countries out there. In your
| opinion we should all focus our energy on shunning and
| hating each other because of it?
| a3n wrote:
| No I don't.
|
| This situation is acute, and will spread.
|
| The only way Germany was stopped in 1945 was by a
| collective decision to defeat them militarily, by
| multiple participating countries.
|
| That won't happen this time around, because WWIII is all
| but unthinkable.
|
| The only thing left is for Russian citizens to be
| motivated enough to stop it. That's a hard lift, but if
| they feel it long enough, they might get it.
|
| In any case, after arming Ukraine, it's about all we
| have.
| booleandilemma wrote:
| I'm a US citizen, and I recognize my country has done
| some terrible things, but I shouldn't have to personally
| feel the consequences for those things.
|
| At the same time, I wouldn't want random Russian citizens
| to have to feel the consequences for things their
| government has done.
|
| Your bad argument is the same one that spurs Islamic
| terrorists into stabbing random people.
| jfengel wrote:
| Our government is doing some terrible things. I voted for
| this government and I feel I should take some
| responsibility for it. I accept that there may be
| consequences, potentially awful ones.
|
| I am afraid we are about to vote in a government that
| will do even more harm -- including to me personally. I
| think that a lot of people are choosing that harm
| deliberately. But even worse is a lot of people who are
| willing to accept that harm to me but without feeling any
| responsibility at all.
|
| The world is difficult. We make hard choices to live
| together. We do our best, or at least most of us do. I
| wish there were more empathy, and I accept that this
| means I feel guilt.
|
| The Russians are not really a democracy and their
| understanding of the world is severely warped by their
| media. And even those more clear on the situation can do
| only a little. But the more they individually feel a
| responsibility, the sooner they can collectively do
| something.
| krick wrote:
| Did you ever consider that USAians are not really a
| democracy and their understanding of the world is
| severely warped by their media? It is 100% true, by the
| way.
| jfengel wrote:
| Of course. But I'm as certain as I can manage (in an
| epistemologically challenging world) that we're closer to
| those goals than Russia is.
|
| I'm not especially interested in false equivocation as an
| argument. It's cheap and boring.
| sho wrote:
| > I'm generally pragmatic about things
|
| Not nearly pragmatic enough. Of course the war is terrible
| and of course Russia is to blame. But the world doesn't stop
| moving and high level co-operation still needs to continue.
| Russia is still a big, powerful, important country and we
| can't just cancel everything in a fit of spite.
|
| I mean, even Ukraine, even while it's being brutalized by its
| neighbor, still maintains high level connections to organize
| prisoner transfers. There's regular communication between the
| RUAF and NATO to deconflict and identify each other's assets
| to avoid misunderstandings and accidents. All of this
| continues, war or not, because everyone knows the alternative
| is just that much worse.
|
| It's no different for the scientific cooperation. War or not,
| everyone knows it is in everyone's best interest for
| cooperation to continue. The scientific ties long predate the
| war, and will continue long after everyone has forgotten it,
| too.
|
| And I'm surprised you then completely contradict your moral
| point - which I disagree with, but it is a point - by
| suggesting the West engage with China, a prospect against
| which almost the exact same argument can be made. Of course,
| taking the "we only co-operate with partners with sparkling
| moral rectitude" line even further, you could argue that no-
| one should be co-operating with the USA, with its two
| disastrous recent wars, either. See where this goes?
| bawana wrote:
| This project highlights the complexity of the real world. Not
| all of russia is evil. So why should the good be isolated,
| starved, punished? True, people in power can cause
| irreparable harm to neighboring nations, or even their own
| (Stalin?) Do we therefore obliterate all contributions of
| Soviet math, science and engineering and expunge them from
| our internet?
|
| In the face of injustice caused by politicians and
| corporations, we must privately support those individuals
| doing good work.
| bosco_mcnasty wrote:
| I see it more simplistically. If there's two guys love
| neutrinos, neutrinos is they passion, one happens to be born
| in Russia, one in US (neither one chose to be born there),
| and they want to work together to understand life, the
| universe, everything, then so what? What matters more, life,
| the universe, everything, or some years-long dramatic
| squabble, years long on the scale of a 5 billion year old
| planet and millions year old species and perhaps tens of
| thousands of years old civilization.
|
| The "ideal" of science is that there should be this purity,
| this honesty, etc. Deviations do occur, politics are common
| in science itself, data falsification, etc, but we must not
| let that deny the purity ideal. In the same way, I believe
| the idea here is to acknowledge that purity over political
| differences as something transcendent to politics. But yes,
| such collaborations do have political value in terms of being
| a "relationship". And yes of course I don't want to poo-poo
| politics. Whereas it's true that politics is as inescapable
| to the human condition as say language, perhaps we shouldn't
| let political constraints guide and dictate scientific work
| just as we shouldn't let linguistic barriers limit science,
| both part of the human condition, both miniscule in the face
| of the work being done.
| paganel wrote:
| As far as I can tell the US is fully, and I mean fully, on
| Israel'a side, even though the genocide now happening in Gaza
| is a very real thing.
| chr1 wrote:
| > The fact that 3 years in we are still collaborating with
| Russia on the ISS and in other scientific programs is deeply
| disturbing.
|
| Do you think Putin cares about scientific programs enough to
| stop killing people?
|
| All the "we won't talk to Putin, but will buy Russian gas
| reexported by another murderer Aliyev" is very nice and
| emotional, but it did not have any positive effect.
|
| If instead of all of this theater with sanctions, EU and US
| gave more weapons from the start, and removed regulations to
| drop oil prices, Ukraine would have won at the end of 2022,
| and at a much smaller cost than damage to the EU economy
| already caused by sanctions.
| qnleigh wrote:
| Is there any reason to think that Gallium would be a particularly
| good source of sterile neutrinos? Or is it more that if regular
| neutrinos oscillate into sterile neutrinos, then this would be
| the first experiment that could detect so at this scale?
| pavel_lishin wrote:
| The gallium isn't what's producing the neutrinos; there's a
| radioactive source that the gallium is being irradiated by, and
| I believe that's the source:
|
| > _In an underground lab shielded by a mountain of rock, highly
| radioactive material sits inside a vat of liquid gallium,
| blasting out particles called neutrinos that break the gallium
| down into atoms of germanium._
| gus_massa wrote:
| Gallium is not a source of sterile neutrino. Gallium is a good
| "electonic neutrino" target.
|
| The problem is that they only detect the 80% of the "electonic
| neutrino" that they expect and they have no clue of the cause.
| One of the posibilities is that the other 20% of the "electonic
| neutrinos" mutate to "sterile neutrinos" during the trip.
|
| (Note that there are 3 types of neutrinos and it's possible
| that there are also a few types of sterile neutrinos (3 is a
| good guess).)
| dmurray wrote:
| I'd still like to ask a version of the same question, is
| gallium so special that it only makes sense to do this
| experiment with gallium?
|
| If sterile neutrinos cause the production of germanium from
| gallium to be 80% of what we thought it was, will there be
| other nuclear reactions that we now don't understand? E.g. a
| given plutonium reaction produces 100g of uranium, currently
| consistent with the theoretical model, after sterile
| neutrinos are confirmed will we be saying hang on, this
| should only produce 80g of uranium with the new model,
| something else is wrong?
|
| Presumably not, at least with well-understood reactions, so
| why is gallium so special here?
| jarsdel wrote:
| Given the potential implications of discovering sterile
| neutrinos, what other anomalies or unexplained phenomena in
| particle physics might be re-evaluated in light of this new
| understanding?
| kseistrup wrote:
| A Capella Science: Massless (Muse neutrino parody):
| https://youtu.be/dBxcC8zV46E
| keepamovin wrote:
| Could the gallium anomaly be explained by something far more
| prosaic? For example, in water, there are all kinds of species of
| different anions and cations present, existing in equilibrium
| with each other. Water forms complex semi-crystalline structures
| by virtue of hydrogen bonds. Although they are not true crystals,
| the supramolecular structures of individual water molecules and
| the valence species create a sophisticated structure, even in a
| seemingly homogenous substance.
|
| Now, consider if something similar happens with gallium. What if
| the electron configuration of gallium's orbitals means that
| gallium, in its liquid form, also has various anions and cations?
| Moreover, what if gallium can form analogs to hydrogen bonds,
| leading to semi-crystalline or structured forms?
|
| This structured form could provide some shielding to the gallium
| atoms, making them less likely to be converted via neutrinos to
| germanium. Instead of impacting a nucleus at the expected rate,
| the overlapping orbital bonds and electron resonance might offer
| a form of shielding. This shielding could make the gallium atoms
| more stable and less reactive, thereby reducing their conversion
| to germanium.
|
| While this idea applies a chemical concept to nuclear chemistry
| or physics, and may not align perfectly with the traditional
| views of high-energy particle physicists and astronomers, it
| offers a potentially more prosaic explanation for the gallium
| anomaly. This perspective might not have been top of mind for
| those focused on high-energy interactions and could be worth
| considering further.
| baxtr wrote:
| Unfortunately many physicists believe chemistry is just applied
| physics. In reality most physicists have no clue of chemistry
| beyond the H2 molecule.
|
| Based on that, your "less prosaic" could be a good candidate
| for an explanation.
| aw1621107 wrote:
| > This structured form could provide some shielding to the
| gallium atoms, making them less likely to be converted via
| neutrinos to germanium. Instead of impacting a nucleus at the
| expected rate, the overlapping orbital bonds and electron
| resonance might offer a form of shielding. This shielding could
| make the gallium atoms more stable and less reactive, thereby
| reducing their conversion to germanium.
|
| Might this be covered by this bit from the article?
|
| > Another proposed explanation was that physicists had
| miscalculated the probability of neutrinos from the source
| interacting with the gallium. But in September 2023, Haxton and
| his colleagues also ruled out this possibility. "You can't get
| rid of the anomaly," he said.
|
| Maybe they don't consider the scenario you outlined in their
| calculations, but I lack the training to understand the paper
| [0].
|
| In addition, speaking more generally I'd be curious how your
| proposed mechanism would work physically. Given the size of the
| nucleus compared to that of the electron cloud, the fact that
| (known) neutrinos only interact via the weak interaction and
| gravity, and the range of the weak interaction, a big question
| to me is how big your proposed effect could have in this case,
| if any.
|
| [0]: https://arxiv.org/abs/2303.13623
| alleztarmac wrote:
| If I understand idea, this sounds like what physicists might
| call a 'collective phenomena' effect introducing some type of
| screening. It's possible -- if true it could independently be
| tested. I know there are models for this type of stuff in
| denser matter (and in more extreme conditions), but not sure
| whats known in situations like the experiment. I assume there
| is a reason that _isnt_ mentioned, but would love to know from
| an expert why.
|
| Collective phenomena do show up in high energy/particle
| physics, albeit rarely, ex: when you collide large enough
| nuclei together at high enough speeds, you create a highly
| energy-dense nuclear plasma which effective 'screens' jets of
| particles that would travel through the center of the
| collision. If you go to smaller nuclei or lower energy, you can
| start to see these jets of particles pass through the collision
| area.
| jnurmine wrote:
| Gallium likes to form alloys with other metals, does this anomaly
| happen with the gallium-containing alloys as well?
| tlogan wrote:
| Question for experts:
|
| If sterile neutrinos exist, would they be the best candidate for
| dark matter? Additionally, would it be impossible to detect them
| since they do not interact with anything and possess only mass?
|
| EDIT:
|
| My reasoning is as follows:
|
| - Low-energy neutrinos might not be relativistic. For example,
| relic neutrinos from the Big Bang, which have a temperature of
| around 1.95 K, would travel at approximately 4.5% of the speed of
| light.
|
| - I've also read that sterile neutrinos are hypothesized to have
| a large mass (though I'm not sure).
|
| So "slow neutrino" + "not so light like normal neutrino" => dark
| matter
| d_silin wrote:
| All neutrinos are relativistic (moving at almost speed of
| light) and our current model assumes dark matter is "cold"
| (moving at relatively slow speeds).
| tlogan wrote:
| Thank you. I updated my question with my reasoning.
|
| But I assume that in order for these sterile neutrinos to be
| dark matter they need to be really slow ...
| eigenket wrote:
| The known (non-sterile) neutrinos are very light, but
| there's no particular reason a hypothetical sterile
| neutrino would be.You can cook up sterile neutrinos with
| _very_ large masses if you want to
|
| https://arxiv.org/abs/1303.6912
| raattgift wrote:
| There is excellent evidence for then-relativistic cosmic
| neutrinos from the cosmic microwave background acoustic
| oscillations. As with the CMB, these neutrinos cooled into a
| "relic" field with the metric expansion.
|
| A cooling gas of relativistic neutrinos becomes non-
| relativistic when the average neutrino momentum becomes
| comparable to their rest mass. The present cosmic neutrino
| background (CNB) temperature is about 1.9 kelvins
| corresponding to ~ 1.7e-04 eV/c^2 which is smaller than some
| neutrino masses.
|
| This is still "hot" compared to Cold Dark Matter, and CNB
| also only a small fraction of the required CDM energy
| density.
|
| The lightest cosmic neutrino background mass eigenstates
| could be relativistic at present, so how the CNB is split
| between (FLRW) radiation and dark matter is ripe for
| research. It will mostly be "hot" DM because of the heavier,
| colder species. But not hot enough to leave clusters of
| galaxies, unlike neutrinos produced by present-day
| astrophysics (and our own laboratory experiments and nuclear
| power generation).
|
| https://en.wikipedia.org/wiki/Cosmic_neutrino_background
|
| https://bigthink.com/starts-with-a-bang/cosmic-neutrino-
| back...
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