I think that the hypotheses of these apparent phenomena are incorrect.

We have always presumed that gravity is a linear effect, i.e. increase mass and you will have an equivalent increase in gravity, F=ma.

However, that is only relative to our observations on our planet. What if gravity and mass weren't in a linear relationship; squared or more, even exponential. In the centers of massive conglomerations of matter - galaxies, you would see a rapid increase in gravity solving the problem of the matter gap.

Also, imagine if space was elastic. In deep space between galaxies where gravity is almost non existent then you would see expansion.

You titled the thread "dark energy, dark matter, = dark ignorance" but then you go way off on a tangent trying to speculate differing scenarios for the force of gravity on other planets, then space expansion, then Big Bang universe expansion. What do you want to know? Dark matter is just a hypothetical word sometimes used to refer to the matter that we cannot yet account for. We can easily see and prove the force of gravity, and on other planets and matter in the universe, by calculating it's force of attraction. We know that the universe is expanding - even in deep space.

I think you need to read up on why there are the two hypotheses of DM and DE.

1. to explain why galaxies are 'held' together.

From our observations of the amount of mass in a galaxy it appears, from models, to be impossible to hold the them together. To do so, modellers have had to invent Dark Matter.

2. To explain why the space appears to expanding at a more rapid rate than present theories explain, scientists have invented Dark Energy.

OK

Dark matter is a big joke.

I admit that I do not know much about dark matter or dark energy, but that is what this thread is titled and no one has yet to address the subject, let alone try to describe it. Your initial posting says nothing about it and goes off on multiple tangents unrelate to dark matter. So what is it that you want to discuss on this forum?

Dear oh Dear, ES has explained it to you already.

To explain why galaxies are held together, science has invented Dark Matter. It must account for 90 % of the matter in a universe and it must be omnipresent within a galaxy. It is all around us, and within us.

To explain why the universe is expanding more rapidely than current theories suggest, science has invented Dark Energy, pushing the galaxies apart.

Sound far fetched, I agree entirely with ES. Dark Energy and Dark Matter simply underline the black hole of our understanding.

' and the flame of a sword which turned every way, to guard the way to the tree of life and the tree of knowledge'

There will always be things beyond our comprehension.

We are a pathetic little mold on our pathetic little grain of dust and we think we know it all.

Dark Matter + Dark Energy = Flat Earth

Look, learn, listen and put your ego on the back seat

There will always be things beyond our comprehension.

Not for me.

We are a pathetic little mold on our pathetic little grain of dust and we think we know it all.

Of course we know everything, even though we currently don't want to accept it. After all, we created the universe!

Dear oh Dear, ES has explained it to you already.

To explain why galaxies are held together, science has invented Dark Matter. It must account for 90 % of the matter in a universe and it must be omnipresent within a galaxy. It is all around us, and within us.

To explain why the universe is expanding more rapidely than current theories suggest, science has invented Dark Energy, pushing the galaxies apart.

Sound far fetched, I agree entirely with ES. Dark Energy and Dark Matter simply underline the black hole of our understanding.

' and the flame of a sword which turned every way, to guard the way to the tree of life and the tree of knowledge'

There will always be things beyond our comprehension.

We are a pathetic little mold on our pathetic little grain of dust and we think we know it all.

Dark Matter + Dark Energy = Flat Earth

Look, learn, listen and put your ego on the back seatThis is no explanation of what dark matter is, it is simply a hypothetrical construct: a word that you are using to explain what we do not know yet.

Dark Matter + Dark Energy = Flat Earth????????????????????????????????????

Could you be a little bit more precise and scientific!

This is no explanation of what dark matter is, it is simply a hypothetrical construct: a word that you are using to explain what we do not know yet.

Dark Matter + Dark Energy = Flat Earth????????????????????????????????????

Could you be a little bit more precise and scientific!

Not to worry, Valich. This is just someone wanting to talk about something without knowing anything at all. Just making noises in the dark (weak pun.) ;)

And the "Dark Matter + Dark Energy = Flat Earth" bit is nothing more than an attempt to show we are as ignorant about those two things as back when people thought the Earth was flat. Nothing profound or revealing there - of course we don't know anything about the topics - they are simply specualtion at this point. We may eventually drop the whole idea and go in a different direction, but for the moment they seem to describe what we're observing. Who knows where it will eventually go? No one.

Yeah, you're right. I guess I got a bit carried away when he stated:

"Dear oh Dear, ES has explained it to you already."

I was thinking nothing was ever posted about this, but ES is right because he already explained in the forum title! My mistake. I agree: "dark matter + dark energy = dark ignorance." So where else can this forum possibly go from here?

Yeah, you're right. I guess I got a bit carried away when he stated:

"Dear oh Dear, ES has explained it to you already."

I was thinking nothing was ever posted about this, but ES is right because he already explained in the forum title! My mistake. I agree: "dark matter + dark energy = dark ignorance." So where else can this forum possibly go from here?

Nowhere, really, since there's nothing known about dark energy/matter and the fact that it's merely an idea. I don't think any discussion was ever intended. The original poster just wanted to make a statement - nothing more that I can see except to challenge current thinking on the subject (which really takes no intelligence or effort to do). Pretty futile, actually.

The basis of science is to challenge current thinking and see if it can be refuted, there's a name for this kind of phylisophical approach - but I can't remember it. Some bright spark (who makes an effort to think about something) comes up with a hypothesis and then it is challenged. Some Hypotheses, such as evolution or relativity are very difficult to verify. But unless you can dispute them rationally, they remain.

The greeks never knew that the Earth was round, but all of their observations supported the hypothesis that it was a sphere. There was never a rational arguement for it being flat - but it became entrenched. Consequently, the hypothesis for the earth being round was proved - therefore ceasing to become a hypothesis, by becoming a fact. Get it?

Is the universe infinite? Probably, all observations point to it, but nobody knows. Is there life on other planets? Mathmatical probability suggests that, yes there probably is, but nobody knows.

Is there a rational arguement for Dark Matter? I think that's the point of the thread

Can you dispute ES's hypothesis? Could you? Do you know anything about the subject or any other? From what I read, I doubt it. A little bit out of your depth.

I think that the hypotheses of these apparent phenomena are incorrect.

They might be correct, incorrect, or anywhere in between. Seeing as there exists entire galaxies which are not visible (unless we start looking with radio waves) seems to provide support for the hypothesis.

Ultimately, time will tell how close to the truth these assertions are; however, I think they are good as any as long as they mesh up mathematically and can be tested at some point.

Mmmm, bit of weak argument.

There are billions of objects out there that are not visible to us. Not everything emits radiation in the visible spectrum. Black holes aren't visible but we know they are there.

For our galaxy to hold itself together, using the dark matter model, 9 times the mass that we know is there, must exist as dark matter and be omnipotent

Why could we not measure the extra gravitational pull created by this dark matter rather than have to add it for our models to work? Where does this question leads us?

It probably leads us to the fact that we measure gravity relative to our position in our galaxy with a background of gravity created by all the objects around us. I.e. it's relative. Take the entire solar system out of the milky way and place it in true deep space then we would have a different measurement of gravity than that we now have. Put the Solar system closer to the center of the Galaxy and something different would happen.

Remember, gravity is a symptom of the distortion of mass on space, similar to the effect of heavy balls on a stretched cotton sheet. Imagine that sheet to be elastic, with a modulus of elasticity, which when reached starts to make the effect of mass different than before it’s reached.

Gravity is, therefore, not linear. Take this view and you can discard Dark Matter and Dark Energy. I think this is a new idea.

Mmmm, bit of weak argument.

There are billions of objects out there that are not visible to us. Not everything emits radiation in the visible spectrum. Black holes aren't visible but we know they are there.

For our galaxy to hold itself together, using the dark matter model, 9 times the mass that we know is there, must exist as dark matter and be omnipotent

Why could we not measure the extra gravitational pull created by this dark matter rather than have to add it for our models to work? Where does this question leads us?

It probably leads us to the fact that we measure gravity relative to our position in our galaxy with a background of gravity created by all the objects around us. I.e. it's relative. Take the entire solar system out of the milky way and place it in true deep space then we would have a different measurement of gravity than that we now have. Put the Solar system closer to the center of the Galaxy and something different would happen.

Remember, gravity is a symptom of the distortion of mass on space, similar to the effect of heavy balls on a stretched cotton sheet. Imagine that sheet to be elastic, with a modulus of elasticity, which when reached starts to make the effect of mass different than before it’s reached.

Gravity is, therefore, not linear. Take this view and you can discard Dark Matter and Dark Energy. I think this is a new idea.

Let's see if we can strengthen that argument to your satisfaction then. After all, I aim to please. I'll expand upon the 'dark galaxy' notion (remember it's an entire GALAXY... not just a planet, solar system, black hole, or star). Throw those existing conclusions out the door concerning what dark matter is as well as gravity (which could consequently result from anything between spatial distortion to gravitons).

About 50 million light years from earth there is a galaxy labeled Virgo 1121. We would expect galaxies to have stars or some kind of visible objects and this one has ZERO. The only way this galaxy can be seen is with radio wave detectors (a radio wave telescope would work fine).

It's composed of a big swirling mass. One component of the mass is hydrogen and it accounts for ~100 million times more mass than our sun by itself. The speed of the galaxy's rotation shows there is far more total mass in this swirling cloud... and guess what? It cannot be detected by any known means (not even radio waves).

So, we know the total mass of the galaxy by it's rotation, we know that hydrogen is only part of it, and we have no idea what the rest of the mass is... but it's there and emit's no discernable signal. That's what is being referred to as dark matter.

No. As was pointed out and very explicit in the title "Dark Matter = Dark Ignorance."

This is a stupid posting that basically is just pointing out our own ignorance: and he's right! The 90% of unexplained matter in the universe, we just don't know what it is? So we give it an arbitrary name: "Dark Matter." And? There is no other "and."

Any further intelligent scientific reference to this really belongs under the Physics category in Sciforum, not here.

Was that in response to my post? It wasn't clear.

Mr essential lifelong learning?
If you don't ask the questions you wont get any answers

Was that in response to my post? It wasn't clear.No, no, no! eternal sunshine, the one who started this thread. Read all the resulting incoherent confused posts that followed. He's just trying to say we're all ignorant: not asking for any answers at all. So what's the point of the thread?

The reason for any thread is to create a topic for discussion. Valich does not seem to ask any questions or give any answers. If you don't want to discuss the topic then don't feel obliged to respond.
Crunchy cat is running with the assumptions of previous generations of scientists. An unproven hypothesis can spawn many hypotheses based on it's assumptions. If the original hypothesis fails, then the others can fall like dominoes. So you need to examine your statements more carefully.
The example galaxy, virgo 1121 exhibits the same contradictions as all galaxies. The assumption that you 'know the mass' because of the rotation speed is exactly that, an assumption. We know the strength of the gravity required to hold a galaxy together , we then work backwards and calculate the amount of mass required to create that amount of gravity and , hey prestoe, we have a figure of mass which is 9 times greater than we can see to be there (visible or non visible).
I think this figure is just too great an order of magnitude for it to be feasible.
If we progress on the hypothesis that gravity is not linear in relation to mass, then we could reduce this amount of unseen mass greatly. For this to be so, then we would have to create an elastic Universe as suggested by Okconor. Then, not only could we explain the phenomena of dark matter, but could also explain the phenomena of dark energy and why the galaxies are accelerating away from each other even though the impotus from the big bang is over.

valich, if a forum seems pointless and dead-ended, why not just stop checking it and move on to a new topic? it's what most do (i hope).

and I have a question: regarding dark matter, assuming it exists, does that account for antimatter? I ask because it doesn't make sense, why would matter exist both as visible and "dark" matter whereas antimatter has yet to be detected as a natural substance in our universe and is presumably all "dark" matter? it's disproportional! anyone got an idea why?

Curiousity may kill the cat but I'm not a cat as regards to where this forum goes.

Dark Matter is a generalized term to explain what has yet to be explained. There is no such matter that is actually called "Dark Matter." Dark Matter doesn't exist: "dark energy, dark matter = dark ignorance."

"The universe today appears to be dominated by a mysterious form of energy known as dark energy. Approximately 70% of the total energy density of today's universe is in this form. This component of the universe's composition is revealed by its property of causing the expansion of the universe to deviate from a linear velocity-distance relationship by causing spacetime to expand faster than expected at very large distances. Dark energy in its simplest formation takes the form of a cosmological constant term in Einstein's field equations of general relativity, but its composition is unknown and, more generally, the details of its equation of state and relationship with the standard model of particle physics continue to be investigated both observationally and theoretically....Einstein's theory of gravity predicts a gravitational singularity where densities become infinite. To resolve this paradox, a theory of quantum gravity is needed. Understanding this period of the history of the universe is one of the greatest unsolved problems in physics."
http://en.wikipedia.org/wiki/Big_bang

eternal sunshine - have you read up on VSL theory? By allowing for the variation of the speed of light over time, you likewise eliminate the need for dark matter/energy in calculations. It also clears up big bang issues like inflat(r)ons and other crap that's been invented over the years to make the math work.
http://en.wikipedia.org/wiki/Variable_speed_of_light
It isn't perfect, but it's a great example of the evolution of science, and the basic premise of *always* questioning the mainstream.

Also, Dark matter is NOT THE SAME THING as "Matter that doesn't emit visible light", as an earlier poster suggested; that there are galaxies that we can only see in the infared spectrum, and that is evidence of dark matter. Dark matter theory relies not on matter that emits only in the non-visible spectrum, but on matter that we cannot detect at all. IE inert matter which is non-excitable by any detectaable radiation.

IMO, DM and DE theories are simply the modern "eather". It is possible, but unlikely, and the only evidence for it relies on our own calculations to be considered 'evidence'. Much the same as the last time an all-pervading and unseen substance was proposed, only to be shot down years later by better math. More likely, there is something in our calcualtions that is wrong, such as the constant speed of light, or the linear gravity that we currently assume.

For DE/DM counter evdence, why is the Voyager space vehicle so much farther out that expected? Why is it moving faster than planned? To the DM theorist, this is counter-intuative; to the DE theorist, this is way too strong of an effect. DM should provide the opposite effect of what we are seeing, and DE should provide less of an effect.

Our theories aren't perfect, and neither is our math. Claiming DE and DM are like inventing God. "Well, this isn't what we expected, DM/DE must have done it." IMO, scientists don't get that luxury.

Yes, I know Dark Matter isn't dark: just unexplained. Let me read over the wikipedia article, do some research, then reply. Thanks.

Wow you guys adhere to Wikipedia way to often :o

valich, if a forum seems pointless and dead-ended, why not just stop checking it and move on to a new topic? it's what most do (i hope).

and I have a question: regarding dark matter, assuming it exists, does that account for antimatter? I ask because it doesn't make sense, why would matter exist both as visible and "dark" matter whereas antimatter has yet to be detected as a natural substance in our universe and is presumably all "dark" matter? it's disproportional! anyone got an idea why?

To answer your question without referencing the Wiki, All that "antimatter" really is, is a negative nucleus surrounded by positive electrons, if that did not make any sense than picture an Atom with Negative "nuclei" (protons & Nuetrons) that looks just like a conventional atom, but instead of electrons colliding around they are surounded by their inverse called "positrons"

"Dark Matter", Which I don't understand why some above has refuted its existence, why is it so hard to grasp the idea that "exotic" matter can exist in a galaxy where our "rules" may or may not apply? We have created elements through technology like fusions, so is it not probable to think that elements not listed on the periodic table exist in a foreign (maybe desolate) place?

"Dark Matter", Which I don't understand why some above has refuted its existence, why is it so hard to grasp the idea that "exotic" matter can exist in a galaxy where our "rules" may or may not apply? We have created elements through technology like fusions, so is it not probable to think that elements not listed on the periodic table exist in a foreign (maybe desolate) place?
It certainly possible. But is it more likely than other options? That there is an all-pervading mass that we cannot detect locked in a constant battle against an all-pervading energy that we cannot detect, or that our equations are not as accurate as we think?

It certainly possible. But is it more likely than other options? That there is an all-pervading mass that we cannot detect locked in a constant battle against an all-pervading energy that we cannot detect, or that our equations are not as accurate as we think?


That i cannot answer, because i am incapable of solving such complex equations. quick question, not sure, but haven't we picked up waves of unique radiation from what is speculated to be the "dark energy"

I think no one is saying that "Dark Matter" cannot be explained or understood except the original poster of this forum thread. We just don't know exactly all what it is yet.

It certainly possible. But is it more likely than other options? That there is an all-pervading mass that we cannot detect locked in a constant battle against an all-pervading energy that we cannot detect, or that our equations are not as accurate as we think?

But that's just it, we can detect dark stuff through its gravitational effect. It wouldn't be science if we couldn't. Now, is it possible that GR (or the Newtonian limit in the case of galaxies) is simply invalid at these levels? Certainly, but GR has worked so fantastically well so far that there is no reason to abandon it now. In particular, I think GR's need for dark stuff will be one of its greatest predictive triumphs when the dark stuff is successfully identified. Let me also say that some dark matter is perfectly ordinary baryonic matter that we just can't see (in the generalized sense) for any of a variety of mundane reasons. On the other hand, exotic dark matter must interact very weakly with electromagnetism, but is this such a stretch? Of course not, we already know that neutrinos don't interact with the electromagnetic field directly. Now, neutrinos are almost certainly not the required dark matter, but the point is that we already know of particles that are invisible to electromagnetism. Take some neutral particle produced in a neutral weak decay (unlike the neutrino) and voila: dark matter. The simplest supersymmetric theories actually predict such a particle which is called the neutralino. It remains to be seen if this conjecture has any experimental basis (LHC fingers crossed) or if it can be made to fit the bill for dark matter, but possibilities abound. I freely admit that dark energy is more troublesome, but even with this very recent discovery there are many possibilities. The picture I have given is simple, but I hope it illustrates that the mainstream approach is far from dead and actually has some considerable theoretical and experimental support, much more so than other more speculative ideas.

We have ongoing research still trying to detect neutrinos. Have we yet?

Also, since antimatter is so rare, do we consider the yet-to-be-discovered forms as dark matter?

There are many experiments which have detected neutrinos. In fact, recent experiments have confirmed a phenomenon known as neutrino oscillations. There are three types of neutrinos which are observed - electron neutrinos, muon neutrinos and tau neutrinos. It is now known that these neutrinos can actually change from one type to another as they travel, due to an interesting quantum mechanical effect.

Antimatter emits light the same way that matter emits light, because an anti-photon is the same as a normal photon. So, antimatter cannot account for dark matter.

Anti-matter is said to exist for every form of matter, yet we've yet to find it all. Therefore, it cannot be contributed as being part of the matter that we know of. Dark matter is just a general term to describe that which we still have not accounted for yet, so where do we classify the unfound antimatter?

Sorry, valich, I don't understand your point. Are you claiming antimatter hasn't been detected? If that's the case, you're quite wrong. Or are you claiming antimatter might comprise part of the dark matter? That's also wrong. Or something else?

There are many experiments which have detected neutrinos. In fact, recent experiments have confirmed a phenomenon known as neutrino oscillations. There are three types of neutrinos which are observed - electron neutrinos, muon neutrinos and tau neutrinos. It is now known that these neutrinos can actually change from one type to another as they travel, due to an interesting quantum mechanical effect.

Antimatter emits light the same way that matter emits light, because an anti-photon is the same as a normal photon. So, antimatter cannot account for dark matter.This is fascinating. Can you recommend a good source on this.

What I was getting at was that we have found plenty of small element antimatter for electrons-positrons; quarks-anti-quarks; but hardly if any for complex elements. From what I've read, theory states that antimatter exists for all elements, but antimatter has not been found past hydrogen or hydrogen isotopes, or if it has, it's been very scarce. There's a large unfound gap here beyond this.

valich,

I don't have any really convenient sources at hand. There was a good summary article on neutrino oscillations in a recent edition of the American Journal of Physics, but that is not easy to get a hold of unless you have access to a university library.

I'm sure a google search for "neutrino oscillations" will give you a lot of good information, if you're interested.

Regarding anti-matter: when a particle meets an anti-particle the two particles annihilate each other, releasing energy. Because of this, we will never find large quantities of antimatter on Earth, because any such quantities of antimatter would immediately annihilate with the ordinary atoms making up all the substances on Earth.

There is a question of why our universe seems to consist overwhelmingly of antimatter rather than matter. Current theories suggest that almost (but not exactly) equal quantities of matter and antimatter were produced in the big bang, but because there was slightly more matter over all, we ended up with a matter universe after all the annihilation had stopped.

That's good enough of a source for me to go on. Thanks.

As I lay in bed last night, I was anticipating that you might reply by saying this (reverse the words in the first sentence in your last paragraph though, right?).

Anyways, if there were (are) equal quantities of matter/antimatter.....There should be, no? What is the reasoning behind saying that there was "slightly" more matter than anti-matter. Sounds just like a "guess" explanation as to why we cannot find that missing 95% or so antimatter. There's no proof or evidence in such a theory except to say that today we have mostly matter: can't find the antimatter. Circular argument.

Uh... there is lot within the first post that I find 'disturbing'. If I have misread anything then please point out but...

(Astrophysics if my forte, particularly Cosmology but by no means am I an expert)

We have always presumed that gravity is a linear effect, i.e. increase mass and you will have an equivalent increase in gravity, F=ma.

Newton's second law of motion, more precisely given by dp/dt = m* dv / dt.

This is a statement of inertial mass not gravitational mass. Newton's later formula:
F = GMm/ r^2

'Suggests' that gravitational mass and inertial mass are coincidentally the same.
Special Relativity assumes the two are the same but still allows for the two quantities to be coincidental, aka weak equivalence.
General Relativity says the two must be the same, aka strong equivalence.


However, that is only relative to our observations on our planet. What if gravity and mass weren't in a linear relationship.

Such as inverse-square law as per Newton's theory of gravitation.

Also, imagine if space was elastic. In deep space between galaxies where gravity is almost non existent then you would see expansion.

You do see expansion between galaxies. This is also known as the "Hubble flow", I believe Edwin Hubble was the first to predict that the island universes were galaxies and indeed expanding relative to each other.

Hubble said that the velocity of recession of these galaxies is given by V = H*d.

D is the distance to the galaxy, and H is the Hubble parameter (roughly constant for a chosen epoch). Recession away from us can be determined by redshift of light.

Sorry about the messiness of the formula's, I'm not brave enough to attempt MathML at this time of night and Latex images are also too much hassle. Ultimately, I'm not saying that the theories for DE or DM are correct just aiming to correct the physics at play.

Another consideration is vacuum energy, strictly vacuum energy and DE are no the same. Another term for expansion is to do with whether space is curved or not, currently space is believed to be flat.


Anyways, if there were (are) equal quantities of matter/antimatter.....There should be, no? What is the reasoning behind saying that there was "slightly" more matter than anti-matter. Sounds just like a "guess" explanation as to why we cannot find that missing 95% or so antimatter. There's no proof or evidence in such a theory except to say that today we have mostly matter: can't find the antimatter. Circular argument.


The percentage is > 99%, I can't remember the exact number but something of the order 1 in 10^-12 particles were different. Anti-matter can be created in particle accelerators, so we know what it looks like and how it should behave. We can't explain why we have more matter than anti-matter, we just simply do. The most round-about explanation says that an asymmetry arose between particle pairs about the time of recombination or 10^5 years after the big bang. The cosmic microwave background is the 'evidence' for recominbation occuring.

It is hoped that further study beyond the "Standard Model" of particle physics will explain this violation of symmetry. It is definitely hinted at by the fact there there seems to be three "flavours" of particle (this relates to the neutrino oscillations etc).

Got it! Though, this needs further study!

"Neutrino oscillation is a quantum mechanical phenomenon whereby a neutrino created with a specific lepton flavor (electron, muon, or tau) can later be measured to have a different flavor. More specifically, the probability of measuring a particular flavor for a neutrino varies periodically as it propagates. Neutrino oscillation is of theoretical and experimental interest, as observation of the phenomenon implies nonzero neutrino mass. The discrepancy between the amount of electron neutrinos predicted to reach Earth from the Sun by models of Solar fusion and the actual amount detected was the initial experimental evidence for neutrino oscillations. Further evidence was also provided by experiments measuring the neutrino flux from the upper atmosphere, nuclear reactors and particle accelerators....("matter particles") only have mass because of interactions with the Higgs field (Higgs boson). These interactions involve both left- and right-handed versions of the fermion (Chirality physics). Neutrinos are special, since as electrically-neutral particles they may have another source of mass, Majorana mass (which cannot work for electrically-charged particles since it would allow particles to turn into anti-particles which would violate conservation of electric charge). Neutrinos are also special because only left-handed neutrinos have been observed." http://en.wikipedia.org/wiki/Neutrino_oscillations

Why haven't right-handed neutrinos been found? We live in a quantum right-handed universe?

"Bruno Pontecorvo's work in neutrino physics is examined and due emphasis is given to the audacity of his ideas both theoretically and experimentally. The account ends with the first solar neutrinos detected by Raymond Davis in 1967 using the radiochemical method developed by Pontecorvo in 1945"
Source: "Bruno Pontecorvo: From slow neutrons to oscillating neutrinos," by Luisa Bonalis, American Journal of Physics, June 2005, Vol.73: 6, pp.487-499

"Neutrino oscillations are purely quantum mechanical effects that occur over macroscopic time and distance scales."
Source: "Teaching neutrino oscillations," by Chris Waltham, American Journal of Physics, June 2004, Vol.72: 6, pp.742-752