Can someone tell me about neutrinos?

Same here, unable to ” wrap my brain ” around it as well. Yet it’s seems simple enough to grasp that neutrinos are so small a particle and carries no electrical charge that if and when it passes through anything, it can’t be detected. So as to it’s effect in everyday life I guess it’s nothing. Scientists are excited to “catch” or detect some. Sounds like neutrinos are ghost particles.,

I’m not sure if I can make this any more clear than a Wikipedia article, but I’ll take a shot at it.

Let me back up a little, first.

Atoms consist of nuclei surrounded by a “cloud” of electrons. The nuclei consist of protons and neutrons and those in turn consist of trios of up and down quarks. Photons convey the electromagnetic force, and gluons convey the force that keeps quarks togther (a sort of residue of this interaction keeps nuclei together through the exchange of pions). This takes care of most of the physics and chemistry that we can see, but nature turns out to be a bit more complicated.

The first big wrinkle in the simple picture I sketched above is that there are three “families” or “generations” which provide two sets of copies to the electrons as well as the up and down quarks. So there are muon and tau particles which are exactly like the electron but about 200X (muon) and 3000X (tau) heavier. (Correspondingly, there are charm, beauty, bottom and top quarks.)

Now the second wrinkle is that the electromagnetic force has (for reasons we don’t know yet) a weird twin sibling that we call the weak nuclear force. It is nothing at all like electromagnetism, but is inseperable from it. The combined electroweak force theory dictates by its mathematical symmetry that alongside the electron, muon and tau there must be neutral fermionic partners: electron neutrinos, muon neutrinos and tau neutrinos. There are three force-carrying particles for the weak component of the electroweak force: the positive and negative W particles and the neutral Z particle.

OK, so you have these neutral particles called neutrinos. They are neutral, so the electromagnetic force does not effect them. As leptons, they don’t “feel” the strong nuclear force either. Only exchanges of W and Z particles will effect them. But these particles are quite heavy, so their spontaneous emission-and-absorption through the vaccum can only take place over short distance and time scales (in contrast to electromagnetism, where photons are massless). At the same time, the coupling constant for the nuclear force is tiny (10^-6 compared to 1/137 for electromagnetism and 1 for the strong force). So the weak force is indeed weak and only acts over short distances. This makes the chances that neutrinos will interact with ordinary matter astronomically small.

Here is another article about neutrino detectors
http://en.wikipedia.org/wiki/Neutrino_detector

Probably the most significant thing about neutrinos is that they are produced by the process of beta decay.

@ladymia69 In layman’s terms what @hiphiphopflipflapflop & @Rarebear are saying is that you shouldn’t worry if youn cna’t wrap your head around neutrinos, because they can’t wrap their heads around you either. :-)

Great Question, BTW.

@hiphiphopflipflapflop To make that make any sense to me, you would have to provide me with a very basic glossary of what most of the terms in your answer meant, and I shall not waste your time. I thought maybe it could be capsized into a nutshell, or maybe a metaphor??

;-)

“Make everything as simple as possible, but not simpler.” – Albert Einstein

Mankind was quite happily ignorant of the neutrino until its existence was hypothesized to account for “missing” energy in beta decay in 1930, and only a very small subset of humanity has ever really worried about that, but @ladymia69 was obviously curious enough to look up a Wikipedia article about neutrinos before asking and I won’t pass up an opportunity to pontificate on what we have discovered as the building blocks of nature. :-)

@ladymia69 it might help me come down out of the clouds if you could tell me what circumstances led you to ask about neutrinos in the first place. That might allow me to put them in some sort of context for you.

Here’s a picture that might help.

This is a Feynman diagram of beta decay. The vertical axis is time and the horizontal axis is roughly three-dimensional space squashed down to one dimension.

Starting at the bottom of the diagram, we have three lines labeled u, d, and d. This represents a lone neutron which is made up of one up quark and two down quarks.

As time moves forward the three quarks move off to the right. Then something happens. The three lines kink and suddenly they are moving off to the left.

Not only did the neutron change direction, it changed its identity. The three lines are now labeled u, d and u. That third line changed from d to u, meaning that quark changed from a down quark to an up quark. Two up quarks and one down quark mean the neutron is now a proton.

Look at where the third line kinked. It is emitting a squiggly line labeled W-. What that is saying is that at that moment, that second down quark in the neutron emitted a W- particle and became an up quark. That is the weak nuclear force in action.

Now follow the squiggly line and you see it breaks into two straight ones labeled e- and nu-sub-e-bar. (Arrggh! Greek letters and bars and superscripts… hey Fluther crew, give us some code goodies for this!) This is saying that the W- particle is turning into an electron and an electron anti-neutrino. They go flying off to the right while the proton-that-used-to-be-a-neutron is going off the left.

(Note the arrow is pointing down for the anti-neutrino, this convention comes from the idea that anti-particles are like normal particles but travelling backwards in time.)

Neutrinos are said to penetrate, on average, solid lead to a thickness of more than one light-year without a collision ref. Now that’s “weak interaction!”

I am also reminded of a poem about neutrinos
(c) 1960 by John Updike:

Cosmic Gall
Neutrinos, they are very small.
They have no charge and have no mass
And do not interact at all.
The earth is just a silly ball
To them, through which they simply pass,
Like dustmaids down a drafty hall
Or photons through a sheet of glass.
They snub the most exquisite gas,
Ignore the substantial wall,
Cold-shoulder steel and sounding brass,
Insult the stallion in his stall,
And, scorning barriers of class,
Infiltrate you and me! Like tall
And painless guillotines, they fall
Down through our heads into the grass.
At night, they enter at Nepal
And pierce the lover and his lass
From underneath the bed –– you call
It wonderful; I call it crass.
————————

…informatively deconstructed (scroll to the bottom) here.

@hiphiphopflipflapflop , Is there any means of detecting the presence of neutrinos? I know the theory says that they must exist, but how do we confirm the theory is correct?

@LostInParadise See my post above about neutrino detectors.

@LostInParadise Yes, see @Rarebear ‘s post.

This might also help: Cowan-Reines neutrino experiment, this produced conclusive proof neutrinos existed back in 1956.

Thanks. I missed @Rarebear ’ s post.

@hiphiphopflipflapflop Your link was defective—I think here was intended.

Effect for us in everyday life? None. Unless there’s a supernova near Earth, which is extremely unlikely. Then we’d feel the effects of massive neutrino bursts. In fact, we would detect these neutrinos before visible light and gamma rays reaches us.