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-   -   Neutrinos...back into the picture? (http://www.physicsforums.com/showthread.php?t=36916)

 urtalkinstupid Jul27-04 04:39 AM

Neutrinos...back into the picture?

Hey, guys! I have exciting news about neutrinos.

Neutrinos are fundamental particles that are neutral in charge and approximately the size of an electron. They come in three favors, and these flavors are: electron neutrion, muon neutrino, and tau neutrino. There symbols are $\nu_e~,~\nu_\mu~,~and~\nu_\tau$ respectively. Solar neutrinos are being detected through experiments. The Super-Kamionkande is one example of a team of scientists who are researching neutrinos. The method they are using to detect neutrinos only detects one flavor of neutrinos. That flavor is the electron neutrino. The electron neutrino is the smallest of the three flavors of neutrinos. The electron neutrino flux across the earths furface is approximately $5.90315332 \cdot 10^{14}~m^2/s$. That means that there are $5.90315332 \cdot 10^{14}$ electron neutrinos passing a square meter of the earth's surface every second. Scientists only detect one-thirds of the total neutrino count predicted to be emitted by the sun. Where is the rest?

All of the neutrino flavors have rest mass. They all differ. When neutrinos are made during fusion on the sun, scientist believe that all of the flavors are mixed together. Upon leaving the sun, they accelerate to near light speed. The electron neutrino travels the fastest out of the three flavors; tau neutrinos travel the slowest. As the neutrinos travel to earth, they separate. This is known as neutrino oscillation. The probability that a $\nu_e$ will not oscillate is given by:
$$P_\nu_e (x) = 1-sin^22 \theta_\nu sin^2 (\frac{\varphi m^2x}{4E})\xrightarrow{x \rightarrow \infty}1-\frac{1}{2}sin^22 \theta_\nu$$
$$\varphi m^2=(m_1^2-m_2^2)eV^2$$
$$E =Neutrino~Energy~(MeV)$$

Oscillation of neutrinos is close to being confirmed. I should say, "More support for a theory." These oscillations are undetected, because the techniques used for detecting neutrinos only detect electron neutrinos (I said this perviously). I think we know where I'm getting at. Gravity is a push. Electron neutrions are small; I'll admit that. They rarely interact. Tau neutrinos, on the other hand, are theorized to flux a bit less, but their momentum makes up for it. The upper energy limit of a $\nu_\tau$ is approximately 31MeV. Compare this to the $\nu_e$ which has a energy limit of 3eV. This could give the $\nu_\tau$ enough energy to emitt and be absorbed by objects to apply a force. Given a high enough flux, this could account for gravity being a push force rahter than the current theorized pull force.

Take this analogy into consideration. You set a can on a fence post. You shot a small bullet at a considerable high speed at the can. The bullet goes straight through without interrupting the can. Now, take a more massive bullet. Shoot it at the can. It travels slower, but its mass makes the momentum stronger. The bullet actuall has an affect on the can now. Same thing with electron and tau neutrinos. One is smaller and travels faster; the other is more massive and travels slower. The latter of the two is able to exert a more powerful force.

I haven't lost faith in the push theory just yet. Please, no childish antics this time. Last time, thread got closed because of them. :cry:

 beatrix kiddo Jul27-04 01:45 PM

finally!

i'm glad u actually restarted the thread. it's about time we continued our explanation of the push theory! :smile:

 ArmoSkater87 Jul27-04 03:57 PM

*sigh* Alrighty gentlemen, lets continue...here we go again. :D

Ok, now what im wondering is how tau neutrinos cant be detected despite having a much greater mass, but the electron neutrinos can...that seems odd to me. After all, the 3 flavored neutrinos are the same in any way, except their mass.

"The upper energy limit of a is approximately 31MeV. Compare this to the which has a energy limit of 3eV"
31MeV??? Thats insane, even IF its a tau neutrino. (im assuming you are talking about a single tau neutrino)

Look, i agree with you that they have a rest mass, (even though i think its insanly small), BUT even if they do, not even a tau neutrino could have enough mass to have 31MeV...not to mention that almost none would interact with anything.

 beatrix kiddo Jul27-04 05:10 PM

tau neutrinos do have enough mass to have 31 Mev.. in fact i've read else where that they can have more...... oh here it is... http://en.wikipedia.org/wiki/Neutrino it's a simple encyclopedia source. but BAM! i've got a source..

 Entropy Jul27-04 07:13 PM

This isn't news. People have know about neutrino oscillations for awhile.

Quote:
 Scientists only detect one-thirds of the total neutrino count predicted to be emitted by the sun. Where is the rest?
Even if the other two-thirds of solar neutrinos somehow interacted with Earth, it wouldn't account enough energy to explain gravitation.

Quote:
 This could give the enough energy to emitt and be absorbed by objects to apply a force. Given a high enough flux, this could account for gravity being a push force rahter than the current theorized pull force.
Very unlikely. High-energy tau neutrinos are thousands of times less common that their muon neutrino and electron neutrino counterparts. They require energetic events like supernovae (few MeV) and GRBs (100s MeV). These events aren't really that evenly dispersed throughout the sky (meaning a certain side of the Earth gets bombared with billions of times more neutrinos than the other side sometimes) so there would be massive changes in Earth's gravity if neutrinos caused gravity.

Why are you starting up about the exact same topic? Tom closed the other thread for a reason. You can't just start the same thing all over again. Its not as simple as just created a new thread.

 ArmoSkater87 Jul27-04 08:35 PM

Enrtopy is very right...it wont be enough to cause gravity. Look people, its ok to continue this thread, the problem before was simply that everyone that believed the theory was being very arrogant, and the whole situation was becoming personal. Which is why Tom closed the other one down, everyone was acting immaturely. Just dont have the same thing happen again.

 Hurkyl Jul27-04 08:42 PM

If the push theory is correct, how can the moon "tug" with the same force as always during a solar eclipse?

 ArmoSkater87 Jul27-04 08:55 PM

Cool site btw, I liked it. Oh, and in it, it says that..."Because the neutrino only interacts weakly, when moving through ordinary matter its chance of interacting with it is very small. It would take a light year of lead to block half the neutrinos flowing through it"
That right there completely proves the theory to be impossible.

 beatrix kiddo Jul27-04 11:31 PM

i know that's what it said, but i was trying to get u a quickee source. doesn't mean i necessarily agree with all of it. armo, u seem like a pretty open-minded(?) kid... we both play video-games.. we're both into astronomy... so look at this: http://www.pioneer-net.com/~jessep/
i've sited this before, but in case u didn't see it just read it. i'm not kidding, this guy makes a lot of sense. and if u can debunk his theories he'll give u thousands of dollars! what's to lose, armo? just read it...

hello hurkyl... i've come across this arguement before. but, a "tug" is more related to einstein's model of gravity. maybe u meant a "shove" because that would be relevant to our model. ok, during a solar eclipse, the moon absorbs part of the neutrinos from the sun going to the earth, but it also produces neutrinos, so there's no noticeable difference. on the other side of the planet there is a slight difference in ur weight (hardly noticeable) but ur still pushed down on the planet via neutrinos from other bodies in the solar system.

 urtalkinstupid Jul28-04 12:12 AM

stuff

Wow, I haven't been home all day. Heheh...

Quote:
 Quote by Entropy Even if the other two-thirds of solar neutrinos somehow interacted with Earth, it wouldn't account enough energy to explain gravitation.
Yea, uh huh, right. If one-third of the neutrinos hitting the earth in the form of $\nu_e$, the rest are in the form of $\nu_\mu$ and $\nu_\tau$. All of this together can add up. Tau and Muan neutrinos have a greater mass than the electron. Tau's mass is impressive for a neutrino. Plug and chug to get the combined neutrino flux and amount of energy exerted every square meter of earth every second.

Quote:
 Quote by Entropy Very unlikely. High-energy tau neutrinos are thousands of times less common that their muon neutrino and electron neutrino counterparts. They require energetic events like supernovae (few MeV) and GRBs (100s MeV). These events aren't really that evenly dispersed throughout the sky (meaning a certain side of the Earth gets bombared with billions of times more neutrinos than the other side sometimes) so there would be massive changes in Earth's gravity if neutrinos caused gravity.
Yawn...you are the only one bombarding things. Yes, I agree with you on the statement that tau neutrinos require high sources of energy to be produced. Our sun is incapable of producing that amount of energy, ergo only solar neutrinos are produced. These neutrinos oscillate into muon and tau neutrinos. As stated earlier, the majority of the neutrinos are much heavier than the electron neutrino. The Earth's atmosphere provides a great source of muon neutrinos! :smile: Tau are not as rare as pepole think. They set up the capture device far underground. Tau neutrinos are more massive, ergo they interact more before they can reach the capture device.

Quote:
 Quote by ArmoSkater87 Ok, now what im wondering is how tau neutrinos cant be detected despite having a much greater mass, but the electron neutrinos can...that seems odd to me. After all, the 3 flavored neutrinos are the same in any way, except their mass.
I'm sure I already explained why tau neutrinos weren't previously detected. When neutrinos were theorized to exist, the only forms said to come from the sun were electron neutrions. After setting up experiments to measure the flux, scientists only measured one-third of the total expected flux. The devices they set up were only made to detect electron neutrinos and that is it. Kamionkande and Super-Kamionkande are two examples of projects that were set up for the soul detection of electron neutrinos. SNO, recently have set up a capture device to detect muon neutrinos, as well as tau neutrinos. The results were just as expected. Neutrinos do oscillate, and this oscillation compensates for the other two-thirds of neutrinos.

That's it for now. I'll have more later. I just wanted to get a couple of things out.

 ArmoSkater87 Jul28-04 12:34 AM

This was at the earlier website..."Because the neutrino only interacts weakly, when moving through ordinary matter its chance of interacting with it is very small. It would take a light year of lead to block half the neutrinos flowing through it"

Whats ur comment on that??

 ArmoSkater87 Jul28-04 01:07 AM

Beatrix, i read that site u gave me...and i can only say, LOL!!!!
This guy is more full of crap than anyone else i've ever seen!! Sorry but i couldnt help laughing my butt off from reading how full of himself he is. He is basicly saying what Stupid said, except he doesnt even say whats being blocked. In the case we have, its neutrinos, but what he says is just terrible.

Alrite, anyways, i though that guy was full of it..and now lets get back to the thread. If what you say is true, then how come a more massive object accelerates due to gravity the same way that a much lesser massive object will?? And also...if what you say is true, then if ALL the neutrinos would be blocked off, then the force exerted by ALL the neutrinos hitting you would be so great, that there would be no escape velocity great enough to overcome the force. It seems like i got that out of the blues, lol, but i didnt. I got it from the simple fact that black holes have such massive gravity that nothing escapes it. Now i understand why urtalkinstupid doesnt believe in black holes...LOL. :D I dont mean to be mean in any way, im simply giving my reasons for my belief, so please do be friends with me :).

 urtalkinstupid Jul28-04 02:31 AM

My comment is that they are mainly referring to the electron neutrino. It's mass is so small that it rarely interacts. Tau neutrinos have mass that is greater than an electron. If it doesn't interact electromagnetically, it's bound to interact by colliding and exerting forces. SNO is working on the neutrinos and determining how they interact and how many there are. I'll try to keep you people updated. Newton never had a definite way of explaining his theory. It took awhile for his theory to be explained. Einstein explained it years later.

 chroot Jul28-04 02:50 AM

"Colliding" in the macroscopic sense is actually due to electromagnetic forces, urtalkinstupid. Neutrinos (all flavors) interact only via the weak force. Even though the taus are more massive, the interaction cross-section for all three flavors is the same, ~10-38 cm2. Taus do not interact more often with matter than do the other flavors, but their interactions are more energetic.

- Warren

 ArmoSkater87 Jul28-04 02:53 AM

Quote:
 Quote by chroot "Colliding" in the macroscopic sense is actually due to electromagnetic forces, urtalkinstupid. - Warren
EXACTLY!!!

 urtalkinstupid Jul28-04 03:31 AM

Oooh, may I have a source that says all of that. If something is more concentrated, it is likely to make contact more. Concentrate something by 66%, and it will more than likely interact at a larger rate. They will periodically bunch up, making their volume and force bigger? This bunching up, will make them bigger in a sense and allow them to not get through places they they could previously get through, resulting in some type of interaction? Add more mass to the same amount of volume, and you get the ability to take place in interactions more? (Throw a piece of gold in an oxygen environment. Then increase the number of oxygen molecules by 66%. Observe that the increased drag force is due to more interactions with oxygen molecules.) It encounters more resistance, because the oxygen molecules are more compact.

Why are all of these neutrinos in the Universe? Obviously, they serve some purpose. No wonder it's so hard for people to understand physics. Most of the theories do not make sense.

Note: urtalkinstupid, I pressed the wrong button by mistake and edited your post. I apologize. If I left anything out of your post, feel free to edit it.

 chroot Jul28-04 03:42 AM

Quote:
 Oooh, may I have a source that says all of that.
Try a textbook.
Quote:
 If something is more concentrated, it is likely to make contact more.
"Contact" is not well-defined in this context. Macroscopically, when two objects are "touching," they are experiences forces due to electromagnetic repulsion. In other words, the atoms in your butt and the atoms in the chair you're sitting on repel each other, thus preventing you from falling all the way down to the center of the Earth.
Quote:
 Concentrate something by 66%, and it will more than likely interact at a larger rate.
That's correct. More neutrinos in a given volume corresponds to more interactions in that volume. So?
Quote:
 They will periodically bunch up, making their volume and force bigger?
I have no idea where "bunching up" comes from, why it would happen, or why it would have anything to do with either volume or force. I'm afraid you'll have to provide a little more detail for this to make any sense at all.
Quote:
 This bunching up, will make them bigger in a sense and allow them to not get through places they they could previously get through, resulting in some type of interaction?
Once again, I have no clue what this means.
Quote:
 Add more mass to the same amount of volume, and you get the ability to take place in interactions more?
As I've already said, more interacting particles in a given volume corresponds to more interactions in that volume. I'm not sure what's hard to understand about this.
Quote:
 It encounters more resistance, because the oxygen molecules are more compact
It has a higher resistance because it encounters more oxygen molecules. The oxygen molecules are not smaller, they are just, on average, closer together than before.
Quote:
 Why are all of these neutrinos in the Universe?
To conserve lepton number, I guess.
Quote:
 Obviously, they serve some purpose. No wonder it's so hard for people to understand physics. Most of the theories do not make sense.
What purpose do photons serve? What purpose does an atom of beryllium serve? What purpose does the positron serve? What kind of anthropic, philosophical, hand-waving argument is neutrinos don't serve a purpose, so they don't make sense anyway? Come on, man.

- Warren

 urtalkinstupid Jul28-04 05:18 AM

Helooo Warren,

Ok, I'll explain what I was getting at. As of recently, the neutrino flux is only 1/3 of what it is supposed to be. With the new theory on neutrino oscillation, it is thought that neutrinos oscillate between the three flavors. The other 2/3 of the flux is said to be in the flavors of tau and muons. So, if all of the flux's were combined, this would result in an increase in the number of neutrinos hitting a volume of the Earth every second. This would increase the density of neutrinos right? If so, this would be just like the oxygen molecules hitting the gold. When less dense, they have little effect. When more dense, they have noticeable effects. The oxygen molecules as a system are more dense; this system is able to act upon other systems more as well. I'm thinking the same would be true about neutrinos, if their density was high enough including the muon and tau flux. As a system, they would be more dense, and would interact with outside systems more?

Photons are here to illuminate objects, so that our eyes can catch the reflecting rays. Beryllium has a cool name. :frown: Positron are theorized to be part of the proton. Well, I read that somewhere. If you think otherwise, I'll try to find the source and show you.

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