Neutrinos have mass... what does this mean?

[gopunk]

my physics professor (here at UW, which has one of, if not the top physics programs in nation) told us in class that it had recently been found that neutrinos have mass. not even knowing what a neutrino is, i'm wondering what this means. it sounds like it is a big deal

 

[hoihtah]

are we talking about my jimmy?

nef.

 

[ElFenix]

if so that could account for a lot of the hidden mass in the universe

 

[gopunk]

<< if so that could account for a lot of the hidden mass in the universe >>



yea, i think he mentioned that. something about dark matter and dark energy. i'm guessing we take measurements, and also calculate things with mass as one of the variables, and they don't match up?

 

[Adul]

it isa big deal, even though they are such tiny particles.

 

[fatalbert]

Neutrinos have mass :Q

thats news,


Neutrinos are smaller than the electron I believe, they have something to to with Neutron flux, I don't remember exactly. But it would account for a lot of things that were not understood.

 

[Darein]

If I'm not mistaken neutrinos are really, really small, so small they bombard our planet, our bodies and go right through. There was a detector up in Canada a mile or so underground with 1,000 gallons (I think it was) of heavy water and it still only got bombarded (atoms getting hit by neutrono and breaking apart) a few times an hour.

 

[Descartes]

<< There was a detector up in Canada a mile or so underground with 1,000 gallons (I think it was) of heavy water and it still only got bombarded (atoms getting hit by neutrono and breaking apart) a few times an hour. >>



Correct. Also, apparantly it lets off a glow that allows them to calculate it's mass.

 

[Random Variable]

Must not matter have mass, even if it's negligible?

 

[ragazzo]

WIMPS and MACHOS are the other possibilities for dark matter.

 

[SagaLore]

Nothing has mass.

All atomic matter is composed of spacetimewave frequency differentials.

Try to visualize an inverted bubble. "gravity" is the differential causing near items to fall into it. This differential is what is responsible for light slowing down when passing through solid transparent objects... the "inverse bubble" is also what is responsbile for the fractal effect in crystals and such... imaginary numbers aren't so imaginary...

 

[Haircut]

<< Must not matter have mass, even if it's negligible? >>


Matter doesn't have to have a rest mass. For instance photons (particles of light) have zero rest mass, yet they have a relativistic mass <==> they have momentum.

 

[yakko]

That is nothing new.

 

[StinkyMeat]

Neutrinos have mass?



I didn't even know they were Catholic...

 

[Piano Man]

So if neutrinos have mass, I wonder if its possible that photons have mass. Now that would be HUGE news, as it would change some laws of physics for us.

 

[Kadarin]

<< So if neutrinos have mass, I wonder if its possible that photons have mass. Now that would be HUGE news, as it would change some laws of physics for us. >>



It would certainly put a whole new perspective on the "is light a particle or a wave" debate.. However, I'm not a physicist or a rocket scientists, so I'm not qualified to comment on any of this..

 

[StinkyMeat]

I thought protons did have mass.

 

[oblizue]

<<

<< So if neutrinos have mass, I wonder if its possible that photons have mass. Now that would be HUGE news, as it would change some laws of physics for us. >>



It would certainly put a whole new perspective on the "is light a particle or a wave" debate.. However, I'm not a physicist or a rocket scientists, so I'm not qualified to comment on any of this.. >>



Light is a particle and a wave. Everything has a duality nature, so all of us have wavelenghts as well. They're just infintimal.

 

[Piano Man]

<< Light is a particle and a wave. Everything has a duality nature, so all of us have wavelenghts as well. They're just infintimal >>



Could you care to elaborate on this? I don't follow. I know about light, but everything?

 

[joohang]

Nice thread.

I wrote exactly on this topic for my IB Extended Essay in high school. I'll dig back my old essay and see if I can post anything interesting.

I've been so into History and programming recently that I forgot a lot of my physics.

 

[joohang]

<< my physics professor (here at UW, which has one of, if not the top physics programs in nation) told us in class that it had recently been found that neutrinos have mass. not even knowing what a neutrino is, i'm wondering what this means. it sounds like it is a big deal >>


I am not aware of any breakthrough discovery recently but there have been several findings in the past decade to suggest that neutrinos did have mass.

A quote off my high school paper:


<< The Super-Kamioka Nucleon Decay Experiment (Kamiokande) detects neutrinos generated in the atmosphere of the Earth in a tank containing 50,000 tons of pure water. The atmosphere of the Earth is constantly bombarded with energy from outer space known as cosmic rays. These cosmic rays collide with the atoms of air molecules to generate unstable particles such as pions, which decay into muons and muon antineutrinos (see [Figure 7]). The muon shortly decays into an electron, electron antineutrino and a muon neutrino (see [Figure 8]). Hence, the Super-Kamiokande detector should observe approximately twice the amount of muon neutrinos than that of electron neutrinos. Since muon neutrinos interact to form only muons and electrons to form only electrons, it is possible to distinguish them from one another. Based on the data obtained over two years, the results from the Super-Kamiokande team show the ratio of muon neutrinos to electron neutrinos to be about 1.3 to 1, far different than the expected 2 to 1.


?&agrave; [Figure 7] The Decay of a Negative Pion


?&agrave; [Figure 8] The Decay of a Muon

To explain this unexpected result, physicists theorized the oscillating nature of neutrinos. They describe neutrinos using Quantum Mechanics, stating that the neutrino is a superposition of two quantized waves that propagate at different speeds. The interference pattern of two waves then determines the probability of the neutrino flavour. Since the waves travel at different speeds, at least one flavour of neutrino must have mass because if they are both massless, the interference cannot possibly occur. The data of the Super-Kamiokande experiment show that the muon neutrinos generated directly overhead meet the expectations, but approximately half of the anticipated amount is reached from the opposite side of the Earth. Hence, the Super-Kamiokande team concludes that the muon neutrinos oscillate into tau neutrinos while they travel thousands of kilometres through the Earth. >>



Here's an interesting article, although there may be more recent ones:
Edward Kearns, Takaai Kajita and Yoji Totsuka, ¡§Detecting Massive Neutrinos,¡¨ Scientific American. Vol. 281. August, 1999 p.67

 

[Rakkis]

Just wanted to add that the existence neutrinos was first postulated by Frederick Reines, professor at UCI, who received the 1995 Nobel Prize for this work.



yay UCI!!!

 

[Moonbeam]

<<Neutrinos have mass... what does this mean?>>

It means they weigh something.

 

[flood]

<< my physics professor (here at UW, which has one of, if not the top physics programs in nation) told us in class that it had recently been found that neutrinos have mass. not even knowing what a neutrino is, i'm wondering what this means. it sounds like it is a big deal >>


heh, im at the UW and work on neutrino reseach
ever heard of WALTA?

 

[gopunk]

<<

<< my physics professor (here at UW, which has one of, if not the top physics programs in nation) told us in class that it had recently been found that neutrinos have mass. not even knowing what a neutrino is, i'm wondering what this means. it sounds like it is a big deal >>


heh, im at the UW and work on neutrino reseach
ever heard of WALTA? >>



nope... i'm technically a physics major, but i really don't have that big of an interest in physics i heard the UW had a big part in the research... oh btw my prof is watts.