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Neutrino Mass Confirmed

Zonk posted more than 8 years ago | from the they-do-exist dept.

318

biohack writes "BBC News reports that results from the MINOS experiment have confirmed that neutrinos have mass. To look for neutrino oscillations, scientists created muon neutrinos in a particle accelerator at the Fermi National Accelerator Laboratory (Fermilab). After passing through a particle detector at Fermilab, a high intensity beam of neutrinos travelled to another particle detector 724km (450 miles) away in a disused mine in Soudan, US. The set up established that fewer particles were being detected at the Soudan site than had been sent from Fermilab, which confirmed that some neutrinos changed their flavor on the way - an effect called neutrino flavor oscillation, which requires them to have mass. 'To put it simply, if they are heavy, it means that there is a lot more mass in the Universe than we thought there was,' said Professor Jenny Thomas from University College London."

cancel ×

318 comments

Duh (-1, Redundant)

Anonymous Coward | more than 8 years ago | (#15044054)

Duh this was on Nova years ago.

Re:Duh (-1, Flamebait)

Anonymous Coward | more than 8 years ago | (#15044178)

Is this sonofabitch moronic haha-day over?

Goddamn, I never thought I could hate that fucking fuckstain Zonk even more.

bragging time (4, Interesting)

phlegmofdiscontent (459470) | more than 8 years ago | (#15044056)

I've actually seen the detector at the Soudan Mine. Pretty impressive. Kinda hard to get to (300 mile drive into the middle of nowhere followed by a half mile trip underground).

Re:bragging time (2, Informative)

Tyball (139432) | more than 8 years ago | (#15044096)

How did you like the elevator ride down? Dark and kinda clanky. I worked on this project when I was in school--good to see some results already!

Re:bragging time (1)

metamatic (202216) | more than 8 years ago | (#15044172)

The bats are cool.

Re:bragging time (1)

theneutralnewt (965433) | more than 8 years ago | (#15044182)

I saw the tunnel for the detector at Fermilab. A little easier to get to than the mine was for you, I think (about 4 miles from my house).

Re:bragging time (1)

LiMikeTnux (770345) | more than 8 years ago | (#15044191)

woo, you rule! i live in Roselle, i make the trip to Fermi every now and then...one of those being for the severe weather seminar april 8th, but they have a really cool intro peice about fermi, and about the neutrino studies.

Re:bragging time (1)

Xzzy (111297) | more than 8 years ago | (#15044224)

I toured it too. I think the more interesting part is that this experiment has only been running for a year, when they started it up they were predicting it could take years to get enough data to make conclusions.

They only expected to see one or two neutrinos hit the targets per day, out of billions of particles being shot.

Re: open house (0)

Anonymous Coward | more than 8 years ago | (#15044228)

The MINOS experiment will have its annual open house on May 6th 2006. Don't remember if it is free -- maybe it is. But tour only of the physics lab.

The summer tourist season starts after labor day, and some, but not all, tours include the physics tour in addition to the historical mining tour.

Re:bragging time (1)

Guppy06 (410832) | more than 8 years ago | (#15044289)

"Kinda hard to get to"

I am not a physicist, but it's my understanding that that's kind of the point. Neutrinos are finicky enough and rather difficult to detect that I doubt you'd want lots of people and civilzation around to screw anything up.

Soudan, US (3, Informative)

Wyatt Earp (1029) | more than 8 years ago | (#15044058)

Thats is sloppy on the BBC's part, they should have put the State in there. In this case it is Minnesota.

http://www.dnr.state.mn.us/state_parks/soudan_unde rground_mine/physicslab.html [state.mn.us]

Re:Soudan, US (1, Offtopic)

aktzin (882293) | more than 8 years ago | (#15044137)

That kind of sloppiness is rare for the BBC, but typical for US media. It's probably because so many USians don't know or care about world geography. It would sound weird/inaccurate to hear news about "San Francisco, USA" without mentioning California. But this is exactly how it sounds when US news mention a city in another country and ignore the state/province/region/department where it's located. Here's a good example of a double-whammy courtesy of CNN:

http://www.cnn.com/2006/POLITICS/03/30/bush.cancun /index.html [cnn.com]

"CANCUN, Mexico (CNN) --" (Cancún is in the state of Quintana Roo)

"Mexico's Vicente Fox, a conservative in the final months of his presidency, is host to Bush and Canadian Prime Minister Stephen Harper in the Yucatan resort."

They didn't do their homework here. Yucatán is the state NW of Quintana Roo. The Yucatán Peninsula contains these two states plus Campeche:

http://www.lib.utexas.edu/maps/americas/mexico_pol 97.jpg [utexas.edu]

Re:Soudan, US (0)

Anonymous Coward | more than 8 years ago | (#15044184)

Actually, when you hear "Yucatan" in the US, it usually refers to the Yucatan peninsula, and not the Mexican state.

Re:Soudan, US (0, Troll)

j. andrew rogers (774820) | more than 8 years ago | (#15044231)

It's probably because so many USians don't know or care about world geography. It would sound weird/inaccurate to hear news about "San Francisco, USA" without mentioning California. But this is exactly how it sounds when US news mention a city in another country and ignore the state/province/region/department where it's located.

The US is a federation of 50 sovereign states (each with the size and economy to match), and saying "Foo City, US" would be like saying "Foo City, EU" (though Europe has the advantage of many languages to broaden the name space). Geographical namespaces in the US are only unique at the State level, just like in Europe, and there are many, many naming collisions between cities, towns, and other geographical identifiers in the US across states. There are a few city names in the US that seem to be used in a significant fraction of all the States, so specifying which State things are in is useful. I do not think EU-ians would be happy if we used the naming convention for the EU that you are suggesting is a good idea for the US. Apparently you don't know or care about world geography.

Re:Soudan, US (5, Informative)

Bonker (243350) | more than 8 years ago | (#15044291)

The US is a federation of 50 sovereign states (each with the size and economy to match), and saying "Foo City, US" would be like saying "Foo City, EU" (though Europe has the advantage of many languages to broaden the name space).

While this is true, it's somewhat misleading, especially to those will limited knowledge of U.S. history or government. Even many Americans don't understand the difference between as state and a province.

State governments in the U.S. function approximately equally to provincial governments in countries that are not federations. Most of them were not originally independant countries, but were instead provinces and territories that were sponsored into statehood.

A significant fraction of the United States were indeed independant countries at one point. ALL U.S. states have significantly more rights than any given province. Each has its own constitution and government, and, contrary to popular opinion, the states elect the President and Senators. The U.S. president is *not* elected by a popular vote. (Although there have been calls to change this.) A few, most notably Texas, still claim the right to secede from the Union, although no state has really had this right since the end of the American Civil War in the late 1800s.

The U.S. constitution sets up the states as individual entities, unlike provinces. They can each impose their own taxes and own laws. In fact, this is one of the major contentions in our government to this day. States can theoretically impose any law that the constitution doesn't reserve for the Federal government. This causes a lot of conflict and consternation since States are also required to respect contracts formed in other states, frequently under a different set of laws and regulations.

The conflict over gay marriage contracts is one of the more recent flaps this has caused.

States can also each maintain their own militias. Many states have 'State Troopers', who usually do the same kind of jobs as normal policemen, albeit with greatly expanded jurisdiction. A few states have 'State Guards', although they usually don't server a military purpose. They usually come to the fore during natural disasters and the like.

While the U.S. is an extremely tight federation-- the word 'Union' is very accurate-- it is still a federation. Each state is indeed its own nation.

Re:Soudan, US (2, Informative)

Guppy06 (410832) | more than 8 years ago | (#15044357)

We're talking about trying to give the reader a rough idea of where a story comes from, not what belongs on a properly-addressed envelope.

"That kind of sloppiness is rare for the BBC"

The US is the country where 100 years is a long time. The UK is where 100 miles is a long distance. Even the British can be guilty of the ol' "Oh, you're from the US? Do you know $PERSON from $SIX_STATES_AWAY?"

The only countries bigger than the US are Russia and Canada, and I don't believe either has anywhere near the number of individual, named communities. And while it's rare for a story coming from Russia to mention what constituant part of the Russian Federation a particular town is in (forgivable, as the system of oblast, okrugs, etc. is truly byzantine), stories from Canada and China consistently mention what province the news come from. As for mentioning "department," most countries that subdivide themselves that way (e. g. France) are comparable in size to a single US state, so mentioning the department would make as much sense as mentioning what county in a state a city was in.

"It would sound weird/inaccurate to hear news about "San Francisco, USA" without mentioning California."

It would be ambiguous. There's a San Francisco in California, New Mexico and Texas. Depending who you talk to, "San Francisco, USA" may also refer to a city in Puerto Rico.

""CANCUN, Mexico (CNN) --" (Cancún is in the state of Quintana Roo)"

There is only one Cancun; the place isn't named after something so convenient as a Catholic saint. Besides, the typical Mexican state is considerably smaller than the typical US state: Quinas Roo is about the median for the area of a Mexican state at 19th, but it would fall between West Virginia (41) and Maryland (42) in the US. Chihuahua, the largest Mexican state, is a little smaller than Michigan.

"They didn't do their homework here. Yucatán is the state NW of Quintana Roo."

"Yucatan" refers to both a state and a geographical region. "St. Louis is a major Mississippi port" doesn't mean I believe that the city of St. Louis is in the State of Mississippi, and "Honolulu is a Hawaiian city" doesn't mean I believe Honolulu is on the same island as Hilo.

Re:Soudan, US (1)

lahvak (69490) | more than 8 years ago | (#15044181)

Thats is sloppy on the BBC's part, they should have put the State in there. In this case it is Minnesota.

I don't think it's sloppy. That's not like anybody really cares. When you read news from Germany, they usually don't tell you whether it is Saxony or Bavaria or whatnot.

Re:Soudan, US (1, Insightful)

Anonymous Coward | more than 8 years ago | (#15044200)

That's because the US is many times the size of Germany, and has many more cities. In this case the article mentioned a small obscure town in the US, and yes, people would like to know where it is. I'm *from* Minnesota, and I didn't know that the town mentioned in the story existed...

Re:Soudan, US (1)

Hao Wu (652581) | more than 8 years ago | (#15044239)

Thats is sloppy on the BBC's part, they should have put the State in there. In this case it is Minnesota.

Minnesota [wikipedia.org]

*shakes head* (5, Funny)

Monkeys!!! (831558) | more than 8 years ago | (#15044061)

You know you are a serious geek when you read the headline and say 'YES!' out loud.

Re:*shakes head* (3, Funny)

MeanMF (631837) | more than 8 years ago | (#15044145)

You're ok as long as you didn't have that reaction to the "OMG BARBIE LINUX LOL!!1!!!!" headline...

Re:*shakes head* (1)

blueZhift (652272) | more than 8 years ago | (#15044186)

You know you are a serious geek when you read the headline and say 'YES!' out loud.

Absolutely! This is the kind of stuff that made me go into physics in college. I've been waiting for some resolution of the neutrino mass issue for the last 20 years or so. This is the cool stuff! w00t!

Re:*shakes head* (1)

Draveed (664730) | more than 8 years ago | (#15044309)

What a relief to know I'm not the only one to do that.

Re:*shakes head* (3, Interesting)

barefootgenius (926803) | more than 8 years ago | (#15044365)

And you know you are a sceptic when your next thought is,"hold on, they sent these particle's through an object they know next to nothing about and then use the fact that some of them didn't turn up as proof".
Then you read more and you get,"Of course, most of them travel right through our detectors as well, but once in a blue moon one of them will interact - about one or so per day."

I suppose I am being pedantic, but can anybody explain to me why I should believe their explanation that their not turning up in such large numbers is proof?

Already Known (3, Insightful)

physicsphairy (720718) | more than 8 years ago | (#15044062)

Neutrino mass has been an established fact since 1998 (courtesy work at the Super-Kamiokande).

Would slashdot also be interested in posting my own confirmations that light has a finite speed?

Re:Already Known (4, Informative)

rewinn (647614) | more than 8 years ago | (#15044098)

... as claimed in 1998 Scientific American article [hawaii.edu]

Re:Already Known (1, Informative)

Anonymous Coward | more than 8 years ago | (#15044162)

"Confirmed" in this case should be taken to mean "Already known because Super-Kamiokande convinced us it was true in 1998, followed by more evidence from the Sudbury Neutrino Observatory and the K2K expeirment, and then also KamLand, but isn't it nice that this newer experiment sees (confirms) the same thing."

The experiment in this article has been designed to improve on these previous measurements, and as a first step there, they have presented initial results after only 8 months of operation.

(Didn't read the BBC article, but I do work in a mine.)

Re:Already Known (0)

Anonymous Coward | more than 8 years ago | (#15044176)

"Would slashdot also be interested in posting my own confirmations that light has a finite speed?"

Actually light has an infinite velocity "speed" in it's own reference frame, as dose any thing traveling at C with respect to a stationary object.

Re:Already Known (2, Interesting)

qbwiz (87077) | more than 8 years ago | (#15044212)

AFAIK, light doesn't have a reference frame. Likewise, nothing can travel at a velocity of light and have a reference frame.

By relativity, the velocity of light in all reference frames is equal/constant. Therefore, if you were in light's reference frame, then light would be moving past you at c. However, you are in light's reference frame, so you are moving with the light and the light is not moving past you. Contradiction.

Of course, I'm not an actual physicist, so take this with a grain of salt.

Easy, peasy, lemon squeezy (0, Offtopic)

Expert Determination (950523) | more than 8 years ago | (#15044230)

Would slashdot also be interested in posting my own confirmations that light has a finite speed?
Um...given how easy this is nowadays why would anyone want to publish your confirmations?

Re:Already Known (3, Insightful)

n0mad6 (668307) | more than 8 years ago | (#15044292)

Perhaps simply reading the title would give a hint as to why this is important (i.e., note the word "confirmed"). Experimental results aren't really useful unless its a result that can be reproduced. The MINOS result is simply the first confirmation of the earlier Super-K result.

April Fools! (2, Funny)

MobileTatsu-NJG (946591) | more than 8 years ago | (#15044064)

Minos? Muons? Soudan? They're just making stuff up! This article just reeks of April Fools!! /Peter Griffin Voice

Pardon me, but. . . (1)

kimvette (919543) | more than 8 years ago | (#15044065)

. . . if it's matter, isn't it required by definition to have mass?

Re:Pardon me, but. . . (1)

syntaxglitch (889367) | more than 8 years ago | (#15044088)

Not really; consider a photon. Just because something is a particle does not mean it's necessarily what you think of as "matter".

Re:Pardon me, but. . . (1)

onx (956508) | more than 8 years ago | (#15044111)

The thing is, it is possible for things to have mass, but have a mass equal to zero. An example of this is the photon which has zero mass (zero rest mass).

Re:Pardon me, but. . . (5, Informative)

bcrowell (177657) | more than 8 years ago | (#15044141)

A hundred years ago, physicists generally classified things like this:
  • Matter has mass and is made of particles.
  • Light has no mass and is made of waves.
Nowadays it's more like this:
  • Fermions are wave-particles that have half-integer spin. Atoms are made of fermions.
  • Bosons are wave-particles that have integer spins. Bosons are the things that carry forces.
All the familiar, everyday fermions have nonzero rest mass, and the only familiar, everyday boson -- the photon -- has zero rest mass. However, there are bosons that have nonzero rest mass (e.g., gluons), and it's also possible that there are fermions that have zero rest mass. (Experiments so far only measure the differences between masses of different types of neutrinos, so it's still possible that the electron's neutrino has zero mass.)

Re:Pardon me, but. . . (1)

Guy Harris (3803) | more than 8 years ago | (#15044193)

However, there are bosons that have nonzero rest mass (e.g., gluons)

So color symmetry is broken?

Re:Pardon me, but. . . (1)

bcrowell (177657) | more than 8 years ago | (#15044208)

Oops, you're right -- a better example would have been the W and Z bosons.

Re:Pardon me, but. . . (1)

modecx (130548) | more than 8 years ago | (#15044341)

Gluons? Are those like pasties?

Creighton Mine (2, Informative)

pipingguy (566974) | more than 8 years ago | (#15044066)


SNO Detector [queensu.ca] .

This is new? (2, Informative)

fatduck (961824) | more than 8 years ago | (#15044071)

This was proven in the late 90's in a Japanese lab. The experiment was similar and involved muon neutrinos changing flavors to electron neutrinos in a large particle accelerator. The real question is how many eV are the combined masses of the three flavors? The answer to that question portends much for the state of the universe.

Re:This is new? (1)

MustardMan (52102) | more than 8 years ago | (#15044174)

Got a link? The only Japanese neutrino experiment from the late 90s that I can recall is super-K, which was most certainly NOT a particle accelerator. Super K is just a massive cherenkov radiation detector - an empty mine that was meticulously cleaned and filled with very pure water, and contained a whole bunch of PMTs to detect single photons given off by cosmic particle interactions.

Re:This is new? (4, Informative)

bcrowell (177657) | more than 8 years ago | (#15044179)

Yes, this is a confirmation of something that had already been shown by one experiment.

The experiment was similar and involved muon neutrinos changing flavors to electron neutrinos in a large particle accelerator.
No, it wasn't an accelerator, and the experiment wasn't similar. [wikipedia.org]

The real question is how many eV are the combined masses of the three flavors? The answer to that question portends much for the state of the universe.
No, not really. Not unless the mass of the electron's neutrino is surprisingly large compared to the mass differences among the different types of neutrinos.

Re:This is new? (1)

Joiseybill (788712) | more than 8 years ago | (#15044258)

The FermiLab press release speaks about this new experiment being much more precise in measuring the number of Neutrinos and the energies expended in their oscillations.

They also refer to the earlier experiments, "Our first result corroborates earlier observations of muon neutrino disappearance, made by the Japanese Super-Kamiokande and K2K experiments. Over the next few years, we will collect about fifteen times more data, yielding more results with higher precision, paving the way to better understanding this phenomenon. Our current results already rival the Super-Kamiokande and K2K results in precision."
http://www.fnal.gov/pub/presspass/press_releases/m inos_3-30-06.html [fnal.gov]

In other news today (3, Funny)

edwardpickman (965122) | more than 8 years ago | (#15044085)

New evidence has confirmed that the Universe does in fact have mass. Science advisor for the Bush administration was quick to point out that this is a theory and there was still no hard evidence. "The Bible makes no mention of the Universe having mass so we'll have to wait until a method is devised for weighing the Universe. We don't want any more psedoscience like that Darwin character was spreading."

Re:In other news today (1)

fatduck (961824) | more than 8 years ago | (#15044099)

A republican-backed appropriations bill was signed by President Bush today amidst much controversy over an "11th hour" rider attached which allocated up to 186 billion dollars by 2009 to a multinational project to "drastically improve the 'scales of justice'"

You're making that UP! (1)

MickLinux (579158) | more than 8 years ago | (#15044215)

We need to put you in for a job at the NYTimes.

TEACH THE CONTROVERSY!!! (1)

rewinn (647614) | more than 8 years ago | (#15044355)

"Some people say the universe is governed by universal laws. Others say it is but a joke of the Elder Gods [hello-cthulhu.com] .

"I think that part of education is to expose people to different schools of thought." someone said. [sfgate.com] "You're asking me whether or not people ought to be exposed to different ideas, the answer is yes."

significance (1)

bcrowell (177657) | more than 8 years ago | (#15044092)

The quote from Thomas seems odd to me. Although massive neutrinos do add to the mass of the universe, I don't think their contribution is really all that important cosmologically. My understanding is that we're currently in an era dominated by the cosmological constant, with second place occupied by some unknown exotic form of matter (not baryons or neutrinos), third occupied by baryonic matter, and neutrinos a distant fourth. Although neutrinos are numerically very common (more than atoms, I think), their mass just isn't all that big.

To me, what seems more significant about it is that knowing about neutrino masses and oscillations makes neutrino astronomy viable. For instance, we can find out directly about the interior of the sun, which is something we just can't do with electromagnetic or gravitational fields.

It depends. (1, Informative)

jd (1658) | more than 8 years ago | (#15044183)

We already know that some "dark matter" calculations were thrown off by using Newtonian mechanics and not Relativistic ones. Any failure to account for the mass of neutrinos may also have created an illusion of more "dark matter" than actually exists. Now, I agree that it is possible that the correction is very small. However, alterations in the modelling may result in a significantly different understanding of the role of the Cosmological Constant (if one exists) and "dark matter" (if any is needed) and therefore may result in a very different theory of what these actually consist of - or even alter the requirement for them to exist at all.


Yes, neutrinos are important in understanding the interior of the sun. They are not the only method, however, as "holes" do occur through which we can see very limited snapshots of segments of the interior. They are also not perfect, as less than half of the expected number of neutrinos ever reach the Earth, presumably through changes in flavour or through being absorbed.


Neutrinos are also very important in understanding the mechanics of radioactive decay. Remember, the entire premise from which neutrinos came from was that decay needed a massless particle that could carry with it rotational momentum. Since neutrinos have M amount of mass, then the sum of all other actual and effective masses being emitted must be reduced by M, for the calculations to still balance out.


(You're also much more restricted in the energy a neutrino can have, as you must now not only balance momentum but also kinetic energy. For things to equal out, this will place significant constraints on the state of a neutrino.)


All in all, this sort of work generally has massive repercussions and it will only be truly known what significance the mass has when ALL physical systems involving neutrinos have been adjusted accordingly. Again, the magnitude of the mass is totally unimportant. What matters is whether it breaks an existing model (eg: by violating the requirement for quantized states) or whether it eliminates any variables or constants (because they are no longer needed).


I am a great proponent of science, but I am getting tired of the complacency that has slowly been creeping in - the Victorian illusion that we are approaching the end of knowledge. If neutrinos having mass throws huge chunks of the physics community into disarray, I believe it will be a Good Thing and about time. We need something that will cause a major headache and a revolution in thinking.

Re:It depends. (2, Informative)

bcrowell (177657) | more than 8 years ago | (#15044203)

Yes, neutrinos are important in understanding the interior of the sun. They are not the only method, however, as "holes" do occur through which we can see very limited snapshots of segments of the interior.
Um, no, you're just completely wrong here.

Neutrinos are also very important in understanding the mechanics of radioactive decay. Remember, the entire premise from which neutrinos came from was that decay needed a massless particle that could carry with it rotational momentum. Since neutrinos have M amount of mass, then the sum of all other actual and effective masses being emitted must be reduced by M, for the calculations to still balance out.
No, the mass/energy scale -- eV -- is wrong for it to have any significant effect on nuclear beta decay, where the mass/energy scale is MeV.

Re:significance (1)

biohack (955639) | more than 8 years ago | (#15044238)

I'm sure that BBC picked the Thomas quote for the same reason that I chose to include it in the post - it provides a reasonably concise answer to the "why do I care about this?" question for most people. And I haven't seen anybody yet describe the various caveats of the Standard Model and its extensions in one sentence.

Perhaps the closest is a recent Why Files story, which gives a good summary of Big Bang cosmology [whyfiles.org] , updated from the recent microwave background measurements. You're right, that up to 3/4 of the mass is in dark energy, whatever that might be. You're also correct that there are a lot more neutrinos (and photons) than atoms (or protons). And apparently, because of the large numbers of neutrinos, their masses could matter if they were heavy enough. According to Wikipedia [wikipedia.org] , for example, "If the total energy of all three types of neutrinos exceeded an average of 50 electron volts per neutrino, there would be so much mass in the universe that it would collapse." The fact the Universe does not collapse is actually used to determine limits on possible neutrino masses (0.3 eV).

Neutrino masses also affect the fine-tuning of the Standard Model (SM), so any new experimental results will make a generation of graduate students and theorists happy, as the current problem is finding significant enough discrepancies in the SM to provide direction for fixing it in the future. Having results from several different experiments, which effectively look for oscillations on different length-scales (Earth-to-Sun vs. 10s or 100s of miles), provides additional constraints in that search.

Neutrino astronomy is something that requires much larger detectors, such as Ice Cube [wisc.edu] . At the moment, the models of neutrino production in the Sun were actually used to look for flavor oscillations, not the other way around, so neutrino astronomy is primarily intended for cosmological measurements. And hard as it is to detect neutrinos, we still have not been able to detect any gravitational waves, so the two are not competitors as astronomy methods, and won't be for a while. Perhaps you were thinking of solar quakes being used to probe the interior of the Sun?

Re:significance (1)

bcrowell (177657) | more than 8 years ago | (#15044270)

According to Wikipedia, for example, "If the total energy of all three types of neutrinos exceeded an average of 50 electron volts per neutrino, there would be so much mass in the universe that it would collapse." The fact the Universe does not collapse is actually used to determine limits on possible neutrino masses (0.3 eV).
Hmm...actually what the WP article says right now (could be different from what it said when you read it) is:
A much more stringent constraint comes from a careful analysis of cosmological data, such as the cosmic microwave background, galaxy surveys and the Lyman-alpha forest. These indicate that the sum of the neutrino masses must be less than 0.3 electron volts (Goobar, 2006).
So AFAICT it had already been established, regardless of this measurement, that the neutrino masses can't be big enough to have a big cosmological effect.

Neutrino astronomy is something that requires much larger detectors, such as Ice Cube. At the moment, the models of neutrino production in the Sun were actually used to look for flavor oscillations, not the other way around, so neutrino astronomy is primarily intended for cosmological measurements. And hard as it is to detect neutrinos, we still have not been able to detect any gravitational waves, so the two are not competitors as astronomy methods, and won't be for a while.
I didn't say anything about gravitational waves, just gravitational fields (e.g., you can measure a star's mass, and the other multipole moments of its mass distribution). I also didn't say that neutrino detectors currently in operation were already telling us anything new about astronomy.

It will be cool if we can eventually measure the energy spectrum of the solar neutrinos (or at least put constraints on it).

If they are heavy they have more mass? (1)

tetrahedrassface (675645) | more than 8 years ago | (#15044093)

okay. Well maybe the universe is heavier than we thought.. I know my own mass is quite larger than it should be. ;)

I have something kinda off topic but its "heavy" as well. Ever seen a pepsi with a wire in it?

Thats right! A stainless steel wire in an old unopened pepsi. Can we find out how that happened? If you want to see it here it is.. http://www.regardingspace.com.wireinpepsi.jpg/ [wireinpepsi.jpg] Happy April 1. The image is legit though.

Dark Matter (3, Interesting)

ruiner13 (527499) | more than 8 years ago | (#15044094)

Could these particles having mass explain the "missing matter" that scientists formerly attributed to dark matter? I wonder what other particles are there taking up space that we never thought had mass, either.

Re:Dark Matter (4, Informative)

syntaxglitch (889367) | more than 8 years ago | (#15044122)

http://en.wikipedia.org/wiki/Dark_Matter#Compositi on [wikipedia.org]
http://en.wikipedia.org/wiki/Hot_dark_matter [wikipedia.org]

...short answer is: yes it has been considered, but current models of neutrino formation suggest they can't account for all dark matter (or even a significant component of it).

Re:Dark Matter (2, Interesting)

mrpeebles (853978) | more than 8 years ago | (#15044149)

Another problem is that at least some of the dark matter needs to "clump" together, and there is no way to imagine neutrinos clumping. Or so the astronomers and astrophysicists tell me. Incidentally, fundamental particles of matter, like electrons and neutrinos, aren't thought to take up space, exactly.

Re:Dark Matter (2, Informative)

brian0918 (638904) | more than 8 years ago | (#15044159)

They aren't really "point particles"; it's just mathematically easier to consider them such, for most problems.

Re:Dark Matter (1)

mrpeebles (853978) | more than 8 years ago | (#15044260)

What examples are you thinking of where they aren't treated as point particles?

That is nice and all (1)

linzeal (197905) | more than 8 years ago | (#15044101)

But what inquiring minds want to know is what does it taste like?

Re:That is nice and all (1)

thomasa (17495) | more than 8 years ago | (#15044185)

Being as some are probably passing through your body right now, you should be able to answer that question for yourself.

Re:That is nice and all (0)

Anonymous Coward | more than 8 years ago | (#15044301)

It tastes like... burning.

Soudan (0)

Anonymous Coward | more than 8 years ago | (#15044103)

Growning up in Minnesota, we always passed the soudan mine on the way to our cabin and would stop there now and then to go on the tours they have of the mine. I remember years ago wondering why in the hell there were books in the gift shop on neutrinos. It wasen't untill much later I learned of the detector and the scientific work going on at the mine. I've really wanted to go back since then, because i hear they have tours of the scientific area now. Ignoring the particle detection work there, i would still suggest anyone passing by there to take the tour of mine itself, its quite incredible when you're half a mile below the ground and they shut off all the lights...

AND I CARE, BECAUSE?? (0)

Anonymous Coward | more than 8 years ago | (#15044108)

this is so old. I read this on digg in 1998

That's not nice! (1)

brian0918 (638904) | more than 8 years ago | (#15044113)

You know how impressionable neutrinos are.. always changing their flavor to match the latest fads.. and now call them massive?!

They'll decay in no time...

Re:That's not nice! (1)

Duhavid (677874) | more than 8 years ago | (#15044232)

Maybe if they got outside and played instead of playing nintendo.

Meet the new boss (4, Interesting)

pdq332 (849982) | more than 8 years ago | (#15044130)

Although the article implies that the Standard Model will have to be revised as a result of this experiment, this result does not really change the Standard Model all that much. The theoretical method used to establish neutrino mass, ie- that neutrino oscillations imply neutrino mass, is itself a Standard Model prediction. Rather the results fixes some of the unbound parameters of the theory. In other words, the arguments are better known now, but the method signatures remian the same.

OMG PONIES!!!! (1)

vishbar (862440) | more than 8 years ago | (#15044131)

OMG PO...damn. I'm too late.

Wow slashdot is retarded (0, Troll)

eternal_drake (953628) | more than 8 years ago | (#15044134)

old news old news old news gg faggots

31derful Flavors? (1)

X1088LoD (918610) | more than 8 years ago | (#15044150)

Can I get my ice cream with neutrino flavor oscillations?

Isnt that like chocolate with gummi bears?

Implications regarding the Standard Model? (4, Informative)

TechnoGuyRob (926031) | more than 8 years ago | (#15044158)

This is a very interesting conclusion. I am currently taking a modern physics II class at a college in my town, and I live 15 minutes away from Fermilab. In fact, our professor is a scientist at Fermilab that only comes in this term to teach our class. The interesting question, though, is (and I know it's small), what is the exact mass that they obtained (if any so far)? Of course, this would have to be given in eV (electron volts), but assuming it's very small (~E-3 eV) (EDIT: I just looked at the press release linked to at the end of this post, and indeed, it is on that scale!), this could prove to have some interesting conclusions. I actually found this passage in the article that explains it better than I could:
"In particle physics there is the Standard Model which describes how the fundamental building blocks of matter behave and interact with each other," explained Dr Falk Harris.

"And this model tells us that neutrinos should have no mass. So the fact that we have now got independent measurements of neutrinos saying that they must have mass, means that this Standard Model is going to have be revised or superseded by something else."
This is very interesting because of its possible re-affirmation of Wikipedia [wikipedia.org] . I'm not going to take out my string theory book right now to see if calculations of a positive neutrino mass correspond to any viable conception in string theory, but a re-affirmation and eventual proof of string theory could spur as great of an innovation as the concept of an atom.

We'll have to wait and see, but for anyone who would like more information, Fermilab's website [fnal.gov] has an article about the discovery.

Re:Implications regarding the Standard Model? (1)

eternal_drake (953628) | more than 8 years ago | (#15044161)

tl;dr

Re:Implications regarding the Standard Model? (2, Interesting)

TechnoGuyRob (926031) | more than 8 years ago | (#15044163)

I mean, String Theory [wikipedia.org] , not Wikipedia, sorry about that (forgot to include the title of the article, silly me).

explanation about oscillation/mass relationship (2, Informative)

SetupWeasel (54062) | more than 8 years ago | (#15044168)

There is a large bit of hand waving here. Why are neutrino oscillations and neutrino mass inseparable?

I hate when people act as if a complicated issue is simply true. So, as a public service to the Slashdot community:

Here is a site that attempts to explain it. [uci.edu]

My quantum physics knowledge isn't teriffic. Any particle physicists know of a better source?

Re:explanation about oscillation/mass relationship (5, Informative)

Anonymous Coward | more than 8 years ago | (#15044196)

Okay, as a particle physicist, I learned about this in terms of the Hamiltonian evolution of a wavefunction, and some analogy to neutral kaons, and a page of math. But thats not what you wanted to hear.

A physicist on the recent Nova special "The Ghost Particle" (Maybe it was Boris Kayser) had a nice explanation. If neutrinos have no mass, then they travel at the speed of light. If they travel at the speed of light, then they would not experience "time". Since changing flavor is a process that takes time, or duration, or something like that (this previous clause is maybe a non-trivial thing to say), then if neutrinos change flavor, they must experience time, so they must travel slower than the speed of light, so they must have some mass.

Re:explanation about oscillation/mass relationship (1)

SetupWeasel (54062) | more than 8 years ago | (#15044214)

I really should have payed more attention in Quantum class. What you said makes sense. Is the explanation and mathematical proof in that site accurate?

More attention required (1)

Expert Determination (950523) | more than 8 years ago | (#15044242)

I really should have payed more attention in Quantum class And English.

Re:More attention required (1)

SetupWeasel (54062) | more than 8 years ago | (#15044267)

I'm sure your spelling and grammar are always perfect when posting in a forum. This does not make you any less of a tool.

MOD UP (0)

Anonymous Coward | more than 8 years ago | (#15044220)

Not sure that parent's explanation is free from logical fallacies, but it's an interesting post...

Re:explanation about oscillation/mass relationship (1)

bcrowell (177657) | more than 8 years ago | (#15044245)

Hmm...interesting argument. The only thing that makes me a little uneasy about it is that it would seem to imply that a photon can't oscillate either, and yet I'm convinced that the photons I see oscillate at a certain frequency, ~10^15 Hz. Probably there's a correct argument hidden in there, but I think there's some more justification needed.

Re:explanation about oscillation/mass relationship (1)

Vilim (615798) | more than 8 years ago | (#15044248)

I first learned of the neutrino oscillation through a profs class notes. Since I respect the guy too much to actually put up his PDF (it was an example in the application of matrix diagonalisation) the best I can do is give the reference he used at the end. It looks like it has alot of detail (51 pages) but apparently it is suitable for an introductory quantum course (I haven't read it so I cannot attest).

You can do a google search for arXiv:hep-ph/9905257 or the URL for the PDF is http://www.int.washington.edu/PHYS554/2005/neutrin o1.pdf [washington.edu] (the first link in the google search)

Explains the physicist... (0)

Anonymous Coward | more than 8 years ago | (#15044170)

Of course, most of them travel right through our detectors as well, but once in a blue moon one of them will interact

To give you a feeling for how much this represents, it's about the same as the hit rate of April Fools joke on slashdot. So it's pretty small, but you got to have faith people!

... continues the savant: - about one or so per day.

No explanations needed here, you all now how long a day can be by now.

ponies, straight, gay? (1)

Devistater (593822) | more than 8 years ago | (#15044190)

How is this physics story about gay ponies? (tags)

Re:ponies, straight, gay? (1)

Stephen Samuel (106962) | more than 8 years ago | (#15044272)

Because It's still April Fools day, and some people don't follow the noon limitation???

Ouch! (1)

paiute (550198) | more than 8 years ago | (#15044201)

Calculations of the flux due to the sun shows that 60 billion neutrinos pass thru your thumbnail every second. So that's the tingling sensation.

AHHH (1)

balsy2001 (941953) | more than 8 years ago | (#15044217)

I can feel myself becoming swiss cheese as the nutrinos zoom through me. I felt so much better before they had mass.

Another assumption: They stopped for lunch. (1)

Futurepower(R) (558542) | more than 8 years ago | (#15044219)

Quote from the Slashdot story: "The set up established that fewer particles were being detected at the Soudan site than had been sent from Fermilab, which confirmed that some neutrinos changed their flavor on the way ..."

Or, some of the neutrinos stopped along the way to have a beer.

Actually, it confirmed nothing except that fewer neutrinos were detected. It is utterly foolish to think that particle physics is enough understood that accurate guesses can be made.

Another topic, but still about this Slashdot story: How is this slashdot story about "[+] ponies, straight, gay, science, physics (tagging beta)".

How do Slashdot editors make connections between April Fool's Day and being gay? Is that an indication of poor social skills?

--
Before, Saddam got Iraq oil profits & paid part to kill Iraqis. Now a few Americans share Iraq oil profits, & U.S. citizens pay to kill Iraqis. Improvement?

Re:Another assumption: They stopped for lunch. (1)

tftp (111690) | more than 8 years ago | (#15044316)

How do Slashdot editors make connections between April Fool's Day and being gay? Is that an indication of poor social skills?

It is at least an indication that you are unaware of all the meanings of the word 'gay':

Main Entry: gay
Pronunciation: 'gA
Function: adjective
Etymology: Middle English, from Middle French gai
1 a : happily excited : MERRY b : keenly alive and exuberant : having or inducing high spirits
2 a : BRIGHT, LIVELY <gay sunny meadows> b : brilliant in color
3 : given to social pleasures; also : LICENTIOUS
4 a : HOMOSEXUAL b : of, relating to, or used by homosexuals

The #4 is quite a recent addition.

It was a long haul .... (5, Interesting)

rhatcher (53923) | more than 8 years ago | (#15044251)

Boy, was it great to see our result presented on Thursday. Though I'm a little disappointed that the story here didn't link to, say, our press release or even to the Fermilab [fnal.gov] or MINOS experiment [fnal.gov] home pages.

I joined the experiment in 1995 soon after the collaboration came together and created the proposal. In that time I've written simulation ("Monte Carlo"), reconstruction and framework code for the experiment. It's been a pretty exciting 10 years. The push to get everything together this last month has been exhausting. But after presenting the results on Thursday do we physicists take a well deserved break and party like 1999? Well, noooo. We spend Friday, Saturday and Sunday IN MEETINGS! Today (Saturday) we were there from 8:30am to 7:00pm discussing how further to proceed. We've got 50% more data "in the can" that we didn't yet present (cross checks to perform, fits to perform). Plus plans for more data taking after the accelerator comes up again in June. Plus other physics results we're still trying to extract. Plus more improved simulations to do in order to yield improved limits. Such is the life of a physicist.

Further links (1)

rhatcher (53923) | more than 8 years ago | (#15044283)

Search for links in the news [google.com] . Though I hate Fox News in general, I have to say they have the best title for their copy: Physicists Lose Some Neutrinos, Gain Some Information.

Re:It was a long haul .... (2, Informative)

rhatcher (53923) | more than 8 years ago | (#15044306)

Oh, yes, and the distance from Fermilab to Soudan is 735 km. Converting to miles, rounding and then converting back to km is presumably how the value given in the story came about ... but really ... quoting it as 724km (450 miles) is just silly.

I haven't seen mentioned any of the news reports point out the, ah, irony [no pun intended, well, okay, yes it was] of the "coal to Newcastle" aspect of transporting 5.4 kilotons of steel into an iron mine. I just like to point that out..

umm.. (2, Funny)

ShaunC1000 (928875) | more than 8 years ago | (#15044262)

is this an April fools joke I'm too dumb to understand?

Re:umm.. (1)

Locus Mote (307298) | more than 8 years ago | (#15044275)

I's think soh. Me not understand to good too. May be I watch to much teveee, uh... OMG Ponies!!! LOL LOL!!!

Oblig. Stargate (1)

Kredal (566494) | more than 8 years ago | (#15044293)

If you had been paying attention, you'd know that Nintendos pass through everything!

Oh Derr! (1)

Whiteox (919863) | more than 8 years ago | (#15044310)

"....it means that there is a lot more mass in the Universe than we thought there was,'

Isn't that some kind of tautology? http://en.wikipedia.org/wiki/Tautology [wikipedia.org]

I mean how can you determine a finite quantity in an infinite universe?
The collective mass of an infinite universe cannot be known.

Re:Oh Derr! (1)

anothy (83176) | more than 8 years ago | (#15044330)

while it's still early to know for sure (and may always be so), the universe is not generally understood to be infinite by physicists or cosmologists; rather, as einstein described it, the universe is most likely "finite yet boundless", in much the same way the 2-d surface of a balloon is finite - having a definite area of measurable size - yet boundless - having no edges nor limit to the distance you can travel in a given direction.

in the end, einstein was right to only be sure about one thing being infinite.

Obligatory- (4, Funny)

capz loc (752940) | more than 8 years ago | (#15044311)

Neutrinos have mass? I didn't even know they were Catholic!

Why are they always prattling about missing mass? (1)

Ungrounded Lightning (62228) | more than 8 years ago | (#15044320)

One thing that drives me NUTS is that the physicists are always talking about neutrinos only being all or part of the explanation of the "dark matter" mass of the universe if they have rest mass - and this ends up in the media as if only the rest mass has gravitation.

ALL mass has gravitation - both rest mass and the mass equivalent of all the other forms of energy (including momentum) that go into the creation of the particle. So neutrinos have the same damned mass and gravitation whether they have rest mass or not.

Now if the issue is that they can't explain the galactic spin anomalies if they don't have rest mass because if they have none they fly away at the c and if they have some part of them get decellerated and stick around in clouds, somebody should bloody well SAY so.
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