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Scientists May Have Detected Neutrinos From Another Galaxy
The Bad Astronomer writes "A experiment called IceCube — consisting of sensitive light detectors buried deep in the Antarctic ice — has detected two ultra-high-energy neutrinos, each with over a peta-electronVolt of energy (a quadrillion times the energy of a visible light photon), the highest energy neutrinos ever seen. The two events, nicknamed Bert and Ernie, have a 99% chance of originating outside our galaxy, likely created either by a supermassive black hole or an exploding gamma-ray burst."
What will it be in joules, 1 peta electronVolt?
Could I boil a kettle on this neutrino (potentially)?
It was obviously the explosion created from the enormous energy from a supergate in the galaxy Atlantis lives in.
That would be our galaxy. It moved here in the final episode (San Francisco I think).
I am a free slashdotter. I will not be modded, blogged, DRM'd, patented, podcasted or RFID'd. My life is my own.
WORD! That's a fly name for an experiment dawg!
anything happening inside the event horizon of a black hole doesn't really matter...
Are you saying matter doesn't matter ?
Jicehix
So many words for all of them to be so wrong.
but doesn't it correlate to any possible event yet, or are we just guessing about were it came from?
In my country a person like you would be called an ant-fucker. Because ant-fuckery is the only way to describe this level of pedantry. Don't get me wrong, it's not meant as a grave insult. Polite people use the term in casual conversation and nobody is offended.
So if I flip a coin and cover it up, and ask you "What are the chances it is heads?" you would answer back "it's either 100% or 0%"? What kind of pedantic choice of interpretation is that?
A Neutrino is a Neutrino. It has no identifying characteristic.
Way to be oblivious there. If they are detecting a passing neutrino, then the particle has a velocity, right? So, a finite mass moving at a finite velocity has an energy, which is different than that of the same particle moving at a different speed (independent of direction). And if the energy of two identical particles can be different, then you can identify a difference between them. Which is kinda the whole point of TFA, and the IceCube experiment itself. The scientists try to understand all the data they collect, not just what some pedant wants them to look at. As TFA states, the energy of the detected neutrinos is what scientists are using to infer where the neutrino came from. There are certain events which can give a neutrino such energy, and these events haven't been observed in our galaxy. And just like that, someone who chooses to think can understand a bit more :)
Its the nrg. The point of origin can be norrowed down by eliminating sources that don't have that amount of nrg. Simple.
Python: 'And then suddenly you have a language which says "we're all stuck with whatever the whiniest coder wants".'
These neutrino's were not the neutrinos they were looking for
I believe it is Sithic philosophy that states you are either absolutely for or absolutely against something.
So I would not argue with Troyusrex, unless you want to get force choked.
it must have been a good day.
Neutrinos, as matter, have plenty of characteristics that could be used to identify them. And saying that it comes from a specific place is not really that difficult since things coming in from space don't take U-turns or pit stops. They come at us in a straight line only perturbed by gravity or other objects that we can observe and compensate for. So if a particle has a certain energy level and direction that does not match anything inside the galaxy, you can do a pretty reasonable job of figuring out where it came from.
As for black holes, yes, nothing is coming out of a black hole's singularity, but the black hole does affect matter outside its event horizon and it is expected that certain black holes will cause matter to be accelerated in such a way that it attains highly energetic characteristics. This is what they mean, or they mean that the neutrino was created in the initial supernova/hypernova that generated the black hole to begin with. Probably the former, as most large black holes are probably generated by accretion over time, and not sudden stellar compression.
Troyusrex: I'm familiar with this use of probability, so allow me to clarify:
There's no need for quantum anything. Probability is simply how one quantifies uncertainty. Here's an example: suppose I flip a coin and you do not see it. I might see it come up heads, and so I would assign a 100% probability that it came up heads. You would assign a probability of 50% to each possible outcome. Who's right? We both are: we're both describing our personal states of awareness about what happened, and they are different.
In this case, the scientists who conducted the experiment are 99% sure that they originated outside our galaxy, presumably because they were able to reject most in-galaxy source explanations. But they cannot be 100% sure.
If you want to learn more, read about Bayesian probability theory.
I have moderation points but unfortunately there is not a +1 Pedant mod.
Please explain for the layman that I am, how can these neutrinos be so energetic ? I thought neutrinos were very elusive particles that don't interact much with matter, and that's why they're so difficult to detect. With that much energy, these neutrinos should interact with matter and do heavy 'damage', à la cosmic particles, no ?
While the angular resolution of IceCube is not GREAT it DOES detect the direction from which the particles it detects came. This happens because, as others pointed out, the neutrino has a momentum. When it slams into a nucleus in the dectector the resulting collision debris carries away that momentum, thus the velocities of those particles, which are easily determined allows an estimate of the velocity of the original neutrino and thus its point of origin in the sky.
Of course the distance it came from is not readily determined, but if there's nothing terribly energetic nearby, then presumably you're looking at something from further away, and when we're talking about PeV neutrinos it has to be VERY energetic, not something we'd likely miss if it was nearby. Remember, we detected 2 neutrinos, that means there were literally trillions more (well, far more than that probably) that simply passed on through the detector with the same energies.
"Malo periculosam, libertatem quam quietam servitutem." -- Jefferson
The neutrino is going to go straight through you with a 99.99999% probability. But if it does stop inside your body and deliver its energy, it should give of one hell of a whack. Wonder if you would be able to feel that?
10 ?"Hello World" life was simple then
I can't explain completely, but I can say the energy level has most to do with the momentum of the particle. The faster a particle goes, the more energetic it is. It's a very simplistic explanation, and only one facet of what energizes a particle, but should work for laymen such as us. As for the interaction: if I remember right, neutrinos are very small. They tend to fly between the atoms, which at that scale are very far apart.
"Only a Sith deals in absolutes."
Therefore, Obi Wan is a Sith.
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Thanks ! It's a bit clearer now.
So why would a neutrino from a gamma ray burst in a galaxy far far away have more energy than one from a gamma ray burst within our own galaxy? And then there's the probability of being in the path of one in our own galaxy vs outside....
One of the properties that IceCube takes advantage of is that at higher energies, neutrinos are much more likely to interact with matter and produce particles that it can detect. There's actually a specific energy close to the observed energy of these particles for an electron anti-neutrino where there is a spike in the probability to interact with electrons (6.3 PeV, the Glashow resonance).
Or a -1 Pedant mod
Back when it was thought that neutrinos were massless, it was impossible to believe that there were huge masses of neutrinos surrounding galaxies, as they would have to travel at the speed of light. But now that we know that neutrinos have mass, maybe they could travel a lot more slowly, slow enough to be captured by a galaxy.
Think about it; there are a huge amount of neutrinos created every microsecond in every star in every galaxy, and they hardly interact with anything. They've been accumulating since the big bang.
What happened to the early photons? Those created as the universe first became transparent initially were very high energy indeed, but as the universe has expanded they've lost energy, to the point that they correspond to a temperature of just 3 degrees kelvin. What happens to neutrinos of a similar vintage?
I love Mondays. On a Monday, anything is possible.
The surrounding ice around the detector array acts as a scintillator which generates a minute track of light as the particle passes thru the area. That immediately gives directionality, and energy in eV is computed by summing the light response from the entire detector array during that "event".
Chance. I do not think that word means what you think it means.
From the galaxy called, Neutrinos With Attitude!
I swear to God...I swear to God! That is NOT how you treat your human!
Because neutrinos don't interact much, there are very few ways for them to release their kinetic energy, even when there is a lot of it. Neutral refers to the fact that neutrinos don't interact electromagnetically. They also don't interact via the strong force, and gravitational interaction of anything on this scale is negligible (although neutrinos are believed to have very small but nonzero masses). That leaves only weak nuclear interactions, which happened to occur twice in this detector.
Since when we do know for sure that neutrionos exists?
The scary part is when those galaxies insist we return them.
Table-ized A.I.
LOL, i agree with you. We should set a quota for these nasty mexi...i mean aliens. Like, no more than 50% foreign neutrions...
From now on in all job interviews I shall state my hobby as "Intergalactic Neutrino Detector" and refuse to work for anyone who doesn't giggle or laugh.
XML is a known as a key material required to create SMD: Software of Mass Destruction
Same thing happened to the neutrinos as happened to the photons. They cooled down. Currently, the neutrino background is ~1.7K, I believe (they're a bit cooler than photons as photons decoupled from matter much later in the early universe than neutrinos did). Neutrinos are, on cosmological scales, treated mostly the same way photons are (they behave in a similar fashion). In any case, the current energy in neutrinos is about ~60% of that in photons, and photons are about 4 orders of magnitude below the energy in dark matter.
We can also predict how the universe would evolve if neutrinos made up the bulk of dark matter. Since it didn't evolve that way, dark matter has to be something else.
"None can love freedom heartily, but good men; the rest love not freedom, but license." --John Milton
Note that this is different than an aunt-fucker, which is sort of like a cross-eyed mother fucker.
The neutrino is going to go straight through you with a 99.99999% probability.
Actually that is probably not quite true. For the vast majority of neutrinos you encounter on a daily basis (from radioactive decay, relic Big Bang neutrinos, solar etc.) you are completely correct. Indeed for these, as the article states, they will pass through the earth without blinking.
However PeV neutrinos are NOT your everyday neutrino. These guys have such an incredible energy (over 100 times the proton energy in the LHC) that the earth is actually opaque to them. In fact if you look at the IceCube analysis they look for down going neutrino i.e. ones coming in from above despite the problems with the back grounds from cosmic rays. This is because they cannot look for neutrinos which have passed through the earth because, at these energies, there will be none!
The reason for this is that neutrinos interact with matter through W and Z bosons. These have a mass ~80 to 90 times the mass of a proton. The reason that normally neutrinos do not interact is that there is insufficient energy to make a "real" W or Z in the interaction and this heavily suppresses the chance of it happening (due to quantum mechanics it can till occur though). Above a PeV the energy becomes high enough that this energy suppression effect gets a lot smaller and so the chance of interacting becomes a lot higher - eventually becoming slightly stronger than electromagnetism at really high energy when real W's and Z's can be created.
So the upshot of this is that a really high energy neutrino might actually have a reasonable chance of interacting in your body and the article is completely wrong when it describes the earth as basically transparent to these neutrinos...although it is an understandable mistake given that it is transparent to most neutrinos.
What kind of pedantic choice of interpretation is that?
Internet-pedantry, where either 1) pedantry is misapplied because the word in question does not have a single, precise definition to be pedantic over, and both the the original and the "pedant's" "pedantic" correction are correct or 2) pedantry is possible because the word does have a precise technical definition, but the "pedant" has no idea what that is and is wrong while the original usage was correct.
The enemies of Democracy are
Nope.
Or at least, they could still only account for a small fraction of observed dark-matter.
http://www.astro.princeton.edu/~dns/MAP/Bahcall/node6.html
Slashdot gets worse every day... Pipedot: News for nerds, without the corporate slant
Mark your preferred definition of probability
[ ] Bayesianism
[ ] Frequentism
[x] Ridiculous frequentism
No, your wife being an aunt doesn't make you an aunt fucker. You would also need to fuck your wife.
If you want to learn more, read about Bayesian probability theory.
Not to get into a Bayesian vs. frequentist debate here, but note that this is not the only interpretation of probability out there. The frequentist interpretation is, in spirit, a statement "in hindsight". Troyusrex's point is that it's meaningless to talk about probabilities of things that are fixed quantities; the frequentist interpretation gets around that by making statements about quantities that have yet to be determined. So one only speaks of probabilities before an experiment has been performed and a measurement made. In practice of course we give things like p-values and confidence intervals based on actual observations, but we interpret all probabilities in terms of an infinite number of identical hypothetical experiments.
weinersmith
At best we can only detect vector and derived energy, but we don't know where they came from or if they actually came from dark matter space in an area we don't traditionally think of as an origin point.
-- Tigger warning: This post may contain tiggers! --
The bigger question is how did a chargeless neutrino particle get accelerated to that energy. Most current theories like 2nd order Fermi acceleration act on charged particles bouncing among moving plasma shock waves. Imagine a ping pong ball bouncing between between two walls in a cubic room that are approaching each other. There's no limit to how fast the ball can go because upon each bounce it gains a bit more speed from the wall and it doesn't matter that the ball speed is greatly higher than the wall speed. The walls (standing in for the shock waves) have infinite mass in comparison to the ball (the particle) so they don't effectively slow down much with each reflection.
Probably what happened was there was another particle with charge, it was accelerated to high energy via the standard ways like 2nd order Fermi acceleration and moving in Earth's general direction, then on the way here that particle decayed to produce a neutrino among its products. That's the neutrino that got detected.
When a neutrino impacts a particle in the detector, it creates a cascade of new particles. Since the momentum of the neutrino is conserved in the cascade of particles that can be more easily detected, the direction that the neutrino came from can be determined.
If you want a vision of the future, imagine a youtube comments section scrolling - forever.
Say WHAT? There isn't even consensus that these cosmic neutrinos are either neutrinos or cosmic, much less where they come from. Extra-galactic is reasonable, but I would put it more in the 20-30% range, not 99%.
From the ABSTRACT of the actual paper:
well he lives in a cave and his favorite past-time is scaring the natives... sure sounds like sith to me.
world was created 5 seconds before this post as it is.
In my country a person like you would be called an ant-fucker. Because ant-fuckery is the only way to describe this level of pedantry. Don't get me wrong, it's not meant as a grave insult. Polite people use the term in casual conversation and nobody is offended.
Welcome fellow citizen of Kazakhstan! How much for sister?
To have a right to do a thing is not at all the same as to be right in doing it
So if I flip a coin and cover it up, and ask you "What are the chances it is heads?" you would answer back "it's either 100% or 0%"? What kind of pedantic choice of interpretation is that?
A mathematically correct, but absolutely useless one. The guy's obviously an actuary.
To have a right to do a thing is not at all the same as to be right in doing it
A GRB results from an explosion, so that's perfectly accurate. It's like saying "an exploding flash of light." Just a tiny bit of poetry, nothing wrong with it.
If the detected Neutrino's actually do have PeV energies, doesn't that essentially give them Mass? And if so, Dark Matter Candidate # 1
"If the only tool that you have is a hammer, every problem looks like a nail." Donny Rumsfeld
I like how that got modded insightful. Only on Slashdot does one earn praise for arguing Star Wars on a science news post. =)
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Wait, how did scientists get to another galaxy?
where light is the absolute limit. I have always and will always with my limited capabilities and understanding feel and think that it is the framework, the theoretical limit in the framework used by people today when trying to understandd the all and everything of reality as it is perceived, not just the absolute limit because einstein said so, did he actually say so, or did he just pone it as an IF ... THEN conditional statement from which all others were derived ?
...
i have a picture here of the man but he doesn't do much more than just sit there and smile this buddha smile like 'i know something you will never understand and if i explain then you will never understand since when you dont figure it out yourself, you will miss all the heavenly glory that comes with it, like a finger, pointing away at the moon'
i sometimes get confused, i can always blame it on one of the brands they labelled me with that's not the problem but why is this so absolute ?
i have seen and read about a few things that surpass light speed so , sometimes i think me as the guy who doesn't get it gets it better than some who do
but i dont have the math to slap others around with so
i just shut up
and sit there
smiling
(lol)
carry on now
Free speech was meant to be free for all... how can anyone grow up in a nanny state ?