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Recently, a group of physicists have been working to measure the neutrinos generated from a particle accelerator at CERN. This group discovered neutrinos arriving faster than would have been expected and they appear to be traveling ...
Recently, a group of physicists have been working to measure the neutrinos generated from a particle accelerator at CERN. This group discovered neutrinos arriving faster than would have been expected and they appear to be traveling faster than the speed of light itself, but they draw no definitive conclusions. This has been widely reported as being the end of Relativity, but this is not the case at all. Let?s take a look at what is going on in the experiment and what was reported in the journal article.
First, it might help the reader to gain an understanding of the neutrino. Neutrinos are interesting little neutral particles that have almost zero mass. Due to their nature, they can pass through matter without being absorbed. There are three known types of neutrinos: the electron neutrino, the muon neutrino, and the tau neutrino. The experiment in the journal article is referred to as CERN neutrinos to Gran Sasso, or CNGS. The CNGS team is searching for a phenomenon known as neutrino oscillation where muon neutrinos may change into tau neutrinos. A secondary goal of the experiment is to measure neutrino velocity to a great accuracy.
In the experiment, neutrinos are generated at the Super Proton Synchrotron (SPS) particle accelerator at the CERN LHC complex in Geneva and further accelerated down a 1 km beam line toward the Gran Sasso National Laboratory in Italy. At Gran Sasso, a detector instrument called OPERA measures the neutrinos. The distance from CERN to Gran Sasso is 732 km straight through the Earth, traveling up to 11.4 km below the Earth?s surface. Remember, neutrinos don?t interact with matter so the Earth is invisible to the tiny particles.
The distance between the two systems is known to within 20 cm. Time is also measured with extreme precision utilizing GPS timing signals and a cesium atomic clock. The GPS used in timing also allows the team to track any small movements in the Earth itself. This even allowed consideration of the effect of the L?Aquila Earthquake that moved the OPERA detector 7 cm. Due to the nature of the experiment, the time is not calculated with a simple, stopwatch style, start to finish measurement. It instead relies on measurements and comparisons of probability distribution functions at the source and the detector. In other words, there is a lot of math involved. In addition to understanding the timing and position variations in the experiment, the physicists also took into account many other variables, such as day versus night and seasonal changes. The sensitivity of this experiment is roughly an order of magnitude better than previous experiments.
The speed of neutrinos is measured and compared to the speed of light by subtracting the expected time for light to travel the distance from the time for the neutrinos to travel the same distance. One would normally expect this to be zero for neutrinos traveling at the speed of light or negative for any value below the speed of light. The case presented in the article shows a positive value of 60.7 nanoseconds with statistical and systematic errors providing not nearly enough potential difference to account for the positive value. This value has six-sigma significance. This is, obviously, a stunning finding.
Despite the large significance of the measurement reported here and the stability of the analysis, the potential great impact of the results motivates the continuation of our studies in order to investigate possible still unknown systematic effects that could explain the observed anomaly. We deliberately do not attempt any theoretical or phenomenological interpretation of the results.
This is an important paragraph. This is the group of physicists, together, stating that they don?t know how they came to a result that shows neutrinos apparently exceeding the speed of light. They are not drawing any conclusions in this article and are simply providing the finding and the methods used to obtain the finding. They are trying to find where there could be errors in their measurements. They do not claim that the neutrinos are actually exceeding the speed of light, only that the measurements to date show something unexpected. They are reaching out to the high-energy physics community to improve the experiment and data analysis. They are not looking to fundamentally change physics but to ensure that they are producing sound data. We may find that nothing comes of this. We may find that there is an effect known in physics that accounts for the difference. We may find that neutrinos are capable of moving slightly faster than the speed of light. It is simply too early to make definitive, wide-reaching conclusions.
The conclusion that can be drawn from this article is that a group of experimenters found an unexpected result using some of the most amazing and precise instruments and techniques ever created. No matter what is found to be the actual cause of this 60.7 nanosecond variation, the conclusion you can draw is that it is an amazing time in history where such measurements can be made and an exciting time to be a practitioner or admirer of science. Imagine the findings that will be made by the next couple generations of scientists who are sitting in elementary classrooms right now and just learning that a rainbow is the spectrum of sunlight. Einstein wouldn?t be disappointed by these findings; he would be intrigued and proud to see the legacy of great science continuing forward.
Brian is a NASA engineer by day and a GeekDad contributor by night. Opinions shared are my own and do not necessarily reflect the opinion of NASA.
Time for a pretty good time-travel joke:The bartender says "We don't serve faster-than-light particles in here."A neutrino goes into a bar.
I realize that the details of the experimental protocol and subsequent analysis would be quite complex and mathematically dense, but it would be nice if someone with real credentials and communications skills would break down some of the more perplexing aspects of this finding for well-read laymen.
For instance, it has been known for years (since 1987) that neutrinos generated by supernova travel at light velocity, since several Earth based detectors picked up streams of neutrinos that had been generated just prior to the collapse of a star, which was then followed up by a light burst as predicted by the Standard Theory. Since the two streams (neutrinos and photons) reached Earth in the expected sequence and time-frame after traveling vast distances, why isn't this finding given greater credibility than the CERN experiement? Doesn't the earlier finding all but dictate that some unknown error has been introduced into the design or analysis in Europe?
The other question I have is how does modern physics reconcile the two apparently contradictory facts that neutrinos have mass (albeit tiny) and yet can travel at light speed (let alone supraluminal speeds)? I thought that special relativity precluded that, yet I have not seen an explanation that addresses this contradiction, which was apparent even before the CERN results.
These are issues that the general, well-read but non-technical public would enjoy hearing about, if it comes from someone with the proper credentials, and not some yammerer with too much time on their hands.
With regard to neutrinos generated by a supernova travelling at the speed of light, the neutrinos are emitted first from the supernova. Photons (i.e. light, electromagnetic radiation, etc. ) are emitted afterwards. There is a time gap between the emissions which causes neutrinos to reach Earth first. Neutrinos were considered to not travel at the speed of light because of the mass they carry. According to Einstein's theory of special relativity, in order to move at the speed of light your mass must completely convert into energy. That's why photons do not have mass. However, neutrinos do have mass. Some may say it is negligible; however, their mass is present. It's extremely tiny. Also in certain mediums ( air, water, rock, metal, etc.) light does not move at its maximum speed (Max speed: 299,792,458 m/s = 186,282 miles per second ).The refractive index (n) of the material determines the speed of light in that medium ( Speed in medium: v = c / n, c = max speed of light, n is refractive index ). In these situations, neutrinos do move faster than light. This makes absolute sense since neutrinos were clocked at moving at speeds very close to the maximum speed of light. The maximum speed of light is only observed in a vacuum. The very mysterious property of a neutrino is that it moves the same in any medium. It is considered to travel as if it was in a vacuum in any environment. That's why this "discovery" is a big issue. If light was to travel the same distance that the neutrino traveled in a vacuum, the experiment suggests that the neutrino would be faster.
The misconception with neutrinos is that they move at the speed of light. Before this "discovery", it was never observed or considered that neutrinos moved faster or even at the max speed of light. In fact, it goes against the very laws that were created around nature. Einstein's laws forbid this. Modern physics forbids this. That is what physics theories are derived from. If this is true, all hell will break loose. Time travel becomes possible, black holes become escapable, it may not cost infinitely amount of energy to move at or faster than light, pretty much everything in Star Wars and Star Trek would be plausible.
Thank you for a nice explanation of the 1987 supernova findings. There are now several possibilities, most of them interesting. I'm not sure all hell breaks loose - what happens is that our observations tend to disconfirm a previously established model. This has happened many times before. Lots of people get upset, but we generally get a better, truer, picture of reality from it.
The standard model has always had certain (I'd say major) problems, but these have generally been relegated to the status of "minor fixes needed". Now? Maybe not.
Neutrinos moving faster than light entails neither backwards causation nor time travel. The notion that a particle moving faster than light would travel backwards in time is based upon Special Relativity's formula for time dilation - time would take on imaginary value for velocities greater than c. Some have taken this to mean the particle would be going backwards in time - but the better interpretation is that in the context of Special Relativity such a velocity is meaningless. Both interpretations, however, are moot given that observing a particle with mass (like neutrinos) moving faster than light in vacuum shows that the theory breaks down at some point.
The speed of neutrinos and the mass of neutrinos has not been absolutely nailed down - they are both fuzzy areas that are defined as no more mass than X and no slower than Y. Those error bars still have lots and lots of overlap.
For example neutrinos with really, really tiny mass can get really, really close to c without causing problems. The error bars have plenty of room in them. Scientists are working on narrowing down those areas.
From the back-of-the-napkin calculation I ran: IF neutrinos moved faster than light at the rate the CERN measurements saw, the neutrinos from the 1987A supernova would have arrived here at earth over 4 years before the light did. That obviously didn't happen.
However, there are different types of neutrinos. The CERN study is looking at muon neutrinos, and that may or may not be different than the neutrinos generated by the SN 1987A supernova.
Most everything modern physics is doing right now is fuzzy and that's because they use this imaginary thing called "time" to make measurement and calculations. Once the physics community realizes time (as we have defined it) is not a fundamental part of nature and we move forward to find a better way to calculate things at an atomic level, then we will be in the true golden age of physics.
Also its hard to tell if the neutrinos from 1987A arrived 4 years earlier, no one was looking for them and no instruments were set up to detect them. Was there?
The Wikipedia article on Neutrinos discusses exactly the issues you raise in the subsection titled "Speed". Short answer from a yammerer: modern physics doesn't know how to reconcile the results yet. That's why this data requires further study and attempts at an independent replication.
thats a good point about how something that has mass can somehow travel at the same speed that light and other massless things travel at....how? is it just small enough...........
Supernovae are detected by their neutrino emissions, and then photon-detecting telescopes in the X-ray and visible light bands are slewed around to point at them. Until SN2008D, no supernova onset had ever been seen in photon bands, and there was no neutrino signature from that SN, I believe due to its great distance. Using the neutrino -> telescope slew -> photon detection method, the quickest a supernova has ever been seen is seven seconds, which obviously does not allow one to pick up slight discrepancies.
Prior to this experiment, it was assumed that the true velocity of neutrinos is slightly less than c, but within the error of measurement. We don't know what the rest mass of a neutrino is; we can only place upper bounds on the mass through speed measurements.
Too bad we don't have a space-based neutrino detector. We could then generate Earth-based beams of neutrinos of varying energy levels in its direction along with a simultaneous burst of light and see which one wins the race. That would eliminate one source of variability and potential error. And, yes I realize how much mass would need to be launched into space to build the detector, so I know it's impractical using current detection methdologies.
Not necessarily. We've bounced laser beams off the moon for decades after Apollo, so the effects of the Earth's atmosphere on a light beam's speed should be reasonably well measured by now.
They have done the opposite experiment, measuring neutrinos and photons coming off of a super nova. They were found to be in perfect agreement.
Thanks for this article. Given the media's constant shameless sensationalizations it's good to see some resources where people can get a sane, accurate perspective on what's going on in science - which is ironically more interesting than "EINSTEIN WAS WRONG" considering that such a statement really means nothing to the layperson and that the initiated already know better.
THIS JUST IN! - Superstringcheese confirms "EINSTEIN WAS WRONG" on internet blog post. And in other news, everyone in the world is murdered in a 10-alarm fire. 5th and 6th degree burns reported by zombie soap-opera doctors. But first, 58 minutes of padding.
Slight correction to the last sentence in the 3rd paragraph: Neutrinos DO interact (weakly) with matter or we would never detect them and they would never oscillate between types (and measuring neutrino oscillation was the point of this experiment in the first place). By the way, if the measurement proves correct, then it may not be special relativity that has to be revised. It may instead be the theory of neutrino mass. Neutrinos are very poorly understood. So there are a number of possibilities that have to be checked.
Well, this isn't "Nothing to see here" actually. It some scientists who absolutely know the implications of their findings being as thorough, rigorous and circumspect as they can possibly be about it. Which is proper. It does nothing to dispel the major ramifications if they are correct.
Maybe I'm reading the wrong articles, but I didn't see the shameless sensationalizations you seem to be responding to. Everyone else has been saying the same things: the results are preliminary; the group is not ready to draw theoretical conclusions yet, but they're making their data public so that it can be scrutinized and their experiments can be duplicated or not.
P.S. Even if neutrinos can travel faster than light, it would not necessarily make Einstein / relativity "wrong" any more than Einstein proved Newton "wrong." Each provided a very reliable, detailed, useful layer in our framework for physics. As we find exceptions to the laws known so far, we are just building on the foundations established by Newton, Einstein and others.
I agree with you but there is no doubt a dogmatic acceptance of Einsten't theories. His equations are like great melodies that get stuck in your head. Hubbel was the first to "prove Einstein wrong" - but his research was merely an elegant extension of Einstein's theories. It just happens that the universe is expanding, not static.
Kudos for providing a proud, enthusiastic, and even corrective, rational voice to offset some of the muddled, irrepressible hype about these otherwise very exciting times, indeed. GeekDad rules.
Of course, Einstein had no concept of a neutrino when he published his general theory. There was none until the 1930s. If the neutrino is faster than a photon, is it true that we need to rethink all the general theory of relativity, or just recalibrate it to the neutrino? Instead of light, perhaps the neutrino is the "c" in the famous equation?
Or there are, as many other experiments seem to indicate, more than three spatial dimensions, which would be very, very helpful in explaining most everything perplexing about neutrinos (and dark matter, etc).
The problem is neutrinos appear to have mass. This is measured because they are directly affected by gravity. A photon is only affected by gavitational lensing, where a dense body actually curves space-time, thus are assumed mass less.
If I'm wrong then please tell me. At the speed of light 60 nanoseconds equates to 20.01 cm. Which just happens to be the "margin for error" of the distance ? If I'm being daft then please tell me ....
type "what is the speed of light * 60 nanoseconds" in google, and you get 18 metres, not 20 centimetres. i.e. much further than the margin of error.
Also, if I understand the math correctly (I probably don't), the result was based on tons and tons of data collected over more than three years. The length measurement margin of error should have averaged out over the long run, unless there is something fundamentally wrong with the measurement technique. That's why they are asking for scrutiny.
Speed of light is about 3 x 10^8 meters/second. Time discrepancy is roughly 60 nanoseconds = 60 x 10^(-9) sec. The corresponding distance (speed x time) is 3 x 10^8 m/s x 60 x 10(-9) s = 18 m. If the distance measurement is in error, they have to account for a difference of 18 meters.
The speed of light is about 1 foot / ns, or about 30 cm / ns. So that means that light can travel 18 meters in that 60 ns, not 20 cm.
anyone else find it annoying that people with little to no formal education on particular topics still feel compelled to give their opinion?
No. I don't find it annoying. Opinions are all we have. It is annoying that those who do have formal education on particular topics also feel compelled to give their opinion mistaking abstractions for concrete facts.
I don't think the media is to be faulted for sensationalism in this instance. If the finding is upheld, it will force a radical re-interpretation of fundamental physics. The speed of light is not some arbitrary limit on how fast something can go. The speed of light limit in relativity is consequent to the very structure of spacetime proposed by relativity and its notion of simultaneity. Even a slight violation of this limit blows apart our supposed understanding of the geometry of spacetime, and relativity would fail as a fundamental theory. Observed relativistic effects to date would have to be seen as a special case of something deeper, as was the case with Newtonian mechanics. Yet relativity itself is proposed as a fundamental explanation of spatial, temporal, and causal relations across transformations of reference frames. If it were to fail, we are back to square one and have to admit that we fundamentally understand nothing about these matters, and it is not the least bit clear where we would begin to construct a new theory.
I just got a $827.89 iPad2 for only $103.37 and my mom got a $1499.99 HTV for only $251.92, they are both coming tomorrow. I would be an idiot to ever pay full retail prīces at places like Walmart or Bestbuy. I sold a 37" HTV to my boss for $600 that I only paid $78.24 for. I use Gr?bPenny.
Regarding "GPS timing signals and a cesium atomic clock", it seems possible that there is an error when measuring when the neutrino left and when it arrived. Can someone break this down?
Some of the hypotheses I see here are intriguing; others, of course, are plainly false. However, until these results are more rigorously proven (through repetition by other scientists, and a more thorough statistical and experimental analysis) there's no reason to believe a hypothesis is needed...
It'd be nice if your sound reminder of the scientific method would echo and reverberate in the other hallowed halls of science that brought us the THEORIES of natural selection and global warming...
Incidentally, contrary to what you imply, science as a whole has no ego when it comes to global warming, natural selection, or even gravity. Simply propose a theory that explains the evidence we see in some better way and science will surely follow - but be prepared to have your claims scrutinized!
Science has no ego? Surely you jest. How else do you explain a buffoon like Al Gore getting the Nobel Peace Prize? The scientific method, if followed, is what keeps scientific egos in check.
If global warming is correct (which it almost certainly is, based on the evidence), it will lead to the complete submersion of huge swaths of land, which include the habitats of hundreds of millions of people. I'd say trying to encourage people to respond before that happens is DEFINITELY related to peace.
For global warming, no less. Peace and global warming do have everything to do with one another. Oh wait, they don't. You guys need to find another religion besides the one you've created.
P.S. I don't have a religion. Science and religion are basically opposites, conceptually. If you don't see that, then you have effectively zero understanding of the scientific method.
Well, science and religion are NOT basically opposites. Indeed they lived together for millennium. Just because today's scientists generally choose not to discuss what is "meant" by their discoveries does not mean they do not carry their own opinions of of what it means.
Global Warming will cause political unrest, i.e. wars, massive starvation, etc.. Thus it seems to me it has everything to do with peace. Peace is the opposite of war.
I don't. Seriously, a decent definition of science would be "the lack of worship". Nothing is sacred to a proper scientist; everything is subject to doubt.
Michael you should read Darwin, he explains in his book how a specie can evolve from one type into multiple different types, His research was on (among other things) birds, and how they each developed different beaks, with each type having a beak that was adapted to it's method of procuring food. That is pretty fundamental, are you trolling or really that unaware of the reasons why people believe in evolution?
Of course, the entire concept of "science" is dictated by what the Nobel Peace Prize Committee says and does. In fact, by awarding the Nobel to Obama, the committee also inferred the existence of dark energy, which we now accept as physical fact... or something.
And what does that have to do with anything? Al Gore isn't a scientist, nor are the people awarding the PEACE prize. You're obviously very confused.
If you were trying to show that you don't know what you're talking about, you did a great job. Otherwise, this comment is a total failure.
This neutrino experiment is a SINGLE experiment. One of the fundamental pillars of the scientific method is that results must be reproducible. Another is that great scrutiny must be applied to the experimental methods, to be sure that systematic errors are negligible. THAT is why this CERN study does not immediately destroy the theory that the speed of light is the universal "speed limit".
Evolution, on the other hand, is backed by countless studies and experiments. Microevolution can even be directly observed in the laboratory (in fact, it can even be directed by scientists!). And the logical connection between micro and macro evolution is as simple as saying "every time a year passes, I age a year; therefore if 50 years pass I will age 50 years".
And I'll point out that science from many, many disciplines all agrees about evolution and global warming. In fact, we know hundreds (if not hundred of thousands) of times more about evolution than we do about gravity.
Although i do support your 2nd paragraph, I do not support your second paragraph. Even though Macro evolution seems to be a logical step, there are some flaws, such as the eye. Until the eye would have fully developed and provided sight , it would have allowed an attacker a soft hole into the brain.
I am not saying that all of evolution is wrong. All i am saying is that macro evolution has holes in it. It is they best the scientific community has come up with, but it cannot be the answer since it does not answer all of the questions.
Basically, the issues you raise here with macroevolution have already been considered and thrown down by evolutionary theorists. I posted a comment with a couple links, but it requires moderator approval.
Search google for "Richard Dawkins eye evolution" and "convergent evolution" if you want these links without waiting for the moderator to approve them.
Neutrinos faster than the Speed of Light. Wired.com http://t.co/VQXOUH7x La relatividad puede ser descartada, que otras verdades podran.
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