# Can neutrinos travel Faster Than Light **URL:** \ **Category:** Factual Questions\ **Created:** [September 22, 2011, 10:59pm UTC](https://boards.straightdope.com/t/can-neutrinos-travel-faster-than-light/597266 "2011-09-22T22:59:06Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![NineToTheSky](https://avatars.discourse-cdn.com/v4/letter/n/b5a626/32.png) [@NineToTheSky](https://boards.straightdope.com/u/NineToTheSky)\ **Post date:** [September 23, 2011, 10:52am UTC](https://boards.straightdope.com/t/can-neutrinos-travel-faster-than-light/597266/21 "2011-09-23T10:52:15Z")
Subir Sarkar, head of particle theory at Oxford University, explained eloquently to the Guardian the significance of OPERA’s research. "If this is proved to be true it would be a massive, massive event. It is something nobody was expecting. “The constancy of the speed of light… underpins causality, which is the fact that cause comes before effect. Cause cannot come after effect and that is absolutely fundamental to our construction of the physical universe. If we do not have causality, we are buggered.” ---
**Author:** ![IAmError403](https://avatars.discourse-cdn.com/v4/letter/i/dec6dc/32.png) [@IAmError403](https://boards.straightdope.com/u/IAmError403)\ **Post date:** [September 23, 2011, 11:00am UTC](https://boards.straightdope.com/t/can-neutrinos-travel-faster-than-light/597266/22 "2011-09-23T11:00:39Z")
> [@NineToTheSky](#): > > Subir Sarkar, head of particle theory at Oxford University, explained eloquently to the Guardian the significance of OPERA’s research. "If this is proved to be true it would be a massive, massive event. It is something nobody was expecting. > > “The constancy of the speed of light… underpins causality, which is the fact that cause comes before effect. Cause cannot come after effect and that is absolutely fundamental to our construction of the physical universe. If we do not have causality, we are buggered.” I just don’t see why we can’t say that the speed of light wasn’t the actual limit. perhaps the speed of neutrinos are the true cosmic speed limit. Obviously things must travel faster than the speed of light given that ‘stuff’ does escape from Black Holes. Don’t those jets of plasma that escape from the center of a Black Hole have to travel faster than light? ---
**Author:** ![Asympotically\_fat](https://avatars.discourse-cdn.com/v4/letter/a/e47c2d/32.png) [@Asympotically\_fat](https://boards.straightdope.com/u/Asympotically_fat)\ **Post date:** [September 23, 2011, 11:09am UTC](https://boards.straightdope.com/t/can-neutrinos-travel-faster-than-light/597266/23 "2011-09-23T11:09:49Z")
> [@IAmError403](#): > > I just don’t see why we can’t say that the speed of light wasn’t the actual limit. perhaps the speed of neutrinos are the true cosmic speed limit. Obviously things must travel faster than the speed of light given that ‘stuff’ does escape from Black Holes. Don’t those jets of plasma that escape from the center of a Black Hole have to travel faster than light? It’s possible, however that would mean a massive photon, changes to electromagnetic theory, QED, etc. As **Chtonos** points out though the magnitude of changes needed may’ve already been ruled out by experiments measuring the upper bound of the photon’s mass. At this point in time I would say “wait and see”. Whilst everything in science is falsifiable, when you have an observation like this that seemingly goes against the grain of much of established physics, the best counsel is to approach the result with caution. You don’t want to throw out a lot of good physics over a systematic error say. ---
**Author:** ![Asympotically\_fat](https://avatars.discourse-cdn.com/v4/letter/a/e47c2d/32.png) [@Asympotically\_fat](https://boards.straightdope.com/u/Asympotically_fat)\ **Post date:** [September 23, 2011, 11:12am UTC](https://boards.straightdope.com/t/can-neutrinos-travel-faster-than-light/597266/24 "2011-09-23T11:12:06Z")
And on black holes: No the ‘stuff’ that ‘comes out’ of a balck hole does nto travel faster than the speed of light. The jets you talk of actually come from the accretion disk outside ofg the black hole’s event horizon. ---
**Author:** ![JohnT](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johnt/32/15048_2.png) [@JohnT](https://boards.straightdope.com/u/JohnT)\ **Post date:** [September 23, 2011, 11:12am UTC](https://boards.straightdope.com/t/can-neutrinos-travel-faster-than-light/597266/25 "2011-09-23T11:12:25Z")
From my limited understanding, the plasma jets emanating from a black hole are “merely” escaping the gravity well and not the singularity itself. So, no, the jets are not traveling faster than light. **These are my own pants** posted at the same time I did, but his post arrived first. More proof! 😉 ---
**Author:** ![Bakhesh](https://avatars.discourse-cdn.com/v4/letter/b/3da27b/32.png) [@Bakhesh](https://boards.straightdope.com/u/Bakhesh)\ **Post date:** [September 23, 2011, 11:15am UTC](https://boards.straightdope.com/t/can-neutrinos-travel-faster-than-light/597266/26 "2011-09-23T11:15:22Z")
> [@Chronos](#): > > The only extraterrestrial neutrino sources which have ever been detected are the Sun and Supernova 1987a. The neutrinos from 1987a arrived at darned near the same time as the light, though this is complicated by the fact that they weren’t produced at quite exactly the same time (a supernova is a process that takes tens of seconds for the really interesting parts). If you account for that, the best fit to the data seems to be neutrinos moving just slightly slower than c, consistent with them having a mass of a few eV. My understanding of particle physics is limited, but I would say this proves that neutrinos **can** travel at the same speed as light, not that they can’t travel faster. ---
**Author:** ![willthekittensurvive](https://avatars.discourse-cdn.com/v4/letter/w/91b2a8/32.png) [@willthekittensurvive](https://boards.straightdope.com/u/willthekittensurvive)\ **Post date:** [September 23, 2011, 11:16am UTC](https://boards.straightdope.com/t/can-neutrinos-travel-faster-than-light/597266/27 "2011-09-23T11:16:03Z")
would this explain why the GPS route planner always thinks I should make a U-turn on a oneway drive? ---
**Author:** ![Grumman](https://avatars.discourse-cdn.com/v4/letter/g/43a26b/32.png) [@Grumman](https://boards.straightdope.com/u/Grumman)\ **Post date:** [September 23, 2011, 11:19am UTC](https://boards.straightdope.com/t/can-neutrinos-travel-faster-than-light/597266/28 "2011-09-23T11:19:37Z")
> [@NineToTheSky](#): > > Subir Sarkar, head of particle theory at Oxford University, explained eloquently to the Guardian the significance of OPERA’s research. "If this is proved to be true it would be a massive, massive event. It is something nobody was expecting. > > “The constancy of the speed of light… underpins causality, which is the fact that cause comes before effect. Cause cannot come after effect and that is absolutely fundamental to our construction of the physical universe. If we do not have causality, we are buggered.” The phenomenon remains the same, regardless of whether humans understand it or not. It’s like saying “Our understanding of gravity is wrong. Without gravity, we’re all going to die!” ---
**Author:** ![Asympotically\_fat](https://avatars.discourse-cdn.com/v4/letter/a/e47c2d/32.png) [@Asympotically\_fat](https://boards.straightdope.com/u/Asympotically_fat)\ **Post date:** [September 23, 2011, 11:23am UTC](https://boards.straightdope.com/t/can-neutrinos-travel-faster-than-light/597266/29 "2011-09-23T11:23:12Z")
> [@Grumman](#): > > The phenomenon remains the same, regardless of whether humans understand it or not. It’s like saying “Our understanding of gravity is wrong. Without gravity, we’re all going to die!” No, what he is saying is that if correct this may pull the rug from underneath our current understanding of the universe. ---
**Author:** ![naita](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/naita/32/5862_2.png) [@naita](https://boards.straightdope.com/u/naita)\ **Post date:** [September 23, 2011, 11:27am UTC](https://boards.straightdope.com/t/can-neutrinos-travel-faster-than-light/597266/30 "2011-09-23T11:27:40Z")
> [@Chronos](#): > > The only extraterrestrial neutrino sources which have ever been detected are the Sun and Supernova 1987a. The neutrinos from 1987a arrived at darned near the same time as the light, though this is complicated by the fact that they weren’t produced at quite exactly the same time (a supernova is a process that takes tens of seconds for the really interesting parts). If you account for that, the best fit to the data seems to be neutrinos moving just slightly slower than c, consistent with them having a mass of a few eV. If I’ve done the maths right and have the right information the neutrino discrepancy was 60 ns over the distance given, a 0.000025 in 1 difference from the speed of light. Applying that to 1987a’s distance of 168000 light years we get a difference of 4.2 years. So either the supralumial neutrinos result is wrong, or supernovas don’t send out neutrinos but 4.2 year old supernova remnants do, or neutrinos only go faster through planetary crusts. ---
**Author:** ![Grumman](https://avatars.discourse-cdn.com/v4/letter/g/43a26b/32.png) [@Grumman](https://boards.straightdope.com/u/Grumman)\ **Post date:** [September 23, 2011, 11:33am UTC](https://boards.straightdope.com/t/can-neutrinos-travel-faster-than-light/597266/31 "2011-09-23T11:33:36Z")
> [@These are my own pants](#): > > No, what he is saying is that if correct this may pull the rug from underneath our current understanding of the universe. Still, that’s a good thing. If this pans out, it means we are _no longer_ buggered, because we’re now on the right track instead of clinging to a “law” that is false. ---
**Author:** ![Ximenean](https://avatars.discourse-cdn.com/v4/letter/x/aca169/32.png) [@Ximenean](https://boards.straightdope.com/u/Ximenean)\ **Post date:** [September 23, 2011, 11:40am UTC](https://boards.straightdope.com/t/can-neutrinos-travel-faster-than-light/597266/32 "2011-09-23T11:40:02Z")
Maybe the Earth happened to heading against the ether when they took the measurement? ---
**Author:** ![Alessan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/alessan/32/465_2.png) [@Alessan](https://boards.straightdope.com/u/Alessan)\ **Post date:** [September 23, 2011, 12:00pm UTC](https://boards.straightdope.com/t/can-neutrinos-travel-faster-than-light/597266/33 "2011-09-23T12:00:44Z")
> [@These are my own pants](#): > > No, what he is saying is that if correct this may pull the rug from underneath our current understanding of the universe. Which is \*always \*a good thing. Scientists like to be right, but it’s better for science when they’re wrong. ---
**Author:** ![colonial](https://avatars.discourse-cdn.com/v4/letter/c/34f0e0/32.png) [@colonial](https://boards.straightdope.com/u/colonial)\ **Post date:** [September 23, 2011, 12:06pm UTC](https://boards.straightdope.com/t/can-neutrinos-travel-faster-than-light/597266/34 "2011-09-23T12:06:01Z")
Here is the first media skeptic I have been able to find who invokes science: [Neutrino Blog](http://neutrinoscience.blogspot.com/2011/09/arriving-fashionable-late-for-party.html) Apparently there is a _big_ discrepancy with inferred speed of neutrinos emitted by Supernova 1987a, as in approx. one year: (from link) > [@](#): > > [FONT=Trebuchet MS]The paper (Superluminal neutrino study) quotes a fractional difference between neutrino speed and that of light of > > [/FONT]_(v-c)/c = δt/(TOFc - δt) = (2.48 ± 0.28 (stat.) ± 0.30 (sys.)) x 10-5_ > > Supernova 1987a was a distance of 166,912 ± 10.1 light years [2] from Earth when it died. Taking these values we can calculate that the time difference between the neutrinos arriving at the neutrino observatories and the telescopes seeing SN1987a would be > > _2.48 x 10-5 x 166912 = 4.14 years_ > > [FONT=Trebuchet MS]Combining the errors on the SN1987a distance, systematic and statistical errors of the Opera result we get a value of > > [/FONT] > _4.14 ± 0.97 years_ > > [FONT=Trebuchet MS]There is no evidence to support that this is the case - as I mentioned the neutrinos were seen just 3 hours before SN1987a was seen by optical telescopes. In this case the neutrinos did not arrive early for the party it was the light that was fashionably late! > > _Addendum_ There are of course loopholes to this argument, for instance there may be higher order quantum gravity effects which violate Lorentz invariance. Either way the result will be hotly debated - is it an unknown systematic error or some exciting hint at new physics? [/FONT] ---
**Author:** ![Asympotically\_fat](https://avatars.discourse-cdn.com/v4/letter/a/e47c2d/32.png) [@Asympotically\_fat](https://boards.straightdope.com/u/Asympotically_fat)\ **Post date:** [September 23, 2011, 12:08pm UTC](https://boards.straightdope.com/t/can-neutrinos-travel-faster-than-light/597266/35 "2011-09-23T12:08:22Z")
> [@Alessan](#): > > Which is \*always \*a good thing. Scientists like to be right, but it’s better for science when they’re wrong. That’s totally illogical, so it would be better if scientists were always wrong? ---
**Author:** ![Asympotically\_fat](https://avatars.discourse-cdn.com/v4/letter/a/e47c2d/32.png) [@Asympotically\_fat](https://boards.straightdope.com/u/Asympotically_fat)\ **Post date:** [September 23, 2011, 12:10pm UTC](https://boards.straightdope.com/t/can-neutrinos-travel-faster-than-light/597266/36 "2011-09-23T12:10:43Z")
> [@Grumman](#): > > Still, that’s a good thing. If this pans out, it means we are _no longer_ buggered, because we’re now on the right track instead of clinging to a “law” that is false. I do not understand were you are coming from, like I say let’s wait and see before making bold statements. ---
**Author:** ![Grey](https://avatars.discourse-cdn.com/v4/letter/g/b782af/32.png) [@Grey](https://boards.straightdope.com/u/Grey)\ **Post date:** [September 23, 2011, 12:31pm UTC](https://boards.straightdope.com/t/can-neutrinos-travel-faster-than-light/597266/37 "2011-09-23T12:31:11Z")
> [@naita](#): > > If I’ve done the maths right and have the right information the neutrino discrepancy was 60 ns over the distance given, a 0.000025 in 1 difference from the speed of light. Applying that to 1987a’s distance of 168000 light years we get a difference of 4.2 years. So either the supralumial neutrinos result is wrong, or supernovas don’t send out neutrinos but 4.2 year old supernova remnants do, or neutrinos only go faster through planetary crusts. Well what we really need is for an other SN1987a to happen while 3 or more neutrino experiments are active. Then we can use the distance between detectors to determine actual vs. expected arrival times. ---
**Author:** ![ZenBeam](https://avatars.discourse-cdn.com/v4/letter/z/3ab097/32.png) [@ZenBeam](https://boards.straightdope.com/u/ZenBeam)\ **Post date:** [September 23, 2011, 12:35pm UTC](https://boards.straightdope.com/t/can-neutrinos-travel-faster-than-light/597266/38 "2011-09-23T12:35:29Z")
Here’s a [New Scientist article](http://www.newscientist.com/article/dn20957-dimensionhop-may-allow-neutrinos-to-cheat-light-speed.html)on the subject. ---
**Author:** ![Darth\_Ayebaw](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darth_ayebaw/32/9870_2.png) [@Darth\_Ayebaw](https://boards.straightdope.com/u/Darth_Ayebaw)\ **Post date:** [September 23, 2011, 12:46pm UTC](https://boards.straightdope.com/t/can-neutrinos-travel-faster-than-light/597266/39 "2011-09-23T12:46:05Z")
With over 15,000 attempts, and given that the discrepancy was 60ns when the margin of error is 10ns, this could be significant. Either that or there’s a fundamental flaw in the experiment, which seems more likely, but who knows. Like others have asked, what practical applications are there for this, assuming it’s true? I mean it’s ‘only’ 7.4km/s faster than c, so it’s not like we could send a message to Alpha Centauri and have it arrive in a few months. How could this be used to interrupt causality? Or would it just mean a slightly faster version of this [Stock trades to exploit speed of light, says researcher - BBC News](http://www.bbc.co.uk/news/science-environment-12827752)? ---
**Author:** ![ZenBeam](https://avatars.discourse-cdn.com/v4/letter/z/3ab097/32.png) [@ZenBeam](https://boards.straightdope.com/u/ZenBeam)\ **Post date:** [September 23, 2011, 12:47pm UTC](https://boards.straightdope.com/t/can-neutrinos-travel-faster-than-light/597266/40 "2011-09-23T12:47:19Z")
Regarding the neutrinos from Supernova 1987a, they wouldn’t know if _some_ neutrinos arrived 4 +/- 1 years early. They only know that some arrived when expected. There could be neutrinos obeying the speed limit, and others traveling faster. I’m not sure how you’d theoretically get two discrete speeds, but that would (IMHO) seem to be an easier problem than FTL neutrinos in the first place. [Previous page](https://boards.straightdope.com/t/can-neutrinos-travel-faster-than-light/597266.md?page=1) [Next page](https://boards.straightdope.com/t/can-neutrinos-travel-faster-than-light/597266.md?page=3)