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Scientists at CERN have found apparent evidence that neutrinos can travel faster than light.
Suppose that tomorrow historians at Harvard find apparent evidence that the South won the American Civil War — not in some metaphorical “they accomplished their goals” sense, but in the literal sense that it was actually Grant who handed his sword to Lee at Appomatox and not the other way around.
Question: Of which conclusion would you be more skeptical?
Of course your answer might depend on exactly what this new “apparent evidence” consists of. So let me reword: As of this moment, which do you think is more likely — that neutrinos can travel faster than light, or that the South won the Civil War?
That neutrinos can travel faster than light. Because science has been wrong about such details before (especially regarding what happens at ultra-fast speeds, or on the scale of ultra-large or ultra-small distances). But I don’t know of any historical event where millions of people were recorded witnessing the direct effects, that has since been discovered not to have happened.
(This would not include historical events where millions of people bore witness to the *secondary* effects. Billions of lives have been affected by Jesus’ “resurrection”, but only because of the actions of other people who *believed* that it happened, regardless of whether it actually happened, so that doesn’t prove anything. On the other hand, millions of people did witness the South’s troops pulling out, the North’s policies being enacted, etc. which were all part of the South’s actual surrender.)
@Bennett – I don’t think millions of people witnessed the handing over of the sword. Maybe the South won, but somehow word got around that the North had, and everyone acted as if it had because they *believed* it had. Would that explain what we observe today?
My answer – I think it’s more likely that the South won. However, this judgement tells you more about me than about evidence or history or anything else. Specifically, I’ve thought a lot more about relativity than about American history. If I suddenly learned the south had won, I’d say “really? Funny, I’ve had that wrong all along”. However, concepts of relativity are much more intwined into the way I see the world. If you specified some other historical event (say, to borrow Bennett’s example, the resurrection of Jesus), my answer might be different – yet it would still inform you more about me than about the history or the physics.
I agree with Bennett. Plus, if the South won the Civil War, why is the United States still one country?
A very good question that I find difficult to answer.
But, being a physicist, I naturally want to know what independent experiments have reproduced the North’s victory over the South.
Plus, if the South won the Civil War, why is the United States still one country?
That’s part of the reason he framed the question this way. Our existence today requires that the North won the Civil War, therefore it’s unthinkable they actually lost. Likewise, our atomic existence today requires that neutrinos do not surpass the speed of light, therefore it’s unthinkable they somehow went faster.
It’s just that most people comprehend the former and not the latter, and thus don’t see how absurd the latter is.
I think unless there was some mysterious multi-PeV event that may have caused things to get wacky, yet went unnoticed otherwise, its not likely at all. Everything else in our model has fit so well.
That said, we also can’t ignore the small chance that the South actually won and we are all brain-experiments long after, where the Victorious South is deciding which integration method of slaves is best.
James Thurbur wrote a wonderful story, “If Grant Had Been Drinking at Appomattox.” It’s a wacky alternative history. Grant awakens hung over, can’t remember anything except wrestling some general, and, when Lee shows up and an aide prompts Grant by whispering “the surrender, General,” Grant draws his sword, hands it to an astonished Lee, and says that he could have beaten him if he’d been feeling better. Almost surely didn’t happen, but it could have. If I had to choose, I’d take that one before the faster-than-light neutrinos. Hey, if neutrinos are faster than light, couldn’t somebody from the future come back with tanks and planes, side with the South, and win the war for them in 1865?
I mean depends what new evidence you’re talking about here obviously. If the new evidence is that we’re all in the matrix and because the south won and put everyone in said matrix then well then that might effect our models of physics too but you made the point about what new evience yourself.
The CERN thing (if true) would mean that our model(relativity) breaks down under some extreme conditions. All models are wrong some are useful, so it doesn’t strike me as too unbelievable that something might go faster than light. Of course I’m not a physist so I might be missing something.
Winning or losing a war is a social construct: the North won because everyone agrees the North won. There is no fundamental truth that could be rediscovered. We could decide to say the South won instead, but that’s different from *discovering* the South “actually” won.
Neutrinos do or do not travel faster than light. So unless our host is suggesting that “travelling faster than light” is a linguistic trick one way or the other, I’d have to say “neutrinos faster than light” is the more likely choice.
@Andy_Wood: But, being a physicist, I naturally want to know what independent experiments have reproduced the North’s victory over the South.
– Conditions imposed on South for reintegration into Union (e.g. Reconstruction-era amendments), and South’s obeying them;
– South’s inability to defy Supreme Court rulings (e.g. integration, Voting Rights acts) after 1865
– South participating alongside Union troops in subsequent wars, in contravention of the former’s pre-Civil War objectives.
You get the idea…
Another question:
Who should be more skeptical towards new claims about physics: 1) Us, when faced with the claim that neutrinos can travel faster than light, or 2) People living 100 years ago, when faced with the claim that Newtonian physics was wrong?
That the south won the civil war. The presumption that we know the laws of physics is an extrapolation and a hope. It’s been dashed before.
I do want to point out that Steve obligingly asked which are we more skeptical of, repeat, which do we believe more likely. Leads to a certain ambiguity. :>
If Grant surrendered to Lee, then it was incredibly generous of Lee to donate his home to the Union Army and allow them to bury their dead on his lawn, in what is now Arlington National Cemetery. In reality, Quartermaster General Montgomery Meigs confiscated Lee’s land for the cemetery.
I don’t know how to answer the question posed, but it seems most likely that the faster than light neutrino is really measurement error.
“We don’t allow faster than light neutrinos in here” said the bartender. A neutrino walks into a bar. – Mike Rundle on Twitter, via Boing Boing.
Both seem very unlikely; so unlikely that it’d be difficult to put a number on it.
I’ve read some things about history, so to me the civil war is more familiar territory than particle physics. I don’t know whether neutrino speed being slightly higher than light speed changes much. Would it mean a complete redefinition of reality, or simply a slightly higher “top speed” for the universe? I wouldn’t know until someone told me. But the South having won would make me change many beliefs immediately. I think that’s why it seems less likely to me.
It seems likely that Steve is asking this question to make the point of how unlikely it is that neutrinos travel faster than light. Less likely, even, than the civil war having been won by the South.
It seems *unlikely* that many lay persons would agree with this, which I suppose is the point. To some extent, it is Science’s own fault for inflating its confidence in past theories, if people distrust its current level of confidence. But I have a feeling we’re about to see more than a confidence report from a scientist.
One way to convince lay people that neutrinos most likely can’t travel faster than light is to give them a list of commonplace facts: things they know about the world with as much confidence as the fact that the South lost the war, which would not be true if neutrinos were too fast. (together with the underlying logic)
Alternatively, maybe the two events can actually be directly *connected*. Like, if neutrinos can travel faster than light, then it opens the door to time travel hijinks which can alter the outcome of the civil war.
In any case, I am curious to see what comes next.
@Silas:
I don’t this you get my point. Aren’t the points you made all measurements that were recorded as part of the original experiment?
I agree with Xan. I expect Steve will declare that the chances of faster than light particles are far less. Because it means that causes follow effects etc. Like the neutron in a bar. But the problem with this is, how often? That matters.
In celluar biology the “central dogma” is dna to rna to protein and never the other way round. But is we find some rare bizarre microbe in the depths of the ocean that has once reversed this, that would be surprising but not a refutation of all of cellular biology.
Xan
“Alternatively, maybe the two events can actually be directly *connected*. Like, if neutrinos can travel faster than light, then it opens the door to time travel hijinks which can alter the outcome of the civil war.”
Is the suggestion that Steve is going to argue that the belief in faster-than-light travel by neutrinos should entail a distrust of all of history? I’d be interested to see that argument. I believe that time travel would be extremely difficult even if neutrinos (which are likely massless) could travel faster than light.
I pretty much agree with Bennet Hassleton – both are extremely unlikely, but the South having won the war is less likely. I assume someone will come up with the reason why the measurement of the nutrino’s speed was wrong, rather than requiring re-writing the laws of physics. But hey, how exciting if it turns out to be true. Maybe, together with the non-existence of the Higgs Boson (should that prove to be the case), and the incompatability of gravity and quantum mechanics, it will all become obvious, once it is proved that light is not the fastest speed.
@Andy_Wood: No, the use of federal troops to enforce Brown v. Board was not part of the Civil War “experiment”.
In any case, from the perspective of the Supreme Court, they were “experimenting” in the sense that they (implicitly) expected different results to obtain if the South had won vs. had it not; and that they acted in such a way as to change the future from what it would otherwise have been.
If you deny that, then I don’t think you can count anything as an experiment, because it’s just “another measurement” from some arbitrarily-early “initial experiment”.
Travelling faster than light? Yawn. I’lll just pop back a couple of weeks to share my thoughts on this.
Look, there’s no reason to be obtuse here. We all subscribe to the scientific method, right? So simply re-run the experiment and see if we come up with the same results. I understand that people are already planning to re-run the neutrino experiment to project a beam from Illinois to Minnesota. Now we just need to re-run the Civil War and we’ll have a full complement of data to review. Having reviewed the past several presidential elections, I’ve sometimes wondered. So who knows? Maybe this time around Rhett will give a damn.
I often say there is more evidence of “evolution” than the Spanish American war.
This one is a very close call.
It might be worth considering that our theories of relativity and quantum mechanics are known to be incompatible with each other and thus incorrect at some level, whereas our understanding of the Civil War is not thought to be incompatible with any other known historical events.
@Silas: My comment was meant to be a joke – as in someone running the civil war again, just to check that it wasn’t a freak result the first time.
But if you can take a serious point from it, then fair enough.
I surmise Landsburg’s point is to emphasize the extraordinarily counter-intuitive conclusion arising from this new research, and to put it in analogous terms that the broader public might appreciate viscerally. The idea that we might have been wrong about something as fundamental as the outcome of the battle at Appomattox seems inconceivable.
EPISTEMIOLOGY: But, to veer off Landsburg’s rhetorical point and onto his literal one, how important is the scientific method to what we “know”? I suspect that I have garnered NONE of my knowledge from the scientific method (and, yeah, yeah, that explains a lot….) But seriously, I can’t recall ever having designed an experiment, conducted it, and published the results to elicit the review of my peers.
So where did I get all this stuff in my head? Some of stuff in my head comes from being told. I learn science in this fashion. I learned my name in this fashion. I learned the location of my car keys this morning because my wife put them in an unusual spot, and I had to ask her where they were. And I learned the outcome of the Battle of Appomattox in this fashion. Now, I’ve had the pleasure of visiting a Civil War battlefield and seeking the collection of antiquities there. But I’d have been hard pressed to draw many conclusions about the outcome based simply on the archeological evidence dating from the time of the battle; I relied heavily on others to tell me what happened.
Other stuff in my head comes from personal experience – which is, if not exactly scientific, at least empirical. Much of this learning comes from recurring experience. In this manner I’ve learned to avoid hot stoves. I’ve learned standard English. I’ve learned the local dialect. I’ve learned where my wife usually puts the car keys. Etc.
And some of the stuff in my head has come from revelation – that is, from personal experience which I cannot replicate. The people who witnessed the Battle of Appomattox learned in this fashion. They could then go around telling people about the outcome, and could point to certain evidence in support of their accounts, but could never really offer the kind of proof we expect of science. Yet even science-minded folk credit this kind of “learning” all the time.
In short, I learn science from people telling me about stuff that I could, in theory, replicate to test. I learn about history from people telling me stuff that neither I nor anyone else has any expectation of being able to replicate. This suggests that science is more reliable than history – not matter what science and no matter what history.
INTUITION: History is the story we create to explain events. In this sense, it’s most relevant quality is not accuracy but plausibility. On the other end of the spectrum, a scientist can forthrightly present seeming implausible results, assuming he can reproduce them for all to see. This leads to the observation that OF COURSE truth is stranger than fiction; fiction has to make sense.
To some extent, this explains the differences among the social sciences, and among social scientists: The less confident you can be of your data, the more humble and conciliatory is your affect. The more confident, the less humble and conciliatory. Economists have a lot of “hard data” and apparently deterministic models to point to – and, famously, you can’t invite too many of them to a dinner party before you ruin the conversation.
I sense Landsburg is saying that his familiarity with the theory of relativity gives him an intuitive understanding – he has internalized the schema — and this understanding undermines his willingness to keep an open mind about these new findings. We who are not encumbered with Landburg’s understanding are better able to receive these new experimental results with equanimity – just as we who are ignorant of history are more open to considering alternative endings to the Battle of Appomattox.
Hey, we ignorant doesn’t have a lot going for us. Don’t begrudge us the opportunity to celebrate open-mindedness.
It’s something of a false choice, of course. I believe that the chance of either is, effectively, zero. That is, I have no reason to doubt the historical conclusion of the US Civil War and I don’t see any likely emergence of new information that would cause me to revise my view of history. (*)
Physics, as a largely theoretical enterprise, is continually involved in a process whereby past theories and explications are disproved in the light of new findings. We didn’t all live in a Newtonian Universe and then suddenly the world changed – the world remained the same, and our ability to explain it improved. I will, therefore, admit that there is some minuscule possibility that under some conditions some neutrinos might be observed to exceed the speed of light and that explaining that observation just barely maybe might require some refinement of the theory. I rate this as a VERY low probability, but it’s a higher probability than a companion hypothesis that says, for example, that ALL neutrinos move faster than the speed of light under all circumstances.
(*) Note that we do revise our understanding of history, falsifying often long-held beliefs. For example, recent scholarship seems to show that the sentence “The US dropped the atomic bombs on Japan to hasten the end of the war and avoid a costly invasion” is likely false. Instead the sentence “The US dropped the atomic bombs on Japan to force a surrender to the US on favorable terms versus a surrender to Russia on terms much worse to us and probably to the Japanese as well” is more probably true.
It is much more likely that neutrinos can travel faster than light. Neutrinos are barely detectable and this is a very slight effect. Only 20 years ago, everyone was convinced that neutrinos go at exactly the speed of light. Then there was some surprising evidence that they go slower. There have already been a lot of papers on the possibility that neutrinos do not obey relativity.
Prof Landsburg – what are your thoughts?
If neutrinos move faster than c, I think that means that some very smart people made mistakes or generalized physical laws in ways that don’t apply.
If the South really won the Civil War, that would probably involve a whole lot of lying by a whole lot of people (troops, eye-witnesses, etc.) not to mention a whole lot of convincing other people.
From what I’ve seen, mistakes or math errors in theoretical physics seem far more likely than a huge government cover-up.
Out of curiosity, have people ever done experiments where neutrinos move slower than c?
I don’t think that you can say “our existence depends on neutrinos moving faster than light” in the same way that you can say “our existence depends on the South losing the war”.
The statements are comparable if you assume that existing knowledge is all correct. But if existing knowledge is not all correct, they’re not. FTL neutrinos are inconsistent with our existence because we can conclude that from other parts of science; we can resolve this if those other parts of science contain mistakes of the kind that humans often make. The South winning the war is inconsistent with our existence in a way that could only be resolved if many very gross and very unusual mistakes were made.
How about this: if anything can travel faster than light, the whole idea of “history” and causality breaks down. So I guess the answer is “both things are equally likely”…
Let me try again: if nothing can travel faster than light, the North won. If anything can travel faster than light, it can go (could have gone?) either way(and some more – maybe there was no war at all, or the America was never discovered?). So I guess it is more likely that neutrinos can go faster than light… I see a problem though: maybe neutrinos can’t, but something else can..? Or maybe the bottle of wine I have just drunk speaks on my behalf? :)
Quick question,
Maybe we have just always measured the speed of light slightly incorrectly (slower than it actually is)? How robust could our estimate be anyway?
Not sure how significance etc. works here…
Nick: The speed of light has to equal the ratio between the strengths of the electric and magnetic fields, which is surely known to a far greater degree of precision than your explanation would allow.
Copying your logic from previous writings on trade and evolution:
There is sound theory and empirical evidence that suggests that neutrinos cannot move faster than the speed of light. There is empirical evidence but no theory that suggests the South lost the Civil War.
Therefore, I think that you find it more plausible that the South won the Civil War.
My question to you is: how much empirical counter-evidence does it take to throw out a sound theory?
Not being a physicist, I have nothing to contribute to the discussion about neutrinos moving faster than the speed of light. But I can ask how many times would this study need to be replicated before you would update the theory of relativity.
I very much doubt that the ratios of the magnetic and electric constants have been measured to anything like the precision of the speed of light – 299,792,458 km/sec exactly, since the meter and the second are defined in terms of it. http://en.wikipedia.org/wiki/Speed_of_light
ted: Yes, I believe I spoke too quickly.
@JLA : My question to you is: how much empirical counter-evidence does it take to throw out a sound theory?
This depends what you mean by “sound”. If you mean “logically consistent”, hey, there are logically consistent theories where neutrinos travel faster than light too. But how do you pick which sound theory to believe? If you mean “supported by empirical evidence”, then your question becomes simpler :
There is
sound theory andempirical evidence that suggests that neutrinos cannot move faster than the speed of light. There is empirical evidence but no theory that suggests the South lost the Civil War. My question to you is: how much empirical counter-evidence does it take to throw out empirical evidence?So you actually only have to worry about evidence. The soundness of a theory is just a tool for evaluating evidence.
Unless you prefer some other method of determining what is true.
NB – as another commenter intimated, a special-relativistic universe could accommodate faster-than-light neutrinos. However, it could not accommodate simultaneously both faster-than-light and slower-than-light neutrinos.
Would be interested to hear from those with expertise.
I would have thought that the question isn’t so much how precisely we know the speed of light per se, but rather how precisely we have measured the invariance of the speed of light to inertial frame.
Might it be that light travels very close to the relativistic limit (which now would be established by the measured speed of neutrinos), so that our measurements to date that show it to be invariant are within the error of measurement. Or perhaps 60 ns is too much for this to be consistent with measurements to date. Anyone know?
Andrew Metz: If light travels at anything other than the exact relativistic limit, then Maxwell’s equations are not Lorentz invariant, which strikes me as more than extraordinarily unlikely. To put this another way: If light travels at anything other than the relativistic limit, then there’s very little reason to believe in relativity in the first place.
While we’re at it, which would shock you more:
that neutrinos can travel faster than light?
that the South won the civil war?
or that Peano’s axioms are inconsistent? (see <a href="http://golem.ph.utexas.edu/category/2011/09/the_inconsistency_of_arithmeti.html"here)
@Steve, to clarify:
Maxwell’s equations can easily be modified to account for a non-zero photon mass in such a way that they remain invariant under the Lorentz group, although they would no longer possess gauge symmetry under the group U(1).
According to Wikipedia (http://en.wikipedia.org/wiki/Photon#Experimental_checks_on_photon_mass), an upper limit of ~10^-14 eV/c^2 (~10^-50 kg) on the photon mass has been found, with even lower, model-dependent limits from some observations. Long wave radio consists of photons of energy ~10^-10 eV, which would mean that they travel slower than the relativistic limit by no more than about 1 part in 10^8. I think the discrepancy in the neutrino experiment is about 1 part in 10^5.
Andy Wood: Ah. Thanks for this.
It is possible that photons are Lorentz invariant, but not neutrinos. See Lorentz-violating neutrino oscillations.
Well, was Isaac Newton proved wrong? I would say he was proved to be incomplete and Einstein gave us a more nuanced view of the world — a truer view. This happens regularly in science. The better theories explain better and explain more.
You are asking me how sure I am that it all ends at relativity? If we have repeatable observations that can’t be explained by relativity, then I’m not as sure as I thought.
On the other hand, nothing has happened to make me doubt the Union won the Civil War.
harking back to the quantum mechanics post, and the many worlds interpretation, the South did win the war, just not in the universe we happen to occupy.
I definitely think it’s more likely that neutrinos can travel faster than light.
I have no direct knowledge of either fact. All I know about relativity is what I’ve read in dumbed-down accounts of people who have far greater knowledge than I (by “dumbed-down” I’m referring to college-level texts on the subject; still a far cry from the knowledge of a practicing particle physicist). All I know about American history I’ve also read in (relatively) dumbed-down accounts from historians, who themselves read about the Civil War from other accounts.
In either case, there could be a massive conspiracy to propagate a falsehood. I’d be equally susceptible to either such conspiracy, assuming it was sufficiently well-orchestrated. In either case, there could be no conspiracy but the evidence could be wrong; that is, we could “discover” that the South won the war or that neutrinos travel faster than light. As mentioned above, “winning” the war is a social construct – whether Lee surrendered to Grant or the other way around, I can observe that Americans for the past 145 years have behaved as if the North won the war. On the other hand, there’s a whole lot I don’t know about physics, and the field is progressing at an astonishing rate. Current physics could be wrong. In fact, current physics is almost certainly wrong in some respects. This may or may not be one of them. As a layman in both fields, I have a lot more first-person evidence that the North won the war than that neutrinos cannot travel faster than light.
Economiser:
In fact, current physics is almost certainly wrong in some respects.
Ditto current history.
@ Steve Landsburg:
True, however as a layman in both fields, I think I have more direct evidence that the North “won” the war than that neutrinos can’t travel faster than the speed of light. For example, I’m able to go about my everyday life in a united America. If the South won, I’d expect at the least to live in a smaller country.
Perhaps a better analogy would be, say, that the Roman Empire never existed. I could more easily imagine the current world existing as-is if Rome were simply some big mistake than if the South “won” the war.
At first, I thought this was going to be an analogy pointing out the silliness of talking about there being a significant possibility of physics being upended. If a letter from 1866 were discovered in which the author referred to the South as the winners of the Civil War, it’s doubtful that news coverage would be taking the tack of “do we need to revise history?” But while both are extremely unlikely, the South winning is more unlikely. If neutrinos don’t travel faster than light, there are all sorts of explanations for the reports. It could be experimental error, or a massive conspiracy, or something else. If the South won, then there pretty much has to be a massive conspiracy (and one involving way more people than the hypothetical physics conspiracy). A massive conspiracy is less likely than a massive conspiracy OR experimental error, so South winning is less likely. To believe history, you have to believe what other people tell you. To believe science, you have to believe what other people tell you (unless you’re going to replicate every single past experiment) AND the theoretical framework.
Xan said “One way to convince lay people that neutrinos most likely can’t travel faster than light is to give them a list of commonplace facts: things they know about the world with as much confidence as the fact that the South lost the war, which would not be true if neutrinos were too fast. (together with the underlying logic)”
Except that there is no such list. You can give them the results of various experiments, along with the theoretical framework, but those would not be “commonplace facts”, nor “ things they know about the world with as much confidence as the fact that the South lost the war”.
Ken B said “In celluar biology the “central dogma” is dna to rna to protein and never the other way round.”
Isn’t that what retroviruses do?
Maznak said “How about this: if anything can travel faster than light, the whole idea of “history” and causality breaks down. So I guess the answer is “both things are equally likely”…”
FTL doesn’t necessarily mean time travel, and even if time travel is possible, that doesn’t mean the idea of history breaks down. It only breaks down if time travel is happening, not if it’s possible.
http://www.thebigquestions.com/2011/09/05/moral-matters/
you just closed the comments without publishing mine which shows very weak communicative skills !!!!
irgendeiner: Comments are open and yours is here!
Edit: Oh! I see! You were tryinig to comment on the earlier post, which *is* closed.
Comments close automatically after (I think) three weeks. The idea is that after that long, nobody’s reading the thread anymore anyway, so your comment would go unnoticed even if it were posted.
But hold your thought! I blog on a limited number of topics, and this one is sure to come up again!
There has been previous work about the possibility of neutrinos having a very small imaginary mass. This would be consistent with that.
Is there actually any reason to believe that surpassing the speed of light would result in time travel or is that just popular fiction? I came up with a different outcome using this thought experiment:
3 astronauts on separate ships travel into outer space and return in ten years. The first astronaut travels at close to light speed and only ages 5 years during the voyage (time dilation, you know). The second astronaut travels at exactly light speed and doesn’t age at all on the voyage. The third astronaut travels faster than light. Following the pattern, he should age negatively on his journey. Thus, a faster-than-light neutrino won’t arrive at it’s destination 5 years before it set out, but it may arrive 5 years younger than when it set out.
Even though this scenario is theoretically flawed I find very aesthetically pleasing.