0955: "Neutrinos"

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Re: 0955: "Neutrinos"

Postby bzakharin » Fri Sep 23, 2011 7:52 pm UTC

gingermrkettle wrote:On a non-technical level, some of the coverage has noted that relativistic physics is necessary for GPS receivers to attain the accuracy they do. There seems to be a slightly odd logical sequence of events if the measurements that appear to disprove a theory are reliant on that theory being correct.


Absolutely not. Nothing wrong with a proof by contradiction. If the measurement was off because the theory upon which GPS relies didn't hold, you might not get the numbers right, but you still disprove the theory. It would be more futile to prove a theory relying on it being true in the first place.
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Re: 0955: "Neutrinos"

Postby Samik » Fri Sep 23, 2011 8:02 pm UTC

I wouldn't say "offended".

My comment -
Samik wrote:Oh, I was just finding it funny that we both seem to agree on the point that Kurzweil-style singularity predictions focusing largely on processing power are flawed, but that you seem to move from that understanding towards a near-term singularity, whereas I use the same point to argue against one (see my earlier post, if you hadn't already).

- was merely meant to point out that it amused me. It was in no way shape or form an assault on your beliefs - really, is there anything in that paragraph that can be construed as a meaningful critique of your position? The first assault came from your direction towards mine, in the next post.
dash wrote:You have made no argument as to why it should be even later than 2045. Your "argument" is just the assertion, "This is a very hard problem! It's going to take a long time!"

Well, at this point you've critiqued me, so I considered the door open to critique in return.


As to your point about whether or not what I wrote in my longer post contains "argument" or "opinion", this is certainly a valid concern. However, I think you're taking a single word in a single paragraph and focusing on it so heavily to try to represent what I've written as something that it is not.

Would it have been less problematic for you if I'd instead written -
Samik wrote:Oh, I was just finding it funny that we both seem to agree on the point that Kurzweil-style singularity predictions focusing largely on processing power are flawed, but that you seem to move from that understanding towards a near-term singularity, whereas I move from that understanding away from one


After all, if you'd really read the post I linked to, you surely wouldn't have missed:
Samik wrote:"I just personally believe..."

Samik wrote:"But that's just, in my opinion..."



But even that is almost missing the point. I never claimed my "argument" was rock-solid irrefutable, logically sound/valid reason to buy what I was selling. I was doing what people do when they talk about stuff - bringing up beliefs I had about why given-characteristic-A of said stuff was likely/unlikely to be true. For you to come back and basically say 'you're not saying anything worth listening to / there's no point in talking about this / this is all just a waste of time' comes across as ever-so-slightly antagonistic.
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Re: 0955: "Neutrinos"

Postby RichardPrice » Fri Sep 23, 2011 8:08 pm UTC

blowfishhootie wrote:
Sir_Read-a-Lot wrote:
I think this is a pretty great explanation, especially the last line. The person to whom you are responding seems to have a fundamental misunderstanding as to the nature and purpose of scientific theories.


Actually, I am the one being misunderstood - I know that scientific theories stand on experimental evidence until proven wrong by further experimental evidence, and I know that theories are continually tested.

However, my point is that quite often to the layman, Einsteins theories are put forward as inviolable, completely set in concrete as the truth - and thats the stance that I disagree with.

We base todays evidence on todays ability to do science - what if tomorrows ability to do the same science produces better results, results that don't entirely support the theories supported today, what if tomorrows ability brings better accuracy, or a new interpretation, or reveals new considerations.

I have absolutely no doubt that in the next 1000 years we will find at least one thing that will go faster than light, but to quite a few people that belief is an anathem simply because of the inviolable acceptance by some of Einsteins theories.
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Re: 0955: "Neutrinos"

Postby JordanL » Fri Sep 23, 2011 8:09 pm UTC

If you guys actually want to discuss this at length, go here: http://physicsforums.com/showthread.php?t=532620

The basic consensus so far has been thus: Systemic error is more likely than anything. However, should systemic error not prove to be the problem, we may have found our first negative mass particle. It's unlikely that the Neutrinos are tachyonic though, because our observed Neutrinos from stellar phenomena are about 1000 times less energetic, and tachyons actually increase in speed at lower energies.

It's of course not a demolition of SR and GR if proven true. It's simply a limiting of the scope that GR and SR can be applied to.
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Re: 0955: "Neutrinos"

Postby dash » Fri Sep 23, 2011 8:17 pm UTC

Samik wrote:
dash wrote:You have made no argument as to why it should be even later than 2045. Your "argument" is just the assertion, "This is a very hard problem! It's going to take a long time!"

Well, at this point you've critiqued me, so I considered the door open to critique in return.


??? I thought I made it clear that putting the quotes around argument was because you were not making an argument, you were stating opinion, and I did my best to paraphrase your opinion.

There is no critique, nor insult intended. I do not believe it is productive to debate opinion.

If you were asking what went into forming my personal opinion, that's another matter. But that would take too long.

Rather let's list what we seem to agree on again:
1) No singularity possible until real AI exists
2) Computing power is not a limiting factor in creating AI
3) Mainstream approaches are almost universally flawed in their approach
4) Mainstream AI is really computer science + algorithms, not real AI
5) Kurzweil can be dismissed (Minsky also?)

I'm not so interested in the singularity, rather I just want AI to come about.
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Re: 0955: "Neutrinos"

Postby Samik » Fri Sep 23, 2011 8:27 pm UTC

dash wrote:??? I thought I made it clear that putting the quotes around argument was because you were not making an argument, you were stating opinion, and I did my best to paraphrase your opinion.


Dash, my point is that the fact that you felt it necessary to point this out implies something. You don't see at all why I feel you were portraying my words as something they were not intended to be?

You're trying to contrast pure opinion with logically valid "premiseA->premiseB->premiseC->Conclusion" argumentation. Of course my post was not an example of the latter, but that's not what people generally mean when they use the word "argue". It was one single word in a paragraph referencing a very long post, that you jumped on to display me as in error somehow.

I'm just saying that that is... either careless or disingenuous.
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Re: 0955: "Neutrinos"

Postby blowfishhootie » Fri Sep 23, 2011 8:43 pm UTC

RichardPrice wrote:However, my point is that quite often to the layman, Einsteins theories are put forward as inviolable, completely set in concrete as the truth - and thats the stance that I disagree with.


I think your original post made it sound like you were talking about the scientific community. If this is what you mean, I think the explanation is simple: Quite often, the layman is an absolute moron, or at least horribly ill-informed (which I believe was the point of the comic strip that prompted this thread). I don't mean to sound harsh, because we are all laymen depending on the subject at hand, but sometimes the answer is as simple as realizing that most people don't have an opinion worth considering on a given topic.
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Re: 0955: "Neutrinos"

Postby Samik » Fri Sep 23, 2011 8:47 pm UTC

All right, dash. I know I'm really bad about the whole getting-the-last-word-on-the-internet thing, so I'm going to say two things, then let it lie.

1.) You really can't tell me that you can't see why your initial reply to my post comes across as mildly deprecating?

2.) Your whole tact in the first place of trying to display what I'd written as nothing more substantial than "This is a very hard problem! It's going to take a long time!", wholly aside from being insulting, is just frankly wrong. For the third time: no, my "argument" was not rock-solid irrefutable, but neither was it intended to be - it was simply intended to possibly stimulate conversation, if anyone cared.

It may be that every single point I bring up can be shown to be nothing other than unsubstantiated opinion, and that there's nothing like a cogent "argument", by any definition, to be found there. But to suggest that the contents of that post can be distilled down to "This is hard!" without losing any content is insulting.




EDIT: I'm trying really hard to assume good faith on your part. I've considered the possibility that I'm getting trolled hard, and decided I'd rather give you the benefit of the doubt than assume bad faith.
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Re: 0955: "Neutrinos"

Postby Eutychus » Fri Sep 23, 2011 8:53 pm UTC

Ptharien's Flame wrote:I'd just like to bring everyone's attention to the following article, which I feel is especially relevant now that the media in general have gotton wind of "FTL neutrinos".
http://www.newyorker.com/reporting/2010/12/13/101213fa_fact_lehrer
Speaking as someone with an arts background, that is brilliant.
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Re: 0955: "Neutrinos"

Postby ESoergel » Fri Sep 23, 2011 9:11 pm UTC

cemper93 wrote:I did never get why everyone thinks that relativity HAS to be right anyway. After all, it makes two assumptions that are AFAIK impossible to prove: That the speed of light in vacuum is constant and that the laws of physics work the same in every frame of reference.
For the first:
c=\sqrt{{1}\over{\epsilon_0\cdot\mu_0}}

but who can be sure that the fundamental constants of nature are really constant and that \epsilon_0 and \mu_0 have always had the same values?
And for the second: Isn't that even a contradiction to the multiverse interpretation of quantum physics, where the same thing can have different outcomes?

DISCLAIMER: I'm not a physicist.
I'm not even a scientist.


That equation is derived from the Maxwell equations, and basically what happens is all the other terms cancel out and you're left with an observable speed of light in a vacuum that does not depend on anything (including the observer's velocity) other than fundamental constants (ie it's fixed). I think the findings relate more to the idea that nothing can travel faster than light, which can be seen more by considering the mass-energy equivalence equation including the Lorentz factor:
e= {{mc^2}\over{\sqrt{1-({v\over c})^2}}}

Energy increases with velocity (although not appreciably until ~10% of c) and becomes infinite as v approaches c. v=c (where you're dividing by zero) can only be true for m=0 (massless particles), and the only nontrivial (nonzero energy) solution to the equation for something with m=0 (such as a photon) requires that v=c (plug in 0 for m and you'll end up with v=c). For v > c, you're taking the square root of a negative number, which has no real solution. That's why no massive (m\neq 0) particle can reach or exceed c.

Anyways, if the findings are confirmed, it won't mean that relativity was wrong anymore than relativity meant Newtonian mechanics was wrong. Newtonian mechanics still holds for the overwhelming majority of cases, but it doesn't completely describe everything; relativistic corrections extend the theory to cover more cases. Relativity IS true, it has accurately predicted a massive number of experimental results. My expectation is that these results won't lead anywhere, and in the event that they do, we've discovered a subset of cases which currently accepted physics is unable to account for. Then maybe we'll have to change the Lorentz factor from
{1\over{\sqrt{1-({v\over c})^2}}} \;\;to\;\; {1\over{\sqrt{|1-({v\over c})^2|} }} \;\;or\;\; {{\sqrt{|1-({v\over c})^2|} }\over{ {1-({v\over c})^2} }}

Both correction factors preserve magnitude for cases up to v=c and still allow for v>c, the latter switches negative after v=c, carrying sign through the square root (and if you're uncomfortable using |x|, remember that \sqrt{x^2} yields the same). A graph of the first on an e vs v plot looks like a graph of |1/x| centered around c, the second looks like -1/x around c. Either one would be pretty cool. The consequences of the first one mean that after surpassing the speed of light, the energy of a particle would decrease to the Newtonian value. The second equation implies that if a particle's speed is greater than c, energy turns negative (it gives off energy). Neither of those seems plausible, but those the are the simplest resolutions I can think of (notice I'm avoiding the inconvenient question of where they got the infinite amount of energy to accelerate past c, my guess is they skipped straight past it with their warp drive)

edit: fixed my grammar
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Re: 0955: "Neutrinos"

Postby arundelo » Fri Sep 23, 2011 9:14 pm UTC

The title text has a typo ("continential" should be "continental").
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Re: 0955: "Neutrinos"

Postby hujackus » Fri Sep 23, 2011 9:21 pm UTC

I'd like to celebrate this theory's increasing popular awareness by watching K-PAX. Reminds me how much science has yet to reveal.
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Re: 0955: "Neutrinos"

Postby ThinkerEmeritus » Fri Sep 23, 2011 9:43 pm UTC

Strictly speaking, the CERN experiment does not by itself violate special relativity. Relativity permits particles that always travel faster than light. What is forbidden is for an object to be capable of going both below and above the speed of light (c). Particles that always move (relative to us) faster than light are called tachyons, and people have been looking for them, but most physicists were not really expecting to find one. If neutrinos turn out to be tachyons, it will be one of the great "right-under-our-noses" events in particle physics history.

There are problems with tachyons. They allow you to communicate, in principle at least, instantaneously with anyone else moving below c. This fact combined with special relativity can cause major problems with causality. You may determine that some kind of event always "causes" a different event some distance away. For it to really be the cause of the other event, you want it to be earlier than the other in all reference frames. When tachyons are let into the picture, you can no longer do that. The result must precede the cause in some frames if tachyons are the intermediaries over that distance in that time interval. So strictly speaking, relativity and tachyons together violate causality, and we don't really want that to happen.

It is possible that we could, if we have to, reinterpret events to preserve causality. We have been able to do that with the idea that antiparticles are just particles traveling backwards in time, which at first glance certainly seems to have the same problem. I don't know what the results are of thinking carefully about that.

I am pretty sure that in any event there would be some serious rethinking of the particle physics Standard Model required if neutrinos are tachyons. The upside of that is that something could turn up that would make dark matter, dark energy, and an accelerating expansion of the Universe more understandable. It might even make cosmology as we observe it something that is so simple that it just had to happen that way.

Nonetheless, it is a good bet that there will turn out to be something subtly wrong with the experiment. Given the care with which the experiment was done, it would have to be pretty darn subtle, but it is still more likely that than a near-complete turn-around in particle physics.

Besides, tachyons have negative mass2, and it would be neat to have some relatively common particles whose mass is entirely imaginary.

EDIT: the vixra blog http://blog.vixra.org/category/neutrinos/ has an observation that the energy dependence of the measured velocity in this experiment isn't consistent with tachyons. A quick check confirms that this observation is quite firm, if the quoted results for two subsets of the data at different energy ranges are correct. So it seems that my comments about the possibly low impact of this experiment, even if correct, on special relativity are unlikely to be correct.
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Re: 0955: "Neutrinos"

Postby JordanL » Fri Sep 23, 2011 10:04 pm UTC

ThinkerEmeritus wrote:There are problems with tachyons. They allow you to communicate, in principle at least, instantaneously with anyone else moving below c. This fact combined with special relativity can cause major problems with causality. You may determine that some kind of event always "causes" a different event some distance away. For it to really be the cause of the other event, you want it to be earlier than the other in all reference frames. When tachyons are let into the picture, you can no longer do that. The result must precede the cause in some frames if tachyons are the intermediaries over that distance in that time interval. So strictly speaking, relativity and tachyons together violate causality, and we don't really want that to happen.


What we want or are comfortable with has nothing to do with what is. That is not an argument for or against any findings, simply a statement that considerations about "ease" are meaningless when it comes to arriving at scientific truth.

EDIT:

The quote in your signature is a paraphrased quote from Neils Bohr. :)
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Re: 0955: "Neutrinos"

Postby kg959 » Fri Sep 23, 2011 10:08 pm UTC

It's possible that the neutrinos are indeed actually moving the speed of light, and what we're observing is a limited amount of high energy spacial folding caused by the energy of the particle accelerator.
It's either a new branch of physics, or the beginnings of warp technology. I kinda hope it's the latter.
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Re: 0955: "Neutrinos"

Postby dash » Fri Sep 23, 2011 10:16 pm UTC

Samik wrote:EDIT: I'm trying really hard to assume good faith on your part. I've considered the possibility that I'm getting trolled hard, and decided I'd rather give you the benefit of the doubt than assume bad faith.


You really need to get past this. I thought I apologized for having paraphrased your statements and also for the quotes around argument. I'm not investing 30 minutes on very carefully writing everything as accurately as possible. This is the internet, after all. Imprecision is the norm here.

But I think you're being overly sensitive.

The key point to take away is that you have your opinion and I have mine. And these days I'm not interested in changing other people's opinions.

The Kurzweil-like statement regarding 2045 just bugs me (made by that other fellow I think). AI research to me is 70 years of unbroken failure. I'm bitter about that.
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Re: 0955: "Neutrinos"

Postby Samik » Fri Sep 23, 2011 10:38 pm UTC

dash wrote:"I'm not investing 30 minutes on very carefully writing everything as accurately as possible. This is the internet, after all. Imprecision is the norm here."

Yeah, we're definitely talking waay past each other here, cause this is my main gripe with what you've written. I dropped the word 'argue' offhand in a sentence where it more or less fit what I was trying to say, and you zoned in on that word and that word alone and used it to case my words in a way I didn't mean them to be read. Then when I pointed that out to you, you ignored me, persisted in miscasting my words, then, finally, turned sarcastic and openly insulting.






Let my try to approach clarifying my position from another angle.
(note: this isn't about Kurzweil - I'm using that to work towards another point.)

You state, with regards to Kurzweil: "I refute his argument."

Definition of refute:
Merriam Webster: to prove wrong by argument or evidence

Now let us see on what "argument" or "evidence" your refutation is based:
dash wrote:I counter with that whole argument being ridiculous. We have supercomputers. The problem we face is the theory, what to actually do with the computational power if it's available.

dash wrote:if we knew the theory of what needs to be computed to make real AI, actually doing it is the easy part. It's easy to improve upon already working technology. That's the trivial part.

Hm. Sounds like a large part of your "refutation" is based on the "opinion" that the processing power we are capable of harnessing now is ready or trivially close to ready to run not just a "strong AI", but a singularity-inducing machine intelligence. But how can you know that, if you don't know exactly what it would actually take to create said intelligence?

You don't. That's your "opinion". "Refute" Kurzweil? You've done nothing of the sort. In fact, I could even go so far as to say:


"You have made no argument as to why [you believe we have sufficient processing power to run a machine intellect capable of brining about the singularity]. Your "argument" is just the assertion, "[Kurzweil is ridiculous! Of course we do!]"


Would that be fair of me to say, dash? Or would it be flawed in the same way that your original comment was flawed? By homing in like a missile on certain very specific parts of what you wrote, when I know darned well the general gist of what you meant to say?
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Re: 0955: "Neutrinos"

Postby dash » Fri Sep 23, 2011 11:04 pm UTC

Samik wrote: then, finally, turned sarcastic and openly insulting.


My goodness! You really have no clue at all, do you?

I'm done talking to you. One would think by now I'd have known better...
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Re: 0955: "Neutrinos"

Postby Samik » Fri Sep 23, 2011 11:12 pm UTC

dash wrote:You really need to get past this.

dash wrote:But I think you're being overly sensitive.

dash wrote:My goodness! You really have no clue at all, do you?

These are called ad hominems. Find a place in this thread (prior to this post) where I spoke to you in the same manner. Please.
I thought I apologized for having paraphrased your statements...

And if this is not sarcasm, then you have a terrible, terrible way with words.


My turn to be snide:

Very nicely done throwing out ad hominems, denigrating my points without ever actually bothering to address them, all the while casting yourself as the aggrieved party,

The last two paragraphs of my previous post are the most clear representation of my train of thought re: why I found your original post to be somewhat antagonistic I can manage. If you care at all to see where I'm coming from (which I know you don't), then that would be where to look.
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Re: 0955: "Neutrinos"

Postby ThinkerEmeritus » Fri Sep 23, 2011 11:13 pm UTC

JordanL wrote:
ThinkerEmeritus wrote:There are problems with tachyons. They allow you to communicate, in principle at least, instantaneously with anyone else moving below c. This fact combined with special relativity can cause major problems with causality. You may determine that some kind of event always "causes" a different event some distance away. For it to really be the cause of the other event, you want it to be earlier than the other in all reference frames. When tachyons are let into the picture, you can no longer do that. The result must precede the cause in some frames if tachyons are the intermediaries over that distance in that time interval. So strictly speaking, relativity and tachyons together violate causality, and we don't really want that to happen.


What we want or are comfortable with has nothing to do with what is. That is not an argument for or against any findings, simply a statement that considerations about "ease" are meaningless when it comes to arriving at scientific truth.

EDIT:

The quote in your signature is a paraphrased quote from Neils Bohr. :)


I agree completely. If there is nothing wrong with the CERN experiment, and further investigations indicate that causality principles need to be modified or abandoned, we will have to do just that. Physics could possibly be very, very interesting for a while. However, "comfort" and "ease" have always had a lot to do, rightly or wrongly, with which experimental results we actually accept quickly.

Thanks for spotting that it was Bohr in my quote. I'll fix the reference.
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Re: 0955: "Neutrinos"

Postby rhomboidal » Fri Sep 23, 2011 11:21 pm UTC

I knew there had to be a way to make money from pure research.
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Re: 0955: "Neutrinos"

Postby Samik » Fri Sep 23, 2011 11:21 pm UTC

ThinkerEmeritus wrote:...and we don't really want that to happen.
JordanL wrote:What we want or are comfortable with has nothing to do with what is. That is not an argument for or against any findings, simply a statement that considerations about "ease" are meaningless when it comes to arriving at scientific truth.

I read that mostly as Thinker trying to give his thoughts a conversational tone, to make them as approachable as possible to the uninitiated (like myself), rather than implying that aesthetics, or something like that, should play an actual role in deciding which scientific truths we allow into our catalog.

(Although that article Ptharien's Flame linked makes you wonder :/)
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Re: 0955: "Neutrinos"

Postby ThinkerEmeritus » Fri Sep 23, 2011 11:59 pm UTC

Samik wrote:
ThinkerEmeritus wrote:...and we don't really want that to happen.
JordanL wrote:What we want or are comfortable with has nothing to do with what is. That is not an argument for or against any findings, simply a statement that considerations about "ease" are meaningless when it comes to arriving at scientific truth.

I read that mostly as Thinker trying to give his thoughts a conversational tone, to make them as approachable as possible to the uninitiated (like myself), rather than implying that aesthetics, or something like that, should play an actual role in deciding which scientific truths we allow into our catalog.

(Although that article Ptharien's Flame linked makes you wonder :/)


I would say that aesthetics shouldn't ultimately control what we consider to be scientific truths. However, the fundamental equations of physics settled upon by experimental results historically have been somewhat aesthetic, at least in hindsight. An experimental error is much less likely to give an aesthetic result. So psychologically, it takes more evidence to convince working scientists that results that appear unaesthetic should be adopted. This prejudice has on the whole sped up the progress of science, so it makes sense. It has also tended to slow down the acceptance of truly revolutionary results, which is unfortunate. A balance is frankly difficult to find.
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Re: 0955: "Neutrinos"

Postby edgey » Sat Sep 24, 2011 1:39 am UTC

I am a first year undergrad physicist, and so my knowledge of particle physics is fairly rudimentary.

Are neutrinos more or less weakly interacting than photons?
That is, is it possible that neutrinos interact with an imperfect vacuum less than photons do, explaining the minor speed difference?
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Re: 0955: "Neutrinos"

Postby ThinkerEmeritus » Sat Sep 24, 2011 2:52 am UTC

edgey wrote:I am a first year undergrad physicist, and so my knowledge of particle physics is fairly rudimentary.

Are neutrinos more or less weakly interacting than photons?
That is, is it possible that neutrinos interact with an imperfect vacuum less than photons do, explaining the minor speed difference?


Neutrino interactions are weaker than photon interactions, much weaker in fact. You are right about the potential difference in speed due the particles being in a medium. However, for this experiment the photons interact enough that they never get to the detector, which is underground. The neutrinos get through, and their speed is then measured and compared to the speed of light in a perfect vacuum. So the fact that the neutrinos have the higher speed means either that there is a mistake in the experiment or that a lot of physics is going to have to be revised.

It would be nice if you could set up a direct "race" between the photons and the neutrinos, for hidden errors would be much less likely. Unfortunately, the detector must be underground to make the detection of neutrinos unambiguous, and the interactions of photons with the surroundings of the detector stop them from finishing the race. Follow-up on this experiment isn't going to be easy (unless someone finds a subtle systematic error whose correction gives a neutrino speed below that of light).
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Re: 0955: "Neutrinos"

Postby Samik » Sat Sep 24, 2011 2:59 am UTC

ThinkerEmeritus wrote:It would be nice if you could set up a direct "race" between the photons and the neutrinos, for hidden errors would be much less likely.


But part of the reason why these results are so difficult to believe is that we have done just this (or, rather, not so much "done" as luckily stumbled upon).

Supernova 1987A. The photons and neutrinos from an emission source 160,000+ lightyears away arrived at essentially exactly the same time. If there was any significant deviation between the speeds of photons and neutrinos, that is where we would have noticed it. 160,000 lightyears worth of chance for the neutrinos to put some distance between themselves and photons trumps 730 kilometers.

Of course, as I understand it, there are some key differences between those kinds of neutrinos and the kinds the OPERA test was using, but... we'll that's really as far as I understand it, at the moment.
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Re: 0955: "Neutrinos"

Postby mitra » Sat Sep 24, 2011 4:27 am UTC

JPatten wrote:If I understand correctly, this is the result of multiple experiments done over a period of time, not just a one time thing. And they are asking for someone to try and replicate their results and go over their findings with a fine tooth comb because it is such a huge impact on our understanding of physics. I am skeptical as well, but its not like these are a couple of fruitcakes in their garage claiming big science is suppressing their research. CERN is a fairly well respected outfit.


Would you put a bet on them? :)
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Re: 0955: "Neutrinos"

Postby mitra » Sat Sep 24, 2011 4:42 am UTC

Samik wrote:
ThinkerEmeritus wrote:It would be nice if you could set up a direct "race" between the photons and the neutrinos, for hidden errors would be much less likely.


But part of the reason why these results are so difficult to believe is that we have done just this (or, rather, not so much "done" as luckily stumbled upon).

Supernova 1987A. The photons and neutrinos from an emission source 160,000+ lightyears away arrived at essentially exactly the same time. If there was any significant deviation between the speeds of photons and neutrinos, that is where we would have noticed it. 160,000 lightyears worth of chance for the neutrinos to put some distance between themselves and photons trumps 730 kilometers.

Of course, as I understand it, there are some key differences between those kinds of neutrinos and the kinds the OPERA test was using, but... we'll that's really as far as I understand it, at the moment.


Supernova neutrinos were 3 orders of magnitude less energetic. This leaves some window...
But... bug in the GPS time sync code or some statistics analysis error seems to be more likely.
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Re: 0955: "Neutrinos"

Postby zemerick » Sat Sep 24, 2011 4:58 am UTC

Samik wrote:
ThinkerEmeritus wrote:It would be nice if you could set up a direct "race" between the photons and the neutrinos, for hidden errors would be much less likely.


But part of the reason why these results are so difficult to believe is that we have done just this (or, rather, not so much "done" as luckily stumbled upon).

Supernova 1987A. The photons and neutrinos from an emission source 160,000+ lightyears away arrived at essentially exactly the same time. If there was any significant deviation between the speeds of photons and neutrinos, that is where we would have noticed it. 160,000 lightyears worth of chance for the neutrinos to put some distance between themselves and photons trumps 730 kilometers.

Of course, as I understand it, there are some key differences between those kinds of neutrinos and the kinds the OPERA test was using, but... we'll that's really as far as I understand it, at the moment.


That's pretty close. The only correction needed is that they did not arrive at the same time. The neutrinos did indeed arrive first, however they did so not because they traveled faster than C, but because the light from the supernova was delayed by a couple of hours on its way out of the supernova. However, and this is the key, the difference seen at CERN would have resulted in the neutrinos arriving more than a year ahead of the light.

From there, you're spot on: They involved different flavors of Neutrinos at vastly different energies. Therefore, this leaves room for both to be valid, but for the Neutrinos from the OPERA experiment to behave differently.

Back to edgey: Neutrinos are completely neutral. As such, they do not interact in any way with the Electro-Magnetic or Strong-Nuclear forces. This leaves only Gravity and the Weak-Nuclear force.

My primary (personal, so not entirely valuable ) theories, from most to least likely, are:
1)An unnoticed error in the CERN experiment. They were testing for something different, so it's not impossible for something related to this not having sufficient accuracy.
2)Neutrinos travel through a 5th dimension in some fashion, allowing for some sort of slight short-cut. They travel through that dimension at the speed of light, but for whatever reason, the distance is shorter. Much as Docmordrid said.
3)It's actually us that travels through the extra dimension. Instead of only occasionally doing this, in a sort of shortcut, we actually slowly travel through it on a constant basis much in the way we travel through time. For normal matter, photons, energy, etc. this would need to be a constant amount of travel ( else we would have previously detected it ), but for some reason Neutrinos can slow down or stop moving in the 5th dimension, allowing for a greater speed in the 3 spatial dimensions without affecting their travel through time.
4)There is something fundamentally wrong with our interpretation of the speed of light. Physics has a flaw at the very core, and sweeping changes unfold in a change not seen since the discovery of Quantum Mechanics or Relativity. (I really doubt this one. There's just too much that works out so nicely for the core to be wrong.)

I am also mulling over possible involvement of Negative-Matter (Matter with a negative mass), but this is tricky to say the least. A particle with Negative Mass would travel faster than C, and therefore backwards in time, but it would also interact opposite to normal ( If you plug a negative mass into any equation, it results in a velocity in the opposite direction of normal. ) This causes things to get rather confusing, and it's late at night...so I'll just leave it at that for now.

Cheers!
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Re: 0955: "Neutrinos"

Postby ijuin » Sat Sep 24, 2011 5:25 am UTC

Samik wrote:I have an outstanding bet with my father for $1,000 that the technological singularity won't have hit by 2045,

I hope you have a contingency for the possibility that your father might no longer be alive by 2045.
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Re: 0955: "Neutrinos"

Postby collegestudent22 » Sat Sep 24, 2011 5:31 am UTC

mkfrancsis wrote:Plates don't drift, they move


They move relative to one another by drifting over the athenosphere. So, yeah, they do drift, under quite a few different definitions of "drift" - one of which is merely "slowly moving without direction or purpose".

mitra wrote:
JPatten wrote:If I understand correctly, this is the result of multiple experiments done over a period of time, not just a one time thing. And they are asking for someone to try and replicate their results and go over their findings with a fine tooth comb because it is such a huge impact on our understanding of physics. I am skeptical as well, but its not like these are a couple of fruitcakes in their garage claiming big science is suppressing their research. CERN is a fairly well respected outfit.


Would you put a bet on them? :)


If I had any money, I would. CERN knows what they are doing, for the most part. It could be that this is a fluke error, or perhaps a misunderstanding of the results. But I doubt it.

zemerick wrote:My primary (personal, so not entirely valuable ) theories, from most to least likely, are:
1)An unnoticed error in the CERN experiment. They were testing for something different, so it's not impossible for something related to this not having sufficient accuracy.
2)Neutrinos travel through a 5th dimension in some fashion, allowing for some sort of slight short-cut. They travel through that dimension at the speed of light, but for whatever reason, the distance is shorter. Much as Docmordrid said.
3)It's actually us that travels through the extra dimension. Instead of only occasionally doing this, in a sort of shortcut, we actually slowly travel through it on a constant basis much in the way we travel through time. For normal matter, photons, energy, etc. this would need to be a constant amount of travel ( else we would have previously detected it ), but for some reason Neutrinos can slow down or stop moving in the 5th dimension, allowing for a greater speed in the 3 spatial dimensions without affecting their travel through time.
4)There is something fundamentally wrong with our interpretation of the speed of light. Physics has a flaw at the very core, and sweeping changes unfold in a change not seen since the discovery of Quantum Mechanics or Relativity. (I really doubt this one. There's just too much that works out so nicely for the core to be wrong.)



Or perhaps the speed of light is changing, as I have heard theories that it is dependent on the vacuum energy level, or perhaps the energy level of the Higgs mass field, or some other non-constant that depends on the current makeup of the universe. This change could be just enough to be detected in this result, but might not be enough to effect the somewhat slower GPS satellites and their corresponding corrections just yet.

ijuin wrote:
Samik wrote:I have an outstanding bet with my father for $1,000 that the technological singularity won't have hit by 2045,

I hope you have a contingency for the possibility that your father might no longer be alive by 2045.


Not difficult. His father could build it into his will - put it in a savings account or something upon his death and release to either a charity or his son, depending on whether the Singularity has hit by 2045. (Personally, I'm with Samik there, I'm thinking it will hit between 2100 and 2200, depending on how much interference is put on the creation of new technologies. Excepting, of course, a collapse of modern civilization in the West due to spending ourselves into oblivion.)
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Re: 0955: "Neutrinos"

Postby mitra » Sat Sep 24, 2011 5:54 am UTC

collegestudent22 wrote:
mitra wrote:
JPatten wrote:If I understand correctly, this is the result of multiple experiments done over a period of time, not just a one time thing. And they are asking for someone to try and replicate their results and go over their findings with a fine tooth comb because it is such a huge impact on our understanding of physics. I am skeptical as well, but its not like these are a couple of fruitcakes in their garage claiming big science is suppressing their research. CERN is a fairly well respected outfit.


Would you put a bet on them? :)


If I had any money, I would. CERN knows what they are doing, for the most part. It could be that this is a fluke error, or perhaps a misunderstanding of the results. But I doubt it.


You don't have to have money now you know. :) Loosing party just need to pony $$ in a few years, when it's resolved. $200? ;)
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Re: 0955: "Neutrinos"

Postby SEE » Sat Sep 24, 2011 6:46 am UTC

ThinkerEmeritus wrote:There are problems with tachyons. They allow you to communicate, in principle at least, instantaneously with anyone else moving below c. This fact combined with special relativity can cause major problems with causality. You may determine that some kind of event always "causes" a different event some distance away. For it to really be the cause of the other event, you want it to be earlier than the other in all reference frames. When tachyons are let into the picture, you can no longer do that. The result must precede the cause in some frames if tachyons are the intermediaries over that distance in that time interval. So strictly speaking, relativity and tachyons together violate causality, and we don't really want that to happen.

We don't want to violate causality because it would make things difficult for our linear-time-perspective brains, though, not because neutrino signaling via closed timelike curves actually cause any contradictions in physics. Assuming Novikov self-consistency works just as well for the physics as assuming cause always precedes effect.
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Re: 0955: "Neutrinos"

Postby E_H » Sat Sep 24, 2011 7:58 am UTC

Beyond the systematic error possibility (the experiment can't match up individual decays with individual neutrino detections, the decay calculations may be imperfect, which could give some new physics, though less exciting), I see a couple of possibilities:

1. Neutrinos are tachyons, but only part of the time, oscillating back and forth between >c and <c, making long trips average near c, but slightly above c on average if they start out tachyonic. The jumps back and forth would probably have to be quantized - the intermediate velocities would be forbidden. Likely this oscillation would be linked to the type oscillation (electron, muon, tau).

2. Photons interact with the vacuum more than neutrinos and thus have a slightly lower speed. The "bare" speed of light may be a bit higher than either velocity.

Error seems most likely, but of the other two I prefer the first, since it seems to cover the evidence better (1987A data, lack of expected degree of energy dependence)
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Re: 0955: "Neutrinos"

Postby philip1201 » Sat Sep 24, 2011 2:33 pm UTC

edgey wrote:I am a first year undergrad physicist, and so my knowledge of particle physics is fairly rudimentary.

Are neutrinos more or less weakly interacting than photons?
That is, is it possible that neutrinos interact with an imperfect vacuum less than photons do, explaining the minor speed difference?


Neutrino's are extremely weakly interacting - they only couple through the weak force which means they have to hit a nucleus exactly right. The neutrino flux on earth is 8 x 10^7 m^-2 s^-1 but in the Super-Kamiokande (size: 50,000 cubic meters of water) there's only 1 reaction every 3 hours.

As stated earlier in this thread, neutrinos can indeed overtake light if it's held up by, for example, the planetary nebula from the supernova that caused the burst in radiation. But from what I understand, they measured the speed of the neutrinos by precisely calculating the distance, not by comparing it to light emitted at the same time. They simply measured Delta x / Delta t > 299792458 m/s.
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Re: 0955: "Neutrinos"

Postby furyguitar » Sat Sep 24, 2011 2:52 pm UTC

Congrats, XKCD, on being referenced in the NYTimes!

Dennis Overbye of the NYTimes wrote:The recent history of physics and astronomy is strewn with reports of suspicious data bumps that might be new particles or new planets and — if true — could change the way we think about the world, but then disappear with more data or critical scrutiny. Most physicists think the same will happen with this finding. The prevailing attitude was perhaps illustrated best by an XKCD cartoon, in which a character explains his intention to get rich betting against the new discovery. (emphasis mine)


For the full article:
http://www.nytimes.com/2011/09/24/science/24speed.html?_r=1&hpw
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Re: 0955: "Neutrinos"

Postby Wnderer » Sat Sep 24, 2011 3:16 pm UTC

And it is written that at the end of times the neutrinos will travel at (666^((6/(6+6))^(6+6+6))) times the speed of light ...
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Re: 0955: "Neutrinos"

Postby Lenoxus » Sat Sep 24, 2011 6:32 pm UTC

This comic was linked to by a New York Times article on the finding:

http://www.nytimes.com/2011/09/24/science/24speed.html

Congratulations, Randall!

Really, linking like that ought to become a standard practice for science journalism. For example, when the platypus genome was sequenced, articles should have linked to blog posts such as this one: http://scienceblogs.com/pharyngula/2008/05/the_platypus_genome.php (except that post is about shoddy journalism, so it's possibly not the best example).

If nothing else, all science news involving correlations, especially with human heatlh, should link to this somewhat well-known PHD Comic: http://www.phdcomics.com/comics/archive.php?comicid=1174
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Re: 0955: "Neutrinos"

Postby madaco » Sat Sep 24, 2011 7:30 pm UTC

@^
um what?
though madaco is my username I am in not affiliated with the company of that name, I picked the username for other reasons.If I say things that you find rude, I apologize, I will likely realize my mistake and fix it.<wit here>
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Re: 0955: "Neutrinos"

Postby Wnderer » Sat Sep 24, 2011 8:16 pm UTC

madaco wrote:@^
um what?


They found neutrinos traveling faster than light. How much faster? 1.0000248 times faster. That's about 4.6 miles per second. That's fast but it's not enough to make it to 3x10^8 meters/second or make to it 1 foot/nanosecond. It's just 299799893m/s compared to 299792458m/s. It's too big to be the ln(20.044). But 1.0000248 is equal to 666^(6/(6+6))^(6+6+6). I think it's funny.

Devil's Neutrinos.jpg
Devil's Neutrinos.jpg (1.59 KiB) Viewed 3510 times


They went looking for the God Particle and found The Devil's Neutrinos. The Devil's Neutrinos coming soon on DVD and BluRay.
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