178 posts • joined 9 Aug 2007
Re: 1.49597871 × 10^15m
Hmm ... Register Units?
About 8 mReg?
(Being 8/1000 of the distance from here to Regulus. Although mysteriously, the Register-star is in the constellation of Leo (probably eating its entrails...), and will be obscured by 163 Erigone on the morning of March 20th - expect articles to go missing or be delayed around that time.)
1.49597871 × 10^15m
... is about 1/6 of a light year, if it helps any.
Presumably this is the peer-reviewed version?
An Objective Bayesian Improved Approach for Applying Optimal Fingerprint Techniques to Estimate Climate Sensitivity
JOURNAL OF CLIMATE 26, n19, 7414-7429 (2013)
A detailed reanalysis is presented of a Bayesian climate parameter study (as exemplified by Forest et al.) that estimates climate sensitivity (ECS) jointly with effective ocean diffusivity and aerosol forcing, using optimal fingerprints to compare multidecadal observations with simulations by the Massachusetts Institute of Technology 2D climate model at varying settings of the three climate parameters. Use of improved methodology primarily accounts for the 90% confidence bounds for ECS reducing from 2.1-8.9 K to 2.0-3.6 K. The revised methodology uses Bayes's theorem to derive a probability density function (PDF) for the whitened (made independent using an optimal fingerprint transformation) observations, for which a uniform prior is known to be noninformative. A dimensionally reducing change of variables onto the parameter surface is then made, deriving an objective joint PDF for the climate parameters. The PDF conversion factor from the whitened variables space to the parameter surface represents a noninformative joint parameter prior, which is far from uniform. The noninformative prior prevents more probability than data uncertainty distributions warrant being assigned to regions where data respond little to parameter changes, producing better-constrained PDFs. Incorporating 6 years of unused model simulation data and revising the experimental design to improve diagnostic power reduces the best-fit climate sensitivity. Employing the improved methodology, preferred 90% bounds of 1.2-2.2 K for ECS are then derived (mode and median 1.6 K). The mode is identical to those from Aldrin et al. and [using the same Met Office Hadley Centre Climate Research Unit temperature, version 4 (HadCRUT4), observational dataset] from Ring et al. Incorporating nonaerosol forcing and observational surface temperature uncertainties, unlike in the original study, widens the 90% range to 1.0-3.0 K.
Re: What an amazing ...
Indeed, it can be rather interesting to treat ancient (or even Medieval) science seriously ... e.g. this (nothing to do with dark matter or pyramids, mind)
A Medieval Multiverse: Mathematical Modelling of the 13th Century Universe of Robert Grosseteste
Bower et al.
Abstract: In his treatise on light, written in about 1225, Robert Grosseteste describes a cosmological model in which the Universe is created in a big-bang like explosion and subsequent condensation. He postulates that the fundamental coupling of light and matter gives rises to the material body of the entire cosmos. Expansion is arrested when matter reaches a minimum density and subsequent emission of light from the outer region leads to compression and rarefaction of the inner bodily mass so as to create nine celestial spheres, with an imperfect residual core. In this paper we reformulate the Latin description in terms of a modern mathematical model. The equations which describe the coupling of light and matter are solved numerically, subject to initial conditions and critical criteria consistent with the text. Formation of a universe with a non-infinite number of perfected spheres is extremely sensitive to the initial conditions, the intensity of the light and the transparency of these spheres. In this "medieval multiverse", only a small range of opacity and initial density profiles lead to a stable universe with nine perfected spheres. As in current cosmological thinking, the existence of Grosseteste's universe relies on a very special combination of fundamental parameters.
Re: Vectored thrust...
Hmm ... surely all thrust is vectored? I mean, how could one make sense of something caller "scalar thrust" (or "bi-vector thrust", for that matter)
/takes of geometric algebra hat and returns to coffee
Re: Lets start ...
I agree. But before you cackle with glee at the thought of how you might cleverly dismantle the data or assumptions behind some research finding or other, you might want to consider that you'll actually have to engage with the technical content, rather than the simanglified version of it reported by your favourite news provider. You will almost certainly find the experience a chastening one - even as a scientist, peer reviewing papers in your own field can be extremely hard work - so how might it be for the non-specialist?
Re: "The research is ours "
Tom 7, that's not necessarily true - even on a directly taxpayer funded grant, you just paid for /some/ of it. I do not want to deny the very significant claim the taxpayer/donor might have as a result of their funding, but if you really wanted to claim the lot - lock, stock, and barrel - then you really should have been paying more than you did.
E.g. EPSRC grants are now calculated on a "full economic costing" basis, which is indeed an attempt to charge for everything associated with a grant (even overheads like fractional office space, etc), whereas before that was not the case. As a result, the taxpayer now pays more, and, I suppose, also gets more claim. I do hope you are enjoying that sense of ownership over your personal fraction of the 1/4 of a room in a 50's office building that I inhabit while at work :-) Some charities (as I understand it) refuse to pay (some types of) overheads, and so, I suppose, have less claim.
In this specific context, note that taxpayer funded research has not always included money for publication costs. If the taxpayer didn't pay publication costs, then they didn't pay to get free access to read the results. Maybe things should have been different, and, as I said above, things are changing now, ... although the result will not be some kind of utopia. Notably, taxpayers/donors will pay for the extra access for everyone that you & I want, but the vast majority of those granted access to the literature will either not bother or find it beyond them.
Every tax payer should have access to *any and all* research ...
Well, I agree. But the funding doesn't work like that yet, although here in the UK we are making the transition. Personally, I try to avoid publishers with illiberal redistribution policies, and put a version of all my output on arXiv irrespective of its appearance in a journal.
There are costs in the new model though - notably authors (mostly taxpayer or charity funded) will (now) have to pay publishing costs themselves, typically in the range £1000-£2000 per article, so the tax payer/charity donor will end up paying this. Further, anyone without funding - say an independent researcher, one whose funding/employment has just terminated, a new PhD trying to write up work independently, someone trying to publish work their institution doesn't care about (or perhaps even doesn't like) - now also has to (will have to) pay these costs, which are not negligible. The "author-pays" model on which your proposal rests will narrow the range of people with the ability to publish their science.
Further, when this new model is in place in the UK, you will perhaps notice that UK taxpayers and UK charity donors are making UK research free-to-view for a global audience, but the arrangement might well not be reciprocated. Some may be unhappy at such a situation.
Lastly, I find that I am inclined to feel that if a journal charges authors, they should also pay the reviewers (such as myself), who currently do it for free. Should peer review turn into a paid-for process?
So: the simple proposal you advance (and with which I generally agree) is not necessary so simple execute in a fair manner, there may well be unintended consequences, and it isn't "free", even to taxpayers & donors.
Re: It's one of the many reasons @ Mike Bell
Yes, but don't think just by calling yourself "Mike" is going to let you off - we all know you personally are responsible for the inequalities, John.
Re: How the hell do you squeeze a vacuum?
Strictly speaking, a squeezed vacuum isn't a vacuum - it has photons in it. It's called a vacuum because it has a zero amplitude, but in fact its quantum uncertainty has carefully arranged correlations, for which some excitation above the true vacuum are required.
Or: a squeezed vacuum not a vacuum, we just call it that because the field amplitudes measure (in average) as zero. But a photon number measurement will be non-zero.
 Assuming we're talking about an electromagnetic (squeezed vacuum) state.
Re: for true innovation / dress to blen in
hmm ... so maybe some episodes in pre-revolutionary France?
good old 1987a
... my favourite ever supernova. Because I volunteered to be sent up a hill in the south island to help (very slightly, and in a not very critical role, as an MSc student) with the building of the JANZOS cosmic ray observatory. I think I might have moved some thingies from here to there, or possibly put one sort of thingy on top of another sort of thingy, or joined thingies together, in somewhat chilly weather.
Re: comic books, novelty ties and ironic t-shirts.
Oh, I don't know. You'd be surprised at how artistic theoretical calculations, computer modelling, and (e.g.) high-vacuum cold atom sculpture is. Especially once it had been properly funded.
Re: Oh yes, power cuts in the '70s
These days I might just hope that at least if the power was to cut out, that it was on a cloudless night, so that for a change I might see the stars properly.
Re: CS graduates are choosing unemployment over becoming teachers?
Remember, they'd have to retrain as teachers - so its not a trivial job switch, and they may well reckon they'll get a more standard CS job before finishing (and paying for) teacher training.
Re: a bit fast to be called flapping.
What do hummingbirds do with /their/ wings then?
I think the "flapping" debate might just as well be applied to slower flying jellyfish; it's more about the action than the speed.
on the subject of an icy north (or not)
... this is an interesting semi-technical read:
Re: It may be a dumb question but ...
I've just skimmed the paper. Although its not my field at all, they have thought about alternatives.
E.g. this quote: "We consider this scenario unlikely as it would require a common recent coalescence of these ancestral wolf and dog sequences from geographically disparate areas. Nevertheless, ..."
But there are plenty of caveats scattered through the paper -- as with lots of this sort of science, their eurodog hypothesis is the most reasonable conclusion >>given the available evidence<<.
Re: cash to waste
Other reporting has pointed out that India's social aid budget vastly dwarfs the money spent on this Mars shot, and that India's poor would benefit more from more effective (and less wasteful) use of their existing budget rather than adding by some tiny fraction to it by cutting sci/tech funding.
 Either or both the Indy or Gruniad articles I read over the weekend, for example.
Re: the worst way of disseminating information.
maybe I didn't look around the site enough, but why is it you think that's how they're proposing the courses are run?
Instead, I would assume some set reading and exercises to set up the lectures; as in e.g. http://arxiv.org/abs/1309.0852
Re: nothing contradictory about both those propositions being true at once
As I understand it (Seth Lloyd's paper), to determine whether or not you have free will or not you need a third proposition:
3. It is physically possible that another (not-you) entity or system could have a model of you that reliably predicts your actions /before/ you so act .
If this (3) is true, then you fail Seth Lloyd's "free-will" test; if false, you pass, and might have free will after all.
 Note: A prediction generated using prior information, but without looking at the outcome, but which is calculated after you act, does not satisfy (3)
Re: "Free will" is rather poorly defined.
Physical models explicitly disallow free will. The most free-will-like thing they can do is add in some statistical uncertainty to either the initial conditions or the dynamics; and then consider this uncertainty to be a proxy for whatever free-will might be. Note that chaos cannot help here, since it is still strictly deterministic, although it can be a handy way of making things more complicated when constructing a pseudo free-will fr your models.
How do you build a mathematical (or physical) predictive model of something with free-will? The notion of a predictive model of free-will is an oxymoron. If I've got a good model, the decisions no longer look free, they are just consequences of the state of the system. Hence, there are (can be) no predictive models of free-will.
Hence the article's focus on "practical unpredictability" -- i.e. "we cannot in-principle predict in advance" -- as a way of assessing the likelihood of free-will being present. It's about as close as we can (currently) get to understanding free-will.
Re: confused, moi?
I once read some Bertrand Russell, and had to read each sentence twice in order to understand it and its in-context meaning. Some time you just have to keep banging the (mental) rocks together and hope it eventually becomes clear.
But if you'd prefer a more IT angle, why not try this instead?
"When does a physical system compute?"
Re: try your body clock
This sort of thing mostly works for me, although I wake seconds earlier, not minutes. If not, then the light from my trusty old Zaurus's screen (as it wakes) wakes me, and if not that, then it's really rather pleasant alarm chirp.
The most exciting radio alarm event I've had was when Mark F decided to play Ministry's "Jesus built my Hotrod" on 4ZZZ at 6:55 one morning, just in time for my usual wakeup. Thanks, Mark!
Re: Who uses bing?
Now that a large proportion (maybe even most) searching is done online, we no longer need a special word to denote online searching. Thus we can use that one we all used to use before we got all excited about computery stuff. You need only say -
"Just search for it"
Re: "wholly out of light"
The only way you get light to not travel at lightspeed is to make it interact with something. E.g. in water, visible light interacts with the water molecules, and it slows by about 30% (hence the refractive index of 1.5). To make light really slow, you have to get it to interact very strongly - in this case, using a specific frequency of light tuned to specific transitions in carefully managed rubidium atoms.
This "slow light" therefore, is a rather misleading name - it isn't just light - it's a strongly coupled light-matter system, which some would prefer to call a polariton.
I can therefore only assume the down votes were for the poor quality joke.
Re: Got a [...] Sharp Zaurus SL-5500
... I not only still have my Zaurus, I still use it :-) ... albeit mainly as an alarm clock and a place to take notes at conferences.
Re: The subheading is also erroneous
In my experience, the embargo is really just a handy way of maximizing press impact, rather than some kind of evil plot. I'm not sure there's any likelihood a journal would refuse to publish a "press-worthy" paper just because the authors didn't want to respect an embargo - it'd still be a good paper, and still publishable.
Remember that this is science news, and is not really all that time sensitive, nor does it matter which day you hear about it. You still get the news (and so not unfair to taxpayers, who aren't denied anything important), just when the science journalists have had a week or so to talk to the authors and get a proper write up done.
Further, in practical terms, the sanctions for breaking an embargo are most likely as weak as "we wont give you pre-notice again" ... which hardly stops any journalist from reporting on the other 99.99% (or whatever) of science that there is out there. Just (eg) subscribe to some journal (ore arXiv) RSS feeds if you want non-embargoed science.
Re: [phone] modem-like add-on
... hmm, my decade-old Zaurus PDA had a CF phone add-on thingy advertised at one point, if I recall correctly (although I never got - or wanted - one at the time). Might not even have been Z specific, I suppose.
Re: Shurely shome mishtake?
Er, nope. You can split photons (although perhaps its better to call it conversion) using an optical nonlinearity, as long as you conserve energy. And since the "colour" of a photon depends on its energy (frequency), splitting a high frequency "blue" photon will (can) give you two "red" ones. And with a different setup you can produce photon pairs with mismatched colours.
Re: New Scientist
I agree the general state of New Scientist is depressing. While I stand by my belief that BBC reporting should remain at a very broadly accessible level, NS is exactly the kind of publication which should pitch to a higher level - indeed, I thought that would have been the entire point of a magazine with that name. That said, when some of my work was reported in NS, I was perfectly happy with the result.
I also distinguish between "(news) reporting", which need not (and imo perhaps should not) be technical at all, especially in the mass media, since the point of news reporting is primarily to make the audience aware of something. This is distinct to features or documentaries, which people usually choose to watch, and where greater expectations of their knowledge are entirely appropriate.
As for "an essential part of the [scientist] job description is to ensure that society gets dragged along with one. The two aspects of the job are hand in glove", I would like to agree. But media & outreach interaction can be a vast time sink, and while I do not begrudge it, it can and does affect research output; and, further, not all scientists are very suited to it, and in many cases, neither is their research topic. By all means call for a larger cohort of science communicators, which is indeed the current trend, but expecting all scientists to turn into some sort of media/outreach enthusiast is neither practical, nor a good use of their time and resources.
Re: Ottman001's generalised perception
> My generalised perception of younger generations is that they are less likely to look something
> up unless it is some fickle celebrity nonsense.
On the face of it, this is a plausible claim. But my understanding of school education these days is that is (at least) intended to promote more self directed learning. Whatever its failings, why would this make "younger generations" less likely to look non-celeb stuff up? So, can anyone provide evidence that it is actually true?
Re: written by someone who clearly has no idea about science or technology
In my experience as a physicist, who occasionally has got media interest, science journalists are well motivated and do the best they can at converting quite difficult things down into a form digestible to their (target) mass market. As for "there is no excuse for general publications to assume all of their readers have no knowledge at all", well, the great majority of their audience probably does have no useful knowledge at all (i.e. on the specific subject being presented). Why should the majority be excluded from mass market reporting? You knowledgeable types can just feel all smug at your extreme cleverness - and know enough to go and find a more specialist publication. Just treat the mass media reporting as a supply of adverts, or trailers, for the real sci/tech story.
ICE Cube - moon shadow
Re: We are in a state of such confusion we will definitely learn something"
Such as: "Actually, we have learned that we are even more confused than previously thought!" :-)
Re: Very Large Phones
hmm ... if you think about it, these Personal Digital devices Assist us in so many ways - phone calls, notes, media , apps, and so on. Maybe we could call them by some sort of related acronym ... e.g. PDA?
Just a random thought. :-)
Re: the problem of how to catalogue, ...
So if big data isn't "big" then "big data" is a pretty silly name for it. Since supposedly the phrase is used to indicate a soup of factoids elements with had to discern structure, we need a better name. Random stuff assembled together in a way posing as something interesting? Hmm... the art world may have got there first ... how about we just call it "dada" (singular "dadum") instead?
Re: Seems rather cruel
Not really. They're just testing the waters to see if they might be able to sell these dolphins phone contracts and subscriptions to fins reunited.
Actually, why not test if dolphins really could get the hang of telephones? It'd be interesting if they could!
Re: First seen here in the 1940s
... indeed, quite a sucessful way of generating scientific output is to trawl through old journals, and re-attempt what failed back then, but with today's technology. (not saying that's what happened here, mind you).
Re: Anyone working on these models like to comment?
Any professional climate scientist would need a thick skin to even contemplate posting commentary here. Climate debate in forums such as this is a pretty ugly process, and, in fact, tends to have very little to do with any of the formal scientific output - it's largely based around rehashed (& sometimes misread) press releases, superfically relevant technical issues, and/or poorly-founded assumptions about conspiracies, groupthink, or special-interests (on any side of the argument).
This thread is a brilliant example of an internet forum "climate debate". But not so much a brilliant example of any science. Really, what would some putative "regtard" climate scientist have to offer this thread? And what would it offer them? Would it really be worth it? Do you really think you could convince them it would be worthwhile? No, really?
Re: Light isn't really so fast.
Feel free to tell us about all the things we might signal with which do go faster than light.
Re: Art? ART?
Or these, maybe (not as good as Jansen, but they have a certain something)
Re: useful presents, eh?
Costly but worthless gifts facilitate courtship
Proceedings of the Royal Society B: Biological Sciences, Vol. 272, No. 1575, p1877-1884 (2005)
by Peter D. Sozou, Robert M. Seymour
What are the characteristics of a good courtship gift? We address this question by modelling courtship as a sequential game. This is structured as follows: the male offers a gift to a female; after observing the gift, the female decides whether or not to accept it; she then chooses whether or not to mate with the male. In one version of the game, based on human courtship, the female is uncertain about whether the male intends to stay or desert after mating. In a second version, there is no paternal care but the female is uncertain about the male's quality. The two versions of the game are shown to be mathematically equivalent.
We find robust equilibrium solutions in which mating is predominantly facilitated by an ‘extravagant’ gift which is costly to the male but intrinsically worthless to the female.
By being costly to the male, the gift acts as a credible signal of his intentions or quality. At the same time, its lack of intrinsic value to the female serves to deter a ‘gold-digger’, who has no intention of mating with the male, from accepting the gift. In this way, an economically inefficient gift enables mutually suitable partners to be matched.
Re: may, might, could
Further to the "unscientific" claim regarding the use of these words, I did a quick search on the APS website for journal papers containing all three words: there were 112k hits. As a quick check against mismatches, notably regarding "May" as e.g. a date or part of a name rather than a Word, I checked 10 of those (with a slight bias towards those with May in the dates), and found only 1 without May as a word.
This would suggest either that that the APS (see http://publish.aps.org/) has published many tens of thousands of unscientific articles, or that instead, contrary to your assertion, that "may", "might", "could" indeed do have a perfectly normal place in the scientific literature.
Re: not how I was trained to express scientific results
In fact, scientific papers often contain words like "may', 'might', 'could', etc Notably in the abstract, introduction or conclusion, when trying to explain the motivation of the study, or to communicate why they think the results are or might be important. Typically the phrases using these words are rather distinct from the specific scientific conclusions reached or methodology used.
However, (media or commentator) reporting of the results tends to focus on those more exciting "may', 'might', & 'could' parts, especially since the technical details are usually way beyond the educational level of their readership.
Re: a lab toy with zero practical use.
Common practical uses for lab toys with "zero practical use" are as a demonstrations, proof-of-concept, or as educational equipment. I think this can function as all three.
Re: Silly question, but...
It's an illusion - it (the event) hasn't gone anywhere, it just doesn't get seen.
Re: the work [...] follows on from a 2010 experiment
I think you meant to say: follows on from the concept as proposed by McCall et al in J. Optics (2010/11), followed up by an experiment at Cornell (published in Nature 2012).
And re "but when it comes to security the ability to drop one's data into a time hole isn't quite as useful as it sounds cool" -- what, sounding cool isn't a useful thing? I mean, it got you to report on it, didn't it? :-)
Re: Does superluminal signalling automatically imply time travel?
To clarify - the "hidden variables" superluminal signalling is only partial; you can only extract information once you get the other part - but unfortunately that has to be sent in the ordinary way - i.e. by lightspeed limited means.
Re: I never totally understood why X couldn't be explained by simple hidden variables
They can - if you also permit superluminal signalling. However, most physicist prefer to live with "spooky action" than with a violation of relativistic causality.
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