Fine Structure Constant May Not Be So Constant 273
BuzzSkyline writes "According to a post at Physics Buzz, 'Just weeks after speeding neutrinos seem to have broken the speed of light, another universal law, the fine structure constant might be about to crumble.' Astronomical observations seem to indicate that the constant, which controls the strength of electromagnetic interactions, is different in distant parts of the universe. Among other things, the paper may explain why the laws of physics in our corner of the universe seem to be finely tuned to support life. The research (abstract) is so controversial that it took over a year to go from submission to publication in Physical Review Letters, rather than the weeks typical of most other papers appearing in the peer-reviewed journal."
Okay (Score:5, Funny)
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It's a Constant alright but only for selected areas.
-- "Desmond will be my constant".
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2 + 2 = 5 for large values of 2.
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When I was studying physics at school I measured the gravitational acceleration of a pendulum and it was 10% different to the accepted value.
Of course back then my teacher called me a dumb-ass and told me to do it again rather than plastering the news all over the media.
Re:Okay (Score:5, Informative)
Your point being exactly what? That your half assed undergrad project is analogous to years of research by a professional team? That only research that agrees with the standard view of things should get published?
Do you understand that the point of research and publication is to foster discussion and thinking?
Sounds like your teacher had you pegged.
Re:Okay (Score:5, Insightful)
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Sounds like your teacher had you pegged.
But he still doesn't know what to do with those tossed salads and scrambled eggs.
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Every scientific instrument from those found in home science kits to an international research labs has an experimental error associated with every measurement made.
It's how certain you can be of reading the right value in terms of percentage error. It's the same principle wherever you work. A real teacher would have asked you to recheck your reading and calculations.
It's the same principle behind a high school physics lab and real world research. Scientists have to figure how the errors in every measuremen
Re:Okay (Score:4)
When a student is given a small pendulum to measure, they usually give it a large displacement to make measurement easier. This violates the above assumption, and thus the pendulum's period will not match [wikipedia.org] that predicted by the common formula. Most early rigorous work with pendulums used massive devices taller than a house to try to minimize this error (as well as reducing air resistance by slowing the velocity).
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Just 10%? At the first try? I don't know if you are making the story more belivable (by reducing the error) or if you are simply missremembering things.
At my first try I got a bit more than 20m/s^2. I've never seen somebody get it within a 10% error.
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Consider the following passage from Feynman's Cargo Cult Science [lhup.edu]:
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It doesn't vary 10% by location, not at any location from which I'd believe he conducted his experiment, that is.
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Alpha can be computed in terms of other fundamental constants, in several ways.
So according to the new research, which of those vary, and which don't?
The speed of light? The electron charge? Planck's constant?
If this is right, the implications are huge.
Well, realistally, it's the vacuum permittivity/permeability that might be different from place to place - since those just properties of the vacuum, and we know "vacuum" is a deceptively complicated thing. c might be different, or might not be if permittivity/permeability change together.
And I suspect "different at different places" is really "different at different times". The concept of the speed of light changing over time is very hard to pin down - how would that be different from the universe expand
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you can't say. Those all are things that have units, so you can always define them as "1" in the proper set of units. (The speed of light, for example, is always one light-second per second.)
You can still say, because even if you define your units so that the constant is 1 unit, if the constant changes, so does the size of the unit. You can then compare this size with the "previous" size, and get a meaningful ratio. It will be unitless, but still correctly represent that the constant has changed.
Just because we define a constant as X units doesn't mean our definition of the unit automagically changes if the "constant" does. For example, right now the meter is defined in terms of the speed of
Awesome (Score:4, Informative)
So how far do we have to go to get out of the Slow Zone?
Comment removed (Score:5, Interesting)
Hexapodia is the key insight (Score:2)
Or i could just say that i wrote a long and insightful post, but it suffered from poor translation over multiple relay hops.
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Terminal World, by Alastair Reynolds, has a similar premise, but is based on Mars.
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Brain Wave [wikipedia.org]? Though that wasn't changing laws of physics per se, it was an unspecified 'field' that limited neural activity. Entering the field caused the Cretaceousâ"Tertiary extinction event, and the book begins as the solar system exits the field.
Reproducibility? (Score:5, Interesting)
Very much want to see independent confirmation of this result, if instrumentation error hasn't been controlled for
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In a sense, this is similar to the 'fast neutrino' story. Potentially paradigm shifting research done on hugely complicated machines that even a team of dedicated researchers (not to mention the hoards of armchair scientists here) cannot fully understand.
Nothing wrong with this - the secrets of the Universe won't necessarily fall to some kid in his basement playing with a hacked Wii, just a cautionary tale.
no obvious errors found yet (Score:3)
Of course there could be systematic error, but the source must be pretty subtle. The authors have done a pretty large study (in two "two be published" papers).
The implied fine structure constant is derived from relationships among various spectral lines not some large overall effect. The paper mentions that there are 6 quasars which have observations at both telescopes, and they used these data to do some reasonably sophisticated statistical checks.
The best fit to the systematic error corrections between th
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The 'fast neutrino' story is not obviously a math error. Some people attempted to come up with explanations (there are at least 50 preprints from various people) but one of the more prominent ones ("you didn't do GPS/relativity calibration right") is strongly disputed by the original team who said in essence "yes we certainly did, you don't understand our work well enough, and we have done lots of analysis which hasn't yet been published yet"
This is not entirely implausible. People can always make mistakes
Link to preprint (Score:2)
Breaks a lot of dependancies (Score:2)
Many astronomical/physics models _ASSUME_ that the universe has the same fundamental laws across the entire universe. If this holds true, it will throw a lot of models into question, including dark energy and dark matter. Personally, I find it very possible that there will be variations across the universe, based on dependencies we don't know/see/understand. Just because I see snow everywhere I look in Antarctica doesn't mean I should expect to see snow everywhere I look in Africa.
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"Just because I see snow everywhere I look in Antarctica doesn't mean I should expect to see snow everywhere I look in Africa."
No, it's not about that. It'is about the snow on the top of Kilimanjaro (when it was still there) having the same 6 ray local symmetry as the snow in Antarctica.
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You don't do well with analogies, do you?
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Where is Bad Analogy Guy when you need him???
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Kilimanjaro and Antarctica is the same place, in the scale of the universe.
Where is it written that natural laws are equal everywhere? all the time? Tomorrow E=mc^3 is improbable not impossible.
On the other hand, even as I'm arguing with atheists all the time, the "finely tuned" terms used to define conditions for life is a post facto rationalization, not an argument. You can't say anything about what would have happened if laws were different, you have not enough power to model such scenario. So if our fin
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Not quite correctly stated. The conclusion has nothing to do with what you believe, it is a belief. The correct statement would be something like: "If a god exists and has sufficient complexity to be considered `alive' and `sentient' and sufficient entropy to be able to experience something like `desire' -- all necessary to "want something", and if there is such a
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The Spinozan Heresy will never die. But here on /. I'd call it "J. Michael Straczynski-ism". Intelligence was created by the universe in order to understand itself. It does have a certain appeal.
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we can do a lot of things today that in the past had been viewed as impossible.
You are of course free to "believe" whatever you want. The universe cares not. Some things we only think are impossible and it turns out we were wrong. Other things are REALLY impossible. I challenge you to come back from the dead in 100 years and prove me wrong.
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Dark energy and Dark matter are very different things which address very different problems in astronomy - the only thing they have in common is the term "dark", used because they are both describing forces and objects which are inferred to exist by - well a force we conventionally don't consider ourselves to "see" (gravity).
Dark matter has been very convincingly observed [stanford.edu] in the bullet cluster, for example.
Your disbelief is essentially a limitation of human senses - we're EM friendly beings, particularly in
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Re:Breaks a lot of dependancies (Score:5, Insightful)
Many astronomical/physics models _ASSUME_ that the universe has the same fundamental laws across the entire universe.
Indeed. It's an assumption that's worked very well for us so far, but it is still just an assumption.
Much like it is an assumption that we live in a causal universe; the loss of this sanity-preserving assumption being one of the possible consequences of the FTL neutrinos being real.
Personally, I find it very possible that there will be variations across the universe, based on dependencies we don't know/see/understand.
If those dependencies are the same everywhere, but local conditions cause the apparent behavior to differ, then our base assumption is still correct, it's just we weren't looking at a fundamental enough set of rules.
Just because I see snow everywhere I look in Antarctica doesn't mean I should expect to see snow everywhere I look in Africa.
The rules that cause it to snow in Antarctica are the same as the rules that cause it to not snow in the Sahara. The rules that cause there to be very little precipitation at all in both places are the same as the rules that cause it to rain a lot in the Amazon.
When one says that one shouldn't expect things to be the same in different places, this is trivial when "things" are conditions and thus effects, and a vastly deeper meaning when "things" are the laws that cause different conditions to result in different effects. It isn't obvious that this is a natural extension or expectation.
It still could be the universe we live in, though. I worry that if the laws of physics are truly different in different parts of the universe -- not that what we think of as the laws are the consequence of a deeper set of laws and varying conditions -- that this means it will be basically impossible for us to make sense of the large-scale universe. Much like how a non-causal universe would mean we might never be able to understand the universe outside of the range of conditions where causality appears to hold.
Schrodinger's Quasars? (Score:2)
Quasars in the northern hemisphere seemed to have a slightly smaller value for alpha, while those in the northern hemisphere tended to have a slightly higher value.
Schrodinger's Quasars? Both larger/smaller in the Northern Hemisphere?
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Or like Heisenberg's. We know so well the Earth's speed and alpha's speed of change, we don't know where we are. :P
Anthropic principle (Score:3, Insightful)
"may explain why the laws of physics in our corner of the universe seem to be finely tuned to support life"
http://en.wikipedia.org/wiki/Anthropomorphic_principle [wikipedia.org]
The universe is not tuned for life. We are tuned for the universe.
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Or how about: out part of the universe is tuned for life?
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rgb
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Is this the latest version of the creationist argument? I'm just curious. We've gone from "we were handmade out of clay" to "conditions were set (by a vast entity with enormous amounts of organized structure that surely must be emergent temporal order arising from a set of internal rules governing the parts from which it is composed) so that we (humans) would randomly evolve"?
Perhaps it is. It seems to me that a being capable of doing "let there be light" has got his hands on the controls of the fundamental constants of the universe.
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I know, I know. They are "magic", right? Or you will say something like "I don't know" as if the very impossibility of imagining a model meta-Universe containing God (and then a meta-meta-Universe and so on as needed) is some sort of excuse for claiming that this one requires an outside explanation (God) but God's Universe
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False Vacuum (Score:3)
I've always wondered about this (Score:4, Insightful)
I am not a theoetical physicist, I don't play one on TV and I didn't stay at a Holiday Express last night.
But I've always wondered how we know that the speed of light is the same regardless, that the gravitational constant is constant throughout space and time. Yes, I understand that you have to assume consistency until proven otherwise. Frankly, I am not convinved that the last two "discoveries" will pan out and that we've found non-constant constants. But it confirms to me that this is not a resolved question like so many others have claimed when I have asked the question.
All of it makes me wonder what the mechanism is that determines c or the gravitational constant, the electro weak force and a myriad of other variables that determine the way the universe exists. The only thing that is clear to me is that we understand so freaking little compared to the way the universe must truly be.
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Because we live in a freaking corner of a small room of a really small house in the middle of a ginormous world. We've been space faring for less than a century and there are only a handful of human beings who have been past LEO. We are woefully ignorant of the universe at this point. It is a starting point. I only ask that we imagine that what we think of as constants may not be constants.
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Re:I've always wondered about this (Score:4, Insightful)
The point is, it is best to believe the things that best fit the data (and satisfy a few other requirements, such as consistency, parsimony, and so on) all the time, but not unreasonably best belief moves around as we obtain more data and discover and resolve inconsistencies. It moves around slowly because we have learned from experience to doubt observations unless/until a certain standard of consistency, parsimony, observational reproducibility, and so on has been reached. New physics is always great fun, skepticism is better than unreasoning belief, but reasoned, evidence-based conditional belief, believing the most in those things one can doubt the least (when one tries to doubt very hard), is a lot better than jumping on and believing every half-assed claim that is made on the basis of possibly flawed methodology and revelling in it just because it proves that "we don't know everything" and that therefore, very smart people aren't as smart as they think they are (closing the gap mentally between yourself, so quick to see the truth of it all, and them, the fools).
Does that pretty much sum up much of the discussion above, so far?
A sound result will prove to be reproducible and even a sound result (as far as the observation is concerned) may have many possible explanations, including (quite possibly) ones that don't mess with the fine structure constant. For example, the precession of the orbit of mercury could be viewed as a violation of the law of gravitation, and in one sense it is, but in a deeper sense it is not -- gravity is all right but it needs to be formulated in a relativistically curved spacetime -- the real error is in assumptions made about space and time itself, not "gravity".
rgb
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"The problem is that there is a lot of data that is perfectly consistent with \alpha being constant. There is a nearly complete lack of data suggesting otherwise."
Until now. And yes, the point is that if you look at stars inside the galaxy and many others \alpha is constant---only with a systematic search on the most distant quasars literally on the other side of the universe do you see an effect which is a relative 0.5 * 10^(-5) deviation.
It's just like the fact that space is nearly exactly flat everywher
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We do have the ability to look out into space, sometimes pretty far, and we can observe that some things happen the same way there as out here.
You can observe things like the color of distant stars, the rotations of galaxies, even the cosmic background radiation. We can see, for example, that hot hydrogen on a distant star has exactly the same kind of spectroscopic signature that hydrogen here on earth does.
The simplest explanation for that is that the fine structure constant is the same there as here. Th
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But we don't, we see a redshifted version. We have explained that this is because the galaxy is moving away but maybe it's something else.
P.S. I am a physicist, an experimental type.
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Right, I didn't want my comment to be any more involved than it already was. I did try to allude to it.
Yes, we see a redshifted version, and the simplest explanation so far that matches the data to a lot of decimal places is that the hydrogen is/was doing exactly the same thing when it left the source, and we see it shifted to the red. Or it could be some other model, but just tinkering with the fine tuning constant (or other constants) doesn't fit the data. You'd need a lot of other changes, which ultim
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Agreed on all points, but then again it wasn't until fairly recently that anybody spotted problems with Newtonian physics.
Physics is based on data, and data is collected only from what you can observe. If all you look at is billiard balls then you'll never come up with relativity. As our ability to gather information about the universe increases we may find more and more stuff that doesn't fit the current mold, and that's a good thing.
Dark matter hints that we don't fully understand gravity on the large s
Duh! "Finely tuned to support life" (Score:2)
"The laws of physics in our corner of the universe seem to be finely tuned to support life."
Now don't run into too quick conclusions! We don't really know whether this corner supports life better than the rest of this vast space, do we?
The life is so complicated.
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It's not so much that that laws were tuned to support life, but that life formed where the laws happened to be suitable.
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Well it's not really about supporting life, but much more basic things like allowing matter to form, allowing stars to exist etc.
Typical Slashdot Summary (Score:3)
Astronomical observations seem to indicate that the constant, which controls the strength of electromagnetic interactions
This is just too glaringly bad to not bash, although there probably have been worse summaries. The constant does NOT CONTROL ANYTHING about the physical universe, as that is obviously the whole point of this research. It is simply a number which we have determined appropriately models the physics we are able to explore and understand to some degree.
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"it is simply a number which we have determined appropriately models the physics we are able to explore and understand to some degree."
as an essential and elementary free parameter of the quantum theory, I'd say that counts as much as anything else as "control something about the physical universe".
Finely tuned for life? (Score:2)
But which constant isn't? (Score:3, Interesting)
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I think the value of pi is different in different regions of space.
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rgb
not new; not really controversial, just wrong (Score:5, Interesting)
First off, the slashdot summary is somewhat misleading, because the result is not new. Their result was announced in August 2010: http://arxiv.org/abs/1008.3907 [arxiv.org] . What is new is that they finally managed to get it published in a peer-reviewed journal. You can't judge whether it's right or wrong simply based on whether it's been published in a peer-reviewed journal. Peer review doesn't judge whether a result is right, or whether it can be reproduced. Peer review just tries to judge whether there are obvious mistakes, and things like whether it properly cites the previous literature. The fact that the journal is a prestigious one also doesn't mean it's right; it just means that *if* it were right, it would be of a high level of scientific importance.
Second, it's not really correct to say that the result is controversial. It's not controversial. It's wrong, and the fact that it's wrong is uncontroversial. Just because there's an overwhelming consensus that a result is wrong, that doesn't mean it can't be published in a peer-reviewed journal. Below is a FAQ entry I wrote about this stuff.
Has the fine structure constant changed over cosmological timescales?
It has been claimed based on astronomical observations that the unitless fine-structure constant alpha=e^2/hbar*c actually varies over time, rather than being fixed.[Webb 2001] This claim is probably wrong, since later attempts to reproduce the observations failed.[Chand 2004] Rosenband et al.[Rosenband 2008] have done laboratory measurements that rule out a linear decrease of alpha with time large enough to be consistent with Webb's results.
Webb et al. have recently made even more extraordinary claims that the fine structure constant varies over the celestial sphere.[Webb 2010] Extraordinary claims require extraordinary proof, and Webb et al. have not supplied that; their results are at the margins of statistical significance compared to their random and systematic errors.
Even if their claims are correct, this is not evidence that c is changing, as is sometimes stated in the popular press. If an experiment is to test whether a fundamental constant is really constant, the constant must be unitless.[Duff 2002] If the fine-structure constant does vary, there is no empirical way to assign blame to c as opposed to hbar or e. John Baez has a nice web page discussing the unitless constants of nature.
J.K. Webb et al., 2000, "Further Evidence for Cosmological Evolution of the Fine Structure Constant," http://arxiv.org/abs/astro-ph/0012539v3 [arxiv.org]
J.K. Webb et al., 2010, "Evidence for spatial variation of the fine structure constant," http://arxiv.org/abs/1008.3907 [arxiv.org]
H. Chand et al., 2004, Astron. Astrophys. 417: 853, http://arxiv.org/abs/astro-ph/0401094 [arxiv.org]
Srianand et al., 2004, Phys.Rev.Lett.92:121302, http://arxiv.org/abs/astro-ph/0402177 [arxiv.org]
Duff, 2002, "Comment on time-variation of fundamental constants," http://arxiv.org/abs/hep-th/0208093 [arxiv.org]
Baez, http://math.ucr.edu/home/baez/constants.html [ucr.edu]
Rosenband et al., 2008, 319 (5871): 1808-1812, http://www.sciencemag.org/content/319/5871/1808.abstract [sciencemag.org]
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I sincerely regret the abuse that I'm certain will be heaped upon you for having the temerity to state the obvious and worse, actually back it up with references. Be thankful that at least it is difficult to reach you with pitchforks and torches.
Ah, well, you tried. I guess I'll continue to skim down and glance at the abuse.
rgb
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In other words, if those experimentalists would just stop publishing data that contradict our beautiful theories we could stop having to add layers of invisible darkness to our models. What will it be called this time?
Wow, welcome to my foe list.
1) He didn't say or imply that, and prefacing it with "in other words" is just a weaselly way to mischaracterize the implications of his post.
2) Statistics matter. When one study shows an extraordinary new result that is directly contradictory to a multitude of previously published, well understood experimental studies, that result must be backed by very statistically significant results.
3) Regarding your dark matter metaphor, the main alternative to dark matter, MOND, was recen
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north and south in the results are obviously not in the Earth's coordinate system, they used the galactic coordinate system.
There are previous results of things which people thought to be ought to be homogeneous which turn out not to be so. The cosmic microwave background turns out to have a peculiar dipole asymmetry, and then there is the related but newer "axis of evil", which shows peculiar polarization asymmetry and even the apparent "spins" of galaxies are inhomogenously distributed.
This, dark matter
Systematics (Score:2)
PRL is really getting
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To be fair, if you RTFA, you'll see a diagram showing the various measurements they had made. I've not counted them, but it appears to be several dozen different "spots" rather than the two that you suggested.
Yes, very true. And they do discuss possible systematics in some detail. But most of the significance of their "dipole" looks like it comes from a very small fraction of the data. Sure, you can fit the data to a dipole and calculate a statistical significance, but does that fit really mean anything? The reasonable conclusion from comparing the Keck and VLT data is that the method, for whatever reason, is a lot less reliable than they are assuming it is. The four-sigma significance quoted is really hard to t
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Please call me when they look at the same spot with two different telescopes, and different spots with the same telescope. Using the same spectral lines.
They've done that. There are a handful of objects that are common across the two datasets. Unfortunately there is a certain amount of hand-waving in their analysis, pointing out that in one case they were able to show mis-calibration between the two datasets, and naively including this "miscalibrated" point in the overall analysis reduced the significance of the final result a lot (2 sigma or so).
Their Figure 2 shows the "dipole" distribution but they have relatively few objects at high angles, so the res
So maybe there's hope... (Score:2)
Then again... (Score:2)
Does that explain the arrow of time? (Score:3)
The article suggests that the change is over time not space.
The real significance is that it would be the first law of physics, aside from entropy that has an arrow of time on it. (And most assume entropy is somehow an artifact of other laws of physics.) Maybe we can reverse this function, so instead of the fine structure constant being a function of time, time is a function of the value of the fine structure constant and its weakening increases the universes entropy.
INAP, but it seems like maybe a decrease in the fine structure constant would increase the tendency of particles to emit and absorb electrons, and therefore make the universe more chaotic over time.
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Observation in quantum mechanics isn't symmetric on time either. It tends to be ignored, because we have no good definition for it, but it exists, is central to one of the most important theories of physics, and is assymmetric.
It's also badly defined, what is worth repeating, because it is simply incredible for a concept that is central to one of the most important theories of physics...
Connection with OPERA (Score:2)
So, a few weeks ago we heard that light travels a little bit slower than the fastest objects we've measured. This week we hear that in galaxies far, far away, either the electric charge is larger, Plank's constant is smaller or the speed of light is smaller. If it's the speed of light that's smaller, the required slow-down is of the same order of magnitude as the factor by which photons are slower than neutrinos as observed by OPERA.
Here's my take. There's a field of undetected particles (dark matter?) t
Anthro-whatever (Score:2)
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Yeah, that could be one interpretation of what he's saying and thank you for correcting that line of thought, but there could be another implication that everyone is missing. He could be trying to explain the lack of life elsewhere ( because the fine structure doesn't allow it elsewhere). So yes,we are tuned to the universe, but maybe sentient life can't exist in other areas of the universe with different fine structure constants.
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Therefore, anywhere a consciousness happens to exist is "finely tuned".
Now you are also stating that physical constants are different in different places.