Has dust clouded the discovery of gravitational waves?

Jun 04, 2014 by Alan Duffy, The Conversation
There’s a lot of dust between us and the edge of the universe. Credit: H Raab/Flickr, CC BY-NC-ND

It's almost three months since a team of scientists announced it had detected polarised light from the afterglow of the Big Bang. But questions are still being asked about whether cosmic dust may have clouded their discovery.

The latest, and most damning, piece was in Nature News last week.

What made the original announcement from the Background Imaging of Cosmic Extragalactic Polarisation (BICEP2) team so exciting was that the twisting pattern on the sky could be caused by .

If true, as we wrote on The Conversation at the time, then these gravitational waves could come from the very earliest times in our universe, a trillionth of a trillionth of a trillionth of a second after it all began. The twisting pattern would be a unique window into these early times.

But as the US astronomer Carl Sagan pointed out: "Extraordinary claims require extraordinary evidence." As much as there was excitement over the BICEP2 announcement, there were also many questions.

And then it all went crazy

A blog post in early May was one of the first to question whether the BICEP2 team might have incorrectly interpreted their data (which they completely deny incidentally).

But it sparked further articles in Nature, Science and NewScientist.

There were excellent, more nuanced summaries in the Washington Post and blogs by physicists Richard Easter and Sean Carroll to name but two who investigated the claims surrounding the result.

It is normal that scientists debate their new findings and confront them against existing theories and data. This is how science works. Such peer-review is a key aspect of the successful, centuries old tradition of the scientific method.

Ordinarily such scientific debate attracts little attention. But with a discovery that could explain the earliest moments of our universe, the stakes were high, and things became very public.

What about the dust?

At the heart of this heated discussion is something quite cold – .

The light from the Cosmic Microwave Background (CMB) has to pass through a lot of intervening material as it travels for nearly 14 billion years to reach our telescopes.

Does the twisted pattern of polarised light in the cosmic microwave background really show evidence of gravitational waves?

Our galaxy, in particular the cold dust grains drifting within it, is a very important source of confusion when trying to understand just how much of the light hitting the telescope is from the CMB and how much from the stuff in the way.

Think of trying to take a picture of a beautiful sunset in a sandstorm and you're getting close.

How you account for dust in our galaxy is crucial. Do it wrong and you can mistake it for the signal you want to find. The best way to remove this dust from the signal is to map the sky in many frequencies (or colours) of light.

The BICEP2 team only had one frequency available in a bid to maximise how sensitive a picture they could make. They then relied on other measurements of the dust to make up for this.

The European Space Agency's Planck satellite is currently doing just this. Unfortunately, this data is not fully processed yet for general use.

A quest for dusty image

So the BICEP2 team decided to estimate the amount of dust using theoretical models, as well as any data available at that time.

One such measurement – and this is where things get messy – is a digitised powerpoint slide (below) of a Planck work-in-progress map of the sky shown at a conference talk.

This is certainly unusual and not to be encouraged (especially as it was preliminary analysis) but not necessarily cause to throw out the result.

However, meticulous reanalysis of both the Planck picture and BICEP2 data by Princeton physicist Raphael Flauger (whose talk you can watch here with slides here) show that BICEP2 has likely been overly optimistic about the level of contamination from the dust.

A typical sandstorm clouds the light from our sun. Credit: Flickr/Lou, CC BY-SA

A paper that presents this analysis suggests that for all but the lowest estimates of the confusing signal from the dust, the BICEP2 results show no strong evidence for gravitational waves.

Yet, as was the case two months ago, Planck (and others currently running experiments) will have the final say on all this.

What lessons we can learn?

Now the is settling on BICEP2 (or at least until Planck releases its results in October) we can ask two important questions, regardless of what has or has not happened within the team's analysis:

  1. what happens if Planck shows BICEP2 to have been right? Who will get to make the claim of the detection as now, seemingly, without Planck no one can actually be sure that BICEP2 was correct?
  2. how has the debate impacted the public's view of science, from the high of the initial announcement to the low of the blog-based questioning and criticism?
The Planck image used by BICEP2 team. Credit: European Space Agency

As a community, we have to decide whether high profile announcements made before publications are peer-reviewed run the risk of the public becoming jaded of science, especially if claims are later retracted.

Or perhaps gaining the public's attention is worthwhile, along the lines of Irish wit Brendan Behan's remark: "There's no such thing as bad publicity, except your own obituary."

Discoveries and debates such as this one will always attract public and media attention. This can only be good for science so long as the public understands that real science is never a straightforward process. It is a slow, diligent process and for every big step forward there are a few back.

There will be discussions and disagreements among scientists along the way. That's all just part of the process of trying to advance the boundaries of our knowledge.

Krzysztof Bolejko receives funding from The University of Sydney.

Alan Duffy does not work for, consult to, own shares in or receive funding from any company or organisation that would benefit from this article, and has no relevant affiliations.

Explore further: Are the BICEP2 results invalid? Probably not

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Urgelt
4.6 / 5 (10) Jun 04, 2014
Worrying about the public becoming 'jaded' about science, should they happen to catch wind of honest debate among scientists where consensus doesn't yet exist, is not the right worry. Transparency is good; science should always be honest about its debates (and they're interesting, too).

The real concern is that public science education has become so poor in the US, many adults believe that uncertainty *anywhere* in science undermines scientific credibility *everywhere.*

That's not a problem that can be solved by going behind closed doors until the scientific method produces a consensus.

Instead, get students excited about debates in science, about the difficulties in interpreting evidence, about the boundaries between the known and the unknown. Teach them to think critically.

HIding science's internal workings will only distance the public even further. And teaching only the consensus part of science will not excite students to enter the field. The unknown is where the fun is.
Teper
Jun 05, 2014
This comment has been removed by a moderator.
antialias_physorg
5 / 5 (7) Jun 05, 2014
We have to recall from time to time that science works at the very frontier of what is barely possible. It's not engineering. And at that frontier mistakes will happen on occasion.

The openness of the debate is a good thing. It reaffirms that science is not something that is invested in s status quo, as some here seem to believe (if it were nothing would ever happen in science)

But in the end the presentation of the debate in the media is irrelevant. The public can't contribute. At best it's a spectator sport (and we all know that 'fans' mean nothing when it comes to how a sport is performed - other than to themselves). So for the public this is science porn.
Teper
Jun 05, 2014
This comment has been removed by a moderator.
antialias_physorg
5 / 5 (7) Jun 05, 2014
Your stance contradicts the idea of "public peer review",

"Public peer review" makes as much sense as asking the public to review legal texts or sports performances.
If you know nothing about a subject then you're not a peer.
The review was triggered by someone in the field who had knowledge of the relevant data getting in contact with the authors. Not by his blog post.
A non-peer without the data cannot do this (and doesn't have the knowhow to judge in any case even if he did have the data) - and therefore cannot initiate a meaningful review.
Incosa
1.5 / 5 (8) Jun 05, 2014
If you know nothing about a subject then you're not a peer.
This is like to say, that the open source programmers can never compete the professionals - actually as we can see, how the professionals often learn from amateurs instead. Many amateurs are actually better oriented in physics, than the closely specialized professionals due to their active interest about wider subject. Whole areas of physics (cold fusion and scalar wave research) is currently driven just with amateurs, as the professionals have no interest about it due to their fear of competition. In addition many bloggers are actually professional researchers in another areas of physics, they're just using to communicate at public.
Incosa
1 / 5 (7) Jun 05, 2014
A non-peer without the data cannot do this
Why do you think? The dismissal of BICEP2 finding can be as simple, as the look at this graph. If you really understand the subject, then it must be evident for you, the background observed wasn't formed BEFORE inflation but AFTER it: the slope of curve says it all and no other math is necessary for it. You can consider it as an analogy of falsification of complex epicycle model just by comparison of order of Venus phases without any actual calculations. Many theorists today survive just because the trivial logical arguments against their theories are ignored. Of course all professionals, who are taking money from tax payers would dismiss and downvote such an opinions instinctively and obstinately by all means possible, because they're economically pretty well motivated into it.
antialias_physorg
5 / 5 (4) Jun 05, 2014
This is like to say, that the open source programmers can never compete the professionals

Programming is not a good comparison. You can learn a programming language in a week. If you practice programming hard you can surely write some worthwhile code within a year. Programming is easy. Anyone can do it.

Science is a bit different. As a non-professional you don't get much of a chance to practice it. You may read some books, but that doesn't compare to 4+ years of studying stuff at uni, 4+ years of getting a PhD and then x+ years of working on a subject 8-10 hours a day under constant testing conditions.

the professionals have no interest about it due to their fear of competition

Fear of competition? No. The professionals just can see that it's bunk (you know: due to the stuff they LEARNED and UNDERSTOOD). Much like that once you learn stuff you understand why something like a perpetuum mobile is a no-go.
antialias_physorg
5 / 5 (5) Jun 05, 2014
then it must be evident for you, the background observed wasn't formed BEFORE inflation but AFTER it:

Erm..you are aware which part of that graph are data points and which part are fiotted curves? You are aware of the notion of error bars?

Yeah...I'd say in your case you're lacking (quite) a bit pf math to get up to speed. But go ahead: Believ that your intuition means diddly squat. You should go to church. You'll feel right at home.

because the trivial logical arguments against their theories are ignored.

They are ignored because they are trivially wrong. At some point you stop arguing with people who are at a kindergarten level of understanding. It's a waste of time. It helps no one. The scientist doesn't get any new insights and it would take years to get the 'child' up to speed. Scientists have better things to do.
For education we have schools. Those that fail to take advantage of them....their loss.
Incosa
1 / 5 (5) Jun 05, 2014
Programming is easy. Anyone can do it. Science is a bit different. As a non-professional you don't get much of a chance to practice it
Nope, science is just about unbiased thinking about relevant data. Everything else is just a politics and a religion. You even have no idea how the contemporary science is generally misleading and wrong, physics in particular. The physicists undoubtedly think, they do their very best all the time, but their obstinate ignorance and censorship of any critique indicates, as a whole they're not very different from opponents of Galileo in his era. The contemporary science is as driven with occupational criterions, as the Holy Church in medieval era - nothing else. In particular, the theoretical physics is just an industry for collection of fees from tax payers. It's nearly completely broken and it cannot get anything correct - even the refusal of BICEP2 is not correct: and now we are talking about correction of otherwise wrong interpretation already.
Captain Stumpy
5 / 5 (6) Jun 05, 2014
You even have no idea how the contemporary science is generally misleading and wrong, physics in particular
@incosa-zephir
personal conjecture based upon ignorance
sorry, science, and physics, are about empirical data, proof, experiments that can be replicated
but their obstinate ignorance and censorship of any critique indicates, as a whole they're not very different from opponents of Galileo in his era
personal conjecture based upon ignorance
when a critique debunks something (like AW/DAW) it is because of the failure of: replicable experiments, empirical data, failure to observe predictions, etc, NOT because politics etc
even the refusal of BICEP2 is not correct
exceptional claims require exceptional evidence
please provide your evidence

Incosa / Teper : these your new sock-puppets? got banned again huh?
antialias_physorg
5 / 5 (7) Jun 05, 2014
Nope, science is just about unbiased thinking about relevant data.

Including lots and lost of background knowledge, lots and lots of experience, and lots and lots of aptitude at maths and (and astronomy, biology, chemistry, what-have-you...depending on your area of expertise). And then add lots and lots of knowledge about an in-depth specialty as a sub region of that area. You don't 'intuit' that. No way no how.

just an industry for collection of fees from tax payers

Since you have no clue about science, have never worked in any area of science, have no education in any scientific field, and have no contact to anyone in any field of science: I call your statement a big fat lie. get out of your chair and try to get some real experience. It'll turn your life around 180°.

You're welcome to live in your fantasy world (as you demonstrably do), but take note that it is just that - a fantasy.
cantdrive85
2 / 5 (7) Jun 06, 2014
Including lots and lost of background knowledge


"Don't let your minds be cluttered up with the prevailing doctrine." Alexander Fleming
Teper
Jun 06, 2014
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Teper
Jun 06, 2014
This comment has been removed by a moderator.
Teper
Jun 06, 2014
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antialias_physorg
4.4 / 5 (7) Jun 06, 2014
"Don't let your minds be cluttered up with the prevailing doctrine." Alexander Fleming

Not doctrine. facts.
An empty mind has nothing to build on. Such a mind will - at best - make the most trivial statements. And anything seemingly even remotely in-depth coming from such a mind will be trivially flawed.
Note that ALL the people who made great contributions to human knowledge had a very solid background in the knowledge of their day (and many were very experienced experimentors to boot). Not a single one was an 'intuiter'.

When you have reliable model on mind, then you can see most of details in advance

A model is only reliable when you have put it to the test. against predictions.

What you just described is the very definition of 'going by intuition'. That's child's play. Why would you ever expect that to deliver any results whatsoever? It hasn't done so througout history.
Teper
Jun 06, 2014
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Teper
Jun 06, 2014
This comment has been removed by a moderator.
Teper
Jun 06, 2014
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cantdrive85
1.8 / 5 (5) Jun 06, 2014
Not a single one was an 'intuiter'.


"Einstein was quite simply contemptuous of experiment, preferring to put his faith in pure thought." Paul Davies
antialias_physorg
5 / 5 (4) Jun 06, 2014
"Einstein was quite simply contemptuous of experiment, preferring to put his faith in pure thought."

But he was not an intuiter. He spent quite some years studying stuff the hard way. And he was by no means contemptuous of the people who did do experiments (like Newton, Hertz, Maxwell, Doppler, and Lorentz from whose work he derived special relativity.)

Read that again: He did not invent relativity out of thin air. He derived it, mathematically, from things that were known, adding his own dash of insight to a deep understanding of then current physics.
zaxxon451
5 / 5 (1) Jun 08, 2014
"Imagination is more important than knowledge. For knowledge is limited to all we now know and understand, while imagination embraces the entire world, and all there ever will be to know and understand."

― Albert Einstein
antialias_physorg
5 / 5 (4) Jun 08, 2014
Imagination is more important than knowledge.

Note the 'more important'. Not 'replaces'..

It's like in racing cars: Is the car more important than the driver? You can argue either way.
but you won't win any races until you have both - and both of an exceptional quality at that.
Currently cantdrive and Zeph have neither imagination nor knowledge. So they're not even at the starting line.

If you forego knowledge the best you can hope for is to become an artist, a priest, or a writer of fiction. (and except for the artist part that's pretty much all the EU-, AWT-, whatever-crowd are)
Incosa
1 / 5 (2) Jun 08, 2014
"Imagination is more important than knowledge. For knowledge is limited to all we now know and understand, while imagination embraces the entire world, and all there ever will be to know and understand."


― Albert Einstein

Albert Einstein was indeed a frontier of physics, an extremely bright and productive mind. You cannot expect, his opinion will fit the attitude of extremely unproductive minds, like the voting trolls at the PO forum. Such an attitudes would be dual, i.e. exactly the opposite at the best case.

The stance of AlphaNumeric is still important, as it illustrates well the mediocre mind of average proponent of mainstream physics, who doesn't take a sh*t about some creativity - the walking in crowd and taking money is everything what he's actually interested about. Not surprisingly he's former scientist already, because the expectations of contemporary scientific community are still higher than that.
Incosa
Jun 08, 2014
This comment has been removed by a moderator.
Captain Stumpy
5 / 5 (2) Jun 08, 2014
as it illustrates well the mediocre mind of average proponent of mainstream physics, who doesn't take a sh*t about some creativity - the walking in crowd and taking money is everything what he's actually interested about
@incosa-Zeph
this is called PERSONAL CONJECTURE based upon delusions, conspiracy theory and ignorance (in your case, stupidity, as you've been shown this is fallacious already)

your problem is that the
formal attitude of contemporary physics
negates your ability to push your pseudoscience DAW religion. GIVEN that there is no empirical evidence supporting your religion, you should drop it and learn real physics before throwing your stupidity around like a badge of honour
This behavior has lead into refusal of aether model
BECAUSE THE EMPIRICAL DATA DISPROVED IT LONG AGO
and it CONTINUES to disprove it!

you forgot your waterbug analogy with your ripples...
methinks you have drank too much Ripple myself
Incosa
1 / 5 (1) Jun 08, 2014
CONJECTURE based upon delusions, conspiracy theory and ignorance
Nope, it just works with all large groups of people, like the lawyers, politicians or for example SW companies. Until they're small, like the Microsoft, Apple in 80's, they remain progressive, when they grow larger, the same rules will make them Big Brothers. There is absolutely no conspiracy in it, this is simply how our universe is working. Even the massive bodies are constructive at the smaller scale, but when they grow into certain size, they will start to destroy these smaller ones. Your obstinate opposition just indicates, you didn't learn anything from physics during whole your life, so you cannot apply your knowledge to another areas and analogies. But it's normal too, many people will remain as silly, as they were born during whole their life. They will collect knowledge, but not wisdom due to their passive stance. You cannot learn a better attitude, if you're not genetically endowed for it.
Incosa
1 / 5 (1) Jun 08, 2014
Actually the aggressive stance of yours toward free thinkers (like me) just illustrates the above model at the case of PO discussions: at the moment, when group of proponents of certain scientific ideology will grow above certain limit, it will not act openly anymore and they will start to suppress all opposite opinions instead.

Aren't just the proponents of science, who are supposed to think most openly and inquisitively at public forums, don't you think? If they're not acting so, what actually changed with their minds? Is some conspiracy behind all of it, or do they act spontaneously and their attitude can be actually predicted? The questions like these ones is just what I'm trying to answer here.
Uncle Ira
5 / 5 (2) Jun 08, 2014
@ Zephir-Skippy, you know you are my old podna from all over the webnet. But you should try to tone it down some with the Captain-Skippy. He is one of the good-guys. He is one of the not many guys who will talk to you nice until you get to writing foolishment at him.

So Neg, maybe you can be a little more calm with him, otherwise I might have to put you on the bad karma point list with Really-Skippy and Reg-Skippy.
Incosa
Jun 08, 2014
This comment has been removed by a moderator.
Uncle Ira
5 / 5 (1) Jun 08, 2014
BTW What kind of dumbness you actually are, if you calling me "Zephir-Skippy"? Such a labeling has absolutely no meaning here. Do you really believe, we are the same person?


Yeah Neg, I really believe you are the same person. I know you for too long podna, Maybe you didn't realize that I am the old Zephir-fan-Skippy so I really know you good me.
cantdrive85
1 / 5 (5) Jun 08, 2014
CONJECTURE based upon delusions, conspiracy theory and ignorance

Nope, it just works with all large groups of people, like the lawyers, politicians or for example SW companies. Until they're small, like the Microsoft, Apple in 80's, they remain progressive, when they grow larger, the same rules will make them Big Brothers. There is absolutely no conspiracy in it, this is simply how our universe is working.


This study agrees with Zeph, the financial system operates as he claims and to suggest the scientific community behave differently is idealistic and naive.

http://arxiv.org/...28v2.pdf

He's just lazy to think and the dumb people do harm no matter how good their intentions actually are (most of downvoters seriously believe, they're guarding the science from crackpots with their activity).

Hear,hear...
RealityCheck
1 / 5 (2) Jun 08, 2014
Hi antialias_physorg. Can't stay, just reading through, but thought this pertinent observation from you on this aspect deserved a brief pertinent observation from me in return.
We have to recall from time to time that science works at the very frontier of what is barely possible. It's not engineering. And at that frontier mistakes will happen on occasion.

The openness of the debate is a good thing. It reaffirms that science is not something that is invested in s status quo, as some here seem to believe (if it were nothing would ever happen in science)
...
Yes indeed. Someone should tell that to any 'pretend scientist' trolls here who 'attack the messenger' instead of question status quo/claims 'published' in patently flawed 'papers' claiming 'discoveries' which are merely 'artifact of data processing', based on assumption and flaws 'built-in' by prior 'flawed papers' such that 'results' of later 'papers' reflect underlying flawed 'methodology' and 'interpretations'. Cheers! :)
zaxxon451
not rated yet Jun 09, 2014
Note the 'more important'. Not 'replaces'..


Of course, knowledge should serve as the springboard for imagination. But Einstein understood the value of epistemological humility. I seriously doubt that humans have the capacity to ever completely understand Reality. Still, the scientific method is a valuable tool, but not the only method of discovering Truth. Plato, Gandhi, Buddha, Martin Luther King Jr., all understood important truths of the human condition without the application of the scientific method.
Captain Stumpy
5 / 5 (2) Jun 09, 2014
Actually the aggressive stance of yours toward free thinkers (like me) just illustrates the above model at the case of PO discussions
@zephir
I don't have problems with free-thinkers as long as they bring evidence, empirical data or at least a logical progression of thought extrapolated from real physical principles (which is what science is all about), so that rules you out
He's just lazy to think
LMFAO! I'm too lazy because you will not bring empirical evidence to the table and prove your point? WOW, zeph! a zinger! good one. that'll teach me! LOL
He is one of the good-guys
@Uncle Ira
Thanks Ira, but Zeph doesn't like me because I keep posting proof against his daw/aw religious belief, or I ask him for empirical evidence, which he cannot supply. he takes it out on me which is fine... at least I can prove my POV.
If zeph calls you names, then you are doing something right.