Following up on the spectacular first year of data reported by the WMAP experiment in February 2003, results of analysis of the next year’s data were initially planned to be released a year later. The release of this data has been repeatedly delayed; for speculation about why, see here and here.
Over the last two years there have been a large number of scheduled colloquia by WMAP scientists that have been cancelled at the last moment. One relatively recent one was an astronomy colloquium at Caltech by Gary Hinshaw with the title “New Results from WMAP” that was initially scheduled for January 4, but was cancelled and now is scheduled for March 22.
From March 23-25 the new Center for Cosmology at UC Irvine will be hosting a workshop on Fundamental Physics With Cosmic Microwave Background Radiation. On the 23rd four WMAP team members are scheduled to speak with titles: “WMAP 0, WMAP I, WMAP II, and WMAP III.”
Over at CosmoCoffee (where I first noticed this), Alessandro Mechiorri is spreading the rumor that data will be released next week, on March 14. There’s also discussion of this at the Bad Astronomy and Universe Today Forum. So, looks to me like it’s maybe next week, and if not, almost certainly the week after.
Update: More news about the state of WMAP from Urbano Franca here.
Update: Looks like it definitely will be very soon now, possibly some time this week. The WMAP Mission Status page says:
Second Data Release
While the first-year results were based mainly on temperature measurements, the continued mission operations are now primarily focused on the much weaker polarized signals – an invaluable “stretch” goal of the extended mission. Analyses of these weaker signals are more difficult. The calibration and systematic error analyses have been completed, and the data files have been documented for use by researchers. For an overview see RESULTS.
This last link is to a New Three Year Results page which right now just says:
Stay tuned for the release of the most recent results from the Wilkinson Microwave Anisotropy Probe (WMAP). Very soon now….
Update: It’s official, the release will be on Thursday. Here’s the announcement:
Dear colleagues:
We are pleased to announce that the next release of WMAP data, along with papers describing the results, are expected to be available on LAMBDA this coming Thursday, March 16 at 12 noon EST.
http://lambda.gsfc.nasa.gov/
There will be no televised press activity associated with this release, so in an effort to reach as wide as possible an audience, please forward this announcement to colleagues of yours whom you think may be interested.
Thank you very much – we look forward to seeing your analyses of the data!
Sincerely,
Gary Hinshaw
NASA/GSFC
for the Legacy Archive for Microwave Background Data Analysis (LAMBDA)
WMAP is the “big mover” in the SPIRES table of citations. astro-ph/0302209 is now in the 7th place, jumping from a 37th last year.
I was, as soon as I heard of it, intrigued by the notion that the universe might be finite, non-Euclidean at the largest scales, and that its topology would make it “multiply connected”. I guess, beyond the quadrupole and octupole anomalies (which I’ve read might suggest interesting topology, but, pessimistically, could likely rather suggest some kind of directional bias in the measurements, as they align with the ecliptic), the evidence points to flat and infinite. Which is kind of depressing (if I understand things at all correctly), as it might mean we really have no idea what else is out there beyond our horizon, and never will. Seems reasonable to me the delay is due to attempts to get a firm grip on the source of the anomalies, and determine whether or not it’s a foreground issue.
Alejandro,
Thanks a lot for generating that list and for the link to it. Do you have any idea about how to generate a list of most heavily cited papers not of all time, but just for 2005? I wrote to the people at SLAC asking if they will be doing this, but haven’t heard back.
Peter, sorry I have tried (I had tried yesterday) but I can not see how to calculate the 2005 most cited from only the. Neither the email interface to SPIRES nor the web one give a hint about how to access the citation count fields. I think that the yearly calculation needs some special script running on the database.
The Spires people is usually hepful, er, helpful. It is only they take its time to answer. But I got finally a good feedback when doing my genealogy projects, and they even implemented the genealogy posibility to hepnames (it has problems with name duplicates, so again it seems is not so easy to interface hepnames from the web).
“from only the available indexes”
(…)data will be released next week, on March 14.
Nice date. Einstein´s birthday (and also mine [grin]).
Thanks for bringing these rumors to our attention.
Christine
Now I think about, it could be possible to use the difference between current and 12/2004 citation counts to get an estimate of the “only2005”; the problem should be about new papers in the list, that should get a default “999” or so, or to approximate from citebase plots. Hmm, to much time needed.
Dumb Biologist and Everybody,
Could the results from the WMAP change our ideas about whether or not the universe is finite? I am just ignorant on what questions it is aiming to answer.
-Andy
“the evidence points to flat and infinite”
The evidence can point to flat, but obviously it cannot point to infinite, though a lot of people who ought to know better will try to tell you otherwise. There are some people who have a theoretical bias in favor of infinite spatial sections, but [a] these arguments are very dubious indeed and [b] there is no possible way that the observations can ever give us any reason to believe in infinite sections. In fact, many of us regard infinite spatial sections as a version of the landscape……
Andy: Being a dumb biolgist, I kind of have to trust the astrophysicists on this one a bit, and others with the head for maths to cast the actively critical eye that I lack. I’m not sure if I have many ideas to change, just an active and enthusiastic interest in what I can only characterize as “awesome” ideas like the universe having a doughnut topology, or some other such mind-bending sort of concept.
Amanda: Can you elaborate? Because part of the reason I find such infinities a little discouraging is precisely because it smells like Landscapology. In fact, I recall reading a Scientific American article some time ago on the subject of an infinite universe that kind of disconcerted me. The bacis gist was even if the laws of physics are the same throughout this infinite section, as you put it, there are other Earths out there, with other copies of myself. Perhaps many. I guess there just have to be if the chance of such a configuration is non-zero. And maybe on some of those other Earths I’m a leading String Theorist. The whole time I was reading this I was thinking “Oh, come on.” That’s the annoying thing about infinity. Anything that can does happen. How can you deal with that scientifically?
Now that I think about it, Andy, I guess I have to admit I do have some biases…and yeah, I probably would have to change my mind about some things. Oh well.
Dumb Biologist and Others,
The reason I was directing the question to you was that you mentioned evidence about “flat and infinite.” I was thinking that you don’t have to be a researcher in the area to know what “the party line” is about what the WMAP data is addressing and maybe you had read something where they explained that this is what they were addressing with the WMAP data. From Amanda’s post it seems that the idea of an infinite universe isn’t even on the table. After I posted my question I thought about it and I thought that they would have to be questioning the big bang if they thought the universe was not finite. I didn’t think they were doing that. So maybe Amanda will tell us some more or maybe somebody else will.
-Andy
One can never tell that the universe is infinite because we can only see a finite fraction of it. It’s always possible that nontrivial topology is just beyond the horizong.
Andy:
Well, what can I say? I keep reading over and over that the WMAP data is reported to fit pretty darn well with a model of the univers that is “flat and infinite”. Now, sometimes folks say the Universe (by “Universe” I mean, of course, what is within our horizon) is infinite in the sense that it will continue to expand forever. Sometimes they seem to be saying “The Universe” (meaning that which is not necessarily within our horizon) really is infinte. Always was, always will be. So, certainly all that we see now once occupied a space no bigger than an atom, but that’s obviously not all there was in this version of the idea. The visible region of space expanded (and continues to do so), but maybe the same was going on beyond our horizon, as far beyond as you like. Or maybe something else is going on. I keep thinking “well how can we know that?”, and, per Aaron Bergman’s statement above, I don’t understand how anyone could assert anything other than “We can’t. Not really.”
Hi all,
I’m a mathematician and my knowledge of physics and it’s terminology is feeble, so I have to questions:
1) When you are saying infinite or finite in this discussion, you mean non-compact or compact spacetime respectively?
2) It makes any physical sense to spacetime being a manifold *with* border? If the answer is yes, the border is (+++) or (++-) and why so?
Thanks in advance
Well, don’t take my word for it, but my understanding is the WMAP data (among other things) implies an “open” universe, which is, I guess, by definition, non-compact, i.e. unbounded.
It’s a bit trickier than that, unfortunately. Spacetime is always noncompact because time seems to be infinite in the future. So, what one ought to mean is that space is compact or not. The problem with that, however, is that there usually isn’t a distinguished foliation of spacetime by spacelike hypersurfaces. Worse, you can sometimes foliate the same spacetime by compact and by noncompact spacelike hypersurfaces.
Nonetheless, you can still ask things like does any closed spacelike surface (w/o boundary) exist. You can also look at the spatial curvature. If it’s positive everywhere, then you better have a compact manifold if I remember my math correctly. If you could, for example, shoot yourself in the back, that has consequences when you look at the sky and people look for those effects.
Or something like that.
Can we trust this data to be free of neoconservative spin, so to speak? And why the f=ck has it taken so long? One hopes there was an apparent anomaly that could not be ignored, and has now been assigned an unknown physical cause because the anomaly is real and can’t be ignored (correlation with the ecliptic plane for example).
-drl
What I’m going to say is my understanding after speaking to a real expert — ie, modulo possible misunderstandings on my part:
Aaron Bergman said:
“It’s a bit trickier than that, unfortunately. Spacetime is always noncompact because time seems to be infinite in the future.”
You’re assuming that it will always accelerate. We don’t have any reason to believe that it will….but anyway, to be really strict about it, a spacetime with a bang and a crunch is non-compact even though its total age is finite [open intervals and all that….]
“So, what one ought to mean is that space is compact or not. The problem with that, however, is that there usually isn’t a distinguished foliation of spacetime by spacelike hypersurfaces. ”
Actually, usually there is: the spacelike sections in which one sees isotropy. The main exception is deSitter, which contains nothing but vacuum energy anyway so it looks isotropic to lots of different observers!
“Worse, you can sometimes foliate the same spacetime by compact and by noncompact spacelike hypersurfaces.”
I think I would say “various parts of the same spacetime”, eg you can’t foliate *all* of deS with non-compact spacelike hypersurfaces [I think!]. Remember that *all* of dS has the topology of a line times a sphere….
“Nonetheless, you can still ask things like does any closed spacelike surface (w/o boundary) exist. You can also look at the spatial curvature. If it’s positive everywhere, then you better have a compact manifold if I remember my math correctly. ”
Assuming they are complete, yes.
“If you could, for example, shoot yourself in the back, that has consequences when you look at the sky and people look for those effects.”
People look for such things, but they have not seen them [yet?]. But absence of evidence is not evidence of absence…
“Or something like that. ”
Agreed. 🙂
So the most likely result is that space is _locally_ infinite?
🙂
Please forgive my ignorance…
Now I know a manifold is something that might look Euclidean up close, but globally could be more complex. A foliation is…? Looks like it’s something with a bit more variety globally, yet locally describes the manifold. Is this at all correct? If you don’t mind helping me a little with pictures, if I were to take a spherical manifold and foliate it in some allowed way (I assume not any sort of foliation is allowed), what would those foliations look like, and what would/could they tell me about the sphere?
D.B.,
We’re getting off topic here, but in this context a foliation just means that you can globally choose hypersurfaces of constant time that can be interpreted as “space”.
More generally a foliation of a manifold is something like a choice of families of submanifolds that fit together to fill up the manifold. One simple example is a fibration, i.e a foliation where all the “leaves” (in this case called “fibers”) of the foliation are isomorphic, and locally the manifold looks (fiber X nbhd. of point).
A famous example is the Hopf fibration of the 3-sphere, a foliation by circles. The general story of what foliations of spheres can look like is quite intricate.
You’re assuming that it will always accelerate.
No. Just that there’s no big crunch. (Although, as you say, there are compactness issues associated to singularities that I was ignoring.)
Actually, usually there is: the spacelike sections in which one sees isotropy.
I was speaking generically; most spacetimes are not isotropic.
“Worse, you can sometimes foliate the same spacetime by compact and by noncompact spacelike hypersurfaces.”
I think I would say “various parts of the same spacetime”, eg you can’t foliate *all* of deS with non-compact spacelike hypersurfaces [I think!]. Remember that *all* of dS has the topology of a line times a sphere….
You can, however, take a quotient of dS so that you’ve covered the whole thing, IIRC.
People look for such things, but they have not seen them [yet?]. But absence of evidence is not evidence of absence…
As I said above, there’s always the possibility that these things are lurking just behind the horizon. All we can do is observe what we’ve got and talk about that.
OK, sorry to get off topic, and thanks for the brief lesson!
drl: I can’t imagine any other reason for the delay that makes sense, given what is known so far. It appears they’ve already seen enough to know there’s either some kind of foreground contamination they can’t get rid of without great difficulty, or there’s new physics of some sort. It seems quite reasonable to expect they’re working hard to make whatever data they release be of the highest quality so they have the highest confidence possible it’s either one or the other.
Db, let’s hope.
Something I’m working on predicts an EM field whenever there is a gravitational field (that is, EM is part of the geometry). If there is a definite correlation with ecliptic, I get a way to determine the effective coupling and so a completely new way to determine the CMB temperature.
How are the raw data handled? Are they available to all “active researchers” who wish to study them?
-drl
Danny,
Data from WMAP is made available at
http://lambda.gsfc.nasa.gov/
How “raw” it is, you’ll have to decide for yourself.
Peter, I have also commented about that here.
For those of us who can read it Padmanabhan’s new paper “Dark Energy, Mystery of the Millenium” http://www.arxiv.org/abs/astro-ph/0603114, is relevant to the finite/infinite question. He takes our limited access seriously: every class of observer has a horizon, and every 2-surface in spacetime can be the horizon for some class of observer, so what can we deduce from that? And he deduces quite a bit!
Thanks for the update, Peter :-)!
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From D.T.’s cite:
“…it is obvious that the cosmological constant is telling us something regarding quantum gravity, indicated by the combination Gh-bar. An acid test for any quantum gravity model will be its ability to explain this value; needless to say, all the currently available models— strings, loops etc.—flunk this test.”
That’s gotta be irritating to somebody…
Peter, you mentioned that you would like to publish some of your latest research, probably later this year. Would you mind telling us what you have been working on? Any amount of detail you’re comfortable with would do.
Michael,
This is completely off topic, and given all your other comments here, I doubt you actually have any real interest in the answer.
I’ve mentioned this several times, but the main thing I’ve been working on is the relation between 2d quantum Yang-Mills theory coupled to chiral fermions and representation theory. The Freed-Hopkins-Teleman theorem is a part of this story, and one of the main conceptual problems I’ve been struggling with is that this seems to require a different way of thinking about BRST than is usual. If I get the BRST issues completely sorted out, I’ll first write that part of this up separately.
At some point in the next few months I’ll try and write some longer blog postings at least explaining some of the mathematics background, stay tuned. But I’m not going to discuss this anymore here in a comment section of a posting on WMAP. If you have a serious interest in it and want to discuss it, feel free to contact me via e-mail.
WMAP isn’t the only NASA physics experiment where the release of data has been delayed mysteriously. Gravity Probe B was launched in April 2004 and finished collecting data last August. NASA’s post-launch schedule called for announcing the results next month. That’s been pushed back a full year.
The $700 million experiment is an extremely sensitive gyroscope in a drag-free polar orbit, whose orientation is compared to a guide star by an on-board telescope. It’s designed to measure two effects predicted by general relativity: One is a geodetic precession of the gyro axis in the plane of the probe’s orbit. The second is the Lense-Thirring effect — a dragging of inertial frames caused by Earth’s rotation, causing the axis to precess in its rotational plane.
The precise outcome won’t be known until the probe’s data is combined with measurements of the guide star’s motion, from a separate group. Those have been embargoed — so it can’t be said the gyro analysis was influenced to give a particular result. Still, the guide star’s approximate motion is known from previous measurements by the HIPPARCOS satellite. And if the Lense-Thirring effect is absent (which I’m predicting) that would be apparent already.
It’s interesting that while NASA is forced to drastically cut science programs to fund the Bush Mars initiative, they’ve chosen to extend this one. According to the Gravity Probe B web site, not all the additional time will be needed for data analysis. That should be finished by summer’s end. Until the following spring they’ll be having the results vetted by various experts. (And maybe garnering support for an unexpected result.)
This additional one-year delay comes on top of many years of others in the probe’s launching. And those of us who’ve staked our futures on the experiment’s outcome are left hanging that much longer.
Peter, don’t lower yourself to respond to Pseudonymous Milquetoast.
-drl
Kris,
> NASA’s post-launch schedule called for announcing the results no later than next month. That’s been pushed back a full year.
As far as I remember, it was always clear that no results would be announced after just one month. Gravity probe B is a unique experiment which will probably not be repeated any time soon. Thus it is very important to get data analysis (by different independent teams) right, which simply takes some time.
There is already a lot of evidence for the Thirring-Lense effect and I would not expect a negative result. But it will be very interesting to see the details of their report.
The strongest evidence for gravitomagnetism comes from binary pulsar measurements, and this is quite compelling. The Lens-Thirring prcession is really nothing more than the most elementary consequence of gravitomagnetism. It is possible that there might be a discrepancy between the observed precession rate and the one predicted by General Relativity; that would be tremendously interesting, although I still think it’s unlikely. However, it would be amazingly improbable that no dragging of frames at all was observed by Gravity Probe B.
The odds of seeing no Lens-Thirring precession at all, is based on evidence from other areas, practically nil. I do not believe this because I have some vested interest in accepted theories being proven true; indeed, precisely the opposite is true. I believe the GR gravitomagnetic predictions will be borne out simply because the evidence is so good in other sectors.
Please stop with attempts to turn this comment section into a discussion forum for one’s favorite alternative ideas about cosmology.
For some information about what will *not* be in the WMAP data, and some interesting advice to Leonard Susskind about grant proposals, see
http://arxiv.org/abs/astro-ph/0603266
Thanks amanda, I hadn’t seen that. Will soon write a posting about this and other news of the multiverse.
“Three year WMAP probe observations” Talk by E.Komotsu
– I guess it cant get more explicit. The talk is on Apr 11.
Look here.
Got this from cosmocoffee.
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