The oldest light in the cosmos

February 11, 2003 4:30 PM

BAM! The Microwave Anisotropy Probe's long-awaited map of the afterglow of the big bang was released today, and all of a sudden, most of the uncertainty in the concordance model of cosmology has disappeared. We now know, to within 1%, that the universe is 13.7 billion years old. We now know that Hubble constant is 71, plus or minus 4. And though the results agreed stunningly well with the weird picture that cosmologists have about the nature of the cosmos, there was one surprise -- the first stars were born way before expected. Great day for science, and a likely future Nobel.
posted by ptermit (25 comments total)

And all this time I thought it was Bill O'Reilly. Who'd of thunk it?
posted by sharksandwich at 4:42 PM on February 11, 2003

This is awesome. Science has really been pulling its weight these last few centuries.
posted by Hildago at 4:44 PM on February 11, 2003

So, this Big Bang, it glows?
posted by blue_beetle at 5:00 PM on February 11, 2003

Great stuff - I actually got the chance to attend a colloquium given by Stephan Meyer today announcing these results (held concurrently with the NASA press conference, as a matter of fact.)

Unfortunately, David Wilkinson, one of the guys who would deserve the Nobel for this (at least in terms of leading the experimental effort), died in September 2002 - hence today's renaming of the satellite to the Wilkinson Microwave Anisotropy Probe...
posted by Johnny Assay at 5:06 PM on February 11, 2003

~flips hand~ ahhh, I just went back in time and tweaked all the numbers so they'd come out to just what those foolish scientists expected them to be.

You learn a lot working for Enron when it comes to cooking the books, let me tell you.

Seriously ... [this is cool]
posted by WolfDaddy at 5:34 PM on February 11, 2003

I get shivers down my spine when I read a sentence like "[w]e now know, to within 1%, that the universe is 13.7 billion years old."

Makes me wonder what happened in that parent other-place 13.75 billion years ago that eventually caused ours to hive off.

Big-wow stuff, thanks.
posted by adamgreenfield at 6:17 PM on February 11, 2003

We are stardust, we are golden, we are four billion year old carbon, and we've got to get ourselves back to the giant blotchy egg!
posted by condour75 at 6:17 PM on February 11, 2003

Plus, you gotta love how they use the very Bucky-eque "universe," in sentences like "we have found a new unified understanding of universe."
posted by adamgreenfield at 6:21 PM on February 11, 2003

The New York Times article about this is pretty good.
posted by mblandi at 7:12 PM on February 11, 2003

In other words, we now know for sure we don't know what %96 of the Universe is. Seems like we don't know much about a lot and a lot about the other %4 which isn't much.
posted by stbalbach at 7:37 PM on February 11, 2003

Stbalbach, the beauty of science is not only that it provides answers to questions, but that it provides new questions to ask.

What wonders will we turn up in 10 years? 100?. Smart people learn how little they know all the time.
posted by madmanz123 at 8:47 PM on February 11, 2003

Yes yes yes....but what was before the Big Bang. I am definitely a skeptic, and not one to put stock in the creationist theory....but I have yet to see a satisfactory explanation for the "something out of nothing" conundrum.

This is still very exciting. Space research certainly needed the victory.
posted by lazaruslong at 8:50 PM on February 11, 2003

There's nothing like a picture of a Space Slug to help instruct me that the universe is flat. So much for wrap-around.
posted by jmccorm at 10:14 PM on February 11, 2003

Yes yes yes....but what was before the Big Bang.

Didn't time begin with the big bang, meaning that before that there was literally nothing? I dunno, I did English at Uni.
posted by Summer at 2:41 AM on February 12, 2003

the weird thing about all this (maybe this is what they nyt article says - i don't have a reg) is that we're left with two things that we don't understand. there's cold dark matter and dark energy. these represent two different (ie independent) variables (putting it simply) in einstein's equation that describes how the universe evolves - general relativity (afaik) provides no connection between them. nor (again, afaik, and i no longer work in astronomy) are they connected in most candidate theories under consideration. this is odd because we're pretty good at physics these days - to have one big thing unexplainable is significant enough.

it reminds me a little (not directly - i'm not that old) of physics near the beginning of the last century, when the two big problems (aether and the uv catastrophe) signalled the way for relativity and quantum mechanics. presumably we're not expecting such a big shake-up now.

oh, and how is religion any better than science at explaining origins? "is started with the big bang" seems no worse than "it started with god"... [on preview - Summer, yes, that's what i understand, but really we don't have a clue because as you go back in time towards the big bang everything becomes hotter and hotter and more dense and we simply don't know what physics is like in such conditions, so you end up just holding up your hands and saying that things were so different then that extrapolating from what we have now is pointless.]

ps what was the original name for this satellite/mission? is it the planck explorer?
posted by andrew cooke at 2:51 AM on February 12, 2003

... we're left with two things that we don't understand. there's cold dark matter and dark energy.

The really funky thing is that there are *three* things we don't understand. There's the 73% dark energy, which is pretty much a total mystery -- there are a few ideas out there, but nothing that's really solid enough to hang your hat on. Dark matter is a twofold mystery; first, there's ordinary dark matter, which belongs to the 4% of baryonic matter in the universe -- visible matter is only about 0.4% of the stuff out there. Then there's *exotic* dark matter, which can't be made out of any of the known particles in the standard model, and makes up that 23%.

ps what was the original name for this satellite/mission? is it the planck explorer?

It was originally just MAP, the Microwave Anisotropy Probe. They added the W yesterday for Wilkinson. Planck will launch in 2007 (I hope) and blow even these measurements away.
posted by ptermit at 4:43 AM on February 12, 2003

I can't think of any other science which could get away with proliferating invisible entities like this. Is there more to "Dark Matter" and "Dark Energy" than "stuff we need to invent to make our equations work"? That all this is presented as a triumph seems very odd.
posted by grahamwell at 5:29 AM on February 12, 2003

it's a triumph partly because nasa is desperate for good pr, but also because it really nails down some free parameters. for a long time (the last ten to twenty years) there's been a lot of uncertainty about the basic details of the evolution of the universe - it's been very hard to measure accurately. it's only the last few years that there's emerged a general consensus (which these observations confirm, in the main).

and, unlike religion, new stuff is welcomed in science. it's hard to make progress when everything makes sense - having something unexplained means that there's more to know (a good thing!). now we have a very well defined behaviour that needs to be explained, theories can be tested in some detail (it wasn't that long ago when the age of the universe was uncertain to a factor of two or three).

of course, new physics may change things so that these numbers (age of the universe etc) are different - they do assume certain basic ideas - but physics at "everyday" scales of size and energy are pretty well known, so any change in our understanding is only going to be important in very extreme conditions (you can't try to explain these observations with a physics that says gravity locally has a different form, because then you'd have a problem explaining why planets go round the sun, for example). so it's not like we're "losing" anything by learning more - we're just refining what we know at extreme scales.
posted by andrew cooke at 5:43 AM on February 12, 2003

The thing that concerns me is, this ol' universe only has about 20 billion years left until it dies of entropy. Is it too early to start packing?

Seriously, though, this is huge; exciting and humbling at the same time.
posted by GreyWingnut at 6:01 AM on February 12, 2003

physics at "everyday" scales of size and energy are pretty well known

.. yes, that there are four fundamental forces, that there are only certain types of particle etc. The problem is that on the large scale this just doesn't work. Galaxies should fly apart, but they don't - the Universe should collapse but it doesn't. The current set of theories need the aid of a clumsy set of patches (the dark stuffs, inflation) to have any purchase. I can't do better, but like a medieval astronomer required to memorise ever increasing numbers of epicycles, I suggest a little scepticism.
posted by grahamwell at 6:15 AM on February 12, 2003

i'm not claiming (baryonic/excotic) dark matter and dark energy have to be different things in a future theory, only that there's no current way of unifying them. it would be nice if a single solution explained them all (but afaik nothing like that is currently on the horizon).

speaking personally, i felt physics was pretty much "done" ten years ago. there was so much noise in the measurements of the hubble param etc that it seemed likely that things could be sorted out without too much worry (maybe a small hiccup in particle physics). now it looks like serious new stuff is absolutely necessary. whether you think that calls for optimism or pessimism depends on your nature, i guess!
posted by andrew cooke at 6:42 AM on February 12, 2003

The contents of the Universe include 4% atoms (ordinary matter), 23% of an unknown type of dark matter, and 73% of a mysterious dark energy.

Mysterious dark energy? Why, that's the Dark Side of the Force. Puny mortal scientists.

Didn't time begin with the big bang, meaning that before that there was literally nothing?

This is exactly right. It's a hard concept for to grasp, because it runs so very much against everything we know and have experienced about reality. In some sense it is completely against our nature to think about absolute nothingness. We are temporal creatures, the sons and daughters of a physical universe, and everything we know and think reflects that. Humans are limited in our capacity to "think outside the box" so to speak, especially when there is nothing outside the box at all.
posted by moonbiter at 7:26 AM on February 12, 2003

Grahamwell: part of the reason this is so exciting is that there are many different lines of evidence all lead to the same conclusions. For example, rotation rates of galaxies, distribution of galaxy clusters, the ratios of d to h in primordial gas clouds, and the CMB all imply there is dark matter. As our instrumentation gets better, then we begin to *see* the stuff; the Chandra x-ray observatory has spotted a lot, gravitational lensing reveals even more, and we're even seeing small MACHOs in the galactic halo... all these are pretty damn direct observations of dark matter.

Sure, there are predictions that haven't yet been observed and phenomena that are not yet understood, but any real breakthrough in physics comes with these predictions -- the existence of the neutrino and the omega-minus, for example, came purely out of the equations and were then spotted. Those predictions don't make it any less of a breakthrough, and, in fact, are what signal the triumphs of these theories. Inflationary theory has been making similar predictions, such as scale-invariant anisotropies in the CMB, that have been verified in a spectacular manner.

If you can't see the difference between this and epicycles, well, I'm afraid you'll be missing out on a lot of excitement over the next few years.
posted by ptermit at 7:28 AM on February 12, 2003

Ptermit: I hope you can appreciate my unease, but I do respect your enthusiasm and conviction. Your points are fair. It does seem - I suspect you'll agree - that cosmological data is running way ahead of what passes for philosophy of science (falsification etc). I suspect that the problem is with philosophy.
posted by grahamwell at 7:54 AM on February 12, 2003

grahamwell: Oh, yes... I can certainly appreciate your unease, especially about dark energy. It's a mindblowing concept, and scientists only have vague ideas about how it could exist.

You're right; in some ways, the data is leading us beyond where the theory was expected to take us, and leading us into areas of speculation. But in other ways, the opposite is happening. The data are pinning down the theories tight, and falsifying models that were previously thought to be plausible. Both prospects are exciting to scientists, especially when one measurement does both -- if it really nails down things in one area and reveals mysteries on the other, the former shows that the theory is likely to be a reflection of the way the universe works, and the latter shows the way forward to a much more profound understanding that we will (hopefully) one day grasp.
posted by ptermit at 4:31 PM on February 12, 2003