astro123

Inflation happened during the first tiniest fractions of a second post big bang. No telescope is going to make direct observations of the inflationary period so I'm not sure what you mean by this.

I worked with someone (this is in astronomy) who said that papers in nature were the most likely to be wrong. They are in nature because they have a dramatic (new/unexpected) result. One good reason for a new/unexpected result is a mistake somewhere.

Edit: I'm not saying anything about this paper. I know nothing about this. Just a meta comment that, in really hard to get published in journals, there might be a bi-modality of papers. Really important and really wrong :)

That's a weird distinction to try to make. Metal does mean the elements, not the spectral lines. The presence of those elements is usually inferred from the spectral lines, but if another method was used we would still say "metal poor/rich".

> It seems significant that the lens galaxy has little dark matter

I don't see that in the article? They centered on galaxy clusters which contain huge amounts of dark matter. DM is needed to account for lensing. There isn't enough mass in the stuff we can see to account for the lensing signal.

> How is DM supposed to cool, anyway

It can't! The way that normal matter cools is by radiating (giving off light). Dark matter doesn't radiate (if it did, we would be able to see it). So, while normal matter cools and settles to the center of the gravity well, dark matter doesn't and (as you say) forms physically larger structures.

I think it was taken at a particular time. If it were the closest, venus would be closer than the sun.

Skimming the paper it looks like it was the positions in Aug 2003

The early universe's expansion was not accelerating, as the early universe was not dominated by dark energy. I don't know off the top of my head exactly when that changed, but z=0.76 seems about right. So I'm pretty sure that is what that is.

The reason the dominant form of matter changes is fairly simple. As the universe expands, the amount of matter doesn't change, so the matter density goes as 1/r^3. The amount or radiation goes as 1/r^4 as there is an extra loss of energy due to redshifting (E = hc/wavelength). Dark energy though is (we think) a constant, so as the universe expands, the amount of it stays constant.

Eek! I guess I'm more OK with this now...

Yup, by fringe I meant "On the edge of what reasonable people are working on". But maybe it's not a great term if people misunderstand.

That's a fair point. I love reading computer hardware rumours, most of which are probably total garbage (and probably obviously so to anyone in the field). And in this case, whether the general public thinks the universe in MOND or LCDM really doesn't matter at all.

My real issue is when this reporting is on things where the general public's opinion does matter. Things that the general public might vote on. Economics, medicine, etc. Having seen this type of reporting in a field that I do know something about (and a field where there is no real incentive to mislead, again MOND vs LCDM, who cares), I'm a lot more distrustful of science reporting in fields I don't know much about (and where there are incentives to mislead).

If they had published the article exactly as is, giving you all the excitement, but just added a single line somewhere saying "this is new work that is up against a large body of previous work that points in the opposite direction. Let's see what happens, but its a cool idea" I'd be totally fine with it.

The astrophysics journal (ApJ) is a really good journal. A majority of good astronomy papers are published in ApJ or in MNRAS. Big things go in Nature/Science + then there are other smaller journals.

(At least this is what I tend to find. This may just reflect my biases - US based, in the cosmology field.)

But just because something gets published doesn't mean it is right :) I think non-scientists don't know what "peer review" actually entails! First, as this was a MOND paper, it could well have been reviewed by someone who favours MOND. Second, even if the reviewer doesn't favour MOND, if the steps taken and the arguments given seem reasonable, I expect they would suggest it should be published.

I have no issue with the paper being published. It is important that theories have advocates who put forward the best argument for them. What I do take issue with is the skewed presentation in popular science. What sells is exciting and new, not slow and steady. And 99% of science is slow and steady.