I first became aware of your efforts when the Dow Chemical/Bhopal news stories hit. It struck me as brilliant at the time; but less than seven years later, it's hard for me to find folks who remember that bit of agitprop (indeed, sadly, it's often challenging to find people who remember what happened at Bhopal at all). In general, it's definitely hard to see any trend towards change in the attitudes of the type of organizations you've lampooned. I wonder sometimes if the most lasting effect of your efforts isn't simply to boost morale among activists who share your views and love seeing you skewer your targets? What do you think? In your opinion, what is the lasting impact of your work?

People have already correctly answered this question in the responses -- it's not expanding into anything -- but it's worth talking about that answer a little.

It's our nature, when confronted with something we don't comprehend, to try and understand it in terms of something else we know about. So when we try to imagine a physical entity of finite extent expanding, we're drawn to things like that in our lives: a balloon blowing up, or a cake rising as it bakes, etc. Indeed, many of the analogies we're given in articles and books appeal to just such an approach to understanding, e.g. "Imagine a 2-D universe. Draw dots on the surface of a balloon, and watch them growing further and further apart as the balloon blows up. The dots are analogous to galaxies, the inflation of the balloon is analogous to the expansion of the Universe, etc." You can find that analogy in a variety of sources. But it's a bad analogy -- it's flawed in that it depends on the existence of a third spatial dimension that is associated with the expansion of the balloon; there is no analogous spatial dimension for the expansion of the Universe. The thing you have to come to terms with is this: all attempts at understanding by analogy to something in our everyday lives will fail, because like quantum tunneling or the Aharonov-Bohm effect, it's simply not analogous to anything in our daily lives.

As Feynman put it, "I can't explain it in terms of something you're more familiar with, because I don't understand it in terms of something you're more familiar with."

I'd turn the question around: why is it that you think that if the government doesn't do it, private industry will? Especially when they could right now, even though the government is in the market -- witness the success of UPS, FedEx, etc. -- and choose not to.

You can only be confident about something like that if you're incredibly impatient, and don't know much about how hard this stuff is. The earliest observational evidence of dark matter came from the 1930s, when Fritz Zwicky measured the line-of-sight velocities of galaxies in clusters and realized that there had to be more mass in clusters than could be attributed to the galaxies alone, or there wouldn't be enough gravity to keep them together as a cluster. It was another 30+ years later that we observed with X-ray telescopes a decent-sized chunk of that missing mass in clusters, in the form of a hot intracluster plasma at temperatures of tens of millions of degrees that fills the space between galaxies in clusters and, in rich clusters of galaxies, contributes several times more mass to the cluster than the galaxies within it. Thirty-plus years, for something that's fairly easy to see once you have the technology that can look there (X-ray telescopes); it took us a while to get it.

All our cosmological theories may turn out to be complete crap. But it's absurd to say so now on the basis of complaints like 'we haven't solved the dark matter problem yet' or 'we can't explain a nonzero vacuum energy.' There was a fair amount of time between Oersted and Maxwell, as well. In the meantime, the most plausible theories will get pursued, and we'll see.

There's too many to read. You won't read them all. But it makes me feel better to say this: thanks. Your work has meant a lot to me.

Uh, pretty much every single article in the BBC, the Guardian, or the Times today? That's why Tim Godwin was repeatedly quoted and shown on TV Monday night as saying that the most essential thing to control Tuesday night's rioting was for parents to keep their kids at home.

Not what I'm seeing on BBC or ITN. Stuff like the two white teenage girls speaking here is a lot more typical.

It started in Tottenham because the Duggan shooting was in Tottenham. Since then it's happened everywhere. Crouch End and Catford, as just two examples, don't exactly strike me as warrens of council housing.

By the "underclass," I presume you mean 13-17 year old kids from middle class families, since that's apparently the makeup of most of the looters.

It's hard to feel much sympathy for the plight of that underclass.

This would make sense if it wasn't for the fact that both arrests, and interviews granted to the media, indicate that the majority of the looters appear to be 13-17 year old boys and girls. That's why a major push towards parents to keep their kids home has been taking place during the last 24 hours -- because it's the kids that have been doing the damage.

I was a graduate student in Ann Arbor at the beginning of the 90s. At the time, the Borders brothers still owned Borders, and there were just two Borders stores: one in (I think) Plainfield (a Detroit suburb), and the original store on State Street. I loved that store like I've never loved a bookstore. The best thing about it was the staff that worked there. To get a job there, you had to pass a written test; and if you showed expertise in a particular subject area, you got to take some responsibility for ordering and stocking that subject area. The result was that if you walked in looking for a book on numerical thermodynamics, or differences in translations of The Inferno, you had a pretty good chance of being able to ask questions of someone who knew about the topic and had ordered the books and could provide you with useful info. Under no circumstances at all were you being helped by a high school kid who didn't know much of anything about the merchandise.

Then the brand got sold (to Waldenbooks/K-Mart, I believe), the State Street store moved into larger quarters (the old Jacobsen's store), they exploded coast-to-coast, and I found myself wandering into Borders in other cities that were certainly big, but didn't have the single biggest thing I liked about Borders: an exceptionally competent staff. Their newer owners had decided to compete purely on price and selection; it was inevitable that an internet vendor was eventually going to be able to beat them on those.

Which leaves me missing what I liked about them in the first place, something no internet vendor (even Amazon) has really replaced.

You're probably going to get modded down for that; but it illustrates the error in the original assertion quite succinctly.

Not such a good idea to appeal to "the people" in a discussion sub-thread where Rosa Parks or Selma was mentioned. When the U.S. judiciary in the 1950s, and the executive in the early 1960s, acted to protect the civil rights of blacks, "the people" were not yet in favor. For instance, the majority of Americans thought Brown v. Board of Education was decided wrongly. Sometimes the U.S. government acts against the popular will of the people -- and thank goodness for it.

That's not to say that your appeal to "the people" is off-base -- not at all. Just that the world has more shades of gray than you seem to be allowing. Similarly, many people here on /. are adamantly opposed to government secrecy of any kind, even though it's easy to point to cases where government secrecy saved lives or prevented horrible things from happening. Those cases are almost always historical -- that is, they happened decades ago -- because at the time such events occur (or are prevented from occurring), the secrets are, well, secrets, so most people don't know about the positive role secrecy played until a long time later when the need for secrecy is no longer present. But that doesn't mean there aren't secrets being kept right now that aren't necessary, despite the black-and-white worldview of a lot of people here.

This has been asked-for many, many times on /.

Nobody here ever makes the effort to substantiate this claim.

However, lots and lots of people here repeat it, nonetheless.

Well, yeah, if you doubt the greenhouse effect, you'll get called worse -- like, say, stunningly ignorant -- since not only is the presence of a greenhouse effect on Earth well-established since the mid-1800s, but human habitation on Earth would be hard-pressed if it didn't exist. The terrestrial greenhouse effect is why the average temperature on Earth is something like 15 degrees C and not -18 degrees C.

Hint: "greenhouse effect" is not a synonym for global warming. Anthropogenic global warming is thought to involve an increase in magnitude of the greenhouse effect. But even if there's no anthropogenic global warming, the greenhouse effect would still be around -- and thank goodness, too.

I left cosmology ten years ago after the dreaded third postdoc, so I've no doubt I'm out of the loop on a lot of things. But still, I'm surprised by a lot of your post. There's a bunch I feel like agreeing with/disagreeing with/asking about, but I don't have the kind of years it must have taken you to write that to reply! So I'll just pick out a couple of things:

Sure, logically you can make that argument. But you have a strong hint, don't you, from the fact that the numbers seem to work out. You have a number of independent ways of getting at the dark matter in clusters of galaxies -- (M/L), the cluster baryon fraction, weak lensing, etc. -- which are fairly consistent with each other. (we'll ignore stuff like the luminosity/temperature/mass functions of clusters, which also seem consistent with everything I'm going to say, but introduce new assumptions about density fluctuations etc.) In the first two -- (M/L) and the baryon fraction -- your method for deriving Omega_matter doesn't depend on the Friedmann eqns, or even the Robertson-Walker metric. I then take that value for Omega_matter, the flatness result from WMAP, and get a value for Omega_lambda. Now I *have* introduced cosmology, because in looking at the power spectrum of temperature fluctuations on the surface of last scattering, my relation of angular scale to redshift depends on the RW metric. And maybe, as you say, those equations don't mean anything physical, so that value of Omega_lambda doesn't really mean anything. But if that's true, then why does the hypothetical universe described by those values of (Omega_matter, Omega_lambda) do so well with observations on a broad range of scales -- such the high-z supernova data or the morphology distribution of clusters at low redshift -- things that wouldn't have to be consistent with each other if the Friedmann equations were meaningless?

From my (admittedly dated) experience, nobody ignores the large scale structure of the universe in arguing for homogeneity/isotropy. They argue instead that we converge to it as larger volumes are considered. The surface of last scattering gives you an opportunity to test this idea, and it doesn't seem crazy. And we've gotten a long, long way with the Robertson-Walker metric, the derivation of which is built on homogeneity and isotropy. Granted that there have been surprises in the application of the redshift-distance relation (derivable from the RW metric), such as the Type Ia SNe data that got the whole "dark energy" mess rolling (I've always wanted to slap Mike Turner for coining that phrase -- can't think of one I hate more); but I can't see how inhomogeneity-induced perturbations to the RW metric would manifest themselves on large scales exactly the opposite from how they manifest themselves on smaller scales, in the near vicinity of structures.

Would someone mind explaining (for those of us who have some C experience, but aren't kernel hackers) what the Big Kernel Lock is? In particular, is this something that will impact the desktop user?