Saturn’s hexagon

Isn’t this gorgeous?

Its not new; BA blogged it last year, from Emily Lakdawalla, but I didn’t notice. I forget why I noticed now. Its all fluid-dynamicsy of course; and it (or something very similar) can be recreated in the lab. There’s another very nice image here.

I think its gorgeous partly because you don’t expect hexagons. And note that this isn’t the same sort of hexagon that you get from packed convective cells; that’s a geometrical thing, and occurs because squishing circles together makes hexagons.


* I ran to Ely

And without mass, there would be no stars, no planets and no atoms?

The Economist, celebrating the Higgs:

Without the Higgs there would be no mass. And without mass, there would be no stars, no planets and no atoms.

But that’s wrong. No stars and no planets, because they are gravitationally bound. But atoms aren’t. Unless they mean in the very indirect sense that most Earthly atoms were created in supernovae?

They continue:

Massless particles are doomed by Einstein’s theory of relativity to travel at the speed of light.

I don’t think I believe that either, really. Relativity doesn’t say massless things have to travel at SOL. Does it?

However, neither that article, nor an accompanying one, tells me anything very interesting. Finding something with the right mass (but they only know the mass so far, not any other properties?) says its a Higgs, and thus confirms to some extent the standard model. But doesn’t provide any hints as to how to go any further. So particle physics still looks stuck to me.

Comparing radiation doses

fukushima-july-2011 This post is more an appeal for info than anything useful in itself. But I’ll probably update it if I get anything. Fukushima refers. My question, in the context of the area around Fukushima that is contaminated by radioactivity, is

how much is actually contaminated, in the sense of now having radioactivity levels higher than naturally occurs in granite-based areas like Cornwall? How much has been officially declared “contaminated” isn’t a very interesting number

In response, M points me to map around FukushimaNPP/; here for example is July 2011 (take care to do what I didn’t, and scroll down to the integrated dose map. But unfortunately I don’t know how that compares to radiation levels in Cornwall. I made brief pathetic efforts on google to find out, but then gave up and wrote this. Over to you.

[Ah, hold on, I’ve just realised something. Thinking forwards, we don’t care about the integrated dose from the start, if we’re worrying about what will be uninhabitable in the future. What we care about is the area that will settle, in say 6 months time, to a value that will be bad, then -W]


* More stupidity about Fukushima
* More dangerous than nuclear meltdowns…
* Kan Canned
* Nuclear meltdown in Hokkaido [that’s enough JEB – ed]

Einstein and car batteries: A spark of genius?

Sez the Economist:

For, according to Dr Pyykko’s calculations, relativity explains why tin batteries do not work, but lead ones do.

His chain of reasoning goes like this. Lead, being heavier than tin, has more protons in its nucleus (82, against tin’s 50). That means its nucleus has a stronger positive charge and that, in turn, means the electrons orbiting the nucleus are more attracted to it and travel faster, at roughly 60% of the speed of light, compared with 35% for the electrons orbiting a tin atom…

If the problem isn’t immeadiately obvious to you, pause a moment before proceeding over the fold.
Continue reading “Einstein and car batteries: A spark of genius?”

Fortuna Imperatrix Mundi

Olim lacus colueram,	
olim pulcher extiteram, dum cignus ego fueram. Actually this is a post about statistics, but what the hell I’ve been listening to Carmina Burana a lot recently, even if Miriam thinks it is bombastic. So anyway, several people have commented on this article which (whilst it makes some points about statistics that are vaguely plausible) far far overgeneralises its bounds of validity: any single scientific study alone is quite likely to be incorrect, thanks largely to the fact that the standard statistical system for drawing conclusions is, in essence, illogical. Tamino points out the obvious: that statistics works, and it isn’t stats faults if you don’t understand it. JA says similar, though unusually for him is quite kind about it. Even Paul linked to it. And this post merely expands my comment there.

Which is: that much of science isn’t statistical at all. A simple example would be special relativity. You can read the underlying paper; there are no stats in it. You could sort-of argue that there is some stats underlying it (that the speed of light is a constant is sort-of a matter of observation, which always come with errors, so need stats to analyse properly) but that isn’t really true. The sciencenews thing itself seems to be mostly thinking about medicine, where they use stats a lot because they don’t know what is really going on.

How I found glaring errors in Einstein’s calculations?

Three posts in one day. And all of such high quality. You lucky people.

Pascal has a go at explaining the std.nutters. Some of it is the usual correct stuff, but some of it is wrong: What you need, over and above all that, is constant social interaction with other practising scientists. Oral tradition and daily exposure to other scientists’ everyday decisions are indispensable. That sounds fairly plausible, doesn’t it? Until you think of Newton. Or indeed, of Einstein.

Polar orbiters and the testing of sci-fi

[Anathem review]

I’m reading Anathem because Paul told me to. And because I’m enjoying it. And because its good and thick and will sustain lots of time. Read Paul’s review if you’re interested in an overview; I’m not going to do that, if only because I haven’t finished it (I’m about half way through, if you care). Some of the following gives away some details of the plot that Paul is careful not to give away, so don’t read on if you’re intending to read it.
Continue reading “Polar orbiters and the testing of sci-fi”

Sustainable Energy – without the hot air?

David J.C. MacKay has a draft book out online, , which is worth a browse. He is due to give a talk here in a bit, which should prove interesting.

The book is an attempt to look at renewable energy from a broad-brush numbers point of view (in which I suspect it does a rather better jobs than “Heat” by Monbiot). But the bit I want to look at is the “offsetting” section, p143 onwards, the Story of Joan and Thambo. Joan flies in a plane, and offsets her emissions by helping Thambo keep warm by not burning his pile of coal. This seems fair enough: she emits X CO2 but her offset money allows Thambo to not emit X. The example assumes that all is above board, as it might not be in the real world. Yet for some reason MacKay seems to view this with suspicion, because the Joan+Thambo combination is not emitting *less* CO2. But this is silly… the purpose of the offset it only to remove what you emit (though you could buy 2* offsets; or just buy the offsets without travel).

What he doesn’t really address is what happens when we run out of such easy methods to offset CO2, which I suspect is a much bigger problem.

Incidentally, p148 has a nice graph of what happens versus the costs of a carbon tax. According to his estimates, sequestration of CO2 from thin air occurs at $130 (per tonne) and impact on US car-driving only occurs at $400. Carbon offsetting, though is available from $7.50.