Sharks and forests

No, sharks don’t live in forests: I have two quick stories today, just sharing a couple of recent good-news stories associated with some really nice photos and videos.

First, forests: a 30-year feud between loggers and green groups in Tasmania ended late last month with a deal between the parties. More than 500,000 hectares of native Tasmanian forest will be protected from logging, while about 140,000 cubic metres of sawlogs will be made available to the timber industry. The agreement doesn’t give any group everything they wanted (which suggests to me that it was probably as fair a balance as we could hope for) but the mere fact that we have an agreement is worth something.

But the main reason I wanted to mention it here is that the Wilderness Society, who have been working for the protection of Tasmania’s wild forests for many years put together this amazing slideshow of the forests which will be saved. Do take a look – it’s beautiful.

Closer to home, sharks made a rare – possibly unique – appearance in a feel-good story on the front page of our local paper which was picked up by the ABC and presented on ABC Queensland news.

The sharks were Leopard Sharks from our Reef HQ Aquarium, so I covered the story, too, in the aquarium volunteers’ newsletter and can share photos with you here as well.

Aquarist Hamish with friend
Aquarist Hamish with friend, as seen in our newspaper
one shark biting another on the fin
Standard leopard shark courting behaviour. Most of us wouldn’t like a love bite like this!

For a little more on Leopard Sharks’ courtship, and its relation to our own, click here for my previous story on the subject.

Technical note: social media

After thinking about it occasionally for months, I have finally added “like” buttons for FaceBook and other social media. They don’t show up on the main page of the blog, (yet, anyway), but they do appear on each individual post, e.g. this one, when a user goes to it as a separate page. Let me know if they don’t work for you, and I can try to fix the problem.

I have also modified the menus down the right hand side of the page as some of them were beginning to take up too much space.

And I have (at last!) chosen one of my own photos for a header instead of the stock image.

Positive strategies for climate action

As my regular readers will know, I am a follower of RealClimate. A recent guest post there, from some Dutch climate scientists, described a new online experiment in fostering dialogue on climate change. It’s fair to say it copped some flack from the experts – deservedly, in my less-expert opinion – but the comments on it included some very positive suggestions for how we should really be trying to move the debate forward. Here are some I particularly liked; visit my source if you want more.


“Real hope, if it is to arise at all, will do so from a bare assessment of the scale of the challenge we now face.”
Anderson & Bows, ‘Beyond dangerous climate change’
Philosophical Transactions of the Royal Society, Jan 2011

… a final message of hope ..
“at every level the greatest obstacle to transforming the world is that we lack the clarity and imagination to conceive that it could be different.”
Roberto Unger



XX wrote: “To dodge the major impending climate catastrophe that we project today, harsh restrictions on energy use by all global citizens will be required”

YY responded: That is just plain false. Photovoltaic panels installed on all the flat commercial rooftops in the USA would generate more electricity than all the nuclear power plants in the country. Concentrating solar thermal power plants on just five percent of the USA’s deserts would generate more electricity than the entire country uses. The same is true of the wind energy resources of just four midwestern states.

And those examples represent just a small fraction of the USA’s vast solar and wind energy resources. According to a study by the Institute for Local Self-Reliance, “At least three-fifths of the fifty states could meet all their internal electricity needs from renewable energy generated inside their borders.” The fact is that we have abundant, endless sources of energy, and we have the mature and powerful technologies needed to harvest those sources, and those technologies are getting more powerful and less expensive every day.

Moreover, because we waste so much energy, we have an enormous opportunity to get more utility out of the energy we consume simply by implementing the most obvious and lowest-cost efficiency measures.

I don’t know why you insist on pretending otherwise. Frankly, your comments often read like coal industry propaganda of the sort designed to discourage people from supporting action to reduce emissions by scaring them with “if we stop burning coal we’ll all have to shiver in the dark and live in caves” alarmism.


Donella Meadows, who held a PhD in Biophysics from Harvard mentions Thomas Kuhn’s  “The Structure of Scientific Revolutions” in her paper titled ‘Leverage Points; Places to Intervene in a System’. I have a hunch she understood science, complex systems, and the social interactions of Great Apes. Here’s the reference:

“You could say paradigms are harder to change than anything else about a system, and therefore this item should be lowest on the list, not second. But there’s nothing physical or expensive or even slow in the process of paradigm change. In a single individual, it can happen in a millisecond. All it takes is a click in the mind, a falling of scales from the eyes, a new way of seeing. Whole societies are another matter—they resist challenges to their paradigms harder than they resist anything else.

So how do you change paradigms? Thomas Kuhn, who wrote the seminal book about the great paradigm shifts of science, has a lot to say about that: 

  • You keep pointing at the anomalies and failures in the old paradigm. 
  • You keep speaking and acting, loudly and with assurance, from the new one. 
  • You insert people with the new paradigm in places of public visibility and power.
  • You don’t waste time with reactionaries; rather, you work with active change agents and with the vast middle ground of people who are open-minded.”

(That last point, incidentally, corresponds exactly with the strategy advocated by Anna Rose at the Townsville launch of her book, Madlands.)

I (don’t always) like my Poplar Gum

Dead leaves on lawn
This happens far too often!

Our Poplar Gum, Eucalyptus platyphylla, is a huge tree. It gives us shade, it is home to innumerable birds and insects and attracts even more when it flowers, and it survives cyclones without falling on our house. But it has an irritating habit of dropping all its leaves and giving us (mostly me, I have to grumble) a lot of extra work.

I have been trying to keep track of just how many times per year its loses its leaves, and this post is part of that effort. For the record, then:

  • It started losing leaves a couple of weeks ago and has now lost almost all of them.
  • It lost a lot, but not all, of its leaves when it flowered in August.
  • It lost some at the end of the Wet, in mid-April.
  • It was losing them at this time in 2011, too.
  • It lost leaves in September 2011 ‘for the first time since Yasi’ (Feb 2011).

This page about poplar gums on Magnetic Island mostly confirms my observations:

The poplar gum flowers from August to October and, unusually for eucalypts, drops some of its leaves when flowering. In good years it may only lose a couple of leaves but in extraordinarily dry years it can drop its whole canopy.

This page about the same species south of us, near Rockhampton, complements it:

The old bark is shed each year to reveal a new trunk of the most exquisite salmon-pink, eventually hardening off to the familiar smooth white trunk. In the late dry season water stressed trees will lose almost all their leaves, while those with access to water will drop their old leaves about the same time as the new ones appear. Flowering is from November to December, the flowers are white and in clusters.

That’s almost enough to see a pattern, isn’t it: it drops its leaves in response to water stress, and the extra energy it needs for flowering adds to any water stress it may be experiencing.

The leaf loss we saw in April doesn’t rate a mention in any references I could find. That may be because it is typically partial – I don’t know.

I do know that I have to go and rake my lawn – again!!

Lightning (and other stuff) for geeks

We have been thinking about thunderstorms pretty often in the last week or so, with the severe storms around Brisbane affecting so many people and smaller storms  threatening us although not quite making it all the way to Townsville. (We watch them on the BoM radar and we see clouds building up behind Mt Stuart and then they just …. go away.) (So far.)

Anyway, here on YouTube is a wonderful super-high-speed movie of a bolt of lightning. Captured at over 7000 frames per second, it lets you see the development of the strike. We found it via xkcd, one of our favourite online cartoonists. He has a weekly “What If?” column “Answering your hypothetical questions with physics,” which is somewhat in the style of Mythbusters in that the science is good, the presentation is informal and no question is too wacky to tackle. His page on lightning explains what we are seeing on the video and answers some more-or-less sensible questions about how lightning bolts behave.

While we are thinking about physics/maths, here are two more web pages:

A mathematically generated butterfly created by Ken Perlin of NYU Computer Science. He has lots more “toys from the blog” on his home page but they didn’t work for me when I tried a few – “inactive plug-in” error. If you fancy your luck, here’s his page.

Jason Kottke’s blog isn’t as heavy on maths/IT as xkcd  (he says, “The editorial direction … clusters around a pair of hand-wavy ideas: the liberal arts 2.0, and people are awesome”) but does have a substantial proportion of maths posts. Start here for the maths stuff, or just go to the main page.