Section 2.10 presents a case study for applying VV&UQ methods to climate models. The introductory paragraph of that section reads,
The previous discussion noted that uncertainty is pervasive in models of real-world phenomena, and climate models are no exception. In this case study, the committee is not judging the validity or results of any of the existing climate models, nor is it minimining the successes of climate modeling. The intent is only to discuss how VVUQ methods in these models can be used to improve the reliability of the predictions that they yield and provide a much more complete picture of this crucial scientific arena.
As noted in the front-matter, since this is a pre-print it is still subject to editorial revision.
There is a belief that you can simply read imperatives from ‘the evidence’, and to organise society accordingly, as if instructed by mother nature herself. And worse still, there is reluctance on behalf of many engaged in the debate to recognise that this very technocratic, naturalistic and bureaucratic way of looking at the world reflects very much a broader tendency in contemporary politics. To point any of these problems out is to ‘deny the science’. ‘Science’, then, is a gun to the head.
We have a little company here in Dayton that does print on demand (Fabbr) with Makerbots. They specialize in printing RepRap kits, but I think I'm going to see if they can print me a little rocket to use with Estes mini-motors.
The 1/4 and 1/2 A motors are 13 mm in diameter and 44 mm long.
The first thing you need to print a part with these hobby printers is an stl file. I followed a some-what torturous route to generating one.
First I made a little python script to find the minimum volume Sears-Haack body that would fit a 13x44 mm cylinder. The bold black curve is the minimum volume body; it happens to have a length of twice the motor length.
As you can see in the script, I also dumped an svg file of that curve. This is easily imported into Blender. Then the svg curve must be converted into a Mesh, and the Spin method applied to generate the body of revolution.
I played with the number of steps to get a mesh that looked like it had surface faces with near unit aspect ratio (not that it really matters, but old habits die hard).
Now I should be able to add some fins and export an stl from Blender for my rapid prototyping friends to play with. The design goal for this rocket will be to have positive static margin with the motor in the rocket, but neutral or negative static margin once the ejection charge pops it out the back (that way it does a tumble recovery).
Well, I was pretty excited that OpenFoam was acquired by SGI, and they created a foundation to hold the copyrights for the project. That is good news for building a healthy open source community around the software. Looks like I jumped the gun with the install from source option I detailed back in November. If only I were a little more patient, I could have installed from rpms. The new release has lots of interesting additions. We live in exciting times for open source CFD.
This state of politics prior is unavoidable, and therefore not unique to the field of climate policy. I think this talk by Kirk Sorensen on the history of US breeder reactor development provides another good example.
The policy maker (Nixon in this case) picked the solution based on desired political outcomes (jobs and lucre for politically useful districts). "The Science" was merely a part of the marketing and public relations campaign for that choice. Dissenting scientific positions (the molten salt folks in this case) were suppressed with "Rickoverian dedication".
See this extensive remix for lots of info on LFTR.
"There's been a very bipartisan approach to scaring the public." Kirk Sorensen (~1:20 or so)
"The whole aim of practical politics is to keep the populace alarmed (and hence clamorous to be led to safety) by menacing it with an endless series of hobgoblins, all of them imaginary." H.L. Mencken
I've been an SVN user for a while, but it seems like more and more projects are going distributed version control systems like Git so I wanted to learn how to use Git. I found this crash course on Git for SVN users which provides a useful Rosetta stone, and this warning:
SVN is based on an older version control system called CVS, and its designers followed a simple rule: when in doubt, do like CVS. Git also takes a form of inspiration from CVS, and its designer also followed a simple rule: when in doubt, do exactly the opposite of CVS. This approach lead to many technical innovations, but also lead to a lot of extra headscratching among migrators. You have been warned.
This sounds a lot link Linus Torvalds' talk, WWCVSND: What Would CVS Not Do?
Github has a set of steps for setting up on linux. Git comes in the Fedora repos (and probably every other repo), so install is easy. A nice bit of documentation that comes with the install is Everyday GIT With 20 Commands Or So.
Since I already use password-less ssh to hop between the boxes in my little network, I didn't move my old public key as in the instructions. I created a config file in the .ssh directory containing these lines:
Host github.com
User git
Port 22
Hostname github.com
IdentityFile ~/.ssh/id_rsa_git
TCPKeepAlive yes
IdentitiesOnly yes
Where id_rsa_git.pub is the key I uploaded to github. Authenticating to github is then just: ssh -T git@github.com
Then you accept their RSA key like you would for doing any other ssh login.
The next thing is to create a repo. Clicking through the instructions brings you to a page with several "next steps". Which for my example are:
mkdir FalknerSkan
cd FalknerSkan
git init
touch README
git add README
git commit -m 'first commit'
git remote add origin git@github.com:jstults/FalknerSkan.git
git push -u origin master
Which gives some output ending in something like: Branch master set up to track remote branch master from origin.
If you'd like, you can read up on the Falkner-Skan ODE at the viscous aero course on MIT's OCW:
(10:40) It's not that regulators don't understand information technology, because it should be possible to be a non-expert and still make a good law. MPs and Congressmen and so on are elected to represent districts and people, not disciplines and issues.
That couple of sentences reminded me of a recent post on single-issue advocacy by Roger Pielke Jr. So, in that spirit, here's a fun word game: How applicable is Doctorow's criticism if you substitute "climate" for "copyright" below?
(22:20) But the reality is, copyright legislation gets as far as it does precisely because it's not taken seriously, which is why on one hand, Canada has had Parliament after Parliament introduce one stupid copyright bill after another, but on the other hand, Parliament after Parliament has failed to actually vote on the bill.
[...]
It's why the World Intellectual Property Organization is gulled time and again into enacting crazed, pig-ignorant copyright proposals because when the nations of the world send their U.N. missions to Geneva, they send water experts, not copyright experts; they send health experts, not copyright experts; they send agriculture experts, not copyright experts, because copyright is just not important to pretty much everyone!
Canada's Parliament didn't vote on its copyright bills because, of all the things that Canada needs to do, fixing copyright ranks well below health emergencies on first nations reservations, exploiting the oil patch in Alberta, interceding in sectarian resentments among French- and English-speakers, solving resources crises in the nation's fisheries, and thousand other issues! The triviality of copyright tells you that when other sectors of the economy start to evince concerns about the internet and the PC, that copyright will be revealed for a minor skirmish, and not a war. Why would other sectors nurse grudges against computers? Well, because the world we live in today is /made/ of computers. We don't have cars anymore, we have computers we ride in; we don't have airplanes anymore, we have flying Solaris boxes with a big bucketful of SCADA controllers [laughter]; a 3D printer is not a device, it's a peripheral, and it only works connected to a computer; a radio is no longer a crystal, it's a general-purpose computer with a fast ADC and a fast DAC and some software.
