Category Archives: Mathematics

Climate Reporting

It’s a hot mess.

[Late-morning update]

A media round up, and some thoughts, from Judith Curry, on the State of the Union:

what is wrong with President Obama’s statements as cited above?

  • His statement about humans having exacerbated extreme weather events is not supported by the IPCC

  • The Pentagon is confusing climate change with extreme weather (see above)
  • ‘Climate change is real’ is almost a tautology; climate has always changed and always will, independently of anything humans do.
  • His tweet about ‘97%’ is based on an erroneous and discredited paper [link]

As for ‘Denial from Congress is dangerous’, I doubt that anyone in Congress denies that climate changes. The issue of ‘dangerous’ is a hypothetical, and relates to values (not science).

And speaking of the ‘deniers’ in Congress, did anyone spot any errors in the actual science from Senator Inhofe’s rebuttal?

The apparent ‘contract’ between Obama and his administrators to play politics with climate science seems to be a recipe for anti science and premature policies with negative economic consequences that have little to no impact on the climate.

BUt the important thing is that they line the pockets of his campaign contributors.

Maybe some day, in a future administration, we can have a grown up conversation about climate change (natural and human caused), the potential risks, and a broad range of policy responses.

Let’s hope.

Weird Linux Problem

Anyone have any ideas why I can’t do a yum update in Fedora? Or rather, why I can’t write to the disk as root?

# yum update
Loaded plugins: langpacks, refresh-packagekit
Cannot open logfile /var/log/yum.log
Repository google-chrome is listed more than once in the configuration

[Errno 30] Read-only file system: ‘/var/cache/yum/x86_64/20/adobe-linux-x86_64/repomd.xml.old.tmp’

Here’s what I’m seeing at /:

# ls -l
total 65
lrwxrwxrwx. 1 root root 7 Dec 11 2013 bin -> usr/bin
dr-xr-xr-x. 6 root root 4096 Dec 22 14:47 boot
drwxr-xr-x. 21 root root 3520 Dec 24 09:15 dev
drwxr-xr-x. 140 root root 12288 Dec 24 09:15 etc
drwxr-xr-x. 4 root root 4096 Dec 20 2013 home
lrwxrwxrwx. 1 root root 7 Dec 11 2013 lib -> usr/lib
lrwxrwxrwx. 1 root root 9 Dec 11 2013 lib64 -> usr/lib64
drwx——. 2 root root 16384 Dec 11 2013 lost+found
drwxr-xr-x. 2 root root 4096 Nov 7 16:53 media
drwxr-xr-x. 3 root root 4096 Dec 20 2013 mnt
drwxr-xr-x. 4 root root 4096 Oct 29 15:18 opt
dr-xr-xr-x. 222 root root 0 Dec 24 09:14 proc
dr-xr-x—. 12 root root 4096 Dec 22 15:33 root
drwxr-xr-x. 34 root root 900 Dec 24 09:17 run
lrwxrwxrwx. 1 root root 8 Dec 11 2013 sbin -> usr/sbin
drwxr-xr-x. 2 root root 4096 Aug 7 2013 srv
dr-xr-xr-x. 13 root root 0 Dec 24 09:14 sys
drwxrwxrwt. 12 root root 280 Dec 24 09:21 tmp
drwxr-xr-x. 12 root root 4096 Dec 11 2013 usr
drwxr-xr-x. 21 root root 4096 Dec 24 09:14 var

Here’s /var:

# ls -l /var
total 112
drwxr-xr-x. 2 root root 4096 Dec 11 2013 account
drwxr-xr-x. 2 root root 4096 Aug 7 2013 adm
drwxr-xr-x. 14 root root 4096 Dec 20 2013 cache
drwxr-xr-x. 2 root root 4096 Aug 5 21:27 crash
drwxr-xr-x. 2 root root 4096 Aug 2 2013 cvs
drwxr-xr-x. 3 root root 4096 Oct 2 09:32 db
drwxr-xr-x. 3 root root 4096 Dec 11 2013 empty
drwxr-xr-x. 2 root root 4096 Aug 7 2013 games
drwxr-xr-x. 2 root root 4096 Aug 7 2013 gopher
drwxr-xr-x. 3 root root 4096 Aug 7 17:19 kerberos
drwxr-xr-x. 46 root root 4096 Dec 24 09:14 lib
drwxr-xr-x. 2 root root 4096 Aug 7 2013 local
lrwxrwxrwx. 1 root root 11 Dec 11 2013 lock -> ../run/lock
drwxr-xr-x. 15 root root 4096 Dec 24 09:15 log
lrwxrwxrwx. 1 root root 10 Dec 11 2013 mail -> spool/mail
drwxr-xr-x. 2 root root 4096 Aug 7 2013 nis
drwxr-xr-x. 2 root root 4096 Aug 7 2013 opt
drwxr-xr-x. 2 root root 4096 Aug 7 2013 preserve
lrwxrwxrwx. 1 root root 6 Dec 11 2013 run -> ../run
drwxr-xr-x. 10 root root 4096 Dec 11 2013 spool
drwxrwxrwt. 539 root root 36864 Dec 24 09:15 tmp
drwxr-xr-x. 2 root root 4096 Aug 7 2013 yp

I tried to just create a file in /root, with no success (though that’s not really surprising, given the permissions). What’s really weird is that I have no problems writing as a normal user. It’s just a problem with root. Which is, of course, a big problem. I’ve tried rebooting, with no joy.

[Later afternoon update]

OK, I’ve gotten the machine beaten into submission. I loaded Fedora 21 on a live USB, and (unlike Fedora 20) it will actually boot with my new motherboard. So I cleaned up the drives, then installed the new OS on the new SSD. I overmounted my old /home drive onto the new /home, and I’m reinstalling software, which is going very fast, because the SSD is very fast. With the new quad-core processor, I’m cooking with Crisco. Nice Christmas present to myself.

[Update a few minutes later]

Wow. Just did a reboot after a bunch of updates. Ten seconds.

The Fatal Conceit

of Jonathan Gruber:

The Times reassuringly described Gruber as “the numbers wizard at MIT,” who has “spent decades modeling the intricacies of the health care ecosystem.” Gruber has “brought a level of science to an issue that would otherwise be just opinion.”

I might note that the Soviets used the term “science” for their own “scientific” planning commission. I drew little comfort from Professor Gruber’s scientific-planning credentials, especially when I learned “he’s the only person you can go to for that kind of thing.” Gruber, aided by his brilliant MIT graduate student assistants, is a one-man Gosplan, the name given to the Soviet Union’s state planning committee. That is not much of a recommendation. Science is better served by competing ideas not by a one-person monopoly.

Both Gruber and the USSR’s Gosplan planners believe their planning is “scientific” and executed by “the best of the best.” Both types of planning commissars suffer from F. A. Hayek’s “fatal conceit”—the belief that we can plan incredibly complex economic systems. As Hayek pointed out in his writings, such “scientific” plans inevitably fall apart under the weight of unintended consequences.

Actually, I’m not sure they’re all unintended.

Gruber The Grifter

Why you don’t want to let “intellectuals” anywhere near power:

Unfortunately, contemporary Washington is calibrated to defer to experts who defer to politicians, providing an intellectual Praetorian Guard for the constant growth of a leviathan. As Denver University professor David Ciepley noted, “Starting in the First World War, and much more so during the New Deal and World War II, American social scientists became part of the autonomous state themselves, helping staff the mushrooming government agencies.” The closer that intellectuals get to politicians, the more weaselly they usually become.

Playing off Mr. Gruber’s derision of average Americans, one wag suggested a new acronym — L.I.E. — for Low Information Experts. Mr. Gruber and many other professors have gotten rich by pretending that government is far more competent than it actually is. Economist Robert Skidelsky, writing about the history of modern socialism, observed that “the collectivist belief system existed independently of the facts of modern life.” The same is true of the academic cadre who profit by vindicating endless government interventions that breed chaos and dependency.

I’d like to think that people will take a lesson from this (particularly with regard to climate models), but history doesn’t make me hopeful.

Interstellar

A light-on-spoilers review.

[Tuesday-morning update]

Uh-oh:

Christopher Nolan’s epic new sci-fi film Interstellar has received measured acclaim from critics, who have praised its ambitious scale and effects but were less convinced about the story.

That was the problem with Gravity, too.

[Bumped]

The New Consensus Study

on evolution:

Our search resulted in 487,629 papers that mentioned “evolution” or “natural selection” in the abstract. However 451,412 of those could not definitively be placed into one of our seven position-defining categories*, no matter how hard we tried with our group of 20 reviewers. [The consensus view among us is that these reviewers are completely independent and objective; their common participation at our web site devoted to presenting pro-selection arguments, but nothing to the contrary, is just not relevant in this case.**]

Of the remaining 36,217 papers, 35,167 (97.1%) supported the consensus position that over half of the observed evolution over the twentieth century is due to natural selection. The fact that only 126 of these 35,167 papers were actually focused on critically evaluating the topic at hand, i.e. the different possible mechanistic explanations of observed evolutionary change and/or speciation (e.g. random drift, founder and other stochastic events, mutation rate variation, instantaneous genetic barriers, etc), is an irrelevant point, a complete red herring. We can reasonably assume that in at least the majority of 50% of the time, none of these 35,167 authors would indicate agreement with a position that they themselves had not carefully investigated, without having more than half of a predominantly pretty good reason for so doing***. It’s just not really half as difficult as people make it out to be when you boil it down. As we have now done. For you.

In conclusion, there is very clearly a very strong consensus as to the influence of natural selection on evolution during the twentieth century and this consensus has been increasing as the evidence increases. It is important that policy makers realize this and take action. Please pick this up and disseminate it widely so everybody knows about it; everyone else is, so you will be part of the consensus effort if you do. Thank you.

Heh.

Peter Thiel And Global Warming

Why he’s skeptical:

“Whenever you can’t have a debate, I often think that’s evidence that there’s a problem,” Thiel said on The Glenn Beck Program. “When people use the word ‘science,’ it’s often a tell, like in poker, that you’re bluffing. It’s like we have ‘social science’ and we have ‘political science,’ [but] we don’t call it ‘physical science’ or ‘chemical science.’ We just call them physics and chemistry because we know they’re right.”

Thiel said no one will be upset if you ask questions about the periodic table, because it is actually science. But referring to man-made climate change as “science” tells you “that people are exaggerating and they’re bluffing a little bit,” Thiel said.

“The weather has not been getting warmer for the last 15 years. The hockey stick that Al Gore predicted in the early 2000s on the climate has not happened,” he remarked. “And I think as this monolithic culture breaks down, you can have more debates.”

Yes.

Judith Curry’s WSJ Op-Ed

She rounds up the (hysterical and unhinged) reactions:

Climate science has been thrown into disarray by the hiatus, disagreement between climate model and instrumental estimates of climate sensitivity, uncertainties in carbon uptake by plants, and diverging interpretations of ocean heating (in the face of a dearth of observations). ‘Certainty’ arguably peaked at the time of the AR4 (2007); perception of uncertainty is arguably greater than any time since the FAR (1991). Yes of course we know more about the climate system than we did in 1991, but more knowledge about the complex climate systems opens up new areas of ignorance and greater uncertainty.

In context of the way climate sensitivity is defined by the IPCC, uncertainty in climate sensitivity is decreasing as errors in previous observational estimates are identified and eliminated and model estimates seem to be converging more. Climate model simulations, when compared with 21st century observations seem to be running too hot, giving creedence to the lower observation-based sensitivity values.

What do the lower values of climate sensitivity imply for policy? Well slower values of warming make it easier to adapt, and provide time to develop new technologies and new policies. But the true believers such as Mann et al. call adaptation, developing new technologies and policies as ‘inaction.’ The policy logic apparent in the essays critical of my op-ed are rather naive.

So we are left with science in disarray and naive logic regarding policy. And the ‘warm team’ wonders why people are yawning?

She should cite my piece on the precautionary principle.

Is There An Open-Source Doctor In The House?

OK, so I installed Gnucash on my machine last week, and it worked like a charm. I rebooted over the weekend after a yum update (which included a kernel rebuild I think) and now when I try to load the program, it crashes, with this response:

Backtrace:
In ice-9/boot-9.scm:
157: 16 [catch #t # ...]
In unknown file:
?: 15 [apply-smob/1 #]
In ice-9/boot-9.scm:
3597: 14 [process-use-modules (((gnucash price-quotes)))]
702: 13 [map # ((#))]
3598: 12 [# (#)]
2864: 11 [resolve-interface (gnucash price-quotes) #:select ...]
2789: 10 [# # ...]
3065: 9 [try-module-autoload (gnucash price-quotes) #f]
2401: 8 [save-module-excursion # ]
3085: 7 [# ]
In unknown file:
?: 6 [primitive-load-path "gnucash/price-quotes" ...]
In gnucash/price-quotes.scm:
41: 5 [# ]
In ice-9/boot-9.scm:
3597: 4 [process-use-modules (((www main)))]
702: 3 [map # ((#))]
3598: 2 [# ((www main))]
2867: 1 [resolve-interface (www main) #:select ...]
In unknown file:
?: 0 [scm-error misc-error #f "~A ~S" ("no code for module" (www main)) #f]

ERROR: In procedure scm-error:
ERROR: no code for module (www main)

Any ideas from anyone what the problem might be? I’ve tried uninstalling/reinstalling, with no joy.

[Update a few minutes later]

Someone else seems to have the same problem, or a very similar one. I’ve emailed Mssr. Villemont.

Also, I’ve come up with a temporary fix to let me get taxes done. Skrooge seems to be able to import the data. It’s more of a personal finance app than for business, but it will let me do what I need to do until I get Gnucash fixed.

[Update a few minutes later]

Great. I can import my personal finances, but it fails when it tries to bring in the business books.

[Update a while later]

Good news. I deleted the file recommended at that page, and Gnucash seems to load properly now.

Global Warming

The statistical meltdown:

The sensitivity of the climate to increasing concentrations of carbon dioxide is a central question in the debate on the appropriate policy response to increasing carbon dioxide in the atmosphere. Climate sensitivity and estimates of its uncertainty are key inputs into the economic models that drive cost-benefit analyses and estimates of the social cost of carbon.

Continuing to rely on climate-model warming projections based on high, model-derived values of climate sensitivity skews the cost-benefit analyses and estimates of the social cost of carbon. This can bias policy decisions. The implications of the lower values of climate sensitivity in our paper, as well as similar other recent studies, is that human-caused warming near the end of the 21st century should be less than the 2-degrees-Celsius “danger” level for all but the IPCC’s most extreme emission scenario.

That’s the wrong answer. It doesn’t justify ending capitalism.

Orbits And Suborbits

I’ve updated yesterday’s piece at Ricochet to clarify, for those in comments. I’ve probably discussed this here before, but…

Per discussion in comments, there seems to be some confusion about the difference between high-altitude flight, suborbital flight, and orbital flight. As John Walker points out, orbital flight requires a minimum speed to sustain the orbit, but while that is necessary, it is not a sufficient condition. In fact, a flight can be suborbital with the same speed (energy) as an orbital flight. The best, or at least, most rigorous way to define a “suborbit” is an orbit that intersects the atmosphere and/or surface of the planet. So if you launched straight up at orbital velocity, it would still be a suborbit, because it would (after an hour or two, I haven’t done the math) fall back to the ground. So John’s numbers in terms of comparative energy are roughly correct for the particular vehicles being discussed here (XCOR Lynx and VG SpaceShipTwo), they can’t be generalized for any suborbital vehicle (e.g., a sounding rocket isn’t orbital, but it goes much higher than those passenger vehicles, often hundreds of kilometers in altitude).

The speed necessary to achieve orbit is partly a function of the mass of the body being orbited, but it is also a function of its diameter, and whether or not it has an atmosphere. If the earth were a point mass, an object tossed out at an altitude equivalent to the earth radius (that is ground level) would have very little velocity, but it would have a lot of potential energy. It would fall, gain speed, whip around the center and come back up to the person who had tossed it. That is, it would orbit. So even for the relatively low-energy suborbital vehicles discussed in this post, the reason that they’re not orbital is simply that the planet gets in the way.

One other interesting point is that, under the definition above, subsonic “parabolic” aircraft flights in the atmosphere, to offer half a minute or so of weightlessness (offered by the Zero G company), are suborbital flights, in terms of their trajectory. I put “parabolic” in quotes because in actuality, if properly flown, they are really elliptical sections, as all orbits and suborbits are. The parabola is just a close approximation if you assume a flat earth, which is a valid assumption for the short distances involved. Galileo did his original artillery tables based on flat earth, which is why beginning physics students model cannonball problems as parabolas, but modern long-range artillery has to account for the earth curvature, and it does calculate as elliptical trajectories.

Finally, one more extension. Ignoring the atmosphere, every artillery shell fired, every ball thrown or hit, every long jumper, every person who simply hops up into the air, is in a suborbit. The primary distinction for the vehicles discussed is that they are in a suborbit that reaches a specific altitude (at least a hundred kilometers to officially be in “space”), and leaves the atmosphere.

Clear as mud?