Thursday, April 30, 2009

I am winner!

I am the winner of the January 2009 Round of the TC-RTC Animations competition. You can see all the remaining entries that I beat out by clicking on those links. Oh, um, but wait, I was the only entry :"-)

Wednesday, April 29, 2009

Monday, April 27, 2009

Hansen's faulty 1988 predictions of global warming.

Once again, I was in an online discussion with some conservatives who were upset about their denomination getting involved in the issue of global warming. They pointed out how it had been shown that the models for global warming are faulty. The 1988 models from James Hansen's Senate testimony were unable to predict the warming that occurred, so we really cannot trust the models today. We really cannot re-order our economic life around predictions that have shown themselves to be faulty.

The problem is that this is all based on a lie. I don't know who started it. Many people may have repeated verbatim information that they got second-hand or third-hand because they trusted the philosophical worldview of the people who were pushing the propaganda. What is the lie?

Here is an example. The example cited to me was the written testimony to the House Ways and Means Committee of John Christy on 25 February 2009. In this public document is a graph comparing James Hansen's 1988 predictions against the actual data. Here's a plot:

Note how the plot purports to be from James Hansen in 1988. Note how there are curves for a Scenario A and Scenario B. They are practically on top of each other.

Look at Hansen's actual 1988 data:

See how the portion of the curve from 1990 to 2010 shows a significant variation between Scenario A and Scenario B. Isn't that special? So, the global warming skeptics are running around telling us that the models in the past were completely unreliable, but then make false claims about what the old models were.

So how does the 1988 curve stack up against the actual data? Here's a plot:
(I hope it does not count as bandwidth stealing if I tell you the above figure comes from the Real Climate blog's article, Hansen’s 1988 projections. The Scenario B lines up pretty well.

John Christy's report says,
"We utilize energy from carbon, not because we are bad people, but because it is the affordable foundation on which the profound improvements in our standard of living have been achieved – our progress in health and welfare."

The problem here is with a view of original sin. If we cannot see the possibility that sin creeps into any aspect of our lives, even our energy use, then we've fallen into Antinomianism. The 1960's showed us the societal impacts of sexual libertinism; as we climb up the curves in Hansen's 1988 plots, we'll see the societal impacts of economic libertinism.

Sunday, April 26, 2009

Overheard on the soccer field.

"Floyd Patterson may not have been one of boxing's greatest heavyweights. He may have been one of its greatest gentlemen."

I just heard this on the ESPN Classic network program, "Who's Number 1?" That comment is a backdrop to the story I'm about to tell. On the soccer field for a league for 3rd graders, I overheard an exchange between a man and a woman, whom I believe were parents of different children on the same team. I didn't hear what the woman said. But the man replied,
"There is no polite in soccer. In fact, there's no sport where you're supposed to be polite."

If I understand the mentality, it is a very tragic and pitiful one, especially if it motivates how you lead elementary age children in sports programs. I believe it means that in sports, in the real world, you're either "impolite" or you're a sissy. How sad. I immediately thought of the difference between "passive," "aggressive," and "assertive," and wondered what "sportsmanship" meant if you didn't have to be worried about being polite. I later thought about the concept of "honor" and "chivalry" in warfare, where apparently you were able to be very "polite" to persons you were trying to kill. Then when I was flipping channels, I heard the quote above touting gentlemanliness in boxing, of all sports.

The attitude of the man stands in contrast to the reputation and life work of Floyd Patterson. It's more like that of Mike Tyson.

Friday, April 24, 2009

Mechsim patch in povray

The program povray has a patch called MegaPov. It adds some pretty cool features to povray's basic abilities. One of them is the mechsim patch.

I dusted off an old project where I made some giant, rubbery blocks fall on the head of our hero, an object constructed out of povray blobs. It makes for a faily entertaining if not realistic show:

Mind you that the path expects objects to be made in a certain way, an iso, and a blob is not one of them. The fact that it works at all with blobs is pretty cool. But the limitation proves fatal for realism if you try to press it too far.

Here's an attempt to have M.I.M.E. Man punch the blocks out of his way. His arms get caught on the vertices of the falling blocks. Oh well. It was fun while it lasted. But perhaps viewers can try out the patch and do some pretty interesting things with more simple geometries. Or if you know a way to code the SDL for the patch to work better, please drop me a note or comment in the blog. thanks.

Wednesday, April 22, 2009

Exoplanet transit of the star Sirius

Here is a project I did in povray. It makes use of media and a simple disc to simulate the sun. The planets look like they are lit by the sun, but simply have a gradient texture to simulate the color patterns you'd get on a planet.

BTW, this is just an artistic simulation, not the real thing, in case you were wondering. :)

Tuesday, April 21, 2009

Antarctic ice data proves global warming hoax?

I saw a conservative in a religious forum post a news article that he said disproved a manmade connection to global warming. He even touted the honesty and reliability of the particular scientists involved in this story, compared to the general population of scientists working on climate change. Let's see.

In the story, Antarctic ice is growing, not melting away, by Greg Roberts, we read:

"Australian Antarctic Division glaciology program head Ian Allison said sea ice losses in west Antarctica over the past 30 years had been more than offset by increases in the Ross Sea region, just one sector of east Antarctica.

"Sea ice conditions have remained stable in Antarctica generally," Dr Allison said.

Okay, there you have it. Dr. Ian Allison , a scientist at the Australian Antarctic Division, is an inherently reliable scientist. What is his opinion on climate change?

He's interviewed in the Reuters story, Q+A: How great is the threat from melting ice sheets?
Ian Allison is leader of the Australian Antarctic Division's Ice, Ocean, Atmosphere and Climate program and a researcher within the Antarctic Climate and Ecosystems Cooperative Research Center.

He has been involved in Antarctic science for over 40 years.


"I think it is now unequivocal that warming of the world is occurring and I think the last IPCC (Intergovernmental Panel on Climate Change) conclusively showed that a major cause of warming is greenhouse gas emissions from mankind.

There you have it. An inherently reliable scientist says that the IPCC "conclusviely showed that a major cause of warming is greenhouse gas emissions from mankind.

Monday, April 20, 2009

Why my 3D work impresses so few people.

It's because it's so 1991. Here's an animation I found at the SIGGRAPH archive at

Sunday, April 19, 2009

A Dailymotion "Video Wall"

This shows the videos I've submitted to Dailymotion. I guess I haven't put many things up there.

Saturday, April 18, 2009

Long-necked turtles

I took this footage at the National Zoo in DC. I thought it was interesting how these turtles moved, both their legs and necks.


Friday, April 17, 2009

The Relativity Train

I created this animation for the TC-RTC
raytracing competition. Unfortunately, I was the only entry for this round, which is "Relativity." I made an animation which tries to show the humorous consequences of the speed of light being constant across all frames of reference. A superhero blasts two robots aboard a train moving near the speed of light. Onboard observers observe them being blasted simultaneously. Stationary observers observe one being blasted first. Only this time there are diplomatic consequences for Earth!

If you're interested in the animation at all, go to the Vimeo page and see it full screen!

The Relativity Train from pterandon on Vimeo.

Friday, April 10, 2009

How to accelerate and decelerate masses for character animation in povray

Oftentimes in making character animation, I've received or heard criticisms about wooden, unrealistic movement. In many 3D applications, it is very easy to make a character move to and fro. The temptation is usually to make the "curve" look like a sawtooth. The character's body part (arm, leg, hand, etc.) moves in one direction for a while and then suddenly reverses in an instant. In most 3D apps, you have the option of tweaking the curves. Problem is, it's quite tedious in the more advanced 3D apps, and not at all obvious how to do in povray.

Note the animation below. The character on the left moves in the stereotypical "sawtooth" fashion. The acceleration and deceleration are instantaneous. The next one has a little more acceleration, increasing up to the fifth one. The sixth character moves in a sin curve fashion.

The way I derived these equations was to integrate x to the n times one minus x to the n. I did this for 1, 2, 3, and 4. The result of these integrations is shown in the formulas below.

I hope this will help someone in povray at some time.