Friday, October 30, 2009

Diesel Exhaust is a Weighty Matter

Scientific American has this online article -

- the point of which is to point out the enormous amounts of pollutants produced by idling truck engines, and that New York City has a law regarding this that really ought to be enforced. I have little doubt that this really is a significant source of pollutions, but this statement made me raise my eyebrows:

"Idling buses, cars and trucks may not seem like a big deal, but in New York City they spew out as much pollution as nine million diesel trucks driving from the Bronx to Staten Island, according to the Environmental Defense Fund. That’s roughly 130,000 tons of carbon dioxide, 940 tons of nitrogen oxide, 24 tons of soot particles, and 6,400 tons of carbon monoxide each year"

Can that be right? That's a lot of trucks making the trip. I'm a statistician, and I wonder about such things like the accuracy of statistics like this. Watching TV on a Friday night, I started doing so some Googling and back-of-the-envelope calculations during the commercials.

The claim of the article: 130,000 + 940 + 24 + 6,400 = 137364 of pollutants released each year, that's 274,728,000 pounds. The distance between the Bronx and Staten Island is 33.9 miles (so says Google Maps), and in 9 million trips that works out to 305,100,000 miles. 274,728,000 pounds divided by 305,100,000 miles is 0.9 pounds of pollutants per mile.

The Economy of Diesel trucks: The average big diesel truck pulling a load gets about 5.5 miles per gallon of fuel (so says Wiki Answers), or 0.182 gallons of diesel per mile. Diesel weighs about 7.2 pounds per gallon (in cold weather yet, so says, so 0.182 gallons/mile times 7.2 lbs/gallon is about 1.31 pounds of diesel per mile driven.

Now 0.9 lbs/mile of pollutants divided by 1.31 ponds per mile of diesel work out to 0.6873, or about 70% of the total mass of the diesel fuel converted to pollution. At this point, I ran into difficulty finding a source for the actual composition of diesel exhaust. 70% might be reasonable; after all, the mass of the fuel has to go somewhere.

But wait, I've made a mistake - most of the 130,000 tons of carbon dioxide is oxygen, without looking up the molecular weights of carbon and oxygen, AT LEAST two-thirds of that mass is coming from the atmosphere and not the diesel fuel. 70% now seems more reasonable.

There is another possible error, which I don't know how to resolve. In my reading I discovered (lost the link, sorry) that idling diesel engines are relatively clean, but produce heavy pollution when under a load (you see this on the road all the time). Therefore the number of idling vehicles must be really huge to make of this difference. This is also quite possible; NYC is a BIG place, but the article does not offer any information about how many vehicles this might be.

I would assume that if NYC has a law that trucks should not idle for more than a minute, there must be some good evidence somewhere to back this up. The original claim seems to come from the Environmental Defense Fund, but I'm too tired for more digging tonight. This has been an interesting bit of fact checking, except that I ran into a wall with limited knowledge of chemistry. Maybe I should ask a Chemist?

[UPDATE, 11/01/2009]
I received this response to my question at About.Chemistry, Sean writes:
the average chemical formula for diesel is C12H23. with that said, the mass of a carbon atom is 12.01 g, and hydrogen is 1.008. so, mathematically, diesel has the molecular weight, on average of 167.304 grams per mole of fuel.
the weight of the oxygen atom is 15.99g (mostly rounded to 16g), so carbon dioxide is 44.01 grams per mole.
in general, this relates to something of the sort:
2 moles of C12H23 +  O2 gas in excess -makes-> 12moles CO2+ 12moles CO+ 23moles H2O. as the formula for the burning of the diesel, if it was a very complete and clean reaction, however, we all know that's never the case. ;.;
as for the 130,000 tons of CO2, that comes to
 117 934 016 200g of CO2

and of that gram mass, 27% is carbon, while 73% is oxygen. that's what...
31842184374 grams of carbon and 86091831826 grams of oxygen.
however, diesel is more of a blend of things and not just the carbon and hydrogen, which pretty much takes all that I have written and makes it almost useless. In my research, though, I've seen more about the fact that sulfur is present in the fuel than the carbon emissions, as that will inhibit the use of catalytic filters to scrub the exhaust clean, as in most vehicles.
also, in response to your lost link, I dug this up
which says that idling is bad for diesel because it produces more exhaust via incomplete combustion.
anywho, I'm not too advanced in chemistry, so forgive me if I supplied you with random nonsense, I was trying to think of a way to equate the mass of fuel to pollutants produced, but as I can't find an exact formula for what the reactions are this is the best I think I can do. I'm hoping someone else can chime in from here and make more sense of things, and of anything, I wish you luck with your search.

Thanks Sean!

After some more digging I turned up an abstract and a paper on wind tunnel experiments (Part 1, Part 2) that are related, but none seem to be the origin of the original statistics. I might have more luck searching from work tomorrow.
-- OR --
I could ask the author of the SciAm article, Mr Brett Israel. Would that make it too easy?

[Further update 12/09/2009]
I never heard back from the author and I've pretty much given up. Sean's comment about catalytic converters is something else I had not thought of that might affect the results. So many windmills to tilt at, and so little time.

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Monday, October 26, 2009

Creation Museum Claims Proven

Dread Tomato Addiction blog signature Proof positive the Man and Dinosaur co-existed!


Check out the video for the full story:

UPDATE: The video originally linked on YouTube has since been removed. Click this link to search for a currently available version.

The Real story being Chuck Jones 1939 debut as the director of Daffy Duck - and so history was made. Dread Tomato Addiction blog signature

Friday, October 23, 2009

Wednesday, October 21, 2009

No Wonder It's Endangered

Dread Tomato Addiction blog signature The hazards of zoology!

I suppose every now and then it may accidentally shag a female of its own species. No wonder it's endangered.

[Via A Simple PropDread Tomato Addiction blog signature

Monday, October 19, 2009

Behe bobbles ball to Blind Locksmith

Dread Tomato Addiction blog signature This is a bit much to explain, but Carl Zimmer hosts an enlightening response from biologist Joe Thornton to creationist wannabee Michael Behe's lastest brain-fart.

This is the same Michael Behe who, when Thornton published the first half of this research, declared it “piddling.”
Why the change of heart? Because Behe thinks that the new research shows that evolution cannot produce anything more than tiny changes. And if evolution can’t do it, intelligent design can. (Don’t ask how.)
I pointed out Behe’s posts to Thornton and asked him what he thought of them. Thornton sent me back a lengthy, enlightening reply. Since the Discovery Institute doesn’t allow people to comment on their site, I asked Thornton if I could reprint his message here.

What are you still doing here? Go read the original at The Loom. Dread Tomato Addiction blog signature

Giant Steps

Dread Tomato Addiction blog signature Just because it's cool.

[HatTips2 dancohen, Open Culture, @hughmcguire, and MetaDeb]

Not to ruin the nice Coltrane vibe, but compare that to a saxophone playing robot. The video below shows the robot in action. The tone is awful, but it will give you some idea of what Coltrane is doing on the keys. Unfortunately it only shows the left-hand keys and we miss out on all the right-hand action, but you see can some of the high-note valves moving, which are operated by the right hand.

[Sax-playing robot image from Hosei University Takashima R&C Laboratory]

[Video nicofar]

The keys are the easy part. The robot can get the notes, but isn't even close to making sounds like Coltrane. Dread Tomato Addiction blog signature

Thursday, October 15, 2009

Monday, October 12, 2009

My Baloney Has a First Name ...

After reading this recent offering from The Sensuous Curmudgeon . . .

The Worst Creationism Book Ever?

I took it upon myself to visit the scene of the crime. I went to the Probed Minihysteries site and ended up reading the "Tuning Up Your Baloney Detector" article. To briefly summarize, they encourage the faithful to protect themselves from errors in critical thinking by "filtering the facts" and therefore committing those very same errors in critical thinking. It is Grade AA stupidity, and that is 5 minutes of my life I won't get back, but it did give me this bit of inspiration:

My Baloney Has A First Name,
it's P-R-O-B-E . . .
My baloney has a second name,
it's M-I-N-I-S-T-R-I-E-S . . .
Oh, I love to filter everyday,
And if you ask me why I'll say. . .
'Cuz Probe Ministries has a way . . .
To Make-Those-Facts-Just-Go-A-Way!

Somehow I doubt it will catch on, but it gave me a bit of entertainment. Here is the original . . .

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Thursday, October 8, 2009

Very Contrary

David Brin has long been one of my favorite authors, but I only recently discovered my more socio-political ramblings. I'm don't agree with all that he says (and I don't think I am supposed to), but he really make me think about think in a different way.

This post is actually an experiment in publishing from Google Sidewiki. A new service that allows you to post comments about any web page. It works, but now I'm going back and editing this monster I have created.

Now back to Brin - - -

- - - Some highlights:

Does The New Right Even Have an Agenda Anymore?

Alas, today's Republican Establishment seems not only incapable but uninterested in negotiation or deliberation. It isn't just the dogmatism, or lockstep partisanship, or Koolaid fantasies spun -up by the Murdoch-Limbaugh hate machine. Heck, even though "culture war" is verifiably the worst direct treason against the United States of America since Fort Sumter, that isn't what boggles most.
No. Given their lack of any other tangible accomplishments across the last fifteen years, one must to conclude that the core agenda of Rush Limbaugh, Rupert Murdoch and their petroprince backers really is quite simple.

To find out just how far they can push "culture war" toward a repeat of 1861.
Alas. This is no longer even about "conservatism" anymore. Barry Goldwater lived long enough to denounce what he saw happening to his beloved movement, and things have plummeted even father, since that great man died

Nowadays, bottom-to-top -- and especially at the very top -- it is all about stupidity.

AND from the comments:

What I'm saying is that this post is sabre rattling. The red-staters will not back down because you remind them that people from blue states could defeat them as they did in the past.
But there is a power center that might push for such a demolition. It is foreign, VASTLY richer than Murdoch, and has openly avowed its wish for a world they control, and without us in it.
in reference to:
- Contrary Brin: A rant about stupidity... and the coming civil war... (view on Google Sidewiki)

Tuesday, October 6, 2009

The Meaning of Gravity

Dread Tomato Addiction blog signature There is SOMETHING happening on the internet! OK, so maybe that wasn't specific enough. Phil Plait of Bad Astronomy Objects, MarkCC of Good Math, Bad Math calls him on it, and I'm honestly not quite sure what they are on about. Something philosophical, I think.

What I do know is that it started off with a comment about the meaning of gravity. Silly people! Douglas Adams explained all this to us long ago!

Here is a more recent version of the story of the Sperm Whale and the Bowl of Petunias.
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Sunday, October 4, 2009

Hammy the Hamster Goes Organic

[Reposting with updated links]

Is Organic food really better? Ask any hamster ...

... and be sure to visit The Cooks Den for the out-takes video and comments too. Me though, I want the data!

Here is the response I posted over at The Cooks Den.

First, I applaud this experiment. Flaws and all, this is great fun, and any discussion taking it seriously or impprove suggesting how to improve the experiment serves to illustrate what is involved in the scientific method. Bravo!

Second, if we must take it seriously, then we ought to do it right: I strongly disagree with the statistical comparisons presented so far. A t-test or ANOVA applied here is wrong. This is categorical data and there is no a priori reason to disregard the indifferent results. In a Chi-square test of homogeneity with a null hypothesis of equal proportion of responses (25 each; conventional, organic, indifferent) the exact p-value is 0.1890. Even if we exclude the indifferent responses, the p-value is still 0.0854. Neither of these meet the typical standard for statistical significance (p less than 0.05). This is not conclusive evidence that Hammy’s choices are anything other than random.

Crap. I hate when I don't spot the typo until after I have submitted the post.
[Update: Updated links for The Cooks Den. Originally poster March 2009]

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Thursday, October 1, 2009

Hello Ardi!

Dread Tomato Addiction blog signature [From Nature News]

At 4.4 million years, Ethiopian fossil clarifies human–chimp relationships.
In a far-reaching reordering of human evolution, researchers report today the discovery of the oldest hominid skeleton, a fairly complete 4.4-million-year-old female from Ethiopia.

The discovery shows that humans did not evolve from ancient knuckle-walking chimpanzees, as has long been believed. The reports, in Science, illuminate how early phases of humans evolved along a separate lineage from the last common ancestor shared by early hominids and extinct apes.

This find has been in the works for 17 (17!) years, go read all about it at Nature NewsDread Tomato Addiction blog signature