Sunday, September 26, 2010

Falling Cats

Cats like high places, and they often fall. Clinics often see cats injured in falls, but they survive falls that would splat people into ketchup.  A good post on falling cats is from Don Burleson, and another is Wikipedia.

A cat falls more slowly than person does, because of its fluffy fur catches the air and light bone structure. Cats have a terminal velocity of 60 mph where as a person falls at over twice that or 130 mph. (Actually ski divers fall more slowly facedown with arms extended, and about 200 mph in a vertical diving position.) Remember that kinetic energy is proportional to the square of the velocity, so the potential damage on hitting the ground is over four times greater for a human than for a cat (on a per pound basis).

Of course cats, orient themselves to land on their feet, as shown at right these cool photos from Berkeley.   The physics of the cat turning involve extending its legs to change it moment of inertia.

  1. Bend in the middle so that the front half of their body rotates about a different axis than the rear half.
  2. Tuck their front legs in to reduce the moment of inertia of the front half of their body and extend their rear legs to increase the moment of inertia of the rear half of their body so that they can rotate their front half quite far (as much as 90°) while the rear half rotates in the opposite direction quite a bit less (as little as 10°).
  3. Extend their front legs and tuck their rear legs so that they can rotate their rear half quite far while their front half rotates in the opposite direction quite a bit less.
  4. Repeat if necessary.
The ability to live though a fall like this certainly gives an advantage to the cat evolutionally. I wonder how this reflex is encoded genetically. 

Friday, September 24, 2010

Factory Farms

This pile of dead pigs is sometimes used to illustrate factory farms.
It actually is from a Mexican farm after a swine flu outbreak in 2009.
I have tried for three days to write something interesting on factory farms, but I am giving up. This entry is an excuse to post the swine flu picture at right -- which you must admit -- is a pretty striking image.

My basic notion is that most large scale industrialized farms are actually "family farms" too. Sometimes statistics are shown about how corporations control large sectors of agriculture, but these only refer to meat packing and not to real agriculture.

"Factory farm" has become a pejorative for anything bad about farming.  Wikepedia says has a hard time defining the term too. They say that large scale corporate farms differ considerably around the world and by the type of animal raised.

I know people who have given up eating meat because of factory farms. It strikes me that so-called organic farms are not likely to be meaningfully different or better. There are probably better reasons to be vegetarian than factory farms.

This report from the Pew Center is on factory farms is pretty good. Not very interesting though:

So that is what I have to say about factory farms. If you have anything more interesting to say about it, leave a comment.

I bet no one does.

Sunday, September 19, 2010

Welcome to the Methanol Economy

Remember back in aught-three when GW Bush, proposed the Hydrogen Economy in a national speech. I was so proud of him. He even knew what switchgrass was. The hydrogen economy is when hydrogen is generated from electricity, solar energy or biofuels. The energy is stored in the form of hydrogen, and then burned directly or in a fuel cell. Burning hydrogen produces only water as a by-product, and this is even carbon neutral -- although Mr. Bush in 2003 did not care about that.  Bush got a fair amount of criticism for being too fringy green, but he was actually ahead of his time.

From Wikipedia
Sad thing was, this was about the last gasp for hydrogen advocates. Making hydrogen from electricity was not that easy, and then burning it for fuel was wasteful as well. On top of that, hydrogen is a bulky gas, and it was hard to carry enough of it to power an automobile. In the jargon, its energy density is low.

The advantage of methanol is that it is a liquid at room temperature with far higher energy density of 15 MJ/L vs 0.013 MJ/L for low density gas or 5.6 MJ/L at 700 bar. This means you could pump it into a regular gas tank like gas. You would need a larger tank since gasoline is three times more energy dense.

Methanol can be made by bacteria from sugar just as easily as ethanol can. Methanol can also be made from synthesis gas. Naturally BASF, my employer, makes catalysts for that. Synthesis gas can be made from nearly any biomatter like corn stover, switchgrass, or aged biomatter like coal.

What I just learned was the methanol is quite efficient in a fuel cell. Although it produces carbon dioxide, the greenhouse gas. If the methanol is originally made from waste carbon dioxide, the whole process could be carbon neutral though.

See my recent post on the stalling of cellulosic ethanol. For further reading on the methanol economy click here.

Saturday, September 18, 2010

Should You Buy "Top Tier" Gas or Save the Money?

I was talking to BASF co-workers about gas and engine oil additives. BASF makes a line of these additives, and I asked how do you know what is a good gasoline to buy.

The EPA requires a minimum amount of detergent in gas, but many people say it is not enough. In the jargon, the Lowest Additive Concentration allowed is called the LAC. At right are some BASF photos showing how the LAC rate is not that much better than no additive.

"Top Tier" gas is trademark held by a consortium of 27 gasoline retailers, big and small -- like Chevron, Exxon-Mobile and Shell, but also including Kwik-Trip. Four automakers, Toyota, GM, Honda and BMW negotiated standards with the gas retailers, and these companies recommend Top Tier gas.

This gas will provide better cleaning action than specified by the EPA minimum standards, and keep valves from sticking. This will improve economy, reduce emissions, and presumably lengthen engine life.

All the gasolines at the "Top Tier" stations will meet the standard, and this means the economy grade will meet the standard, just like the premium. Marketing-wise, it hurts the ability to differentiate.

BP is following a different path. Specifically, their premium gas has more detergent than their regular -- if you believe the website. The former Amoco Oil company, now part of BP, advertised its detergent gasolines prior to the new EPA standards. They are not a member of "Top Tier," and they are endorsed by Ford, who also is not allied with "Top Tier."  The range of quality at BP bothers me, since now I don't know which grade of gas to buy.

I'd like to talk about what these detergent additives are, but this is one of those industries, where compositions are all trade secret. Dow says they are sulfonates, phenates and salicylates.

In summary, it is probably best to trust the judgement of the auto manufacturers, since they do not have a interest in selling overpriced gasoline. If GM, Toyota and Ford all think that gas with the LAC of detergent is not good enough, then I will upgrade to a better quality of gas. Good bye Marathon.

Saturday, September 11, 2010

New Mustang vs. Old Mustang

1970 Ford Mustang Boss
I have wondered how cars have changed in the last 40 years. People talk about old cars prior to environmental controls like it was some kind of golden age. The 1970 Mustang Boss might not be as classic as the 1965 Mustang, but as you can see it looks pretty good.

I am not sure I like the overbite the hood has over the bumper. The tires on these older cars always look too big to my eye. Also the windshield sticks up more abruptly than modern cars making it boxy looking--back in the day it would not have seemed that way.

I would have expected the new 2011 Mustang to be lighter because of lighter weight sheet metal and plastic parts, but not really. The 2011 car is faster, gets twice the gas mileage, and has a smaller, more powerful engine.

The 2011 Mustang beats the 1970 classic in everything.
Consumer Reports Oct 2010 issue page 58

One thing that was better about the 1970 Mustang was the price; it started at $5000, and the new model has a base price of $30495.

The new Mustang still looks good; much more aerodynamic -- perhaps too much like an economy car though. They kept the detail on the door, and the razorback rear end.  

Monday, September 6, 2010

Nanobots Are Coming! Nanobots Are Here!

Fictional Nanobot
Nanobots are fictional nanometer sized robots that Sci-Fi writers have been putting to work healing people or taking over the galaxy.

There have been different kinds of nanobot projects built. Most have been little robots the size of flies.

Fictional illustration of the Oxford nanobots. This illustration
does not indicate that the nanobots crawl along DNA.
An exception is Turberfield at Oxford who has been trying to make motors of DNA, which sounds ambitious.

At left is a drawing of a two legged nanobot.  The real nanobot is made of DNA, and it only crawls on a strand of DNA. The nice thing about this nanobot, is that it is truly nano.

Another way of making a nanobot is to start with a bacteria. The advantage is that it could reproduce itself, and you could add functions from the library of genes already available. Sylvian Martel at Ecole Polytechique in Montreal wants to make a robot they could inject with a catheter, and then guide with magnets to a tumor, and then the robot would deliver a toxic payload. This bacteria has an organelle that orients the bacteria with a magnetic field, and the gene for this was moved in from another kind of bacteria.

This video shows the nanobots moving nano-blocks into a pyramid shape:

Nanobots are a field where writers and visionaries are far ahead of practitioners. Self-replicating nano-bots that are mechanical and not biological, seem years and years away.

Saturday, September 4, 2010

America No Longer Has Lower Unemployment than Europe

European Unemployment in July 2010, US rate was 9.5% and Japan's was 5.2%
American's used to feel superior to Europeans because their social safety net supported a higher level of unemployment and general laziness -- laziness that was not tolerated in the more laissez faire America with its rough and tough economics.

In July European unemployment and American unemployment were the same on average at 9.6%. Key countries had far lower rates like Netherlands at 4.4%, Germany at 6.9%, and the UK at 7.8%. The US can still feel superior to France at 10.0% and Estonia at 20.3%.

The twenty-seven EU countries and their abbreviations are Belgium (BE), Bulgaria (BG), the Czech Republic (CZ), Denmark (DK), Germany (DE), Estonia (EE), Ireland (IE), Greece (EL), Spain (ES), France (FR), Italy (IT), Cyprus (CY), Latvia (LV), Lithuania (LT), Luxembourg (LU), Hungary (HU), Malta (MT), the Netherlands (NL), Austria (AT), Poland (PL), Portugal (PT), Romania (RO), Slovenia (SI), Slovakia (SK), Finland (FI), Sweden (SE) and the United Kingdom (UK).

Of course the cause of this is the "Great Recession," and the depression in housing prices. Ordinarily shockingly low interest rates would spur housing construction across the country, but not this time. There are way too many existing, empty houses.

America needed housing to pull it out of recessions, and this time housing was not there.

Friday, September 3, 2010

Organic Milk Does NOT Prevent Early Puberty in Girls

Cute girl drinking milk.
I was outraged when Time Magazine said organic milk helped prevent early or "precocious" puberty in girls and recommended that people buy organic milk rather than conventional milk.

It used to be the Time did good research, but they dropped the ball here.

There are some small differences between organic milk and commercial milk. The most notable being residual antibiotics, and residual growth hormone BST (bovine somatotropin).

Residual antibiotics may cause antibiotic resistance diseases, but it is not going to affect maturity of children.

BST is a growth hormone even if cow hormones worked on people, and even if it were not digested in the stomach -- it would make girls (and boys) grow bigger and taller; not more mature. The whole argument about sexual development is misconceived.

BST is politically controversial, but not because of health -- BST is just digested in the stomach like any other protein. The controversy has to do with farmers trying to limit milk supply by prohibiting more productive hormone-receiving cows.

Animal lovers, vegetarians, and vegans claim that BST causes the cows to live in pain due to being too tall and having big udders, and there may be some merit to this point of view. There is not much merit to health effects of BST -- really it is just the farmers trying to limit supply to keep prices up.

Cool looking giant cow, maybe because of bovine somatotropin.
(Actually this is a steer. The largest in the UK.)
There are some who say that because milk comes from lactating cows, it has extra estrogen, but organic milk comes from the same kind of lactating cows. Organic feed is not going to make any difference.

Early puberty in girls is due to chemical additives in the diet (see this post, another), and due to girls being over-weight. Fat girls make more estrogen and go through puberty earlier.

Others say milk generally causes early puberty, due to its fat or other ingredients. As discussed above, milk can make girls (and people generally) fat, and this might lead to early "development" because heavy girls make more hormones. Maybe so, but any food from organic milk to Snicker bars would do the same.

Finally, girls are drinking less milk than their mothers did, but puberty keeps getting earlier. If milk were the problem, puberty would be getting later! The source of early puberty has got to be somewhere else.