Sunday, February 24, 2008
One of the most amazing abilities that dinosaurs developed was the ability to fly. Flying dinosaurs came in all shapes and sizes. The largest flying animal ever was Quetzalcoatlus, from the late Cretaceous period in North America. It had a wingspan of about 36 feet (11 M), larger than a small airplane!
Dinosaur wings were each made from one very long finger that supported a thin, but very strong, flap of skin. This flap of skin was attached to the side of the dinosaur's body, and would lift the animal into the air. Most flying dinosaurs lived near river and lakes, where they hunted for insects, fish, and other small animals. Quite a few specimens have been found in central Germany, which was a salty marsh during the Mesozoic Era.
Archaeopteryx is recognized as the earliest known bird. It is one of the most important fossils because it gives evidence supporting the theory that birds evolved from dinosaur ancestors. The mixture of birdlike and reptilian features suggests that this animal was the missing link between dinosaurs and birds. One fossilized feather has been found, and several of the wing bones show impressions of feathers.
A surprising feature of Archaeopteryx is the presence of a wishbone, just as in modern birds. This is made from two collarbones joined together in the bird's chest, and is important because the strong muscles in the wings are attached to it.
The Dromaeosaurids were a fearsome group of predatory flying dinosaurs from the Late Cretaceous Period. They had clawed hands which could grasp prey in their palms, and killing claws on their hind feet. Unlike Archaeopteryx, which flew poorly, the Dromaeosaurids had mental agility and superior balance, which allowed them to fly with precision.
One of the mysteries of the pterosaurs and dromaeosaurids is how they developed the ability to fly. One theory is that they lived in trees, and would jump from branch to branch, eventually managing to glide. Another idea states tat they lived on the ground and jumped into the air to catch prey. Flapping arms would give them the advantage of being able to jump farther and higher, eventually leading to flight.
Excavations currently taking place in India (where dinosaur fossils are very rare) suggest that flying dinosaurs may even have lived alongside primitive versions of our own modern birds.
In either case, some dinosaurs soon developed small feathers on their arms. No one really knows how many dinosaurs were scaled and how many were feathered. Recent discoveries in this area are redefining how scientists see the Mesozoic world.
There are lots of great books about dinosaurs available in the Hansisgreat store!
Posted by Hansisgreat at 11:00 PM
Saturday, February 23, 2008
Predictably Irrational, by Dan Ariely
$14.17 at Amazon.com
We'd like to think that we're usually rational and make smart decisions. Apparently, that's not really the case. Even more surprising: we're usually irrational in the same, predictable ways.
Just how much do we lose when our fleeting impulses deflect us from our long term goals? How much do expectations, emotions, social norms, and other invisible, seemingly illogical forces skew our reasoning abilities?
First, a little bit on the interesting and eminently qualified author.
When he was eighteen, Dan was injured by a magnesium flare and his body was covered with third-degree burns. He spent the next few years in a hospital, in agonizing pain. This experience caused him to challenge the predominant views on human nature, pain and pleasure, and what we'd consider the rational and obvious.
He has since become a leader in the field of behavioral economics, which draws on both psychology and economics to explain our judgement and decision making.
Each chapter in this book deals with another way in which our irrationality sometimes gets the best of us. We pay too much, wait in line too long, procrastinate, and overextend ourselves as a result.
For example, one outstanding chapter deals with the word "free!". The idea of getting something for nothing is a source of emotional excitement, but of course nothing is ever really as free as it seems.
Another discusses the contrast between social and market norms: why we are often happy to do things out of kindness, but less so when we are paid to do them. Social norms are wrapped up in our need for community, while market norms imply comparable benefits and prompt payments. When you are in the domain of market norms, you get what you pay for.
There's a very strange chapter on how being sexually aroused can affect our judgement. You won't believe the crazy experiments that were conducted in this section.
Not only do we make simple and obvious mistakes every day, but we actually make the exact same types of mistakes all the time. Sometimes we seem to make an honest effort to correct our bad behaviors, but just as often we seem to accept our shortcomings even to our own detriment.
Books like this are often dry and hard to get into, but this one was simply irresistible. Funny at times, often thought-provoking, it'll change the way you think about marketing, decision-making, and even the way your own mind works.
From the same tradition as Freakonomics, and just as fun to read, Predictably Irrational is my non-fiction recommendation for the new year!
Posted by Hansisgreat at 8:02 PM
Thursday, February 21, 2008
For those of you just joining us, I've been posting short summaries on each of the elements in the Periodic Table. These are types of atoms, the most basic building blocks from which our entire Universe is made.
Tonight we cover three metals. Metals, as a group, are good conductors of heat and electricity. They are also usually easy to shape by melting and cooling, and become shiny when you polish them.
The great utility of metals for structural and manufacturing purposes arises from their strength, that is, their resistance to breaking when stressed. Metals have also been used throughout history for fine and decorative art.
Consider the following...
Atomic Symbol: Mn
Atomic Number: 25
Manganese was known long before it was isolated as an element. Its common minerals were used by glassmakers to remove the greenish tint of natural glass which is due to traces of iron in the sand from which it is made. It was first distinguished as an element in 1774 by the Swedish chemist Karl Wilhelm Scheele. The metal does not occur in the free state, except in meteors, but is widely distributed over the world in the form of ores.
It is an essential element for all species. For some creatures, such as the red ant, it makes up a significant portion of their weight. Humans also need manganese, although this was only realized in the 1950s, perhaps because the requirement is so modest. It is still not clear exactly for what part of our metabolism it is essential.
The most surprising occurrence of manganese is on the ocean floor, where there is an estimated trillion tons of manganese-rich nodules scattered over large areas.
Atomic Symbol: Fe
Atomic Number: 26
The ancient Hittie empire of Asia Minor appears to have been the first to discover how to extract iron from its ores, beginning around 1500 BC. The Iron Age had begun, characterized by heavier and stronger weapons. These weapons dominated warfare for more than 2000 years.
The Greek philosopher Thales discovered, in 585 BC, that pieces of iron ore that came from Magnesia in Lydia had the strange power to attract iron filings. They were called magnets, after the place from which they came.
In addition to being a key part of hemoglobin, iron also plays a key role in the synthesis of DNA. There are also regions of the brain that are rich in iron.
Iron is in fact the Earth's most abundant element because the 7000 kilometer diameter core consists mostly of the molten metal. In effect, our planet is a large iron sphere.
Atomic Symbol: Co
Atomic Number: 27
Cobalt is a relatively weak metal and a poorer conductor, except at very high temperatures, at which it becomes an outstanding conductor.
This metal is used in alloys to make magnets, and in ceramics and paints to give a blue color. Certain types of stainless steel contain it, including that which is used to make razor blades.
All animal life requires a supply of cobalt in the diet, usually as the central atom in the vitamin B12.
Cobalt was once popular for making "sympathetic ink", now known as invisible ink. This strange liquid remains unseen until it is warmed, which makes it turns dark blue. Exactly who first came across this phenomenon is unknown, but it was used in espionage through the seventeenth century.
My posts on the previous elements are available here.
An exceptional book of reference on the subject is Nature's Building Blocks: An A-Z Guide to the Elements, by John Emsley. This and other fine volumes available through the Hansisgreat Store.
Posted by Hansisgreat at 11:36 PM
Wednesday, February 20, 2008
Ultimate Blogs, by Sarah Boxer
$10.19 at Amazon.com
There are currently more than 80 million blogs on the Internet, and they couldn't be more diverse. Finding good blogs, however, can be a bit difficult. Sarah Boxer checked out thousands of them before compiling this book, a collection of content from some of the best blogs out there.
No, Hansisgreat is not mentioned. Her only major oversight, I'd say. Of course, what makes a blog "great" is highly subjective, but I've got to admit that the assortment Sarah brought us is pretty darn engaging.
She begins with a short introduction, expositing on the effect that blogging has had on writing, the arts, and self-expression. This prelude is interesting in its own way, but very short. Then it's on to the content.
We begin with a woman who refers to herself only as "the bitch", and writes an hilarious tirade about racism in the film King Kong. I'd never really considered it before, but she's actually right: King Kong is, in fact, quite racist.
Some of the blogs are funny, some simply absurd, but just as many touch on very serious issues. My favorite is written by a young Arabic man living in the United States. He writes a chilling tale of being harrassed and nearly refused passage for wearing a t-
shirt with Arabic letters on it to an airport.
Also engaging is the work of an American soldier in Iraq, who gives us a unique perspective on the situation on the ground over there, and how the campaign is being run. There's a peculiar entry about an assortment of women's lingerie on sale for a dime per piece in the soldiers' PX store. Doesn't seem like there'd be much use for it over there.
There's a long philosophical rant about the movie Spiderman 2, using Peter Parker to demonstrate what ethicists call the "doing-allowing distinction". In fact, there's a lot in here about pop-culture as a vehicle for deep social philosophy. Naturally.
Some of them just feature artwork, photos, comic strips. There's a blog focusing on language and the meaning of words that had me laughing aloud while reading it. Did you ever wonder why the words pants, slacks, trousers, and jeans are plural while diaper is singular? You'll find out here.
There are a lot of blogs out there, but very few good ones. This book will guide you to a few of the best.
Posted by Hansisgreat at 9:42 PM