Monday, June 30, 2008
European scientists have recently found three "super-Earths", planets very similar to Earth's size with distances from their host star proportional to our distance from the Sun. This exciting new research is hoping to find planets where life is likely to be found. The key is finding planets with the same characteristics as Earth, and although there are unimaginably huge numbers of planets, finding one just like ours isn't as easy as it seems.
Scientists agree our twin planet would have to orbit a single star; about half the systems in the galaxy are binary stars, with gravity too harsh for life to develop. Additionally, the planet would have to be a terrestrial world like ours, not a gas giant like four of the planets (Jupiter to Neptune) in our system. The planet would have to have a suitable temperature, a breathable atmosphere, and reasonable protection from radiation.
The photo at the left is one of the first taken of Earth from outer space. One of the critical questions astronomers are trying to answer is: are planets like ours rare in the Universe, or are they quite common?
Traveling within our own Solar System is still very difficult, risky, and expensive. Finding extraterrestrial life almost certainly involves visiting other systems, a journey which is a million times more arduous. For this, it would help if we knew where we were headed.
Using powerful telescopes here on Earth, or in orbit, has helped scientists see what kind of planets other stars have. Since the early 1990's, when the first planets outside our solar system were discovered, hundreds of planets with characteristics similar to Earth's have been found.
What makes this job difficult and time-consuming is how unimaginably big the sky is: even a tiny patch may contain hundreds of thousands of stars.Once planets considered "likely" to support life are found, there's the additional challenge of traveling farther into space than humans have ever traveled before to reach them. No one knows how to overcome this obstacle, just yet.
Still, this is an exciting discovery: to find three planets similar in size and composition to Earth orbiting a single star. The smallest of the three is about four times as large as Earth. That may sound like a lot, but it's still much closer to our planet's size than the giant planets in our own Solar System.
Additionally, the discovery demonstrates that there are planets in many unexpected places throughout the Universe. These were found in a section of space previously thought to be devoid of planets. Scientists are more interested in the broader implications of the findings: that the Universe is far more teeming with planets than was previously thought.
Last week a UK team discovered a planet thought to be less than 2000 years old, in its infancy. Studying this phenomenon will help us understand how planets form and develop in a way which encourages or prohibits life. How many stars feature planets comparable to Earth, and are there pockets of space which are particularly rich and worth exploring?
So far we've sent spacecrafts only to celestial bodies already known to be barren and lifeless. One day soon, we may send explorers to a planet just like our own.
For my previous posts on astronomy and the Universe, click here.
If you're interested in a terrific book about space exploration, with lots of glossy pictures, please check out Astronomy: A Visual Guide, by Mark A. Garlick.
Posted by Hansisgreat at 5:10 PM
Generation Kill, by Evan Wright
$10.20 in the Hansisgreat Gift Shop
This outstanding piece of investigative journalism has recently been made into a mini-series on HBO. The author was embedded with a platoon of US Marines in Iraq, a likable group of young guys, and through their experiences he reports the situation from the point of view of the invading forces.
Apparently, at Normandy, a surprisingly high number of soldiers refused to fire their weapons even when facing direct enemy combat. Not these guys. Raised on rap music and Grand Theft Auto, these guys can't wait to kill some people. Born warriors.
They're not just thugs, however. One is recently married, hoping to father a son when he returns to the States. Another has wanted to be a Marine since he was a small boy, and saw one at the mall. This is not a team of lawless marauders, but a group of regular soldiers trying to do a good job over there.
They participated in the assault on Nasirayah, a Hussein-friendly city on the Euphrates River, completely destroyed by invasion forces. By the end of the assault, Nasirayah was nothing but smoldering ruins.
In Al Hayy, the situation is even worse: Wright watches as rioters destroy a recently renovated water treatment plant, and witnesses soldiers who accidentally kill a small girl who was hiding in the backseat of her parents' car. Casualties of war, very sad.
This is a book of the very best sort: it informs, but with a cast of characters and a story to keep the information interesting. I learned a bit about modern warfare, and more about the state of affairs in Iraq. More enjoyable, though, was the camaraderie of a
group of guys whom I found I'd
love to share a beer with, in spite of their grisly work.
Was the invasion of Iraq necessary? Generation Kill doesn't answer that question, nor could any of the soldiers who were actually there, boots on the ground. This is not that kind of story. It's an insightful look into the eyes of the US military, and by proxy, into America's youth.
Filled with excitement, sensitivity, and at times tragedy as well; this is a great summer read for the military enthusiast in your life.
Posted by Hansisgreat at 2:39 PM
Friday, June 27, 2008
Chapter Thirteen: The Struggle for Freedom
The Greek colonies of Asia Minor were conquered by 500 BC. The independent Greek city-states each raised their own armies which followed their own commanders. This failure to achieve political unification caused many heavy losses early in the war with Persia.
Darius died in 485, and was succeeded by his son, Xerxes I. Xerxes prepared leisurely but thoroughly for the second Persian invasion of Greece. When he finally set forth in 481 BC, his army was probably the largest ever assembled before modern times. Herodotus claimed it was composed of 2,641,000 fighting men, with an equal number of slaves, engineers, merchants, provisioners, and prostitutes. It was said that when Xerxes' army drank, whole rivers went dry.
For once, Athens and Sparta worked with a single mind. Delegates were sent to every city in Greece to beg for troops or supplies, most city-states cooperated. It was during this wave of invasions that King Leonidas of Sparta led 300 soldiers to the most heroic resistance in history. The Persians allegedly lost 20,000 to the Spartan 300. Their sacrifice allowed reinforcements time to mount a more powerful defense of their homeland.
Soon afterward the Persian fleet, composed of 1200 ships, entered the Bay of Salamis. Against it were ranged 300 Greek triremes, still under divided command. Themistocles, a Greek admiral, sent a slave to spread a rumor among the Persians that the Greeks ships were planning to flee, which could be prevented only by surrounding them. Xerxes followed this advice, and when his fleet was spread too thin from maneuvering, the Greeks counter-attacked. The invaders lost 200 vessels, the defenders only 40.
The Greco-Persian conflict was one of the most important in European history, because it defined Europe. It won for Western civilization the opportunity to develop its own economic and political institutions, free from foreign oppression or taxation. This freedom would blossom into the Golden Age of Socrates and Plato.
Persia was only stunned, not defeated, and would continue to threaten Europeans in the centuries to come. The borders between the two mighty empires would remain sources of tension and instability through antiquity and into modern times.
For my previous posts on civilization, click here.
Posted by Hansisgreat at 11:24 PM
Wednesday, June 25, 2008
Lawn Boy, by Gary Paulsen
$10.18 in the Hansisgreat Gift Shop
The author is best known for his short novel Hatchet, about a boy who survives being stranded in the Canadian wilderness. This is his newest book, from the teen section of your local bookstore, an outstanding summer read enjoyable for all but especially for younger readers since it's only 88 pages long.
Duane comes from a poor and somewhat eccentric family in an otherwise affluent neighborhood. On his twelfth birthday, his grandmother gifts him an old-school riding mower which belonged to his late grandfather. An unusual gift for a twelve year-old boy, perhaps, but it works out well. Perhaps grandma is clairvoyant.
Left with little to do over the summer in his small town, Duane begins mowing lawns in his neighborhood. In a matter of days, he finds he has more clients than he can handle. As he's about to begin turning new customers down, he meets an immigrant laborer named Pasqual with a large family of out-of-work gardeners. The two forge a deal in which Pasqual's family will mow for Duane's growing business in exchange for a share of the profits.
Sounds reasonable so far, right?
Here's where it starts to get interesting. One of Duane's clients is a day-trading stockbroker named Arnold, who's a talented investor but short on cash. In exchange for having his own lawn mowed, Arnold agrees to invest the money Duane and his companions earn mowing lawns, and then pay it all in a lump sum at the end of the summer.
So how much can a twelve year-old boy earn mowing lawns over the summer? Quite a lot, as it turns out. He's soon making thousands of dollars through his investments, and is hailed as a Wall Street genius.
It's interesting how everything positive in the story happens to Duane by chance: he receives a lawn mower, and people in his neighborhood offer to work for him, hire him, or invest for him. He just shrugs his shoulders and accepts whatever they offer. It's being receptive to the ideas that gets him ahead.
This is a delightful story, filled with interesting character and optimistic plot turns. I finished it in about an hour, so it won't seem like a chore for even the most reluctant reader. At times his successes seem a bit exaggerated: by the end of the story Duane has invested in a prize fighter who doubles as hired muscle when the lawn mowing business runs into trouble. Willing suspension of disbelief carries us through: it does make for an entertaining story.
Paulsen has been awarded the prestigious Newbery Award for fiction three times, and many of his books are now considered light classics.
Lawn Boy is all fun, without sacrifice: a terrific new light read by a distinguished author.
Posted by Hansisgreat at 10:25 AM