Group items tagged

1978 and 2000, they are 95 million strong, compared to 78 million Baby Boomers.

Generation We - the Millennials - has arrived. They have emerged as a powerful political and social force. Their huge numbers and progressive attitudes are already changing America. And the world.

Adapted from Dinosaurs: The Very Latest Information and Hands-On Activities From the Museum of the Rockies, by Liza Charlesworth and Bonnie Sachatello-Sawyer. A Scholastic Professional Book. The last dinosaurs died approximately 65 million years ago. Although the cause of their extinction is still a mystery, climatic change, diseases, changing plant communities, and geologic events could all have played a role. Lately, dinosaur extinction theories have been the subject of much debate and controversy. A recent explanation, supported by many scientists, suggests that dinosaurs died out soon after a huge meteorite crashed to Earth near the Gulf of Mexico. A giant meteorite, they reason, could have landed with an impact that kicked up enough dust and debris to block out sunlight for a long time — leading to a deadly chain of events. Without the sun, all the plants died; without the plants, all the plant-eaters died; and without the plant-eaters, all the meat-eaters died. Sounds reasonable. But there is one problem with this theory: Paleontologists have not yet been able to find dinosaur skeletons in rocks dating to the period of impact. Some evidence even seems to indicate that all the dinosaurs had died before the meteorite hit. What is the answer? As paleontologists search for clues to support their theories, they agree to disagree.

basic laws of physics dictate that energy is conserved and can only be changed from one form to another or into matter.

Fuel, on the other hand, is the accumulation of matter and therefore represents a store of energy.

released in the form of heat when the fuel is burned in chemical or nuclear reactions

In 2002 about 40% of U.S. carbon dioxide emissions stem from the burning of fossil fuels for the purpose of electricity generation. Coal accounts for 93 percent of the emissions from the electric utility industry. US Emissions Inventory 2004 Executive Summary p. 10 Coal emits around 1.7 times as much carbon per unit of energy when burned as does natural gas and 1.25 times as much as oil. Natural gas gives off 50% of the carbon dioxide, the principal greenhouse gas, released by coal and 25% less carbon dioxide than oil, for the same amount of energy produced. Coal contains about 80 percent more carbon per unit of energy than gas does, and oil contains about 40 percent more. For the typical U.S. household, a metric ton of carbon equals about 10,000 miles of driving at 25 miles per gallon of gasoline or about one year of home heating using a natural gas-fired furnace or about four months of electricity from coal-fired generation.

largest monitor lizard or goanna native to Australia

fourth largest lizard on earth

Found west of the Great Dividing Range in the arid areas of Australia