The idea that an asteroid wiped out the dinosaurs was first proposed in 1980 by physicist Luis Alvarez and his son, Walter, a geologist. They said that dust and soot thrown into the air would have blocked out the sunlight. Temperatures would have plummeted, and many animals, including the dinosaurs, would have frozen to death.
Prinn noted that while there was a large extinction, not all animals fared equally badly. The great land reptiles and many kinds of sea life were decimated, but many mammals and plants survived reasonably well. He said his acid rain theory may explain "the peculiar selectivity of the extinctions."
Because limestone would neutralize the acid, fish in limestone lakes might have lived. Hibernating animals deep in burrows might also have waited out the worst of the acid rain storm, and eggs laid in the ground could also have survived.
Plants would have been killed, but their seeds would have remained to sprout after the acid storm cleared. However, plant-eating animals, such as large dinosaurs, would have starved or been asphyxiated.
Many scientists doubt that something from space caused the massive destruction of species. They note that dinosaurs and other long-gone creatures died out over many centuries, not all at once, so a single catastrophe cannot be the culprit.
- Research in Scandinavia suggests that schoolyard bullies are apparently much more likely than other children to be headed for a life of crime, according to Dan Olweus, a professor of psychology at the University of Bergen in Norway.
He said large Scandinavian studies indicate the common phenomenon of bullying in the schools can also damage the emotional health of victims.
The research showed that 60% of boys who were considered to be bullies in grades 6 through 9 had at least one court conviction by age 24, and 40% of the bullies had three or more court convictions by the same age. In comparison, only 10% of children who were not bullies got into trouble with the law at that age.