The great dark matter debate
In the September 10 issue of The Varsity, we ran a piece about the history of the search for dark matter and evidence supporting its existence (“The dark side of the universe”). A recent study led by Douglas Clowe provides indirect evidence for dark matter, from observations of a collision between two large galaxy clusters. The observed bending of light around the massive collision allowed astronomers to infer that a large amount of invisible dark matter was present. Two Canadian astronomers— John Moffat of the University of Waterloo and his graduate student, Joel Brownstein—have publicly disagreed with the work, and propose that a Modified Gravity hypothesis can explain the findings of the study. They believe that changing the current understanding of how gravity works can account for the perceived extra mass. The two stress that direct evidence of dark matter has yet to be found, while Clowe maintains that dark matter exists and that the results of his research are valid. No conclusion to the debate is yet in sight. As one side looks for new sub-atomic particles that could make up dark matter, the other looks to change a long-standing view of how the universe functions, trying to rework the ideas of Newton and Einstein. For simplicity’s sake, I am inclined to believe dark magic is to blame.
Hollywood was right, for once:
As it turns out, Jurassic Park had the behaviour of Velociraptor right. A fossilized stretch of footprints unearthed in China’s Shandong province demonstrates that the dinosaurs travelled together in packs, as the six paths do not overlap and were made at the same time. The fossils also prove another aspect of dinosaur behaviour shown in the movie: the dinosaurs held their long claw off the ground when travelling, possibly to avoid wearing them down. Judging by the footprints, researchers say the dinosaurs would have been around 200 pounds and 1.2 metres high at the hip. Although Steven Spielberg got the dinosaurs right, I still don’t understand why Jeff Goldblum’s character had to survive.
Info graphics are worth a thousand words:
The link below shows the proportion of people across the different countries of the world in a cool info graphic. The distorted world map illustrates the huge amount of people in Asia compared to other continents. Australia nearly falls off the bottom of the map and Canada looks like a thin blanket on top of the United States.
Organism of the week:
The American Bison, scientific name Bison bison. Commonly, although incorrectly, referred to as the buffalo, millions of these brown beasts once inhabited the great plains of the United States. They are the largest terrestrial mammals in North America, reaching three metres in length and two metres in height. They can weigh as much as 900 kilograms, equivalent to the weight of a mid-size car. Curiously, male bison often display strangely amorous behaviour by courting and sometimes mounting other males. Although seemingly slow and laconic animals, bison can easily outrun humans and have been recorded travelling up to 56 kilometres an hour. Surprisingly, there were four times more bison attacks than bear attacks at Yellowstone National Park between 1978 and 1992. Bison were hunted to the point of near-extinction by the mid 1880s. The government sponsored this over-exploitation because, among other reasons, reduced bison numbers reduced costly train delays or damage from herds milling about train tracks. The American government also wanted to starve the Native Americans inhabiting the plains to get them to leave. Buffalo hunting was a lucrative trade for the hides, coats, and meat, and some hunters, such as Buffalo Bill Cody, became famous for killing over one hundred bison during a single hunt. The bison’s impact on the course of early American history is demonstrated in its inclusion on the American nickel from 1913 to 1938. Bison numbers have rebounded quite well, with current estimates at apporixmately 350,000. Comically enough, a subspecies of the animal bears the scientific name Bison bison bison.
Lovelock’s visions of the apocalypse:
The loveable and slightly crazy Professor James Lovelock has a message for the world’s inhabitants: we’re screwed. In a recent speech, he explained that humans have to brace for the inevitable changes that global warming will bring. He agrees that nations should reduce greenhouse gas emissions, but describes the International Panel on Climate Change’s recent report as misleading. He says that it gives the idea that climate change is reversible, which he strongly disagrees with. His dire view is that 6 to 8 billion people will experience serious problems in the future, including issues with water and food supplies. If his name sounds familiar, it’s because Lovelock came up with the Gaia hypothesis, which suggests that the whole Earth functions as a single organism. Although widely criticized—it smells heavily of acid and the ’60s—the hypothesis highlights the importance of interactions between organisms and their environments. Either way, it is enjoyable watching a scientist unafraid to speak his mind.
Better than the Letterman countdown:
Discover magazine has some nifty pieces, especially their “20 things” countdown. The latest edition, on astronauts in space, features some helpful advice: don’t hold your breath if you are ever exposed to the vacuum of space, as it could cause your lungs to rupture. It’s information we can all use, really.
Not even being adorable will save you:
The machinations of the global economy can often produce some bizarre situations. According to The Ecologist, 250,000 lambs in Britain are going to be made into bio-fuel or incinerated. The animals cannot be sold for meat, as meat industry critics say that the abrupt input of a large amount of lamb meat would make already low prices drop drastically. In addition, animal feed has almost doubled in price, making it uneconomical to keep the animals. Little Bo Peep was reportedly devastated at the news.
Mr. Burns, on neuro-surgery:
“Dammit Smithers—this isn’t rocket science, it’s brain surgery!”
