Skip to main content
A New Type of Jet Engine Could Revive Supersonic Air Travel
Since the 1960s engineers around the world have been fiddling with a novel type of jet called a rotating detonation engine (RDE), but it has never got beyond the experimental stage. That could be about to change. GE Aerospace, one of the world’s biggest producers of jet engines, recently announced it was developing a working version. Earlier this year America’s Defence Advanced Research Projects Agency awarded a $29m contract to Raytheon, part of RTX, another big aerospace group, to develop an RDE called Gambit. Both engines would be used to propel missiles, overcoming the range and speed limitations of current propulsion systems, including rockets and existing types of jet engines. However, if the companies are successful in getting them to work, RDEs might have a much broader role in aviation—including the possibility of helping revive supersonic air travel. In a nutshell, an RDE “replaces fire with a controlled explosion”, explains Kareem Ahmed, an expert in advanced aerospace engines at the University of Central Florida. In technical terms, this is because a jet engine relies on the combustion of oxygen and fuel, which is a subsonic reaction that scientists call deflagration. Detonation, by comparison, is a high-energy explosion that takes place at supersonic speeds. As a result it is a more powerful and potentially a more efficient way of producing thrust, the force that drives an aircraft forward.
The Economist
How College Football Is Clobbering Housing Markets Across the Country
Rashe Malcolm loves her son Wayne and his girlfriend, but she’d also love it if they could move out of the three-bedroom home in Athens, Ga., that she shares with the couple, both 23, as well as her husband and two of her three other children. But the rent is too high for anyone to go anywhere, at least locally. “If you go to these newer units, I mean if you can get one for $1,800, that’s considered cheap,” said Ms. Malcolm, 48. “For a one-bedroom — a one-bedroom. It’s like $2,100 on average.” Life in Athens, a city of about 127,000 residents, is centered around its largest employer: the flagship campus of the University of Georgia, which enrolls more than 40,000 students and employs about 10,000 people. Like many U.S. cities, it has seen rents rise over the past few years, even as developers have added new units to the market. “College athletics, in particular college football, have become so enormous in this country, particularly in the Southeast, that it has caused this phenomenon of short-term rentals,” said Adrien Bouchet, director of the DeVos Sport Business Management Program at the University of Central Florida. “On one hand it creates value, but on the other hand, it definitely hurts people that have lived in and around the university for a long time.” Mr. Bouchet pointed to similar market trends in Southern college towns like Auburn, Ala., Tuscaloosa, Ala., Gainesville, Fla., and Oxford, Miss., where football rules the economy during the fall. "They have very wealthy alumni that have no problems buying second houses, whether that's for their kids to go there or whether that's just for them to have a good time seven or eight weekends a year," Mr. Bouchet said. "And that's caused the prices of these houses to go through the roof and push people out of these neighborhoods."
The New York Times