Reflecting the impossible

The Possible ‘Impossible’ Turn

Turning back after engine failure during the take off phase of flight in a single engine aircraft is examined using a simplified analytical model. The important parameters are identified. The analysis shows that the optimum flight path is teardrop shaped with a 45◦ bank angle at stall velocity during the turn. The effects of engine failure altitude, wind direction and velocity, and bank angle o...

The Impossible Thing

W hat is it?,” Sierra Rodriguez asked her older brother. “You’ll have to guess,” Billy answered. Sierra looked up at the object that was hanging —almost as if levitating —from two crisscrossed cables in the barn. “Does it y?” she asked. “Nope. It lights up.” “So you mean it’s just a light,” she said, glaring at her brother. “What’s so special about—” “It’s not just a light.” Billy began moving ...

Imagining the Impossible

Believing the Impossible

Impossible Frontiers

A key result of the Capital Asset Pricing Model (CAPM) is that the market portfolio— the portfolio of all assets in which each asset’s weight is proportional to its total market capitalization—lies on the mean-variance-efficient frontier, the set of portfolios having mean-variance characteristics that cannot be improved upon. Therefore, the CAPM cannot be consistent with efficient frontiers for...