Elliott C. Back: Internet & Technology

US Airways Flight 1549 crashed in New York’s Hudson River today at 3:31 PM after suffering a “double bird strike” at 3,200 feet. The Airbus A320 was carrying 150 passengers, two pilots, and three flight attendants.

As soon as the plane hit the water, “a small flotilla of boats” arrived to rescue passengers, including the Coast Guard Cutter Ridley, and New York Police Department divers. Tom Fox, general manager, brought the New York Water Taxi to assist as well.

Mayor Bloomberg said the pilot did “a masterful job.” I agree–landing a plane dead stick over America’s densest metropolis without a single casualty is amazing. If the City of New York doesn’t award him a stipend and medal, US Airways had better write him a $1M bonus for his excellent performance. The Airforce might also be interested in someone of his talents.

Please see Latest Updates on Hudson Jet Rescue from the New York Times for more information! Gawker has also setup a Hudson Plane Crash tag.

This is hilarious; Iran has apparently photoshopped an extra missile into the photograph they released to the press about their recent missile test:

As news spread across the world of Iran’s provocative missile tests, so did an image of four missiles heading skyward in unison. Unfortunately, it appeared to contain one too many missiles, a point that had not emerged before the photo was used on the front pages of The Los Angeles Times, The Financial Times, The Chicago Tribune and several other newspapers as well as on BBC News, MSNBC, Yahoo! News, NYTimes.com and many other major news Web sites.

This is the image that ran in the papers and has recently been retracted for being “apparently digitally altered” by Iranian state media. Agence France-Presse said the fourth missile “has apparently been added in digital retouch to cover a grounded missile that may have failed during the test.” Here I’ve blown up a portion of the smoke so you can clearly see the ’shop:

I saw this physics interview question pop up on the internet, and thought it might be worth discussing:

A plane is standing on a runway that can move (some sort of band conveyer). The plane moves in one direction, while the conveyer moves in the opposite direction. This conveyer has a control system that tracks the plane speed and tunes the speed of the conveyer to be exactly the same (but in the opposite direction). Can the plane take off?

There are a number of forces here that apply: gravity, the force of the engines / airspeed / lift, and the drag of the wheels against the conveyor / the speed of conveyor. However, the wheels provide essentially a frictionless boundary between plane and ground; unlike car wheels, the wheels of an airplane spin freely in place. So, as the conveyor belt speeds up, the airplane stays in place, but its wheels spin at the same velocity. Furthermore, the lift of the airplane is relative to its airspeed, and its engines push against air. So, the airplane will accelerate forward and take off as normal.

The commenter “Max” has a nice summary as well: “A comparable example in my mind would be a car on a treadmill. If the car is being pulled along by a winch and the wheels are turning freely then the car is going to be pulled at an identical rate whether or not the treadmill is there or not (assuming as you did that the treadmill’s speed is inverse to that of the car).”