Bill Pintas was vacationing in Las Vegas when he decided to stay at the swank new Vdara hotel, a curvy 57-story tower owned by MGM Resorts.  He was sitting at the pool when he encountered something alarming.  He recalls, "I'm sitting there in the chair and all of the sudden my hair and the top of my head are burning.  I'm rubbing my head and it felt like a chemical burn. I couldn't imagine what it could be." 

Like an ant under a magnifying glass, he remembers running to an umbrella, but being unable to escape the hot light.  He recalls, "I used to live in Miami and I've sat in the sun in Las Vegas 100 times. I know what a hot sun feels like and this was not it.  My first inclination was thinking: Jesus we've destroyed the ozone layer because I am burning." 

Speaking with employees, he was alarmed to find out that the hotel staff was aware of the situation.  He recalls, "They're kind of giggling and say: 'Yeah, we know. We call it the death ray."

The "death ray" appears to be created by the glass surface of the hotel itself -- acting as a concentrating parabolic dish -- similar to those used to heat water to a boil in solar power systems.  The dish concentrates light on a 10-foot by 15-foot hot zone moving across the pool.  Temperatures in this area spike 20 degrees Fahrenheit -- or more.

Bill Pintas saw his plastic newspaper bag literally begin to melt.  The bag -- composed of polyethylene -- is designed to withstand temperatures of up to 120 to 130 degrees Fahrenheit.  And the employees recall seeing plastic cups -- which have a melting point of 160 degrees Fahrenheit – actually melting.

Other guests, including newspaper reviewers, have also observed the burning beam.

The hotel management doesn't call it a "death ray", they prefer the more friendly distinction "solar convergence phenomenon".  Gordon Absher, a spokesman for MGM Mirage says the hotel is addressing the problem, and comments, "Because of the curved, concave shape of that hotel, they sometimes get isolated pockets of high temperatures."

The hotel is baffled by how to solve the problem of the "death ray", though.  When initially constructing the building, they anticipated the issue and put a coating over the glass that absorbs 70 percent of the daytime sunlight.  However, that was not enough to reduce its painful effects.  And the ray sweeps across a wide area, making it hard to protect a specific region. 

Comments Mr. Absher, "This is quite literally an astronomical challenge," Absher said. "We are dealing with a moving target."

The mishap in architecture isn't as glaring as some of history's most notable mistakes -- such as the 1940 Tacoma Narrows Bridge, but it is pretty extraordinary.  It serves as a reminder that while many take the science and engineering of designing massive skyscrapers for granted these days, it remains a tricky business.

It looks like the Vdara may have exposed the wrong guest to the death ray, though --  Mr. Pintas is a Chicago-based lawyer.