Tom McMahon

April 27 Tornado Outbreak: Why So Many Deaths?

April 27 Tornado Outbreak

Vince Condella:

The Storm Prediction Center and local National Weather Service offices did a terrific job highlighting the dangers of this weather systems. For several days in advance, residents of Mississippi and Alabama knew they were under the gun for tornado-producing thunderstorms.

The storms April 27 were fueled by strong wind shear due to a low-level jet stream from the south and a southwest-to-northeast flowing stream of high speed winds aloft. This created the wind shear (change of wind direction and/or wind speed with height) that provided strong lift and rotating supercell thunderstorms. The storms were moving very fast - up to 50 miles per hour in some cases. So many of these tornadoes could have simply reached people before they had a chance to get to shelter.

Power was also out when many of the tornadoes struck. That's because morning storms knocked out power and even broadcast towers for NOAA Weather Radio. When the afternoon storms struck, some people had to rely on text message warnings from the National Weather Service or their favorite TV station. And even some cell towers were destroyed in the first wave of storms.

And finally, so many of these tornadoes were powerful, probably EF3 or higher. When winds exceed 165 miles hour (EF4) or 200 miles per hour (EF5), there may be no way to escape. Even if you are in a place of safety, homes can be scraped clean off their concrete slabs. (Many homes in the south do not have basements.)

The Four Temperaments

The Four Temperaments

According to Wikipedia, they are sanguine, melancholic, choleric and phlegmatic. I'm not sure which is which.

Washing of the 200-inch Telescope Mirror on Mount Palomar

Washing of the 200-inch Telescope Mirror on Mount Palomar

Before and After photos. Nice Job, fellas!

Riding The Prime-Focus Cage of the 200-Inch Palomar Telescope

Riding The Prime-Focus Cage of the 200-Inch Palomar Telescope

From Caltech:

Jesse Greenstein passed away in 2002. He joined the California Institute of Technology's Astronomy Department in 1948, just as Palomar was coming on line, and has spent many of the subsequent years using the 200-inch telescope to make spectroscopic observations of faint hot stars called white dwarfs.

Let us take you back to the summer of 1995, when Jesse, then 85, came back one more time to the primary focus cage of the Hale Telescope. He brought with him the trustworthy spectrograph he had used on countless observing nights. Even after so many years, he was still captivated by the atmosphere the observing dome. And his fascination spellbound everyone who had the incredible fortune to share this experience with him.

"When the telescope was built, an observer had to ride throughout the night in the prime focus cage to ensure accurate tracking of the telescope. The astronomer ascended to the cage, eighty feet above the floor, in a specially designed elevator."

"You also had to have a tough bladder because, if possible, if it was a good night, you stayed up from seven o'clock to five. That's ten hours!"

"Working a night in the small cage high above the primary mirror, feeling closer to the stars than the earth, remains an exhilarating and unforgettable experience."

New GE 7-Point Program Helps You Plan And Obtain Nuclear Research Reactor

New GE 7-Point Program Helps You Plan And Obtain Nuclear Research Reactor

The 1950's was such an optimistic decade, eh?

What Happened To All That Oil In The Gulf of Mexico?

Excerpt from NRO:

One thing to remember about oil and the environment is that it does biodegrade. For a lot of bacteria, oil is just food. In this case, it was too much food. It’s kind of like eating salty potato chips — you can only eat so many salty potato chips at a time. Same thing with this

The whole purpose of dispersing the oil wasn’t to make the oil go away or hide it from the public or something like that. You disperse the oil because you make one big slab of oil that the bacteria can’t get to into billions and billions of tiny little drops of oil that the bacteria can easily get to, so you’re just increasing the surface area of the oil by creating millions of dots. And you’re breaking it up, literally, into bite-size chunks, billions and billions and billions of little bite-size chunks of oil so that then the bacteria can do their thing.

The other thing to remember is that bacterial activity doubles with every ten-degree change in temperature, so whatever level of bacterial activity you have at 50 degrees, you get twice as much at 60 degrees, and twice as much as that at 70 degrees, and twice as much as that at 80 degrees. So that’s why your refrigerator keeps your food from spoiling, keeps it down in the low 30s so it’ll last a lot longer than it will sitting in your house in the mid-70s.

The Gulf of Mexico is hot. That’s why it spurs hurricanes — the surface water temperature in the Gulf of Mexico is 80. The amount of bacterial activity you get there is enormous, so if you did what they did, which is disperse a whole lot of the oil in a warm-weather environment like that, it’s going to just magically disappear, in a short period of time, once you cut off the source.

On July 17, 1981, Two 32-Ton Skywalks At The Hyatt Regency In Kansas City Collapsed Into The Hotel Lobby Killing 114 People. It Was The Deadliest Structural Collapse In U.S. History

While Milwaukee is abuzz about the collapse of a concrete panel at the O’Donnell Park parking structure and its resulting fatality, with the passage of time many people have forgotten -- or have never heard of -- the deadliest structural engineering failure in US history.

Before The Disaster: The Tea Dance

From the Engineering Ethics class at Texas A&M University:

On July 17, 1981, the Hyatt Regency Hotel in Kansas City, Missouri, held a videotaped tea-dance party in their atrium lobby. With many party-goers standing and dancing on the suspended walkways, connections supporting the ceiling rods that held up the second and fourth-floor walkways across the atrium failed, and both walkways collapsed onto the crowded first-floor atrium below. The fourth-floor walkway collapsed onto the second-floor walkway, while the offset third-floor walkway remained intact. As the United States' most devastating structural failure, in terms of loss of life and injuries, the Kansas City Hyatt Regency walkways collapse left 114 dead and in excess of 200 injured. In addition, millions of dollars in costs resulted from the collapse, and thousands of lives were adversely affected. The hotel had only been in operation for approximately one year at the time of the walkways collapse.

From the AP:

Sally Firestone went to the Friday night tea dance with three friends after work. She was all dolled up, standing on a suspended walkway at the Hyatt Regency downtown, enjoying a dance contest in the hotel lobby below. The last thing she remembers is hearing a loud "crack." ...

At 7:04 p.m., the band started playing Duke Ellington's "Satin Doll" as a dance contest got under way. About a minute later, the fourth-floor walkway split in two places near the center, falling down onto the second-story walkway, which also collapsed.

The Fourth Floor Walkway Was Suspended Directly Over The Second Floor Walkway, With The Third Floor Walkway Offset To The Side Several Meters

From the AP:

Rescue workers spent the next 14 hours pulling victims, dead and alive, from the tangle of steel and concrete. Cranes and forklifts moved heavy slabs of concrete so emergency crews could reach the injured. A firefighter performed an on-the-spot amputation with a chain saw to free one victim. City buses lined up outside to cart the walking wounded to hospitals. Sally Firestone lay unconscious and trapped for hours under the debris. The most severely injured of the survivors, she was left a quadriplegic with no feeling below her shoulders

Woman Victim Under The Rubble

From frostburg.edu:

The failure of the Hyatt Regency walkway was a combination of things. The most important cause was the design in the walkways. Due to disputes between G.C.E. and Havens, the design changed from a single to a double hanger rod, simply because Havens did not want to thread the entire rod in order to install the washer and nut. Due to the addition of another rod, the load on the nut connecting the fourth floor segment was increased. The original load for each hangar rod was to be 90kN, but the alteration increased the load to 181kN. The box beams were welded horizontally and therefore could not hold the weight of two walkways. During the collapse, the box beam split and the bottom rod pulled through the box beam resulting in the collapse.

Left: Proposed Design    Right: Actual Design

Both designs of the walkways were well below the required safety stress required by the Kansas City Building Code. Take a look at the beam for the third-floor walkway, which did not collapse.

Deformation of the Third-Floor Beam

From Wikipedia:

The Hyatt tragedy remains a classic model for the study of engineering ethics and errors. Gillum's chief engineer continues to share his experiences with others, in the hope that the mistakes which led to the Hyatt disaster will not be repeated. After the disaster, the lobby was reconstructed with only one crossing on the second floor. Unlike the previous walkways, the new bridge is supported by several columns underneath it rather than being suspended from the ceiling. As a result, some floors of the hotel now have disconnected sections on opposite sides of the atrium, so it is necessary to go to the second floor to get to the other side. The hotel later reopened, and has been renamed Hyatt Regency Crown Center. It has since been renovated and now serves as one of the city's most luxurious hotels.

The New Walkway

You can watch Seconds From Disaster - Skywalk Collapse on YouTube.

The largest settlement -- about $12 million of the estimated $140 million total -- went to Sally Firestone. Her thoughts:

"I'm not really bitter. I'm just amazed that no one discovered the problems with the building," said Firestone, who lives in a retirement home in south Kansas City and requires around-the-clock care. "So many things happened along the way that should have been caught."

Sally Firestone Today

I knew Sally Firestone a long time ago, so her reaction does not surprise me. Her father, Rev. Jesse Firestone (a good man, I might add) was the pastor at the First United Methodist Church in my old hometown of Belvidere, Illinois. Although she would be the last one to ask, you might want to keep her in your thoughts and prayers, OK?

The Tactical Deception of Grey Squirrels

From the NY Times:

But the squirrels don’t just bury an acorn and come back in winter. They bury the seed, dig it up shortly afterward, rebury it elsewhere, dig it up again. “We’ve seen seeds that were recached as many as five times,” said Dr. Steele. The squirrels recache to deter theft, lest another squirrel spied the burial the first X times. Reporting in the journal Animal Behaviour, the Steele team showed that when squirrels are certain that they are being watched, they will actively seek to deceive the would-be thieves. They’ll dig a hole, pretend to push an acorn in, and then cover it over, all the while keeping the prized seed hidden in their mouth. “Deceptive caching involves some pretty serious decision making,” Dr. Steele said. “It meets the criteria of tactical deception, which previously was thought to only occur in primates.”

Math Quiz: How Curved Would A Perfectly Flat State of Illinois Be?

Math Quiz: How Curved Would A Perfectly Flat State of Illinois Be?

Lets assume the State of Illinois is perfectly flat and 400 miles long. Due to the curvature of the Earth, that 400 miles is represented by arc BCD above. r is about 3950 miles. So what is s?

Arizona Giant Centipede

Arizona Giant Centipede

An excerpt from The Firefly Forest:

The bold orange or red and black colors of an Arizona Giant Centipede are a form of aposematic (warning) coloration meant to scare away potential predators. Along with their venom and universal warning colors, Arizona Giant Centipedes have another defense against predation, a posterior pseudohead similar in color and appearance to their actual head. The pseudohead even has what appears to be orange antennae like the real head, but these posterior "antennae" are actually modified legs. Arizona Giant Centipedes can move quickly either forward or backward, and if a predator mistakenly grabs the more expendable headlike tail, the centipede can rapidly bend around and attack it with its venomous front legs. In the above photo, the centipede's true head is the one higher up on the wall.