Re Deleted 911 Thread

How could the buildings fall so quickly? It’s been explained very well in the technical literature by Northwestern’s Zdenek Bazant, PhD, and others (see, for example, Bazant 2008). I’ve developed a simpler physics model of the progressive collapses that agrees quite well with the main points of Bazant’s more rigorous results (Thomas 2010b). Here are some of my findings:

Each floor of the towers contained over two million kilograms of mass. The gravitational potential energy of a standing tower with twelve-foot floors extending upward 110 stories can be calculated straightforwardly; it comes to over 420 billion joules of energy, or the equivalent of 100 tons of TNT per tower. This energy, which was released completely during the collapses, is more than the energy of some of the smaller nuclear weapons in the U.S. arsenal, such as the W-48 (72 tons TNT) (Sublette 2006). This is where the energy required to break columns, pulverize concrete, and expel debris through windows came from. (Truthers often compare such expulsions of air and debris, visible several floors below the collapse fronts, to “squibs,” explosive devices often used in demolitions. However, they are readily explained by pressure changes as the towers, acting like a gigantic bicycle pump being compressed, collapsed.)

The Twin Towers used a “tube within a tube” architectural design, which provided considerable open office space in the interiors of the Towers. Much of the structural support was provided by a dense grouping of thick central core columns in the interior and the perimeter walls on the outside. When the towers began to collapse, large parts of the inner cores (called “the Spires” in 9/11 Truth circles) were actually left standing, briefly, before they, too, toppled over. The perimeter walls were largely forced to peel outward in large sections, producing the iconic images of Ground Zero with which we’re all familiar. Between the outer perimeter and the inner core, the weight of the upper sections plowed through one floor after another, breaking the floor connection brackets and support columns, pulverizing concrete decks, and gaining momentum and mass with each additional floor failure. Had the buildings been constructed differently (the Port Authority was allowed to circumvent some existing New York buildings requirements for the Towers), the collapses might not have even happened (Young 2007).

Even the 9/11 Truth movement’s most eminent physicists are confused about the basic principle of the difference between static and dynamic forces. A piece of paper, taped across a jar’s opening, will support a heavy coin such as a quarter indefinitely (static load). However, if the coin is dropped from just a few inches up, it will tear right through the paper (dynamic load). Given the information at hand—for example, the mass of the upper section of the north tower (fifty-eight million kilograms), the distance it fell (3.8 meters, about twelve feet), and the stiffness/rigidity of the lower structure itself, the dynamic force imparted on the lower section can be estimated as some thirty times the upper portion’s weight. This is many times the lower structure’s safety margin, which explains why it was quickly overwhelmed.

Once progressive collapse began, there were decreasing time intervals of free fall (between floors), punctuated by very brief, incredibly violent collisions—decelerations—of the upper mass, for each floor in turn. There was resistance at every step of the collapse, as the upper section collided with and incorporated each floor below. Conservation of momentum shows that the reductions in falling speed were slight as each floor was impacted, going as the ratio of floors before to floors after (e.g. 14/15, or about 94 percent, for the first impact). Accordingly, the upper section fell from rest to about 19 mph, was slowed down to 18 mph by the first impact, continued to fall until a speed of 26 mph was reached, was then slowed down to 24 mph by another impact, and so on. While the first plunge lasted about nine-tenths of a second, the upper section took only four-tenths of a second to fall through the next floor, three-tenths of a second for the next one, and so on until the bottom floors, which were crushed at a rate of just seven-hundredths of a second each, at speeds of over 100 mph. Yes, there was resistance at every step, as many tons of structural steel was demolished; yet the entire process, like an avalanche, lasted only fifteen to twenty seconds, about 50 to 100 percent longer than true “free fall” would have lasted.

Why aren't there answers?

Hamster
From Wikipedia, the free encyclopedia


Hamsters are rodents belonging to the subfamily Cricetinae. The subfamily contains about 25 species, classified in six or seven genera.[1]
Hamsters are crepuscular animals which burrow underground in the daylight to avoid being caught by predators. Their diets include a variety of foods, including dried food, berries, nuts, fresh fruits and vegetables. In the wild, they feed primarily on seeds, fruits and greens, and will occasionally eat burrowing insects.[2] They have an elongated pouch on each side of their heads that extends to their shoulders, which they stuff full of food to be stored, brought back to the colony or to be eaten later.
Hamster behavior varies depending on their environment, genetics, and interaction with people. Because they are easy to breed in captivity, hamsters are often used as laboratory animals in more economically developed countries. Hamsters have also become established as popular small house pets,[3] and are sometimes accepted even in areas where other rodents are disliked, and their typically solitary nature can reduce the risk of excessive litters developing in households.

Although the Syrian hamster or golden hamster (Mesocricetus auratus) was first described scientifically in 1839, researchers were not able to successfully breed and domesticate hamsters until 1939.[3] The entire laboratory and pet populations of Syrian hamsters appear to be descendants of a single brother-sister pairing. These littermates were captured and imported in 1930 from Aleppo [Syria] by Israel Aharoni, a zoologist of the University of Jerusalem.[4] In Jerusalem, the hamsters bred very successfully. Years later, animals of this original breeding colony were exported to the USA, where Syrian hamsters became one of the most popular pets and laboratory animals. Comparative studies of domestic and wild Syrian hamsters have shown reduced genetic variability in the domestic strain. However, the differences in behavioral, chronobiological, morphometrical, hematological and biochemical parameters are relatively small and fall into the expected range of interstrain variations in other laboratory animals.[5]
Early literature
In 1774, Friedrich Gabriel Sulzer, a companion of Johann-Wolfgang von Goethe, devoted a whole academic monography in the domain of social sciences and natural history to hamsters, entitled "An approach to a natural history of the hamster" ("Versuch einer Naturgeschichte des Hamsters"). In several instances, he used the hamster to document the equal rights of all beings, including Homo sapiens.[6]
Etymology

The name "hamster" is a loanword from the German, which itself derives from earlier Old High German hamustro. It is possibly related to Old Russian choměstrǔ, which is either a blend of the root of Russian khomiak "hamster" and a Baltic word (cf. Lithuanian staras "hamster")[7] or of Persian origin (cf. Av hamaēstar "oppressor").[8]
Description



Roborovski hamster
Hamsters are typically stout-bodied, with tails shorter than body length, and have small, furry ears, short, stocky legs, and wide feet. They have thick, silky fur, which can be long or short, colored black, grey, honey, white, brown, yellow, red, or a mix, depending on the species. Two species of hamster belonging to the genus Phodopus, Campbell's dwarf hamster (Phodopus campbelli) and the Djungarian hamster (Phodopus sungorus), and two of the genus Cricetulus, the Chinese striped hamster (Cricetulus barabensis) and the Chinese hamster (Cricetulus griseus) have a dark stripe down their heads to their tails. The species of genus Phodopus are the smallest, with bodies 5.5 to 10.5 cm (2.2 to 4.1 in) long; the largest is the European hamster (Cricetus cricetus), measuring up to 34 cm (13.4 in) long, not including a short tail of up to 6 cm (2.4 in). The Angora hamster, also known as the long-haired or teddy bear hamster, which is a type of the golden hamster is the second-largest hamster breed, measuring up to 18 cm (7.1 in) long.[3]


Yawning white Syrian hamster showing large incisors
The hamster tail can be difficult to see, as it is usually not very long (about 1/6 the length of the body), with the exception of the Chinese dwarf hamster, which has a tail the same length as the body. One rodent characteristic that can be highly visible in hamsters is their sharp incisors; they have an upper pair and lower pair which grow continuously throughout life, so must be regularly worn down. Hamsters are very flexible, but their bones are somewhat fragile. They are extremely susceptible to rapid temperature changes and drafts, as well as extreme heat or cold.
Senses
Hamsters have poor eyesight; they are nearsighted and colorblind.[citation needed] To compensate for their poor sight when in unfamiliar territory, hamsters have scent glands on their flanks (and abdomens in Chinese and dwarf hamsters). A hamster rubs these areas of its body against various objects, and leaves a trail of smells to follow to return to its home den.[citation needed] Hamsters also use their sense of smell to identify pheromones and gender, and locate food. They are also particularly sensitive to high-pitched noises and can hear and communicate in the ultrasonic range.[4]
Diet
Hamsters are omnivores. Although they can survive on a diet of exclusively commercial hamster food, other items, such as vegetables, fruits, seeds, and nuts, can be given, but these should be removed before they become rotten. Hamsters in the Middle East have been known to hunt in packs to find insects for food.[9] Hamsters are hindgut fermenters and must eat their own feces (coprophagy) to recover nutrients digested in the hindgut, but not absorbed.[1]
Behavior

A behavioral characteristic of hamsters is food hoarding. They carry food in their spacious cheek pouches to their underground storage chambers. When full, the cheeks can make their heads double, or even triple in size.[1]
Social behavior


Hamsters fighting
Most hamsters are strictly solitary. If housed together, acute and chronic stress may occur,[5] and they may fight fiercely, sometimes fatally. Some dwarf hamster species may tolerate conspecifics. Russian hamsters form close, monogamous bonds with their mates, and if separated, they may become very depressed. This happens especially in males. Males will become inactive, eat more, and even show some behavioral changes similar to some types of depression in humans.[citation needed] This can even cause obesity in the hamster.
Chronobiology
Evidence conflicts as to whether hamsters are crepuscular or nocturnal. Khunen writes, "Hamsters are nocturnal rodents who [sic] are active during the night...",[5] but others have written that because hamsters live underground during most of the day, only leaving their burrows about an hour before sundown and then returning when it gets dark, their behavior is primarily crepuscular.[citation needed] Fritzsche indicated although some species have been observed to show more nocturnal activity than others, they are all primarily crepuscular.[4]
Wild Syrian hamsters are true hibernators and allow their body temperature to fall close to ambient temperature (but not below 20°C). This kind of thermoregulation diminishes the metabolic rate to about 5% and helps the animal to considerably reduce the need for food during the winter.[5] Hamsters may not hibernate per se, but instead reduce the rate of a number of physiological systems, such as breathing and heart rate, for short periods of time. These periods of torpor (defined as "a state of mental or physical inactivity or insensibility"[10]) can last up 10 days.[citation needed]
Burrowing behavior
All hamsters are excellent diggers, constructing burrows with one or more entrances, with galleries connected to chambers for nesting, food storage, and other activities.[1] They use their fore- and hindlegs, as well as their snouts and teeth, for digging. In the wild, the burrow buffers extreme ambient temperatures, offers relatively stable climatic conditions, and protects against predators. Syrian hamsters dig their burrows generally at a depth of 0.7 m.[11] A burrow includes a steep entrance pipe (4–5 cm in diameter), a nesting and a hoarding chamber and a blind-ending branch for urination. Laboratory hamsters have not lost their ability to dig burrows; in fact, they will do this with great vigor and skill if they are provided with the appropriate substrate.[5]
Wild hamsters will also appropriate tunnels made by other mammals; the Djungarian hamster, for instance, uses paths and burrows of the pika.

All hamsters are excellent diggers, constructing burrows with one or more entrances, with galleries connected to chambers for nesting, food storage, and other activities.[1] They use their fore- and hindlegs, as well as their snouts and teeth, for digging. In the wild, the burrow buffers extreme ambient temperatures, offers relatively stable climatic conditions, and protects against predators. Syrian hamsters dig their burrows generally at a depth of 0.7 m.[11] A burrow includes a steep entrance pipe (4–5 cm in diameter), a nesting and a hoarding chamber and a blind-ending branch for urination. Laboratory hamsters have not lost their ability to dig burrows; in fact, they will do this with great vigor and skill if they are provided with the appropriate substrate.[5]
Wild hamsters will also appropriate tunnels made by other mammals; the Djungarian hamster, for instance, uses paths and burrows of the pika.