Tool bag may reach Earth or burn up

Remains of a tool bag dropped by a NASA astronaut during a space walk last year are expected to reach the Earth surface later on Tuesday. The bag was expected to reach the Earth on July 25, but then scientists recalculated the date. However, specialists still cannot say where exactly this can happen.

“Tools for work in outer space are made of special high-alloy steel, that is why it is quite probable that some fragments will not burn in Earth atmosphere, but will reach the Earth surface,” said an expert. However, the over whelming majority of debris and space garbage burn as they enter the atmosphere.

Endeavour’s Heide Stefanyshyn-Piper lost her grip on the tool bag during a space walk on November 18, 2008. NASA reported then that the backpack-sized bag was one of the biggest objects ever lost by astronauts.

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Celestial Location

To locate the ecliptic, planets, or anything else in the sky, you need something to refer to, a referent system. A referent system is easily established by first imagining the sky to be a celestial sphere just as the ancient Greeks did. A coordinated system of lines can be visualized on this celestial sphere just as you think of the coordinate system of latitude and longitude lines on the earth’s surface. Imagine that you could inflate the earth until its surface touched the celestial sphere. If you now transfer the latitude and longitude lines to the celestial sphere, you will have a system of sky coordinates. The line of the equator of the earth on the celestial sphere is called the celestial equator. The North Pole of the earth touches the celestial sphere at a point called the north celestial pole. From the surface of the earth, you can see that the celestial equator is a line on the celestial sphere directly above the earth’s equator, and the north celestial pole is a point directly above the earth’s equator, and the north celestial pole is a point directly above the North Pole of the earth. Likewise, the south celestial pole is a point directly above the South Pole of the earth.

You can only see half of the overall celestial sphere from any one place on the surface of the earth. Imagine a point on the celestial sphere directly above where you are located. An imaginary line that passes through this point, then passes north through the north celestial pole, continuing all the wary around through the south celestial pole and back to the point directly above you makes a big circle called the celestial meridian. Note that the celestial meridian location is determined by where you are on the earth. The celestial equator and the celestial poles, on the other hand, are always in the same place no matter where you are.

Overall, the celestial sphere appears to spin, turning on an axis through the celestial poles. A photograph made by pointing a camera at the north celestial pole and leaving the shutter open for several hours will show the apparent motion of the celestial sphere with star trails. The moderately bright star near the center is the North Stat, Polaris. Polaris is almost, but not exactly, at the north celestial pole. You can locate Polaris by finding the Big Dipper. The two stars on the end of the dipper opposite the handle are called the pointers. Imagine a line moving from the bottom of the dipper upward through the two pointers. The first bright star that this line meets is Polaris. The angle that you see Northern Hemisphere. Shows the geometric relationships between your latitude and the angle of Polaris above the horizon.

If you observe the constellation night after night, you will see that the stars maintain their positions relative to one another as they turn counterclockwise around Polaris. Those near Polaris pivot around it and are called “circumpolar”. Those farther out rise in the east, move in an arc, then set in the west.

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Fire

Fire is so familiar; it is both friend and foe, slave and master. Fire is a natural force, yet it was used by humanity’s ancestors many hundreds of thousands of years ago. Later, humans developed the ability to artificially generate fire. The control and use of fire has been a major factor in the development of the human race. The control of fire for warmth allowed humans to migrate into cold climates and build diverse and successful civilizations. Fire for cooling greatly increased the number of foods and improved their taste, ease of digestion, nutrition, sanitation, and preservation. Fire has long been used to drive game out of hiding during hunting and to scare away predatory animals during the night. Fire aided agriculture by clearing the land of brush and creating fertilizer with its ashy residue. With the help of fire, humans have been able to expand farmland and pasture against both climatic and vegetational gradients.

The possibilities of fire have stimulated creative thinking, which in turn has spurred human development. One invention has followed another. The use of fire to harden materials led to pottery, cookware, weapons, and more. The ability of produce ever-higher temperatures led to the smelting and use of metals. The use of fire provided the benefits of sterilization, which advanced public health. Fire controlled inside machinery supplies the energy that underlies our civilization. The heat from the burning of oil, coal, and natural gas is converted into the electrical and mechanical energy that powers our industries, the lighting and heating of our homes, and our ability to travel quickly to any point in the world. As a rough estimate of the benefits of fire, through it, each American today has available for her or his personal use the energy equivalent of owning 100 slaves in the past.

The destructive use of fire shifted from trying to control wild animals to trying to dominate other humans. Fire passed from the individual torch to a method of destroying whole cities. For example, troy was so obliterated by fire that its very site remained unknown to the world for nearly 3,000 years.

Another destructive use of fire has been to deny enemies their prize. For example, on 12 September 1812, Napoleon and the French army reached the hills outside of Moscow and looked down on its green, blue, and gold domes. Upon entering the great city, the French found it to be largely deserted with fires burning throughout. For six days, the fires raged until 90 percent of the city was incinerated. The Russians chose to destroy their own heritage rather than let it aid their French conquerors. Denied the support of a conquered populaces, Napoleon began his disastrous retreat from Russia during winter’s harsh conditions. Napoleon won the military battles but lost the war.

New destructive uses of fire were conceived with time and technological innovation. In the twentieth century,” fire” was packaged into bombs that could be dropped from airplanes. During World War II, entire cities were ignited as thousands of tons of bombs created massive firestorms, killing tens of thousands of people in such cities as Hamburg and Dresden.

Fire has always been an important part of the natural world. For example, about 1,800 thunderstorms are in action around the Earth each hour, and their lightning bolts start many fires. Humans have brought fire from the natural world into the cultural world, expanding its role. We control fire for our benefit, but we pay the price when this control is lost. In the United States today, the abundant strikes of lightning start less than 15 percent of all fires. Humans are the main source of fire ignition in the United States, as well as throughout the world.

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