Flying / Balloons

The first manned flight was made by Jean-François Pilâtre de Rozier and François Laurent d'Arlandes in a hot air balloon created by the Montgolfier brothers in 1783.

A hot air balloon consists of a bag called the envelope that is capable of containing heated air. Under the envelope there is the gondola or wicker basket (in some long-distance or high-altitude balloons, a capsule) which carries the passengers and a source of heat. The heated air inside the envelope makes it buoyant since it has a lower density than the relatively cold air outside the envelope. Unlike gas balloons, the envelope does not have to be sealed at the bottom since the air near the bottom of the envelope is at the same pressure as the surrounding air. (from wikipedia)

The Montgolfier brothers' balloon may not have been the first to carry human passengers. The technique has been used for a very long time in different cultures so there could have been human passengers in the balloons as well. There is some speculation that hot air balloons could have been used to design and to observe the mysterious Nazca lines in Peru some 1500 years ago. The Nazcan civilization (also referred to as Nazca people) lived in Peru before the Incas. These lines make up drawings of birds and animals that are comprehensible only from the air because of their gigantic size. The construction of the lines is imaginable but would the Nazca people have worked so hard on something that they couldn't see?

Julian Nott and Jim Woodman tested the idea a few years ago as seen in the picture below. For the envelope of the balloon, they used a cotton fabric that the Nazca people could have woven. The gondola (the basket) was made from the reed of Lake Titicaca. This is what Nott writes about the adventure:

"When Jim Woodman approached me with his idea that the people who created the Nazca lines could have seen them from hot air balloons I was intrigued but skeptical. Yet, we successfully flew in a balloon that could have been built by the Nazca people a thousand years ago. And while I do not see any evidence that the Nazca civilization did fly, it is beyond any doubt that they could have. And so could the ancient Egyptians, the Romans, the Vikings, any civilization."

The Nasca Prehistoric Balloon in flight

It certainly takes a lot of courage to fly with such an ancient design. But there have been some even more breathtaking events in the history of balloons. Could you imagine rising to thirty kilometers above the ground and then JUMP? Sounds totally insane. Well, that's what a man called Joe Kittinger did in 1960. He used a helium balloon and the aim of the mission was to study the effects of high altitude on the human body. During his free fall he reached the speed of 990 km/hour, yet he could only feel the acceleration when he looked up at the balloon, which was the only stable spot around him. He had to wear a pressurized suit to protect his body. One of his gloves were not properly pressurized and his right hand swelled to twice its normal size. This clearly shows what a hostile environment surrounded him up there. Look at the video of the jump.

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Flying / Birds

At the end of the last entry, we left off with planes gliding in the air and let's stay up in the air for a while. 'Flight' has a very complex and tricky definition on wikipedia. My definition is easier: If something is in the air for a long time and it isn't tied to a tree or something then it is very probably flying. Take birds, for instance. Most birds can fly, as we all know. They are usually light and they have wings with feathers. Their wings evolved in a way so that they can create a so called 'lift'. Take a look at the picture to understand it better.















As you can see, the wings have a curve in them so that the air flow above the wings has to travel farther than the air under the wing to get to the end of the wing at the same time. This means that the air above the wing moves faster and this reduces the pressure there. As air has a tendency to move to lower pressure areas, an upward force (lift) is created. Of course, speed is a very important factor here. In order to increase the air speed around the curve, birds flap their wings. However, wings and feathers are not all that you need for flying. Basically, everything about the bird anatomy supports flying in one way or another. Their bones are light, their ears have special balancing capabilities and their feet are perfect landing gears. Some birds can (or rather have to) take up to 50 times as much food than a non-flying animal of the same body weight. They have to do this to provide the immense energy that is needed for climbing against gravity.

Albatrosses are among the largest of flying birds. The great albatross can have a wingspan of over 3 meters. With these huge wings, they are very well designed for gliding in the air. They can travel over incredible distances but as the next funny video shows they tend to have some serious difficulties during take-off and landing.




Now, let's take a look at some bird champions and some interesting facts about birds! The fastest bird (and also the fastest animal) is the peregrine falcon, which can reach flying speeds of about 110 km/h. But that's not all. When this bird is diving to catch a prey, it can accelerate to an incredible 300 km/h. The dive can start from the height of 1 km. This feat would be quite useless without actually seeing the prey from such a distance. The falcon's eyesight is also very special. In clean air, it can spot a pigeon from five kilometers. Although it is the most efficient of all the predators, it is endangered because of the use of pesticides.


















To tell you the truth, at first I didn't believe the story about the speed of this bird. After watching this video, the whole thing sounds a lot more credible.

The wandering albatross has the largest wingspan of any living bird. Some male birds have a 340 cm wide wingspan. It is such an excellent glider that it can sleep while it flies!













The smallest bird is the bee hummingbird, which lives in Cuba. It is about 5 centimeters long and weighs only 1.8 grams. Hummingbirds flap their wings up to 80 times a second. This enables them to hover in the air and even to fly backwards. No other bird can do this. To provide enough energy for such rapid beating of their wings, these birds typically consume more than their own weight in nectar each day. Watch this video about the flight technique of these little jewels.


















The bird with the longest recorded flight is the common tern. A tern that was banded (marked with a little plastic band) in June 1996 in Finland was recaptured alive 16,250 miles away at Rotamah Island, Victoria, Australia in January 1997. It had traveled at a rate of 125 miles a day.












The bird with the largest field of vision is the woodcock. Its eyes are set so far back in its head that it has a 360 degree field of vision, enabling it to see all round and even over the top of its head. If you look at the picture below you can observe the position of the eyes. If it wasn't for the long beak you would think the bird is flying upside down.













The bar-headed goose is one of the world's highest flying birds, having been seen at up to 10175 m. (That is much higher than the peak of Mt. Everest!) It has a slightly larger wing area for its weight than other geese and it is believed this helps the goose to fly high. Studies have found that they breathe more efficiently under low oxygen conditions and are able to reduce heat loss.














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You can read some interesting and useful idioms in connection with the word 'bird' here.