A balloon is a flexible bag that can be inflated with a gas, such as helium, hydrogen, nitrous oxide, oxygen, air or water. Modern day balloons are made from materials such as rubber, latex, polychloroprene, or a nylon fabric, and can come in many different colors. Some early balloons were made of dried animal bladders, such as the pig bladder. Some balloons are used for decorative purposes or entertaining purposes, while others are used for practical purposes such as meteorology, medical treatment, military defense, or transportation. A balloon's properties, including its low density and low cost, have led to a wide range of applications.
Balloons are used for decorating birthday parties, weddings, corporate functions, school events, and for other festive gatherings. The artists who use the round balloons to build are called "stackers" and the artists who use pencil balloons to build are called "twisters." Most commonly associated with helium balloon decor, more recently balloon decorators have been moving towards the creation of air-filled balloon decorations due to the non-renewable natural resource of helium limited in supply. The most common types of balloon decor include arches, columns, centerpieces, balloon drops, sculptures, and balloon bouquets. With the increased aptitude for balloon twisting as well as balloon stacking, the rise of the deco-twister manifests itself as the combination of stacking techniques as well as twisting techniques to create unique and interesting balloon decor option.
Party balloons are mostly made of a natural latex tapped from rubber trees, and can be filled with air, helium, water, or any other suitable liquid or gas. The rubber's elasticity makes the volume adjustable.
Often the term "Party Balloon" will refer to a twisting balloon or pencil balloon. These balloons are manipulated to create shapes and figures for parties and events, typically along with entertainment.
Filling the balloon with air can be done with the mouth, a manual or electric inflater (such as a hand pump), or with a source of compressed gas.
When rubber or plastic balloons are filled with helium so that they float, they typically retain their buoyancy for only a day or so, sometimes longer. The enclosed helium atoms escape through small pores in the latex which are larger than the helium atoms. Balloons filled with air usually hold their size and shape much longer, sometimes for up to a week.
Even a perfect rubber balloon eventually loses gas to the outside. The process by which a substance or solute migrates from a region of high concentration, through a barrier or membrane, to a region of lower concentration is called diffusion. The inside of balloons can be treated with a special gel (for instance, the polymer solution sold under the "Hi Float" brand) which coats the inside of the balloon to reduce the helium leakage, thus increasing float time to a week or longer.
Beginning in the late 1970s, some more expensive (and longer-lasting) foil balloons made of thin, unstretchable, less permeable metallised films such as Mylar (BoPET) started being produced. These balloons have attractive shiny reflective surfaces and are often printed with color pictures and patterns for gifts and parties. The most important attribute of metallised nylon for balloons is its lightweight, increasing buoyancy and its ability to keep the helium gas from escaping for several weeks. Foil balloons have been criticized for interfering with power lines.
Balloon artists are entertainers who twist and tie inflated tubular balloons into sculptures such as animals (see balloon modelling). The balloons used for sculpture are made of extra-stretchy rubber so that they can be twisted and tied without bursting. Since the pressure required to inflate a balloon is inversely proportional to the diameter of the balloon, these tiny tubular balloons are extremely hard to inflate initially. A pump is usually used to inflate these balloons.
Decorators may use helium balloons to create balloon sculptures. Usually the round shape of the balloon restricts these to simple arches or walls, but on occasion more ambitious "sculptures" have been attempted. It is also common to use balloons as table decorations for celebratory events. Balloons can sometimes be modeled to form shapes of animals. Table decorations normally appear with three or five balloons on each bouquet. Ribbon is curled and added with a weight to keep the balloons from floating away.
A decorative use for balloons is in balloon drops. In a balloon drop, a plastic bag or net filled with air-inflated balloons is suspended from a fixed height. Once released, the balloons fall onto their target area below. Balloon drops are commonly performed at New Year's Eve celebrations and at political rallies and conventions, but may also be performed at celebrations, including graduations and weddings.
For decades, people have also celebrated with balloon releases. This practice has been discouraged by the balloon industry, as it has posed problematic for the environment and cities. In recent years, legislation, such as the California Balloon Law, has been enacted to enforce consumers and retailers to tether helium-filled foil (BoPET) balloons with a balloon weight. This ensures that the helium-filled balloons do not float into the atmosphere, which is both potentially injurious to animals, the environment, and power lines. Many states now have banned balloon releases.
It is becoming more common for balloons to be filled with air instead of helium, as air-filled balloons will not release into the atmosphere or deplete the earthly helium supply. There are numerous party games and school-related activities that can use air-filled balloons as opposed to helium balloons. When age-appropriate, these activities often include the added fun of blowing the balloons up. In many events, the balloons will contain prizes, and party-goers can pop the balloons to retrieve the items inside.
Balloons are used for publicity at major events. Screen printing processes can be used to print designs and company logos onto the balloons. Custom built printers inflate the balloon and apply ink with elastic qualities through a silk screen template. In January 2008, the Jewish Community Relations Council of New York organized a display of 4,200 red balloons outside the United Nations Headquarters.
Also in the 1950s at the start of the Cold War, activists in Western Europe uses balloons for propaganda purposes that would float east over Eastern Europe, which would release newspapers and pamphlets. Today, South Korean activists are using the same balloon method to get information to those in North Korea.
Paolo Scannavino set the record of 11 for the most giant balloons entered in 2 minutes.
Water balloons are thin, small rubber balloons filled with a liquid, usually water, instead of a gas, and intended to be easily broken. They are usually used by children, who throw them at each other, trying to get each other wet, as a game, competition, or practical joke. By forcing water out the open end of a water balloon, it is possible to use it as a makeshift water gun.
Solar balloons are thin, large balloons filled with air that is heated by the sun in order to decrease its density to obtain lift.
Balloons are often deliberately released, creating a so-called balloon rocket. Balloon rockets work because the elastic balloons contract on the air within them, and so when the mouth of the balloon is opened, the gas within the balloon is expelled out, and due to Newton's third law of motion, the balloon is propelled forward. This is the same way that a rocket works.
Balloons filled with hot air or a buoyant gas have been used as flying machines since the 18th century. The earliest flights were made with hot air balloons using air heated with a flame, or hydrogen as the lifting gas. Later, coal gas and later still helium were used. An unpowered balloon travels with the wind. A balloon which has an engine to propel it is called a dirigible balloon or airship.
Angioplasty is a surgical procedure in which very small balloons are inserted into blocked or partially blocked blood vessels near the heart. Once in place, the balloon is inflated to clear or compress arterial plaque, and to stretch the walls of the vessel, thus preventing myocardial infarction. A small stent can be inserted at the angioplasty site to keep the vessel open after the balloon's removal.
Balloon catheters are catheters that have balloons at their tip to keep them from slipping out. For example, the balloon of a Foley catheter is inflated when the catheter is inserted into the urinary bladder and secures its position.
There has been some environmental concern over metallised nylon balloons, as they do not biodegrade or shred as rubber balloons do. Release of these types of balloons into the atmosphere is considered harmful to the environment. This type of balloon can also conduct electricity on its surface and released foil balloons can become entangled in power lines and cause power outages.
Released balloons can land anywhere, including on nature reserves or other areas where they can pose a hazard to animals through ingestion or entanglement. Because of the potential harm to wildlife and the effect of litter on the environment, some jurisdictions even legislate to control mass balloon releases. Legislation proposed in Maryland, US, was named after Inky, a pygmy sperm whale who needed six operations after swallowing debris, the largest piece of which was a Mylar balloon. To date, there is no documentary evidence to suggest that the death of any sea mammal has been attributed to foil balloons as a sole cause. In the United Kingdom, foil balloons sold at major theme parks and zoos have balloon weights attached to help prevent accidental release into the environment.
Anthony Andrady says that releases of latex balloons that descend into the sea pose a serious ingestion and/or entanglement hazard to marine animals because balloons exposed floating in seawater deteriorate much more slowly than those exposed in air. Balloon manufacturers will often state that a latex balloon is perfectly safe to release into the environment as it is made from a natural substance and will biodegrade over time. However, a latex balloon can take up to a year to degrade if it lands in the sea and during this time it is possible for a marine animal to ingest the balloon and die from slow starvation if its digestive system is blocked.
NABAS (National Association of Balloon Artists and Suppliers), an organisation that styles itself "The Balloon and Party Professionals Association" and represents the UK balloon industry, publishes guidelines for people holding balloon releases.
When balloons eventually return to the ground, they begin the degradation process. Latex balloons are the most used because of their ability to biodegrade. The problem with this is that it can take at least 4 weeks to show substantial degradation of the polymer in the environment, and around 6 months in aquatic environments. This issue can have an effect on the wildlife on both land and in aquatic systems because animals will confuse deflated balloons as food, nesting material, or simply something to play with. When that happens, it can lead to negative effects for the animals. For example, a bird will use a deflated balloon as a component for its nest. When the eggs hatch, they will get tangled in the balloon and that can lead to death. Another environmental problem with latex balloons is not the effects the balloons have on the environment once they are decomposed, but when they are being made. When latex is being produced, it produces greenhouse gases, such as CO2, CH4, N2O. This is becoming an increasing problem, especially in Thailand which is responsible for 35% of the worlds natural rubber production.
Once inflated with regular, atmospheric air, the air inside the balloon will have a greater air pressure than the original atmospheric air pressure.
Air pressure, technically, is a measurement of the amount of collisions against a surface at any time. In the case of balloon, it's supposed to measure how many particles at any in any given time space collide with the wall of the balloon and bounce off. However, since this is near impossible to measure, air pressure seems to be easier described as density. The similarity comes from the idea that when there are more molecules in the same space, more of them will be heading towards a collision course with the wall.
The first concept of air pressure within a balloon that is necessary to know is that air pressures "try" to even out. With all the bouncing against the balloon wall (both interior and exterior) there will be a certain amount of expansion/contraction. As air pressure itself is a description of the total forces against an object, each of these forces, on the outside of the balloon, causes the balloon to contract a tiny bit, while the inside forces cause the balloon to expand. With this knowledge, one would immediately assume that a balloon with high air pressure inside would expand based on the high amount of internal forces, and vice versa. This would make the inside and outside air pressures equal.
However, balloons have a certain elasticity to them that needs to be taken into account. The act of stretching a balloon fills it with potential energy. When it is released, the potential energy is converted to kinetic energy and the balloon snaps back into its original position, though perhaps a little stretched out. When a balloon is filled with air, the balloon is being stretched. While the elasticity of the balloon causes tension that would have the balloon collapse, it is also being pushed back out by the constant bouncing of the internal air molecules. The internal air has to exert force not only to counteract the external air to keep the air pressures "even", but it also has to counteract the natural contraction of the balloon. Therefore, it requires more air pressure (or force) than the air outside the balloon wall. Because of this, when helium balloons are left and they float higher, as atmospheric pressure decreases, the air inside it exerts more pressure than outside it so the balloon pops from tension. In some cases, the helium leaks out from pores and the balloon deflates, falling down.
"Stories Behind Everyday Things"; New York: Reader's Digest, 1980.
Andrée's Arctic balloon expedition of 1897 was an effort to reach the North Pole in which all three expedition members perished. S. A. Andrée, the first Swedish balloonist, proposed a voyage by hydrogen balloon from Svalbard to either Russia or Canada, which was to pass, with luck, straight over the North Pole on the way. The scheme was received with patriotic enthusiasm in Sweden, a northern nation that had fallen behind in the race for the North Pole.
Andrée ignored many early signs of the dangers associated with his balloon plan. Being able to steer the balloon to some extent was essential for a safe journey. But there was much evidence that the drag-rope steering technique Andrée had invented was ineffective. Yet he staked the fate of the expedition on drag ropes. Worse, the polar balloon Örnen (The Eagle) was delivered directly to Svalbard from its manufacturer in Paris without being tested. When measurements showed it to be leaking more than expected, Andrée refused to acknowledge the alarming implications. Most modern students of the expedition see Andrée's optimism, faith in the power of technology, and disregard for the forces of nature as the main factors in the series of events that led to his death and those of his two companions Nils Strindberg and Knut Frænkel.After Andrée, Strindberg, and Frænkel lifted off from Svalbard in July 1897, the balloon lost hydrogen quickly and crashed on the pack ice after only two days. The explorers were unhurt but faced a grueling trek back south across the drifting icescape. Inadequately clothed, equipped, and prepared, and shocked by the difficulty of the terrain, they did not make it to safety. As the Arctic winter closed in on them in October, the group ended up exhausted on the deserted Kvitøya (White Island) in Svalbard and died there. For 33 years the fate of the Andrée expedition remained one of the unsolved riddles of the Arctic. The chance discovery in 1930 of the expedition's last camp created a media sensation in Sweden, where the dead men had been mourned and idolized.
Andrée's motives have since been re-evaluated, along with assessing the role of the polar areas as the proving-ground of masculinity and patriotism. An early example is Per Olof Sundman's fictionalized bestseller novel of 1967, The Flight of the Eagle, which portrays Andrée as weak and cynical, at the mercy of his sponsors and the media. The verdict on Andrée by modern writers for virtually sacrificing the lives of his two younger companions varies in harshness, depending on whether he is seen as the manipulator or the victim of Swedish nationalist fervor around the turn of the 20th century.Angioplasty
Angioplasty, also known as balloon angioplasty and percutaneous transluminal angioplasty (PTA), is a minimally invasive, endovascular procedure to widen narrowed or obstructed arteries or veins, typically to treat arterial atherosclerosis. A deflated balloon attached to a catheter (a balloon catheter) is passed over a guide-wire into the narrowed vessel and then inflated to a fixed size. The balloon forces expansion of the blood vessel and the surrounding muscular wall, allowing an improved blood flow. A stent may be inserted at the time of ballooning to ensure the vessel remains open, and the balloon is then deflated and withdrawn. Angioplasty has come to include all manner of vascular interventions that are typically performed percutaneously.
The word is composed of the combining forms of the Greek words ἀγγεῖον angeîon "vessel" or "cavity" (of the human body) and πλάσσω plássō "form" or "mould".Balloon (aeronautics)
In aeronautics, a balloon is an unpowered aerostat, which remains aloft or floats due to its buoyancy. A balloon may be free, moving with the wind, or tethered to a fixed point. It is distinct from an airship, which is a powered aerostat that can propel itself through the air in a controlled manner.
Many balloons have a basket, gondola, or capsule suspended beneath the main envelope for carrying people or equipment (including cameras and telescopes, and flight-control mechanisms).Balloon boy hoax
On October 15, 2009, a homemade helium-filled gas balloon shaped to resemble a silver flying saucer was released into the atmosphere above Fort Collins, Colorado, by Richard and Mayumi Heene. They then claimed that their six-year-old son Falcon was trapped inside it. Authorities confirmed the balloon reached 7,000 feet (2,100 m) during its 90-minute flight. The event attracted worldwide attention, and Falcon was nicknamed "Balloon Boy" in the media.National Guard helicopters and local police pursued the balloon. After flying for more than an hour and approximately 50 miles (80 km), the balloon landed about 12 miles (19 km) northeast of Denver International Airport. When Falcon was not found inside and it was reported that an object had been seen falling from the balloon, a search was begun. Later that day, the boy was found hiding in the attic of his home, where he had apparently been the entire time.Suspicions of a hoax soon arose, particularly after an interview with Wolf Blitzer on Larry King Live that same evening. Asked why he was hiding, Falcon said to his father, "You guys said that, um, we did this for the show." On October 18, 2009, Larimer County sheriff Jim Alderden announced his conclusion that the incident was a hoax and that the parents would likely face several felony charges. On November 13, 2009, Richard Heene pleaded guilty to attempting to influence a public servant. He was sentenced to 90 days in jail and ordered to pay $36,000 in restitution, and Mayumi Heene was sentenced to 20 days of weekend jail.Barrage balloon
A barrage balloon is a large kite balloon used to defend against aircraft attack by raising aloft cables which pose a collision risk, making the attacker's approach more difficult. The design of the kite balloon, having a shape and cable bridling which stabilise the balloon and reduce drag, meant that it could be operated in higher wind conditions than a spherical balloon. Some examples carried small explosive charges that would be pulled up against the aircraft to ensure its destruction. Barrage balloons are not practical against very high-flying aircraft, due to the weight of the long cable required.Centralia, Illinois
Centralia is a city in Clinton, Jefferson, Marion, and Washington counties in the U.S. state of Illinois. The population was 13,032 as of the 2010 census, down from 14,136 in 2000.Flight altitude record
This listing of flight altitude records are the records set for the highest aeronautical flights conducted in the atmosphere, set since the age of ballooning.
Some, but not all of the records were certified by the non-profit international aviation organization, the Fédération Aéronautique Internationale (FAI). One reason for a lack of 'official' certification was that the flight occurred prior to the creation of the FAI.For clarity, the "Fixed-wing aircraft" table is sorted by FAI-designated categories as determined by whether the record-creating aircraft left the ground by its own power (category "Altitude"), or whether it was first carried aloft by a carrier-aircraft prior to its record setting event (category "Altitude gain", or formally "Altitude Gain, Aeroplane Launched from a Carrier Aircraft"). Other sub-categories describe the airframe, and more importantly, the powerplant type (since rocket-powered aircraft can have greater altitude abilities than those with air-breathing engines).An essential requirement for the creation of an "official" altitude record is the employment of FAI-certified observers present during the record-setting flight. Thus several records noted are unofficial due to the lack of such observers.Framing (construction)
Framing, in construction, is the fitting together of pieces to give a structure support and shape. Framing materials are usually wood, engineered wood, or structural steel. The alternative to framed construction is generally called mass wall construction, where horizontal layers of stacked materials such as log building, masonry, rammed earth, adobe, etc. are used without framing.Building framing is divided into two broad categories, heavy-frame construction (heavy framing) if the vertical supports are few and heavy such as in timber framing, pole building framing, or steel framing; or light-frame construction (light-framing) if the supports are more numerous and smaller called light-frame construction, for example balloon, platform and light-steel framing. Light-frame construction using standardized dimensional lumber has become the dominant construction method in North America and Australia due to the economy of the method; use of minimal structural material allows builders to enclose a large area at minimal cost while achieving a wide variety of architectural styles.
Modern light-frame structures usually gain strength from rigid panels (plywood and other plywood-like composites such as oriented strand board (OSB) used to form all or part of wall sections), but until recently carpenters employed various forms of diagonal bracing to stabilize walls. Diagonal bracing remains a vital interior part of many roof systems, and in-wall wind braces are required by building codes in many municipalities or by individual state laws in the United States. Special framed shear walls are becoming more common to help buildings meet the requirements of earthquake engineering and wind engineering.Girl with Balloon
Girl with Balloon (also, Balloon Girl or Girl and Balloon) is a 2002-started London series of stencil murals by the graffiti artist Banksy, depicting a young girl with her hand extended toward a red heart-shaped balloon carried away by the wind. The first work was on Waterloo Bridge, and other murals were around London, though none remain there. Banksy has several times used variants of this design to support social campaigns: in 2005 about the West Bank barrier, in 2014 about the Syrian refugee crisis, and also about the 2017 UK election. A 2017 Samsung poll ranked Girl with Balloon as the United Kingdom's number one favourite artwork.
In 2018, a framed copy of the work spontaneously shredded during an auction, by way of a mechanical device Banksy had hidden in the frame. Banksy authenticated he was responsible for the shredding and gave the altered piece a new name, Love Is in the Bin. Sotheby said it was "the first work in history ever created during a live auction."Hot air balloon
A hot air balloon is a lighter-than-air aircraft consisting of a bag, called an envelope, which contains heated air. Suspended beneath is a gondola or wicker basket (in some long-distance or high-altitude balloons, a capsule), which carries passengers and a source of heat, in most cases an open flame caused by burning liquid propane. The heated air inside the envelope makes it buoyant since it has a lower density than the colder air outside the envelope. As with all aircraft, hot air balloons cannot fly beyond the atmosphere. 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. In modern sport balloons the envelope is generally made from nylon fabric and the inlet of the balloon (closest to the burner flame) is made from a fire resistant material such as Nomex. Modern balloons have been made in all kinds of shapes, such as rocket ships and the shapes of various commercial products, though the traditional shape is used for most non-commercial, and many commercial, applications.
The hot air balloon is the first successful human-carrying flight technology. The first untethered manned hot air balloon flight was performed by Jean-François Pilâtre de Rozier and François Laurent d'Arlandes on November 21, 1783, in Paris, France, in a balloon created by the Montgolfier brothers. The first hot-air balloon flown in the Americas was launched from the Walnut Street Jail in Philadelphia on January 9, 1793 by the French aeronaut Jean Pierre Blanchard. Hot air balloons that can be propelled through the air rather than simply drifting with the wind are known as thermal airships.Jeff Koons
Jeffrey Koons (; born January 21, 1955) is an American artist known for working with popular culture subjects and his reproductions of banal objects, such as balloon animals produced in stainless steel with mirror-finish surfaces. He lives and works in both New York City and his hometown of York, Pennsylvania.
His works have sold for substantial sums, including at least one world record auction price for a work by a living artist. On November 12, 2013, Koons' Balloon Dog (Orange) sold at Christie's Post-War and Contemporary Art Evening Sale in New York City for US$58.4 million, above its high US$55 million estimate, becoming the most expensive work by a living artist sold at auction. The price topped Koons' previous record of US$33.7 million and the record for the most expensive living artist, held by Gerhard Richter, whose 1968 painting, Domplatz, Mailand, sold for US$37.1 million at Sotheby's on May 14, 2013. Balloon Dog (Orange) was one of the first of the Balloon dogs to be fabricated, and had been acquired by Greenwich collector Peter Brant in the late 1990s.Critics are sharply divided in their views of Koons. Some view his work as pioneering and of major art-historical importance. Others dismiss his work as kitsch, crass, and based on cynical self-merchandising. Koons has stated that there are no hidden meanings in his works, nor any critiques.List of Royal Air Force aircraft squadrons
Squadrons are the main form of flying unit of the Royal Air Force (RAF). These include Royal Flying Corps (RFC) and Royal Naval Air Service (RNAS) squadrons incorporated into the RAF when it was formed on 1 April 1918, during the First World War. Other squadrons of the RAF include those from Commonwealth air forces which have served within the RAF structure and squadrons of the Fleet Air Arm before it transferred to the Royal Navy in 1939.
Some squadrons have an individual tradition of presenting their squadron number in Roman numerals or using a suffix to their squadron number (such as "(F)" for "Fighter", "(B)" for "Bomber" or "(AC)" for "Army Co-operation") to indicate a past or present role. An example would be No. 18 (Bomber) Squadron RAF which currently actually operates the heavy-lift Chinook helicopter. However, these practices have, at least in the past, been deprecated at higher levels and generally only apply to certain squadrons with long traditions, especially those numbered from 1-20. Historical Squadrons can choose to 'lay up' their standards at RAF Cranwell or in places of worship following disbandment.
Flying training units and operational evaluation squadrons have generally been (Reserve) squadrons, although they are regular active-duty units. The policy of the (Reserve) numberplate was rescinded in February 2018, to coincide with the renaming of 22 (Training) Group to just 22 Group in line with other RAF Groups.
Some Squadron names include the location they were originally formed.Loon (company)
Loon LLC is an Alphabet Inc. subsidiary working on providing Internet access to rural and remote areas. The company uses high-altitude balloons placed in the stratosphere at an altitude of about 18 km (11 mi) to create an aerial wireless network with up to 4G-LTE speeds. It was named Project Loon, since even Google itself found the idea of providing Internet access to the remaining 5 billion population unprecedented and "loony". It may also be a reference to the balloons used. Loon began as a research and development project by X (formerly Google X), but was spun out into a separate company in July 2018.The balloons are maneuvered by adjusting their altitude in the stratosphere to float to a wind layer after identifying the wind layer with the desired speed and direction using wind data from the National Oceanic and Atmospheric Administration (NOAA). Users of the service connect to the balloon network using a special Internet antenna attached to their building. The signal travels through the balloon network from balloon to balloon, then to a ground-based station connected to an Internet service provider (ISP), then onto the global Internet. The system aims to bring Internet access to remote and rural areas poorly served by existing provisions, and to improve communication during natural disasters to affected regions. Key people involved in the project include Rich DeVaul, chief technical architect, who is also an expert on wearable technology; Mike Cassidy, a project leader; and Cyrus Behroozi, a networking and telecommunication lead.The balloons use patch antennas – which are directional antennas – to transmit signals to ground stations or LTE users. Some smartphones with Google SIM cards can use Google Internet services. The whole infrastructure is based on LTE; the eNodeB component (the equivalent of the "base station" that talks directly to handsets) is carried in the balloon.Macy's Thanksgiving Day Parade
The annual Macy's Thanksgiving Day Parade in New York City, one of the world's largest parades, is presented by the U.S. based department store chain Macy's. The parade started in 1924, tying it for the second-oldest Thanksgiving parade in the United States with America's Thanksgiving Parade in Detroit (with both parades being four years younger than Philadelphia's Thanksgiving Day Parade). The three-hour parade is held in Manhattan from 9:00 a.m. to 12:00 p.m. Eastern Standard Time on Thanksgiving Day, and has been televised nationally on NBC since 1952. Employees at Macy's department stores have the option of marching in the parade.Roswell UFO incident
In mid-1947, a United States Army Air Forces balloon crashed at a ranch near Roswell, New Mexico. Following wide initial interest in the crashed "flying disc", the US military stated that it was merely a conventional weather balloon. Interest subsequently waned until the late 1970s, when ufologists began promoting a variety of increasingly elaborate conspiracy theories, claiming that one or more alien spacecraft had crash-landed and that the extraterrestrial occupants had been recovered by the military, which then engaged in a cover-up.
In the 1990s, the US military published two reports disclosing the true nature of the crashed object: a nuclear test surveillance balloon from Project Mogul. Nevertheless, the Roswell incident continues to be of interest in popular media, and conspiracy theories surrounding the event persist. Roswell has been described as "the world's most famous, most exhaustively investigated, and most thoroughly debunked UFO claim".Speech balloon
Speech balloons (also speech bubbles, dialogue balloons or word balloons) are a graphic convention used most commonly in comic books, comics and cartoons to allow words (and much less often, pictures) to be understood as representing the speech or thoughts of a given character in the comic. There is often a formal distinction between the balloon that indicates thoughts and the one that indicates words spoken aloud: the balloon that conveys thoughts is often referred to as a thought bubble.Theodolite
A theodolite is a precision optical instrument for measuring angles between designated visible points in the horizontal and vertical planes. The traditional use has been for land surveying, but they are also used extensively for building and infrastructure construction, and some specialized applications such as meteorology and rocket launching.It consists of a moveable telescope mounted so it can rotate around horizontal and vertical axes and provide angular readouts. These indicate the orientation of the telescope, and are used to relate the first point sighted through the telescope to subsequent sightings of other points from the same theodolite position. These angles can be measured with great accuracy, typically to milliradian or seconds of arc. From these readings a plan can be drawn, or objects can be positioned in accordance with an existing plan. The modern theodolite has evolved into what is known as a total station where angles and distances are measured electronically, and are read directly to computer memory.
In a transit theodolite, the telescope is short enough to rotate through the zenith, otherwise for non-transit instruments vertical (or altitude), rotation is restricted to a limited arc.
The optical level is sometimes mistaken for a theodolite, but it does not measure vertical angles, and is used only for levelling on a horizontal plane.Union Army Balloon Corps
The Union Army Balloon Corps was a branch of the Union Army during the American Civil War, established by presidential appointee Thaddeus S. C. Lowe. It was organized as a civilian operation, which employed a group of prominent American aeronauts and seven specially built, gas-filled balloons to perform aerial reconnaissance on the Confederate States Army.
Lowe was one of few veteran balloonists who was working on an attempt to make a transatlantic crossing by balloon. His efforts were interrupted by the onset of the Civil War, which broke out one week before one of his most important test flights. Subsequently, he offered his aviation expertise to the development of an air-war mechanism through the use of aerostats for reconnaissance purposes. Lowe met with U.S. President Abraham Lincoln on June 11, 1861, and proposed a demonstration with his own balloon, the Enterprise, from the lawn of the armory directly across the street from the White House. From a height of 500 feet (150 m) he telegraphed a message to the President describing his view of the Washington, D.C., countryside. Eventually he was chosen over other candidates to be chief aeronaut of the newly formed Union Army Balloon Corps.
The Balloon Corps with a hand-selected team of expert aeronauts served at Yorktown, Seven Pines, Antietam, Fredericksburg, and other major battles of the Potomac River and the Virginia Peninsula. The Balloon Corps served the Union Army from October 1861 until the summer of 1863, when it was disbanded following the resignation of Lowe.Weather balloon
A weather or sounding balloon is a balloon (specifically a type of high-altitude balloon) that carries instruments aloft to send back information on atmospheric pressure, temperature, humidity and wind speed by means of a small, expendable measuring device called a radiosonde. To obtain wind data, they can be tracked by radar, radio direction finding, or navigation systems (such as the satellite-based Global Positioning System, GPS). Balloons meant to stay at a constant altitude for long periods of time are known as transosondes. Weather balloons that do not carry an instrument pack are used to determine upper-level winds and the height of cloud layers. For such balloons, a theodolite or total station is used to track the balloon's azimuth and elevation, which are then converted to estimated wind speed and direction and/or cloud height, as applicable.