In the animated television series Futurama, set in the 31st century, large pneumatic tubes are used in cities for transporting people, whilst smaller ones are used to transport mail.

I have just asked these questions in the Pentagon, in the White House, in offices of key scientists across the country and aboard the submarines that prowl for months underwater, with neat rows of green launch tubes which contain Polaris missiles and which are affectionately known as `` Sherwood Forest ''.

If you are dreaming of a blue, shimmering pool right outside your living room windows, close your eyes firmly and fill in the picture with lots and lots of children, damp towels, squashed tubes of suntan oil and semi-inflated plastic toys.

They are sometimes preserved within the voids of other organisms, for instance within empty hyolith conchs, within sponges, worm tubes and under the carapaces of bivalved arthropods, presumably in order to hide from predators or strong storm currents ; or maybe whilst scavenging for food.

In the case of the tapering worm tubes Selkirkia, trilobites are always found with their heads directed towards the opening of the tube, suggesting that they reversed in ; the absence of any moulted carapaces suggests that moulting was not their primary reason for seeking shelter.

The gases are contained in a test-tube ( A ) standing over a large quantity of weak alkali ( B ), and the current is conveyed in wires insulated by U-shaped glass tubes ( CC ) passing through the liquid and round the mouth of the test-tube.

* Laparoscopy -- A minimally invasive approach to abdominal surgery where rigid tubes are inserted through small incisions into the abdominal cavity.

The graphite tubes are heated via their ohmic resistance using a low-voltage high-current power supply ; the temperature in the individual stages can be controlled very closely, and temperature ramps between the individual stages facilitate separation of sample components.

Photomultiplier tubes are the most frequently used detectors in LS AAS, although solid state detectors might be preferred because of their better signal-to-noise ratio.

Two connecting tubes are required.

For example, carbon can be found as diamond, which has a tetrahedral structure around each carbon atom ; graphite, which has layers of carbon atoms with a hexagonal structure stacked on top of each other ; graphene, which is a single layer of graphite that is incredibly strong ; fullerenes, which have nearly spherical shapes ; and carbon nanotubes, which are tubes with a hexagonal structure ( even these may differ from each other in electrical properties ).

Patients who are restless may also try to pull on tubes or dressings so soft cloth wrist restraints may be put on.

Externally heated electrodes are often used to generate an electron cloud as in the filament or indirectly heated cathode of vacuum tubes.

Vacuum tubes and sprytrons are some of the electronic switching and amplifying devices based on vacuum conductivity.

Cathode rays ( also called an electron beam or e-beam ) are streams of electrons observed in vacuum tubes.

Cathode rays are invisible, but their presence was first detected in early vacuum tubes when they struck the glass wall of the tube, exciting the atoms of the glass and causing them to emit light, a glow called fluorescence.

These are used in cathode ray tubes, found in televisions and computer monitors, and in electron microscopes.

Cathodes used for field electron emission in vacuum tubes are called cold cathodes.

Hot electron emitters are also used as the electrodes in fluorescent lamps and in the source tubes of X-ray machines.

No modern tube based Hi-Fi systems are known to use this tube type, as simpler and more readily available tubes have again filled this niche.

Thermionic diodes are thermionic-valve devices ( also known as vacuum tubes, tubes, or valves ), which are arrangements of electrodes surrounded by a vacuum within a glass envelope.

Electrons are at the heart of cathode ray tubes, which have been used extensively as display devices in laboratory instruments, computer monitors and television sets.

Vacuum tubes are still used in some specialist applications such as high power RF amplifiers, cathode ray tubes, specialist audio equipment and some microwave devices.

Argon gas also has uses in incandescent and fluorescent lighting, and other types of gas discharge tubes.

However, Curie also worked with unshielded X-ray tubes during World War I, and analysis of her skeleton during a reburial showed a relatively low level of radioisotope burden.

Other forms of agate include Lake Superior agate, carnelian agate ( exhibiting reddish hues ), Botswana agate, blue lace agate, plume agates, moss agate, tube agate ( with visible flow channels or pinhole-sized ' tubes '), fortification agate ( which exhibit little or no banding structure ), fire agate ( which has internal flash or ' fire ', the result of a layer of clear agate over a layer of hydrothermally-deposited hematite ), Mexican crazy-lace agate, which often exhibits a brightly colored, complexly banded pattern ( also called Rodeo Agate and Rosetta Stone depending on who owned the mine at the time ).

While some women's bicycles continue to use this frame style, there is also a variation, the mixte, which splits the top tube laterally into two thinner top tubes that bypass the seat tube on each side and connect to the rear fork ends.

Once destroyers became more than just catchers guarding an anchorage, it was realized that they were also ideal to take over the role of torpedo boats themselves, so they were fitted with torpedo tubes as well as guns.

In addition to the feedback oscillators described above, which use two-port amplifying active elements such as transistors and op amps, linear oscillators can also be built using one-port ( two terminal ) devices with negative resistance, such as magnetron tubes, tunnel diodes and Gunn diodes.

Presence of alkaline metal ions has also detrimental effect to the loss tangent of the glass, and to its electrical resistance ; glasses for electronics ( sealing, vacuum tubes, lamps ...) have to take this in account.

As such it is also used on non-food items, such as medical devices, plastics, tubes for gas pipelines, hoses for floor heating, shrink-foils for food packaging, automobile parts, wires and cables ( isolation ), tires, and even gemstones.

The KUB is also used to assess positioning of indwelling devices such as ureteric stents and nasogastric tubes.

Robert Rines also explained that the " horns " described in some sightings may be breathing tubes or nostrils that allow the animal to breathe without breaking the surface.

Molding plate is also fabricated into tubes and rings for insulation in armatures, motor starters, and transformers.

It also cut costs by allowing Nixie tubes, seven-segment displays, and calculators to be used for the operator consoles, where binary displays were too complex to use, decimal displays needed complex hardware to convert radices, and hexadecimal displays needed to display more numerals.

Partially collapsed lava tubes are visible as chains of pit craters, and broad lava fans formed by lava emerging from intact, subsurface tubes are also common.

By overblowing, that is, increasing the pressure of breath and tension of lips, odd harmonics ( notes whose frequencies are odd-number multiples of the fundamental ), near a 12th in cylindrical tubes, may also be produced.

The goddess is bordered by snake lines which give her a vegetable like appearance and also recall the arrangement of snake tubes which have been found in Minoan and Mycenean sunctuaries.

Pneumatic tubes ( or capsule pipelines ; also known as Pneumatic Tube Transport or PTT ) are systems in which cylindrical containers are propelled through a network of tubes by compressed air or by partial vacuum.

It was also speculated that a system of tubes might deliver mail to every home in the US.

In 1985, the movie Brazil also used tubes ( as well as other anachronistic-seeming technologies ) to evoke the stagnation of bureaucracy.