What is the most important survival tool in the jungle?

WANNA GO FOR A JUNGLE SAFARI:CHECK THIS OUT

That adventure vacation in the Amazon rainforest isn't working out so well. Things were going great until poachers ravaged your camp, stole everything of value, beat you and left you for dead. Now you're alone with nothing but the clothes on your back. If only the marauders had left something behind to help you survive, like a machete or a first-aid kit or your bag of freeze-dried meals. If only you had one solid survival tool.
There are quite a few tools that would help you to survive this kind of scenario. A machete, for example, could help you hack through the dense underbrush and lead you to civilization. Stars are a good way to find your bearings, but under the canopy of the rainforest, you're lucky to find a clearing large enough to see anything stellar. So maybe a compass and a map would be your most valuable tools.
Could a gun be what you need most? After all, you're pretty much dead meat if you wander up on a mother jaguar feeding her young. And, you could use the weapon to hunt. Or perhaps a good survival knife is the ticket. You'd be able to hack down underbrush, protect yourself against danger, hunt wild boar and cut branches to build a shelter. Most survival knives also come with a nice little stash of goods stored in their hollow handles -- fishing hooks and line or some safety matches to start a signal fire. Some of them even come with a compass.
What about a mosquito net or some heavy-duty insect repellent? After all, mosquitoes in the jungle can give you malaria, yellow fever, West Nile virus and Dengue fever. Not to mention the fact that they're a total nuisance and will make your life miserable. Then again, you'll be mighty hungry, so a bag full of freeze-dried dinners could help you to survive for a while and give you the energy to hike to rescue.
While all of these things are pretty handy in the jungle, none of them are the absolute best tools if you're trying to survive for an extended period of time. So, what's the most valuable?

The No. 1 Jungle Survival Tool
So the machete lost out, along with the compass, gun, food, mosquito netting and even the reliable and versatile survival knife. All of those tools are handy and useful, but none of them make a bit of difference if you don't have fresh drinking water. Water is the No. 1 thing you need to survive any environment on Earth -- you simply can't live without it. For this reason, the number one tool you can have to survive in the jungle is a high-quality water filter.

Camping water filters are compact and easy to use -- all you do is drop the suction tube into the water and pump the lever to draw the water into a bottle.
Humans can go for as long as 60 days or more without food as long as they stay properly hydrated. You can't live without water for more than a few days. In hot conditions with no water, dehydration can set in within an hour. Since you're in the hot and humid jungle you also need to worry about heat stroke. Drinking water will cool you down and lower your core temperature. Knowing the signs and symptoms of dehydration can help you prevent a more serious condition.
At this point, your body will go into shock. Your skin will turn a blue-grey color and be cold to the touch because of a drop in blood pressure. Shock is followed by coma and organ failure, and you know what that means -- certain death, the opposite of survival.
The human body contains about 11 gallons (42 liters) of water. In the jungle, the hot and humid conditions can cause you to lose about 25 percent of that water per day. The water leaves your body as sweat, urine and even in the air you breathe. If you're busy hunting, fishing, gathering wood and building a shelter, you can lose even more fluids than that. This means you need to drink at least two gallons of water per day to function at your physical peak.
Some people might argue that the machete is the most important jungle survival tool, and if you're an experienced outdoorsman or survivalist, this may be the case. Trained survivalists know what kind of water to drink, where to find it and tricks to help purify it. But if you're not a survival expert, making a wrong move with water can cost you your life. You also might spend most of your time looking for water and neglect finding food and shelter. And there's no guarantee you can start a fire without a lighter or match in the wet jungle to help you purify any water that you find. If you have a water filter, you know for sure that you can stay properly hydrated at all times, and this is the first step toward ensuring your survival.
If you're still thirsting for more, filter some water from that cesspool

How James Bond Works

With his dry wit and impeccable style, James Bond has been defying death and ruining the plans o­f mega­lomaniacal madmen in service of Queen and country for more than 50 years. From his first appearance in a 1953 novel to his leading role in one of the most successful franchises in film history, Bond has traveled to more exotic locations, romanced more women, escaped from more harrowing death traps and saved the world more times than any other secret agent, real or fictional.
Much about the early life of James Bond remains murky, befitting a secret agent. Even the date of his birth is in dispute -– early accounts suggest various dates in the 1920s, implying that modern-day chronicles of his exploits recount the events of decades past. His Scottish father worked for a British arms manufacturer and was killed while mountain climbing along with Bond's Swiss mother when James was eleven. The orphan attended several prestigious schools before enlisting in the Royal Navy during World War II, where he rose to the rank of commander. Following the War, he entered the British Secret Intelligence Service (SIS), also known as MI6, short for 6th Branch of the Military Intelligence Directorate. His first two assignments were assassinations, which led to his permanent designation as a "double-0" agent, one with a license to kill in the line of duty. As the seventh such agent, he was designated Agent 007.­
Bond is no mere foot soldier. His undercover assignments have taken him to exotic locales that include volcanic islands, Las Vegas, Paris, India, Azerbaijan, Tokyo and even a space station in orbit. He usually operates under an alias, usually as a representative of Universal Exports. His charm and charisma are reinforced by his taste for fine suits, fast cars and his signature beverage: a dry martini, shaken, not stirred. Bond's missions bring him into contact with both sophisticated elites and shady underworld figures. In both situations, he has repeatedly demonstrated (and overcome) his one true weakness -– he can't resist a beautiful woman.
Although Bond is a gifted athlete and well-trained in martial arts, he doesn’t have to rely on his wits and physical prowess alone. The Q Branch of MI6 regularly outfits 007 with clever devices, usually in the form of a mundane object that hides an explosive, a gun or another key item. He also has access to heavily modified experimental vehicles, and often carries a hidden escape device or a means of communicating with his handlers in an emergency. When all else fails, he keeps a Walther PPK .32 caliber handgun tucked into a shoulder holster, though he also uses other weapons when needed.
Bond's missions have varied wildly, but one thing is always consistent: MI6 deploys him when nothing else matters more than getting the job done. Bond is considered a "blunt instrument" of the crown, a man who can accomplish difficult missions regardless of the political, financial or personal consequences. When the fate of the world is on the line, his superiors know that Bond can't take time to worry about offending an ambassador -- or blowing up an embassy.
Propaganda?
A recent campaign gives new details on the life of James Bond. However, this information indicates that he was born in the late 1960s, and includes data on his exploits in more modern theaters of intelligence work. Could this be deliberate misinformation? Or has there been more than one James Bond? That certainly would help explain his youthful good looks after all these decades...
The Spy Who Loved Me: Allies, Enemies and Origins
Just as James Bond is far from your average spy, his opponents and allies have certainly been more than faceless minions. The most prominent opponent in earlier years was the diabolical Ernst Stavro Blofeld. Blofeld headed the organization Special Executive for Counter-intelligence, Terrorism, Revenge and Extortion (SPECTRE), which he used to further his own aims -- mostly world domination or raking in huge sums of money.
Blofeld was known for his bald head, conspicuous facial scar and, in some accounts, his attachment to a white Persian cat. However, he was known to resort to extensive makeup, masking and even plastic surgery to alter his appearance. Blofeld was directly responsible for the murder of James Bond's only wife, Teresa di Vicenzo. He is presumed dead after a fall resulting from a struggle on a helicopter with Bond himself, though with Blofeld, appearances are always deceiving.
Other notable Bond enemies include:
Dr. Julius No -- an atomic scientist who reportedly lost both of his hands
Auric Goldfinger -- a gold-obsessed smuggler who also works for SMERSH, a Russian espionage agency Oddjob -- Goldfinger’s henchman
Max Zorin – a genetically engineered psychopath
Jaws – a massively strong, steel-dentured man
006 -- a former MI6 Agent
Elliot Carver -- a warmongering media mogul

Fortunately, Bond has not been alone when facing these villains. Allies from within and without MI6 have come to his aid at crucial moments throughout 007's career: M -- M is the head of MI6. Bond has served under several different "M"s during his tenure at MI6. M typically finds Bond's personal habits exasperating, but respects his many talents.
Q -- Q is the Head of Q Branch, MI6's research and development division. Unlike M, for many years there was only one Q, Major Boothroyd. As MI6's resident mad scientist, he developed the gadgets and weapons systems that often saved 007's life. He also fretted about the damage Bond always seemed to cause to them. Sadly, Major Boothroyd passed away after decades of service to his country. He has since been replaced by a new Q, formerly his assistant, R.
Moneypenny -- M's personal assistant, Moneypenny is known for her flirtatious verbal jousting with Bond, but it never gets in the way of getting her job done.
Felix Leiter -- Bond's missions often bring him into contact with his American counterparts in the espionage field. Leiter has assisted Bond on at least eight missions. Sources disagree as to whether Leiter works for the CIA or the DEA. General Anatol Gogol -- This former KGB head opposed 007 at times, but Bond came to know him as a man of principle who could be counted on to help defeat schemes that threatened world security.
Bond's Beginnings
Of course, James Bond is a fictional character, created by British author Ian Fleming. Fleming's early life mirrors that of Bond in some ways -– his journalism and stock broker careers were interrupted by World War II. He joined the Royal Naval Volunteer Reserve in 1939 and worked in an administrative position in Naval Intelligence. Fleming also occasionally did field work, including breaking and entering to photograph sensitive documents. The character of Bond as he appears in Fleming's novels is probably a romanticized version of Fleming himself,with additional traits from others. Even after leaving the Navy, " He wrote "Casino Royale" and all the subsequent Bond novels at the estate. After showing "Casino Royale" to a friend who read for a publishing house, the novel was accepted and achieved modest commercial and critical success. Fleming wrote a new Bond novel almost every year, eventually completing 13 of them. After Fleming died from a heart attack in 1964, a book of Bond short stories was released. Other authors were given license by his estate to write additional novels based on the Bond character.
The Original 007?
Some scholars believe that philosopher, scientist and astrologer John Dee was the original 007. In the 16th century, Dee served as an adviser to Queen Elizabeth I. Dee signed his messages to the Queen with two zeros -- symbolizing his job as the Queen's eyes -- followed by a seven with the top drawn out across the zeros. This seven reportedly had some occult meaning to Dee. So, his "codename" was 007, and he performed espionage and counterespionage activities in the Queen's service.
Bonds on Film: Actors and Elements
The first screen appearance of James Bond was in a pilot for a CBS TV series. Based on the novel "Casino Royale," the pilot flopped and the series was never made. Fleming's novels would eventually be made into a successful series of films, starting with "Dr. No" in 1962. The 20 official Bond films released since then (prior to the release of 2006's "Casino Royale") have made about $3.8 billion worldwide, and over $1.2 billion in the United States [Source: Giammarco]. Five different actors have played the role of James Bond in the official films (There are three unofficial films: the CBS pilot, a 1967 spoof of "Casino Royale," and 1983's "Never Say Never Again," a remake of "Thunderball" that arose from a complicated copyright entanglement). Daniel Craig is the sixth Bond, appearing in the 2006 "reboot" of the franchise.
Pierce Brosnan played Bond four times from 1995 to 2002. For younger fans of the series, he is the only Bond. His wry smile and dry wit are reminescent of Roger Moore's portrayal of Bond, but Brosnan also guided the character forward.
Daniel Craig is the sixth actor to play Bond and is also the only blond to take the role. Including 2006's "Casino Royale," he is signed to a three-film contract. Like all other "new Bonds" before him, Craig's selection caused some controversy and angered some fans of the series.
Fast-paced Action
The core of any Bond film is the fast-paced action. Car chases, daring leaps from buildings or mountains, hand-to-hand combat, gunfights, narrow escapes from death traps, even boat and airplane chases are all vital to the success of a Bond film.
Humor
A Bond film is not a gritty exploration of the espionage underworld or a high-minded glimpse into global politics. Even at the most tense moments, Bond finds time for a one-liner, dryly delivered with a half-smile Sexual Innuendo
There is never any graphic sex or nudity in a Bond film, but 007 is with a gorgeous woman at least once in every movie. Even more conspicuous than these tame scenes is the dialogue between Bond and his female co-stars.
Visual Beauty
James Bond doesn't get into a car chase while driving a Pinto through Detroit. He drives a Lotus Esprit along a winding mountain road that overlooks a stunning rainforest. His cases take him to golden beaches, vibrant jungles, even crystalline ice palaces.
Bond Girls
The selection of each Bond Girl is almost as anticipated as the casting of a new James Bond. A Bond Girl is not just beautiful -– she is also a "femme fatale," a woman that will cause Bond great trouble when he inevitably finds himself attracted to her. Some of them are outright villains, while others have their own tragic stories and vulnerabilities that make Bond feel protective. Bond usually wins the girl, but sometimes she betrays him and sometimes she dies in his arms.
The World is Not Enough: Comics, Games and Parodies
James Bond has found success outside of films and novels. A radio adaptation, a series of newspaper comic strips and numerous graphic novels have all featured Bond, either in original stories or versions of the films or novels. However, the most successful non-film medium for Bond has been video games. 1997's "Goldeneye 007" for the Nintendo 64 was a smash hit -- many people continue to play it, although the system itself is outdated.

How Performance-enhancing Drugs Work

Every two years as the Olympic Games begin, we hear about athletes using or at least being tested for performance-enhancing drugs. Every time the Tour de France rolls around, there's talk of possible doping. Sometimes, competitors raise the question when one athlete does particularly well. Other times, tests catch athletes with drugs in their systems. The practice of using artificial substances or methods to enhance athletic performance is called doping. Doping has become such a great concern that the United States formed an Anti-Doping Agency.
We will discuss why some athletes take drugs, what the major classes of drugs and their side effects are and how drug use is tested for.­

How strong are you?

You'd probably be amazed to learn how much force your body's joints and muscles actually support on a daily basis. This interactive segment from Discovery takes you inside the body and explains how much strength your bones and muscles really possess. Other activities let you explore even more of your body's systems to see exactly how they move you through your daily life

Why Some Athletes Use Drugs

Athletes face enormous pressure to excel in competition. They also know that winning can reap them more than a gold medal. A star athlete can earn a lot of money and a lot of fame, and athletes only have a short time to do their best work. Athletes know that training is the best path to victory, but they also get the message that some drugs and other practices can boost their efforts and give them a shortcut, even as they risk their health and their athletic careers.
As far back as ancient Greece, athletes have often been willing to take any preparation that would improve their performance. But it appears that drug use increased in the 1960s. One well-publicized incident happened at the Seoul Olympics in 1988 when sprinter Ben Johnson tested positive for anabolic steroids and was stripped of his gold medal. Athletes may also misuse drugs to relax, cope with stress or boost their own confidence.
Athletes may have several reasons for using performance-enhancing drugs. An athlete may want to:

Build mass and strength of muscles and/or bones

Increase delivery of oxygen to exercising tissues

Mask pain

Stimulate the body

Relax

Reduce weight

Hide use of other drugs

The classes of drugs used for these purposes are shown above. Most of the drugs shown are banned outright in Olympic competitions. However, some of these drugs, such as cortisone and local anesthetics, are restricted in Olympic competition because they have legitimate clinical uses. We'll look at each major class of drug and tell you about the dangerous side effects.

Building Mass and Strength
Mass- and strength-enhancing drugs used by athletes include:

Anabolic steroids

Beta-2 agonists

Human chorionic gonadotropin (hCG)

Luteinizing hormone (LH)

Human growth hormone (hGH)

Insulin-like growth factor (IGF-1)

Insulin

Anabolic Steroids
A steroid is a chemical substance derived from cholesterol. The body has several major steroid hormones -- cortisol and testosterone in the male, estrogen and progesterone in the female. Catabolic steroids break down tissue, and anabolic steroids build up tissue. Anabolic steroids build muscle and bone mass primarily by stimulating the muscle and bone cells to make new protein.
Athletes use anabolic steroids because they increase muscle strength by encouraging new muscle growth. Anabolic steroids are similar in structure to the male sex hormone, testosterone, so they enhance male reproductive and secondary sex characteristics (testicle development, hair growth, thickening of the vocal cords). They allow the athlete to train harder and longer at any given period.
Anabolic steroids are mostly testosterone (male sex hormone) and its derivatives. Examples of anabolic steroids include:

Testosterone

Dihydrotestosterone

Androstenedione (Andro)

Dehydroepiandrosterone (DHEA)

Clostebol Nandrolone

These substances can be injected or taken as pills. Anabolic steroids have a number of possible and well-known side effects, including: Jaundice and liver damage because these substances are normally broken down in the liver Mood swings, depression and aggression because they act on various centers of the brain In males, the excessive concentrations interfere with normal sexual function and cause:
Baldness

Infertility

Breast development

In females, the excessive concentrations cause male characteristics to develop and interfere with normal female functions. The drugs can:
Stimulate hair growth on the face and body Suppress or interfere with menstrual cycle, possibly leading to infertility Thicken the vocal cords, which causes the voice to deepen, possibly permanently If pregnant, interfere with the developing fetus
Beta-2 Adrenergic Agonists
When inhaled, beta-2 agonists relax the smooth muscle in the airways of asthma patients by mimicking the actions of epinephrine and norepinephrine, substances that are secreted by sympathetic nerves. However when injected into the bloodstream, these drugs can build muscle mass (anabolic effect) and reduce body fat (catabolic effect). The anabolic effect appears to directly affect building proteins in the muscles, which is independent of nervous or cardiovascular effects. Some examples of beta-2 agonists include:

Clenbuterol

Tertbutaline

Salbutamol

Fenoterol

Bambuterol

Some of these substances are permitted in inhaler forms with written medical consent. The major side effects include:
Nausea, headaches and dizziness because these substances constrict blood vessels in the brain Muscle cramps because they constrict blood vessels in muscles

Rapid heart beats or flutters because they stimulate heart rate

Masking Pain
Along with training and performing to be a world-class athlete comes the pain of injuries. Sometimes, athletes try to mask their injury pain with drugs, including narcotics, protein hormones, cortisone and local anesthetics.
Narcotics

Narcotics are used to treat pain and include substances such as morphine, methadone and heroin. Narcotics are highly addictive, and the "high" associated with their use can impair mental abilities (judgment, balance and concentration). Also, athletes who continue to compete with an injury run the risk of further damage or complications.
Protein Hormones

Adrenocorticotrophic hormone (ACTH) is a naturally occurring protein hormone that is secreted by the pituitary gland and stimulates the production of hormones from the adrenal cortex. These adrenal cortex hormones are important in reducing inflammation in injuries and allergic responses. So, by using ACTH to stimulate internal adrenal cortex hormones, an athlete could mask an injury. Possible side effects include stomach irritation, ulcers, mental irritation and long-term effects (weakening bones and muscles).
Cortisone

Cortisone is one of the adrenal cortex hormones. Clinically, it is injected to reduce inflammation in injuries and allergic responses. The advantages and side effects of its use are the same as with ACTH.
Local Anesthetics

Local anesthetics, like those used by your dentist or doctor, are used to mask pain in the short-term without impairing mental abilities. They include novocaine, procaine, lidocaine and lignocaine. Athletes may use them so that they can continue to compete while injured. The major problem with their use is the possibility of further aggravating an injury.
Testing Athletes for Drug Use
The majority of drugs that can be used by athletes can be detected in samples of urine. An athlete is told by a drug control officer to submit a urine sample for testing. The sample is then sent to a laboratory for analysis and the results are reported back to the governing athletic agency. For some substances, blood samples may be required.

Gas Chromatography/Mass SpectrometryGas
chromatography and mass spectrometry are the most common methods of chemical analysis. These tests can be done on urine and blood samples. In gas chromatography, the sample is vaporized in the presence of a gaseous solvent and placed through a long path of a machine. Each substance dissolves differently in the gas and stays in the gas phase for a unique, specific time, called the retention time. Typically the substance comes out of the gas and is absorbed on to a solid or liquid, which is then analyzed by a detector. When the sample is analyzed, the retention time is reported or plotted to create a chromatogram. Standard samples of drugs are run, as well as the urine/blood samples, so that specific drugs can be identified and quantified in the chromatograms of the urine/blood samples.
In mass spectrometry, samples are blown apart with an electron beam and the fragments are accelerated down a long magnetic tube to a detector. Each substance has a unique "fingerprint" in the mass spectrometer. Again, standard samples are run for identification and quantification of drugs in the urine/blood samples.
Immuno-Assays
Some substances (such as hCG, LH, ACTH) can be measured in urine samples using an immuno-assay. In this test, the sample is mixed with a solution containing an antibody specific to the tested substance. An antibody is a protein that binds only a specific substance and is how the body recognizes foreign substances. The antibody in the test is usually tagged with a fluorescent dye or radioactive substance. The amount of fluorescent light or radioactivity is measured and is related to the concentration of the tested substance in the sample.
Tests Under Development
Currently, there are no reliable tests for hGH, IGF-1 and EPO. However, a test for EPO is being developed. The EPO test looks at the size of red blood cells. It has been noticed that synthetic EPO produces red blood cells that are smaller and bind more iron then natural EPO. So, the size and iron content of red blood cells from a blood sample are analyzed to determine whether an athlete has used EPO.
Although there is little statistical evidence on how widespread doping is, athletes and coaches stress that most competitors do not take drugs. Nonetheless, drug testing is becoming an increasingly integral part of sports competitions. As new performance-enhancing drugs are developed, new tests are developed to detect these drugs, and the struggle to keep sports clean continues indefinitely.

What if I threw my car into reverse while I was driving?

This is one of those funny questions that pops up in lots of people's minds. As you're driving your car, you can imagine that it would be very easy to move the shifter into the "R" position at any time. You probably would never even consider giving in to your curiosity, though. Because you know that if you DID try it, it would cause the transmission to explode, or something like that. So, instead, you end up constantly wondering....
The reverse gear on any car with a manual transmission is an incredibly simple piece of machinery. There is a shaft that gets its power from the engine, and it has teeth on it that are used for reverse. There's another shaft that will drive the wheels, and it, too, has teeth on it that are used for reverse. To engage reverse, a gear literally gets pushed in between the two shafts to engage the two sets of teeth. It simply slides its teeth into the teeth on the two shafts and engages them.

So it turns out that the answer to this question is pretty anticlimatic. If you were to actually try engaging reverse while rolling down the road, the gear that has to slide into place is going to be trying to engage two spinning gears, and one of those gears is rotating rapidly in the wrong direction. What you will hear (and feel in the shift) is a very obnoxious buzzing sound as the teeth gnash against one another. However, there's no way to get the gear into place while in motion like this, so nothing will happen. The transmission won't explode. Nor will the car stop on a dime and reverse into oncoming traffic, even though that's what happens in cartoons.

About the only time you can actually get a car into reverse is when it's at a dead stop.

What if my brakes stopped working?

Suppose you're driving down the freeway one day. As you're about to take the exit, you tap on the brakes -- and you don't slow down. No matter how hard you press, nothing happens. You have no brakes! What are you going to do?

When you press on the brake pedal in almost all cars today, you're pushing on a piston. That piston pushes on brake fluid in the master cylinder, pressurizing the brake fluid. It flows through thin pipes, called brake lines, to pistons at each wheel. Those pistons apply pressure to the brake pads, and they squeeze against a disk or a drum to stop the car. If you were to have a catastrophic loss of brake fluid or if someone were to cut your brake lines, nothing would happen when you hit the brake pedal.
The first thing to do if you ever find yourself in the "no brakes!" situation is to try pumping the brakes. If your brake lines have a small leak (instead of a cut), you may be able to pump enough fluid into the system to get things under control.
The next thing is to try the emergency brake -- this is definitely an emergency! If someone cut your brake lines, he or she was probably smart enough to cut the cable for the emergency brake as well, so let's say that you find that the emergency break is out of commission too.

Thinking Strategically
Now you officially have a problem. The next thing to try is the transmission. You can downshift a gear at a time and use the engine for braking. Lots of people do this with their manual transmission as a matter of habit. It works just as well with an automatic transmission. Drop to a lower gear, wait for your speed to decrease and then drop down another gear. If there's a grassy median, you can drive onto it to aid the process. The surface of the grass and the uneven ground will provide a little resistance to help slow the car.
If you're doing all this and it looks like you're going to run into something before you get the car stopped, then think strategically. Given a choice between running into something solid -- the massive concrete post of a bridge -- and something that will give way -- a chain link fence -- choose the object that will give way. If you can scrub off speed by edging the side of the car against a wall or a guardrail, that's a good idea. Or, if you can drive up a rising embankment, that will also help.
In other words, if you have time to save the car by using something nondestructive like the transmission or an embankment, use it. If you can't save the car, then save yourself. Do whatever you can to avoid injury to yourself by running into something "soft" or scrubbing off the speed. And if that fails, then relax and hope your airbag is in good shape!

How Patriot Missiles Work

The Patriot missile system has a remarkable goal:

It is designed to detect, target and then hit an incoming missile that may be no more than 10 to 20 feet (3 to 6 meters) long and is typically flying at three to five times the speed of sound. The upgraded Patriot system can also destroy incoming aircraft and cruise missiles.

The Patriot missile system has been in the news recently for two different reasons:
It is able to shoot down enemy missiles like Iraqi Scud missiles and protect soldiers and civilians from a missile attack. Patriot missile batteries have been activated several times in the current war, and were used extensively in the 1991 Gulf war.

It has shot down one British aircraft and targeted an American F-16. The F-16 fired a missile that destroyed the Patriot missile radar.

How Telephones Work

Although most of us take it completely for granted, the telephone you have in your house is one of the most amazing devices ever created.
If you want to talk to someone, all you have to do is pick up the phone and dial a few digits. You are instantly connected to that person, and you can have a two-way conversation. The telephone network extends worldwide, so you can reach nearly anyone on the planet.
When you compare that to the state of the world just 100 years ago, when it might have taken several weeks to get a one-way written message to someone, you realize just how amazing the telephone is!

HOW ABS System WORKS

The theory behind anti-lock brakes is simple. A skidding wheel (where the tire contact patch is sliding relative to the road) has less traction than a non-skidding wheel. If you have been stuck on ice, you know that if your wheels are spinning you have no traction. This is because the contact patch is sliding relative to the ice (see Brakes: How Friction Works for more). By keeping the wheels from skidding while you slow down, anti-lock brakes benefit you in two ways: You'll stop faster, and you'll be able to steer while you stop.

There are four main components to an ABS system:
Speed sensors

Pump

Valves

Controller

Speed Sensors

The anti-lock braking system needs some way of knowing when a wheel is about to lock up. The speed sensors, which are located at each wheel, or in some cases in the differential, provide this information.

Valves

There is a valve in the brake line of each brake controlled by the ABS. On some systems, the valve has three positions:
In position one, the valve is open; pressure from the master cylinder is passed right through to the brake. In position two, the valve blocks the line, isolating that brake from the master cylinder. This prevents the pressure from rising further should the driver push the brake pedal harder.I

n position three, the valve releases some of the pressure from the brake.

Pump

Since the valve is able to release pressure from the brakes, there has to be some way to put that pressure back. That is what the pump does; when a valve reduces the pressure in a line, the pump is there to get the pressure back up.

Controller

The controller is a computer in the car. It watches the speed sensors and controls the valves.

ABS at Work

There are many different variations and control algorithms for ABS systems. We will discuss how one of the simpler systems works.
The controller monitors the speed sensors at all times. It is looking for decelerations in the wheel that are out of the ordinary. Right before a wheel locks up, it will experience a rapid deceleration. If left unchecked, the wheel would stop much more quickly than any car could. It might take a car five seconds to stop from 60 mph (96.6 kph) under ideal conditions, but a wheel that locks up could stop spinning in less than a second.
The ABS controller knows that such a rapid deceleration is impossible, so it reduces the pressure to that brake until it sees an acceleration, then it increases the pressure until it sees the deceleration again. It can do this very quickly, before the tire can actually significantly change speed. The result is that the tire slows down at the same rate as the car, with the brakes keeping the tires very near the point at which they will start to lock up. This gives the system maximum braking power.
When the ABS system is in operation you will feel a pulsing in the brake pedal; this comes from the rapid opening and closing of the valves. Some ABS systems can cycle up to 15 times per second.

How do the engines breathe in diesel submarines?

A diesel submarine is a very good example of a hybrid vehicle. Most diesel subs have two or more diesel engines. The diesels can run propellers or they can run generators that recharge a very large battery bank. They can also work in combination, one engine driving a propeller and the other driving a generator.

The sub must surface (or cruise just below the surface using a snorkel) to run the diesel engines. Once the batteries are fully charged, the sub can head underwater. The batteries power electric motors that drive the propellers. Battery operation is the only way a diesel sub can actually submerge.

The limits of battery technology severely constrain the amount of time a diesel sub can stay underwater. This is the huge benefit of using nuclear power in a sub. Nuclear generators need no oxygen, so a nuclear sub can stay underwater for weeks at a time.

How Lock Picking Works

Most people carry five to 10 keys with them whenever they go out. On your key ring you mighthave several keys for the house, one or two more for the car and a few for the office or a friend's house. Your key ring is a clear demonstration of just how ubiquitous lock technology is: You probably interact with locks dozens of times every week.
The main reason we use locks everywhere is that they provide us with a sense of security. But in movies and on television, spies, detectives and burglars can open a lock very easily,sometimes using only a couple of paper clips. This is a sobering thought, to say the least: Is it really possible for someone to open a lock so easily?
In this article, we'll look at the very real practice of lock picking, exploring the fascinating technology of locks and keys in the process
Keys are one of the most basic and essential machines we use every day.

Master Keys

Master keys are an interesting technology somewhat related to lock picking (because they're means of getting past locks without the main key). Some locks are designed to work with two different keys. The change key will open only that specific lock, while the master key will open that lock and several others in a group. In these locks, a few of the pin pairs are separated by a third pin called a master wafer or spacer.
When three pins are combined in a shaft, there are two ways to position the pins so theyopen the lock. The change key might raise the pins so that the shear line is just above the top of the master wafer, while the master key would raise the pins so the shear line is at the bottom of the master wafer. In both cases, there is a gap at the shear line and the key is able to turn.
In this lock design, the lowest pin would be the same length in each lock in the group, but the master wafer would vary in length. This lets one person, say a building manager, access many different locks, while each individual key-holder can open only his or her own lock.

Right Key and Wrong Key
As we saw in the last section, a basic cylinder lock is like a puzzle that the correct key can solve very easily. Here's how it works: When you insert a key, the series of notches in the key push the pin pairs up to different levels. The incorrect key will push the pins so that most of the top pins are still partly in the plug and partly in the housing, like this.