ratio of word probabilities predicted from brain for key and hammer

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key

hammer

top 10 words in brain distribution (in article):
blade head cut metal design shape century edge modern type top 10 words in brain distribution (in article):
design steel size head cut animal allow tool common shape

top 10 words in brain distribution (not in article):
iron steel handle hair tool nail whip breast hammer size top 10 words in brain distribution (not in article):
key lock switch machine type needle tube bicycle blade knit

times more probable under key 30 20 10 6 4 2.5 1.25 1 1.25 2.5 4 6 10 20 30 times more probable under hammer
(words not in the model)

A key'" is a device which is used to open a lock. A typical key consist of two parts: the "blade", which slides into the keyway of the lock and distinguishes between different keys, and the "bow", which is left protruding so that torque can be applied by the user. The blade is usually designed to open one specific lock, although master keys are designed to open sets of similar locks. Keys provide an inexpensive, though imperfect, method of authentication for access to properties like buildings and vehicles. As such, keys are an essential feature of modern living in the developed world, aing adorned by key fobs and known as a keychain. House keys. A house key'" is the most common sort of key. There are two main forms. The older form is for lever locks, where a pack of flat levers (typically between two and five) are raised to different heights by the key whereupon the slots or "'gates'" of the levers line up and permit a bolt to move back and forth, opening or closing the lock. The teeth or "'bittings'" of the key have flat tops rather than being pointed. Lever lock keys tend to be bigger and less convenient for carrying, although lever locks tend to be more secure. These are still common in, for example, many European countries. The more recent form is that for a pin tumbler cylinder lock. When held upright as if to open a door, a series of grooves on either side of the key (the key's "'profile'") limits the type of lock cylinder the key can slide into. As the key slides into the lock, a series of pointed teeth and notches allow pins to move up and down until those pins are in line with the shear line of the cylinder, allowing that cylinder to rotate freely inside the lock and the lock to open. These predominate in, for example, the United States of America. Car key. A "'car key'" or an "'automobile key'" is a key used to open and or start an automobile, often identified with the logo of the car company at the head. Modern key designs are usually symmetrical, and some use grooves on both sides, rather than a cut edge, to actuate the lock. It has multiple uses for the automobile with which it was sold. A car key can open the doors, as well as start the ignition, open the glove compartment and also open the trunk (boot) of the car. Some cars come with an additional key known as a "'valet key'" that starts the ignition and opens the drivers side door but prevents the valet from gaining access to valuables that are located in the trunk or the glove box. Some valet keys, particularly those to high-performance vehicles, go so far as to restrict the engine's power output to prevent joyriding. Recently, features such as coded immobilizers have been implemented in newer vehicles. More sophisticated systems make ignition dependent on electronic devices, rather than the mechanical keyswitch. Ignition switches locks are combined with security locking of the steering column (in many modern vehicles) or the gear lever (Saab Automobile). In the latter, the switch is between the seats, preventing damage to the driver's knee in the event of a collision. Keyless entry systems, which utilize either a door-mounted keypad or a remote control in place of a car key, are becoming a standard feature on many new cars. Some of them are handsfree. Some keys are high-tech in order to prevent the theft of a car. Mercedes-Benz uses a key that, rather than have a cut metal piece to start the car, uses an encoded infrared beam that communicates with the car's computer. If the codes match, the car can be started. These keys can be expensive to replace, if lost, and can cost up to US$400. Some car manufacturers like Land Rover and Volkswagen use a 'switchblade' key where the key is spring-loaded out of the fob when a button is pressed. This eliminates the need for a separate key fob. This type of key has also been known to be confiscated by airport security officials. Master key. A "'master key'" is intended to open a set of several locks. Usually, there is nothing special about the key itself, but rather the locks into which it will fit. These locks also have keys which are specific to each one (the "'change key'") and cannot open any of the others in the set. Locks which have master keys have a second set of the mechanism used to open them which is identical to all of the others in the set of locks. For example, master keyed pin tumbler locks will have two shear points at each pin position, one for the change key and one for the master key. A far more secure (and more expensive) system has two cylinders in each lock, one for the change key and one for the master key. Larger organizations, with more complex "grandmaster key" systems, may have several masterkey systems where the top level grandmaster key works in all of the locks in the system. A practical attack exists to create a working master key for an entire system given only access to a single master-keyed lock, its associated change key, a supply of appropriate key blanks, and the ability to cut new keys. This is described in Locksmiths may also determine cuts for a replacement master key, when given several different key examples from a given system. Control key. A "'control key'" is a special key used in removable core locking systems. The control key enables a user with very little skill to remove from the cylinder, quickly and easily, a core with a specific combination and replace it with a core with a different combination. In Small Format Interchangeable Cores (SFIC), similar to those developed by Frank Best of the Best Lock Corporation, the key operates a separate shear line, located above the operating key shear line. In Large Format Removable Cores, the key may operate a separate shear line or the key may work like a master key along the operating shear line and also contact a separate locking pin that holds the core in the cylinder. SFIC's are interchangeable from one brand to another, while LFRC's are not. Double-sided key. A "'double-sided key'" is very similar to a house or car key with the exception that it has two sets of teeth, an upper level standard set of teeth and a lower, less defined set of teeth beside it. This makes the double-sided key's profile and its corresponding lock look very similar to a standard key while making the attempt to pick the lock more difficult. As the name implies, this type of key has four sides, making it not only harder to duplicate and the lock harder to pick, but it is also physically more durable. Paracentric key. A "'paracentric key'" is designed to open a paracentric lock. A hammer'" is a tool meant to deliver an impact to an object. The most common uses are for driving nails, fitting parts, and breaking up objects. Hammers are often designed for a specific purpose, and vary widely in their shape and structure. Usual features are a handle and a head, with most of the weight in the head. The basic design is hand-operated, but there are also many mechanically operated models for heavier uses. The hammer is a basic tool of many professions, and can also be used as a weapon. By analogy, the name "'hammer'" has also been used for devices that are designed to deliver blows, e.g. in the caplock mechanism of firearms. History. The use of simple tools dates to about 2,400,000 BCE when various shaped stones were used to strike wood, bone, or other stones to break them apart and shape them. Stones attached to sticks with strips of leather or animal sinew were being used as hammers by about 30,000 BCE during the middle of the Paleolithic Stone Age. Its archeological record means it is perhaps the oldest human tool known. Designs and variations. The essential part of a hammer is the head, a compact solid mass that is able to deliver the blow to the intended target without itself deforming. The opposite side of a ball as in the ball-peen hammer and the cow hammer. Some upholstery hammers have a magnetized appendage, to pick up tacks. In the hatchet the hammer head is secondary to the cutting edge of the tool. In recent years the handles have been made of durable plastic or rubber. The hammer varies at the top, some are larger than others giving a larger surface area to hit different sized nails and such, Mechanically-powered hammers often look quite different from the hand tools, but nevertheless most of them work on the same principle. They include: In professional framing carpentry, the hammer has almost been completely replaced by the nail gun. In professional upholstery, its chief competitor is the staple gun. Hammer as a force amplifier. A hammer is basically a force amplifier that works by converting mechanical work into kinetic energy and back. In the swing that precedes each blow, a certain amount of kinetic energy gets stored in the hammer's head, equal to the length "D" of the swing times the force "f" produced by the muscles of the arm and by gravity. When the hammer strikes, the head gets stopped by an opposite force coming from the target; which is equal and opposite to the force applied by the head to the target. If the target is a hard and heavy object, or if it is resting on some sort of anvil, the head can travel only a very short distance "d" before stopping. Since the stopping force "F" times that distance must be equal to the head's kinetic energy, it follows that "F" will be much greater than the original driving force "f" — roughly, by a factor "D" "d". In this way, great strength is not needed to produce a force strong enough to bend steel, or crack the hardest stone. Effect of the head's mass. The amount of energy delivered to the target by the hammer-blow is equivalent to one half the mass of the head times the square of the head's speed at the time of impact ([Formula 1]). While the energy delivered to the target increases linearly with mass, it increases geometrically with the speed (see the effect of the handle, below). High tech titanium heads are lighter and allow for longer handles, thus increasing velocity and delivering more energy with less arm fatigue than that of a steel head hammer of the same weight. As hammers must be used in many circumstances, where the position of the person using them cannot be taken for granted, trade-offs are made for the sake of practicality. In areas where one has plenty of room, a long handle with a heavy head (like a sledge hammer) can deliver the maximum amount of energy to the target. But clearly, it's unreasonable to use a sledge hammer to drive upholstery tacks. Thus, the overall design has been modified repeatedly to achieve the optimum utility in a wide variety of situations. Effect of the handle. The handle of the hammer helps in several ways. It keeps the user's hands away from the point of impact. It provides a broad area that is better-suited for gripping by the hand. Most importantly, it allows the user to maximize the speed of the head on each blow. The primary constraint on additional handle length is the lack of space in which to swing the hammer. This is why sledge hammers, largely used in open spaces, can have handles that are much longer than a standard carpenter's hammer. The second most important constraint is more subtle. Even without considering the effects of fatigue, the longer the handle, the harder it is to guide the head of the hammer to its target at full speed. Most designs are a compromise between practicality and energy efficiency. Too long a handle: the hammer is inefficient because it delivers force to the wrong place, off-target. Too short a handle: the hammer is inefficient because it doesn't deliver enough force, requiring more blows to complete a given task. Recently, modifications have also been made with respect to the effect of the hammer on the user. A titanium head has about 3% recoil and can result in greater efficiency and less fatigue when compared to a steel head with about 27% recoil. Handles made of shock-absorbing materials or varying angles attempt to make it easier for the user to continue to wield this age-old device, even as nail guns and other powered drivers encroach on its traditional field of use. War hammers. The concept of putting a handle on a weight to make it more convenient to use may well have led to the very first weapons ever invented. The club is basically a variant of a hammer. In the Middle Ages, the war hammer became popular when edged weapons could no longer easily penetrate some forms of armour. Symbolic hammers. The hammer, being one of the most used tools by "Homo sapiens", has been used very much in symbols and arms. In the Middle Ages it was used often in blacksmith guild logos, as well as in many family symbols. The most recognised symbol with a hammer in it is the Hammer and Sickle, which was the symbol of the former Soviet Union. The hammer in this symbol represents the industrial working class (and the sickle the agricultural working class). The hammer is used in some coat of arms in (former) socialist countries like East Germany. In Norse Mythology, Thor, the god of thunder and lightning, wields a hammer named Mjolnir. Many artifacts of decorative hammers have been found leading many modern practitioners of this religion to often wear reproductions as a sign of their faith.

key	hammer
top 10 words in brain distribution (in article): blade head cut metal design shape century edge modern type	top 10 words in brain distribution (in article): design steel size head cut animal allow tool common shape
top 10 words in brain distribution (not in article): iron steel handle hair tool nail whip breast hammer size	top 10 words in brain distribution (not in article): key lock switch machine type needle tube bicycle blade knit
times more probable under key 30 20 10 6 4 2.5 1.25 1 1.25 2.5 4 6 10 20 30 times more probable under hammer (words not in the model)
A key'" is a device which is used to open a lock. A typical key consist of two parts: the "blade", which slides into the keyway of the lock and distinguishes between different keys, and the "bow", which is left protruding so that torque can be applied by the user. The blade is usually designed to open one specific lock, although master keys are designed to open sets of similar locks. Keys provide an inexpensive, though imperfect, method of authentication for access to properties like buildings and vehicles. As such, keys are an essential feature of modern living in the developed world, aing adorned by key fobs and known as a keychain. House keys. A house key'" is the most common sort of key. There are two main forms. The older form is for lever locks, where a pack of flat levers (typically between two and five) are raised to different heights by the key whereupon the slots or "'gates'" of the levers line up and permit a bolt to move back and forth, opening or closing the lock. The teeth or "'bittings'" of the key have flat tops rather than being pointed. Lever lock keys tend to be bigger and less convenient for carrying, although lever locks tend to be more secure. These are still common in, for example, many European countries. The more recent form is that for a pin tumbler cylinder lock. When held upright as if to open a door, a series of grooves on either side of the key (the key's "'profile'") limits the type of lock cylinder the key can slide into. As the key slides into the lock, a series of pointed teeth and notches allow pins to move up and down until those pins are in line with the shear line of the cylinder, allowing that cylinder to rotate freely inside the lock and the lock to open. These predominate in, for example, the United States of America. Car key. A "'car key'" or an "'automobile key'" is a key used to open and or start an automobile, often identified with the logo of the car company at the head. Modern key designs are usually symmetrical, and some use grooves on both sides, rather than a cut edge, to actuate the lock. It has multiple uses for the automobile with which it was sold. A car key can open the doors, as well as start the ignition, open the glove compartment and also open the trunk (boot) of the car. Some cars come with an additional key known as a "'valet key'" that starts the ignition and opens the drivers side door but prevents the valet from gaining access to valuables that are located in the trunk or the glove box. Some valet keys, particularly those to high-performance vehicles, go so far as to restrict the engine's power output to prevent joyriding. Recently, features such as coded immobilizers have been implemented in newer vehicles. More sophisticated systems make ignition dependent on electronic devices, rather than the mechanical keyswitch. Ignition switches locks are combined with security locking of the steering column (in many modern vehicles) or the gear lever (Saab Automobile). In the latter, the switch is between the seats, preventing damage to the driver's knee in the event of a collision. Keyless entry systems, which utilize either a door-mounted keypad or a remote control in place of a car key, are becoming a standard feature on many new cars. Some of them are handsfree. Some keys are high-tech in order to prevent the theft of a car. Mercedes-Benz uses a key that, rather than have a cut metal piece to start the car, uses an encoded infrared beam that communicates with the car's computer. If the codes match, the car can be started. These keys can be expensive to replace, if lost, and can cost up to US$400. Some car manufacturers like Land Rover and Volkswagen use a 'switchblade' key where the key is spring-loaded out of the fob when a button is pressed. This eliminates the need for a separate key fob. This type of key has also been known to be confiscated by airport security officials. Master key. A "'master key'" is intended to open a set of several locks. Usually, there is nothing special about the key itself, but rather the locks into which it will fit. These locks also have keys which are specific to each one (the "'change key'") and cannot open any of the others in the set. Locks which have master keys have a second set of the mechanism used to open them which is identical to all of the others in the set of locks. For example, master keyed pin tumbler locks will have two shear points at each pin position, one for the change key and one for the master key. A far more secure (and more expensive) system has two cylinders in each lock, one for the change key and one for the master key. Larger organizations, with more complex "grandmaster key" systems, may have several masterkey systems where the top level grandmaster key works in all of the locks in the system. A practical attack exists to create a working master key for an entire system given only access to a single master-keyed lock, its associated change key, a supply of appropriate key blanks, and the ability to cut new keys. This is described in Locksmiths may also determine cuts for a replacement master key, when given several different key examples from a given system. Control key. A "'control key'" is a special key used in removable core locking systems. The control key enables a user with very little skill to remove from the cylinder, quickly and easily, a core with a specific combination and replace it with a core with a different combination. In Small Format Interchangeable Cores (SFIC), similar to those developed by Frank Best of the Best Lock Corporation, the key operates a separate shear line, located above the operating key shear line. In Large Format Removable Cores, the key may operate a separate shear line or the key may work like a master key along the operating shear line and also contact a separate locking pin that holds the core in the cylinder. SFIC's are interchangeable from one brand to another, while LFRC's are not. Double-sided key. A "'double-sided key'" is very similar to a house or car key with the exception that it has two sets of teeth, an upper level standard set of teeth and a lower, less defined set of teeth beside it. This makes the double-sided key's profile and its corresponding lock look very similar to a standard key while making the attempt to pick the lock more difficult. As the name implies, this type of key has four sides, making it not only harder to duplicate and the lock harder to pick, but it is also physically more durable. Paracentric key. A "'paracentric key'" is designed to open a paracentric lock.	A hammer'" is a tool meant to deliver an impact to an object. The most common uses are for driving nails, fitting parts, and breaking up objects. Hammers are often designed for a specific purpose, and vary widely in their shape and structure. Usual features are a handle and a head, with most of the weight in the head. The basic design is hand-operated, but there are also many mechanically operated models for heavier uses. The hammer is a basic tool of many professions, and can also be used as a weapon. By analogy, the name "'hammer'" has also been used for devices that are designed to deliver blows, e.g. in the caplock mechanism of firearms. History. The use of simple tools dates to about 2,400,000 BCE when various shaped stones were used to strike wood, bone, or other stones to break them apart and shape them. Stones attached to sticks with strips of leather or animal sinew were being used as hammers by about 30,000 BCE during the middle of the Paleolithic Stone Age. Its archeological record means it is perhaps the oldest human tool known. Designs and variations. The essential part of a hammer is the head, a compact solid mass that is able to deliver the blow to the intended target without itself deforming. The opposite side of a ball as in the ball-peen hammer and the cow hammer. Some upholstery hammers have a magnetized appendage, to pick up tacks. In the hatchet the hammer head is secondary to the cutting edge of the tool. In recent years the handles have been made of durable plastic or rubber. The hammer varies at the top, some are larger than others giving a larger surface area to hit different sized nails and such, Mechanically-powered hammers often look quite different from the hand tools, but nevertheless most of them work on the same principle. They include: In professional framing carpentry, the hammer has almost been completely replaced by the nail gun. In professional upholstery, its chief competitor is the staple gun. Hammer as a force amplifier. A hammer is basically a force amplifier that works by converting mechanical work into kinetic energy and back. In the swing that precedes each blow, a certain amount of kinetic energy gets stored in the hammer's head, equal to the length "D" of the swing times the force "f" produced by the muscles of the arm and by gravity. When the hammer strikes, the head gets stopped by an opposite force coming from the target; which is equal and opposite to the force applied by the head to the target. If the target is a hard and heavy object, or if it is resting on some sort of anvil, the head can travel only a very short distance "d" before stopping. Since the stopping force "F" times that distance must be equal to the head's kinetic energy, it follows that "F" will be much greater than the original driving force "f" — roughly, by a factor "D" "d". In this way, great strength is not needed to produce a force strong enough to bend steel, or crack the hardest stone. Effect of the head's mass. The amount of energy delivered to the target by the hammer-blow is equivalent to one half the mass of the head times the square of the head's speed at the time of impact ([Formula 1]). While the energy delivered to the target increases linearly with mass, it increases geometrically with the speed (see the effect of the handle, below). High tech titanium heads are lighter and allow for longer handles, thus increasing velocity and delivering more energy with less arm fatigue than that of a steel head hammer of the same weight. As hammers must be used in many circumstances, where the position of the person using them cannot be taken for granted, trade-offs are made for the sake of practicality. In areas where one has plenty of room, a long handle with a heavy head (like a sledge hammer) can deliver the maximum amount of energy to the target. But clearly, it's unreasonable to use a sledge hammer to drive upholstery tacks. Thus, the overall design has been modified repeatedly to achieve the optimum utility in a wide variety of situations. Effect of the handle. The handle of the hammer helps in several ways. It keeps the user's hands away from the point of impact. It provides a broad area that is better-suited for gripping by the hand. Most importantly, it allows the user to maximize the speed of the head on each blow. The primary constraint on additional handle length is the lack of space in which to swing the hammer. This is why sledge hammers, largely used in open spaces, can have handles that are much longer than a standard carpenter's hammer. The second most important constraint is more subtle. Even without considering the effects of fatigue, the longer the handle, the harder it is to guide the head of the hammer to its target at full speed. Most designs are a compromise between practicality and energy efficiency. Too long a handle: the hammer is inefficient because it delivers force to the wrong place, off-target. Too short a handle: the hammer is inefficient because it doesn't deliver enough force, requiring more blows to complete a given task. Recently, modifications have also been made with respect to the effect of the hammer on the user. A titanium head has about 3% recoil and can result in greater efficiency and less fatigue when compared to a steel head with about 27% recoil. Handles made of shock-absorbing materials or varying angles attempt to make it easier for the user to continue to wield this age-old device, even as nail guns and other powered drivers encroach on its traditional field of use. War hammers. The concept of putting a handle on a weight to make it more convenient to use may well have led to the very first weapons ever invented. The club is basically a variant of a hammer. In the Middle Ages, the war hammer became popular when edged weapons could no longer easily penetrate some forms of armour. Symbolic hammers. The hammer, being one of the most used tools by "Homo sapiens", has been used very much in symbols and arms. In the Middle Ages it was used often in blacksmith guild logos, as well as in many family symbols. The most recognised symbol with a hammer in it is the Hammer and Sickle, which was the symbol of the former Soviet Union. The hammer in this symbol represents the industrial working class (and the sickle the agricultural working class). The hammer is used in some coat of arms in (former) socialist countries like East Germany. In Norse Mythology, Thor, the god of thunder and lightning, wields a hammer named Mjolnir. Many artifacts of decorative hammers have been found leading many modern practitioners of this religion to often wear reproductions as a sign of their faith.