What is a Machine? – An Essential Guide

Machines, from simple ones to advanced artificial Intelligence, have profoundly shaped humanity and increased our abilities and changed our world. What is a machine, anyway?

This guide will explain the concept of a machine, describe the evolution of machines, how machines work, different types of machines, and examine how society is affected by it.

What is A Machine?

A machine is a physical system that uses power to apply an input force and control movement to make a specific move. Machines are indicative of artificial devices (typically human-made) using engines or motors, and the definition could even be extended to natural biological macromolecules used to describe molecular machines in our body.

A machine is capable of accomplishing some work or are a device having a specific, unique purpose, which augments or replaces human or animal effort in accomplishing physical tasks. Machines can be very simple, like an inclined plane, lever, wedge, wheel and axle, screw, and pulley – these are generally referred to as simple machines. Machines can also be very complicated mechanical systems, like a modern automobile. 

More specifically, the purpose of a machine is to:

• Importantly, machines do not create energy, they only transform or transmit it: In an ideal machine, the output energy is equal to the input energy, but is always reduced even in the most ideal case by friction and other forms of energy loss or waste, usually as heat or sound.
• Change the magnitude of a force: A small effort creates a larger force (a car jack lifting a heavy car).
• Change the direction of a force: An effort is redirected to create a desired move (like with a pulley system, redirecting a pull to lift an object).
• Change the speed or distance of force: Substitute force for speed (for example, bicycle gears let you go faster while using less force, or go faster while using more force).
• Transfer the force from one place to another: Force is passed over a distance, (for example, a bicycle chain transfers power from pedals to rear wheel).
• Transform energy from one form to another: Chemical energy to mechanical energy (for example, an internal combustion engine) or electrical energy to mechanical energy (for example, an electric motor).

The History Of Machines

The history of machines is certainly as long as the history of human ingenuity, if not longer. Even before we had written records, humans were using simple, primitive devices to enhance their strength and capabilities.

Antiquity:

The term simple machines dates back to ancient societies. For instance, around the 3rd century BCE the Greeks engaged in formal studies of levers, pulleys, screws, and other simple machines including their mechanical advantages.

The hand axe (made by chipping flint into a wedge), is arguably one of the first devices humans made to manage their own power.

In addition to these simple machines, some of the earliest complex machines included water-powered grain mills, forges, or sawmills as other examples.

The Renaissance:

The study of the “Mechanical Powers” (or simple machines) moved from understanding the simple mechanics of them to understanding how much valuable work or useful work they could perform.

Galileo Galilei, in 1600, was the first to recognize that simple machines do not create energy but only convert it. Leonardo da Vinci also wrote down principles of friction, but it did not get published for centuries!

The Industrial Revolution (1750-1850):

This time period represented a large shift. Steam engines became the workhorse of human and animal power, running factory machinery and transforming all modes of transportation (locomotive, ships).

There were numerous inventions in the early 19th century (sewing machine, for example) that decreased manual labor, and allowed production to be faster and better.

The factory system was established, with machines operating at the core. The internal combustion engine and the electric motor revolutionized industries and everyone’s life!

20th Century and Beyond:

The shift to much smaller, and much more efficient motors, combined with mass production and automation tremendously raised the standard of living in industrial nations.

Then, in the mid-20th century, computers changed machines from merely physical labor sites into information processing systems. Today, machines are still changing, and at an extraordinary pace, fueled by technology and AI.

How Do machines work?

The most basic definition of how machines work consists of the idea of work, which in physics is defined as force times distance (W=F×d). Machines do not change the total amount of work to do, but rather alters the force and distance being applied to accomplish the work.

Mechanical Advantage: This idea is most important. A machine imparts a mechanical advantage when it allows a smaller input force to induce a larger output force. You can increase advantage by using an input force over distance and while also making the output force act over a smaller distance. An example would be a longer lever arm to apply less force over a greater distance to lift a heavier object but only a very short distance!

• Ideal Mechanical Advantage (IMA): In a system without friction (ideal situations) IMA=distance over which input force applied/distance over which output force applied.
• Actual Mechanical Advantage (AMA): In most real-world situations you will have friction to account for (similar to a real-world situation) AMA would then be equal to: output force/input force. AMA will almost always be less than IMA.

Efficiency: All real machines will have friction that lose parts of the input energy to a lost heat, an energy loss. When we think of machine efficiency we are looking at output power (work output per time) to input power. A “perfect” or 100% efficient machine would essentially be an “ideal machine.” The critical piece here is that all machines strive to operate at the best efficiency they can but no machine can escape reality so there isn’t an “ideal machine” reality.

Energy Transformation: Machines are purpose-built for the intent to convert one form of energy to another form, for example, an electric motor converts electrical energy to mechanical energy; a generator converts mechanical energy to electrical energy.

Mechanism of a machine

Just reading the definition of machine tells you that in any machine the forces and motions are transmitted and changed. The way the components of a machine to connect and guide the input motion through to an output motion you want is the mechanism of that machine.

The piston, connecting rod, and crankshaft make up a system for changing the linear motion of the piston into the rotary motion of the crankshaft in a reciprocating engine.

While force and motion are always involved while machines are working, the main function of a machine may be either the amplification of force or the modification of motion.

A lever is a force amplifier while a gearbox is predominantly a motion modifer, specifically a speed reducer. It should be noted that motion and force are inseparable, and always present in an inverse ratio.

While the output force on a lever is greater than the input force, the output motion is less than the input motion.

Similarly, in the case of a gear reducer, the output speed is less than the input speed, but the output torque is greater than the input torque. In the first example there is obviously a gain in force with a loss in motion, where-as in the second example there is a loss in motion with a gain in torque.

While we can identify the primary function of some machines, it would be unreasonable to classify all machines as either force or motion units; some machines perform both function.

However, all machines must have some motion modifying role because if the parts of a mechanical device do not move then it is a structure and not a machine.

Types of machines

Ultimately, there are many kinds of machine from the simple to the complex. They can be divided into three groups:

1. Simple Machines

Simple machines are simple devices from which more complex machines are constructed, and they typically have one or very few moving parts.

They do not use electricity or complicated power sources, and simple machines do not reduce or increase a force, they simply change the magnitude, direction, or speed of it.

The six classic simple machines are:

• Lever: A bar that pivots on a fixed point called a fulcrum. Seesaws, crowbars, and bottle openers are examples of levers.
• Wheel and Axle: A wheel turns with a smaller rod, or axle, a component such as a bicycle, doorknob or wheel of a car helps to rotate it.
• Pulley: A wheel that has a grooved rim that rope or cable can pass over. Pulleys can be used to change the direction of a force or multiply the force used to lift heavier weight, and examples include flagpoles and blinds under a window.
• Inclined Plane: A flat surface that is tilted so that items can be moved to a higher or lower elevation using less force or effort. Ramps and stairs are examples of inclined planes.
• Wedge: Two inclined planes placed back to back designed to split, cut, or hold an object. Knives, axes, and doorstops are wedges.
• Screw: An inclined plane wrapped around a cylinder. Screws are used to hold two objects together or for lifting an object. Wood screws, bottle caps, and car jacks are screws.

2. Compound Machines

Compound machines are two or more simple machines working together at the same time to do more complex work. Many compound machines still require human power Examples include:

• Bicycle: Head of wheels and axles, levers, which are (pedals, handlebars), and pulleys, (chain, and gears).
• Wheelbarrow: Has a lever, (the handle) and a wheel and axle.
• Scissors: composed of 2 levers with wedge shaped blades.
• Manual Pencil Sharpener: Uses a wedge, (the blade) and a screw mechanism.

3. Complex Machines

These are advanced systems made with sometimes many simple and compound machines and usually, use an external power source, (electricity, fuel, hydraulic power), to accomplish complex or often automatically task.

These machines are used on a larger scale, designed for efficiency and precision. Some examples are:

• Automobiles: [Vehicles] which are made up of many mechanical and electrical components, including engines, transmissions, steering systems, braking systems, Etc.
• Construction Cranes: use levers, pulleys, and large hydraulic systems to move heavy loads.
• Washing Machines: use motors, gears, pumps, and mechanisms to wash clothes.
• Computers: might be commonly thought of as an information processor, however, the hardware is an extraordinary complex assembly of mechanical and electrical engineering.
• Robots: highly sophisticated machines that use mechanical systems, sensors, actuators, and frequently artificial intelligence to operate independently or semi-autonomously.

Advantages of Machines:

• Increased Efficiency and Productivity: Machines allow tasks to be done in a more efficient, accurate, and larger scale and volume than human labor could ever accomplish. thus resulting in more goods/services and in many cases a lower cost to produce them.
• Lowest Human Effort and Labor: Machines mechanize physically intense, repetitive, or dangerous tasks, liberating human workers from physically demanding or dangerous tasks. Using machines has vastly improved working conditions thus reducing occupational injuries.Benefits of Machines:
• Improved Quality and Consistency: Machines often perform jobs with a precision that is unmatched by humans, leading to higher quality and better products and services.
• Economic Growth and Innovation: The research, development, and use of machines creates innovation, whole industries, and improved economic growth. This further services the ability to conduct research and development that leads to new technology.
• Better Skillsets: The use of machines allows for the performance of tasks that previously could not be performed, for example, deep space exploration, complex surgeries, or processing massive datasets.
• Convenience and Quality of Life: Both household appliances or air travel, machines make life convenient and comfortable for billions of people.

Disadvantages of Machines

• Job Displacement: Increased efficiency via automation leads to loss of jobs in trades and industries where machines now perform tasks instead of humans, which engenders unemployment, and necessitates re-training of workers.
• Dependence on Technology: If we depend upon machines too much to do our thinking and problem-solving, we may lose the ability to perform manual tasks in the event of technology failure, and it may impact our critical thinking for problem-solving.
• Health Issues: Prolonged use of certain machines (or the sedentary lifestyle enabled by automation) may also contribute to health-related issues such as obesity, vision problems, and stress.
• Environmental Concerns: Machines carry a heavy environmental burden when manufacturing machines, utilizing machines and disposing of machines. This burden includes depletion of natural resources, pollutants from all aspects of their use, and energy produced from fossil or other fuels.Breakdowns and malfunctions: Machines can stop working, causing delays and financial loss, and in certain situations, cause peril.
• Ethical and societal issues: Machines are becoming more intelligent and autonomous (especially involving AI), and this raises ethical issues with decision-making, accountability, privacy, and the concern that machines will be beyond human oversight.

The Future of Machines and AI

The future of machines is inextricably tied to the development of, and future of, Artificial Intelligence (AI), as well as robotics and machine learning. We are on the precipice of entry into a new era in which machines will not only function as tools, but increasingly intelligent and autonomous partners.

Some trends and predictions regarding machines include:

• Increased Automation and Autonomy: Machines will work more independently and perform even more complex work across many fields of industry, such as self-driving cars, automated factories, automated homes, and autonomous drones.
• Increased AI and machine learning capabilities: AI and ML will make machines far more intelligent by allowing them to be capable of analyzing data, continue to learn, developing models of decision making capabilities. In addition to further developing the next generation of intelligent machines, fields including natural language processing, computer vision, and predictive capabilities will continue to evolve.
• Advances in robotics: Robots will become far more dexterous, collaborative, and versatile (“cobots”), enabling them to further work in tandem with humans across many domains, such as manufacturing, healthcare, and logistics.
• Expansion of the Internet of Things (IoT): Machines and devices can, and will, interconnect so that some of the data generated can be more useful. IoT can be viewed as one facet of machines networking together to create vast networks of systems that are eventually generating vast networks of data together.
• Personalized services on demand and predictive capabilities: Machines will become increasingly powered by AI and are likely to offer hyper-personalized experiences that are more able to anticipate every individual’s personalized experiences (needs/wants/choices) in sectors including consumer services, health care, entertainment, etc.
• Ethical AI and regulation: As machines become more and more intelligent, so too will the push to focus on ethical considerations and transparency (Explainable AI – XAI), and the development of regulatory frameworks to ensure the development and deployment of increasingly intelligent machines for good.
• Continuing human-machine partnership: Again, this isn’t just a narrative about machines replacing humans, it is intended to create keen awareness of “what machines are” and how machines can increasingly augment human capability so that we can do more together.

Conclusion

The machine directly relates to the history of humanity; from a simple tool to an intelligent, powerful system. Machines are first and foremost devices that use power to do work, such that they are built to amplify human capacities and operate in the mental, physical, and social world.

Machines have provided humans incredible benefits in ways that we never could have imagined at the outset of machines’ inception in terms of increasing productivity, low costs, increasing quality of life, etc.

At the same time while utilising machines as a society for significant advancements, challenges have emerged that are unavoidable and we must navigate responsibly.

As we advance closer to the age of significantly more advanced AI and robotics situations, the pragmatic notion of “What is a Machine?” is becoming an increasingly emergent inquiry into a consideration of how we understand a ‘machine’ not only as a definition but also as an ongoing inquiry on how the future of the human-machine experience can positively contribute constructively to human well-being like we all are designed to continue so that we don’t lose our shared humanity in the process.

FAQs