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Before the likes of Galileo and Newton began to unlock the secrets of the universe, our understanding of everything in it was almost entirely absent.
There was no scientifically plausible explanation for any of the phenomena in the night sky and no real understanding of any force of nature.
In short, we were the people in Game of Thrones but without the dragons and magic and zombies.
However, instead of spending thousands of years building large walls instead of inventing things, we have used the discipline of physics to provide answers to many of the mysteries of existence, and with that knowledge the human race has achieved incredible things.
From powering the industrial revolution to sparking the electrical era and unlocking the secrets of the stars, physics has underpinned our technological adventure into the 21st Century.
1. Newton’s laws of motion
Before Isaac Newton, our understanding of how objects moved in the universe came from the Ancient Greeks. Why do objects fall to earth? Aristotle thought it might be because objects longed to be united with the ground. And why do they slow down when you put them in motion? Because they get tired, naturally.
Newton’s infinitely more advanced laws of motion were first published in his legendary Principia in 1687, more than 2000 years after Artistotle’s death. In it, not only for the first time did he definitively describe the force of gravity governing the motion of celestial objects like comets, stars and planets, but also the behaviours of more important Earth-bound objects like warships, cannonballs, buildings and… pears.
2nd law: The acceleration of an object is directly proportional to, and in the same direction as, the net force acting on it, and inversely proportional to its mass. Thus, F = ma.
3rd law: When one object exerts a force on another, the second body simultaneously exerts a force equal in magnitude and opposite in direction to that of the first.
Newton’s three laws of motion ultimately stimulated the industrial revolution of the 18th and 19th Centuries. Machines now operated according to well defined and understood laws – steam locomotives, factories and machine tools were all conceived and designed using Newtonian science.
His mathematics was also instrumental in the construction of the first sky scrapers – the second law can be used to calculate all the forces acting on every square inch of every brick in your house. The third law, meanwhile, is key for understanding jet propulsion which is still our only means of getting into space.
2. Faraday’s Law
If gravity was the first force of the universe to be truly mastered, the second was something you’re using right now – the unified force of electricity and magnetism known as electromagnetism.
For millennia, humans had observed the magnificence and terror of lightning storms in cloudy skies. Ancient paranoid civilisations believed that angry, mean-spirited gods were responsible for lightning bolts, and it wasn’t until the 19th Century that we learned to harness this force down on the Earth.
His major contribution to modern civilisation was through what became known as Faraday’s Law – the discovery of induction. In essence, it’s the realisation that if you place a wire in a magnetic field and move it, the magnetic field will push the electrons in the wire to create an electric current. The electric motor was born on the spot, and electricity was mastered as a useable tool for the first time.
This transformation of electricity from a curiosity into a powerful new technology laid the foundations for the electrical revolution that followed, changing all facets of human life in the developed world. It enabled Nikola Tesla and others to play with early lightbulbs, unlocking the power of artificial light. It combined spectacularly with Newton’s physics to create hydro-electric power plants. It enabled the creation of every single electrical gadget that has ever been invented.
Telephony was one of the most immediate and transformative consequences of this era. It enabled long distance communication in the form of telegrams and later telephones, a technology that would go wireless thanks to James Clerk Maxwell’s electromagnetic waves…
3. Maxwell’s equations
Michael Faraday was never able to fully develop and complete his work with electricity and magnetism, so it was left up to James Clerk Maxwell in 1862 to make possibly the most important discovery in all of science.
Maxwell’s equations describe the relationship between electricity and magnetism in the language of mathematics. He pondered that they must be closely related phenomena, and then discoverd they could combine to create oscillating waves. He used pioneering science of the age to calculate the velocity of these waves and to everyone’s amazement, it was exactly the speed of light. He realised that this was no coincidence, that light itself is an oscillating electromagnetic wave.
This work laid the foundation for, among a million other things, a step change in medicinal diagnostics, enabling such incredible machines such as X-Rays and later PET scans and MRI machines. By understanding how electromagnetism worked, he was able to put it in the hands of those who followed.
4. Second law of thermodynamics
Also known as the law of entropy, and expressed first of all by the Frenchman Sadi Carnot in 1824, this is an area of physics most people know very well without even having to think about it. It hinges on the fact that over time, differences in temperature and other kinds of energy will always decrease to a state of thermodynamic equilibrium.
In other words, it’s why you get cold when you step out into the snow. This is a law that will eventually spell the heat death of the universe, and it’s one of the main reasons you put clothes on this morning.
Understanding the physics of these processes led to the invention of world-changing technologies such as refrigeration. Without refrigeration, we’d be without fresh food and organ transplants. The same principle governs the use of heatsinks to dissipate heat away from the hot microchips inside our computers. Mmmm microchips.
5. Atomic theory
Our understanding of the building blocks of matter – atoms – brought about the next technological age. The computer age.
Undoubtedly the most impactful invention from this science was the humble transistor in the early 20th Century. Without transistors, it is highly doubtful that we would have computers, smartphones or any electronic devices anything like what we see today.
Transistors are made from semi-conducting material and are used to control the movement of electrons through a circuit. The first electronic devices to use transistors were early radios – these first truly wireless communications systems communicated with each other using light waves with the longest wavelength in the electromagnetic spectrum – radio waves.
This transistor technology was very quickly adapted and used to replace primitive vacuum tubes in the first computers, drastically reducing the size, weight and crucially the expense of building them.
The first silicon transistor was later created in 1954 by Texas Instruments, setting in motion the computer age. Silicon was an ideal material because of its abundance in the universe as well as its semi-conducting properties. By packing lots of transistors onto one piece of silicon, computers were suddenly able to make huge numbers of calculations in no time at all.
Moore’s law relates to the prediction of Intel’s Gordon E Moore that the number of transistors on integrated circuits of a certain size would double every two years – effectively doubling computation power. Intel’s current-generation Haswell computer chips use transistors that are just 22nm across – far smaller than the width of a human hair – enabling cheaper production, more and faster simultaneous calculations and better operating efficiency.
Moore’s law will eventually fail – transistors will be so small that they become affected by the bizarre reality of the quantum world and will thus will have reached their optimal size.
6. Quantum theory
Quantum mechanics is an area of fundamental physics which deals with the natural phenomenon encountered at the tiniest scales imaginable. We’ve had a handle on the quantum world for over 100 years but we’re only just starting to do awesome things with it.
Einstein’s jives can explain the way gravity shapes the universe, but say nothing about the seemingly unintuitive ways in which atoms and sub-atomic particles interact with the universe and each other.
Your sat nav is one device that simply wouldn’t exist without this understanding of quantum physics. The global positioning system requires an ability to tell the time with an accuracy of a billionth of a second, and for this we have to use atomic clocks.
Inside atomic clocks are atoms of caesium, a rare metal.The electrons in the caesium atoms are made to jump up to a higher energy level away from the nucleus. Then as they fall back down, they give off a photon of light. These light beams pulse 9 billion times every second, each performing the role of one tick in the atomic second.
A GPS module calculates its position by triangulating the timecodes from satellites in orbit at known distances overhead. Even a minuscule inaccuracy with any of these timecodes would throw the system off to the extent that it becomes entirely useless. In short, without an understanding of the quantum world, global positioning would be impossible.
And how about your Blu-ray player? The lasers inside it are also a product of quantum science. They work by stimulating the electrons orbiting atoms in a gas, which are then emitted as photons of light.
Lasers are awesome, and used for all manor of things in the modern day, ranging from reading data from optical discs to anti-piracy naval energy weapons and even the stimulation of fusion reactions in experimental power stations where physicists are attempting to unlock the potential of Einstein’s famous equation e=mc2. They want to release the power of the stars.
Fusion power will one day unlock near infinite amounts of clean energy, likely enabling the next great era in human endeavour.
7. A quantum future
While we’ve made use of quantum science already, undoubtedly this area of physics has yet to yield the majority of its secrets. The time will come when people of the future look back at our understanding of the universe and snigger about how little we knew. In short, we’re still the people in Game of Thrones.
Quantum has the power to change the world in a similar fashion to the way Newton’s laws of motion kickstarted the industrial revolution.
At the heart of quantum mechanics is the counter-intuitive idea that sub-atomic particles can be in more than one place at the same time. This fundamental law of nature is being used to design quantum computers – computers that are more powerful than your laptop by many orders of magnitude.
While current computers use bits in the form of 0s and 1s, quantum processors use quantum bits (qubits) which can be 1s and 0s and everything else, all at the same time. So when looking for the answer to a problem, it won’t try the possible answers sequentially and take a million years, it’ll just calculate all the potential answers all at once and choose the best one.
Just one of quantum’s early benefits has been quantum encryption. Because the very act of observing a quantum particle will change it (the observer effect), this can be used to guarantee secure information exchange over the internet. For example, if you encode either a 1 or a 0 on a photon of light and send it to a friend, if a third party were to intercept and view that information, they would fundamentally change it, alerting you and your friend.
Banks and intelligence agencies already use this form of quantum encryption, but in the future, all digital securty might revolve around it.
Other uses? Use your imagination. Picture a quantum processor in the PlayStation 26, enabling AmazingD photorealisitc graphics.
Nanotechnology on its own could completely change the way we practise medicine, explore the universe and live our lives on a day to day basis.
We at TechRadar envisage a relaxing future where we can use a huge quantum computer to simulate an infinite number of monkeys to write our pages for us. Monkey reviews! The future is going to be a wonderful place.
Illustrations by Jane Wan