This is an essay provided by one of my friends who studies physics at the University of Birmingham.
In 2010, the United States spent $80bn of its $600bn defence budget on “Research, Development, Testing and Evaluation”, eclipsing the amount of money spent on NASA, public transportation, energy or even education. The research and testing that goes into new weapons has been incredibly important ever since humanity moved on from sharpened sticks and metal in around the 1300-1600’s, which also happens to be around the time when the scientific method really began to take off and become a discipline on its own, separate from philosophy and other more ancient disciplines. In this essay I will be examining how the scientific method and in particular how developments in physics have contributed to the advancement of warfare and the weaponry we use. I will also be looking at the future, at where Physics will take us and how new technologies will take us beyond M.A.D. (Mutually Assured Destruction) to conflicts where human beings may not even be fighting.
Weapons have been around ever since humans have, and the common sword is thought to date back to the Bronze Age, around 3300BC. Although the crafting of swords was a rigorous and arguably scientific process with the use of different metals and alloys, it wasn’t until the use of gunpowder in China that science and physics began to meddle with the ways of warfare. Use of incendiaries has been recorded since the first civilisations warred, flaming rocks spewed by catapults for example, but the rapid combustion of gunpowder and its dominance over hand to hand combat in the centuries following its discovery make it perfect to herald as a landmark, a starting point where science became important in terms of weaponry. Gunpowder, a mixture of sulphur, charcoal and potassium nitrate (saltpetre as it was known then) was first mentioned in Chinese records in around 800AD, and was thought to be weaponised in the few centuries following. Records then suggest that gunpowder spread from China through the Middle East, eventually arriving in Europe in the late 13th century where it was refined and worked upon. It was employed in Europe as a weapon from the 14th century onwards and by the 17th century came to dominate early modern warfare. During the centuries following this, Europe experienced the Scientific and Industrial Revolution, and the discoveries made during this period would change the face of warfare for years to come.
Beginning with Galileo and Copernicus’ work in the 1500’s, the Scientific Revolution began and would continue over the next few centuries. New ideas and theories in all fields led to an emergence from the middle ages and major advancements in technology. In terms of warfare, the state of play was largely the same up until the 19th century with gunpowder still being the weapon of choice, its basic principles unchanged but the technology behind it improving. It is important to note sciences indirect impact on the field of warfare: despite no revolutionary new weapons being made or invented during this era, advances in science made it possible to cast metal better leading to more accurate and powerful guns, advances in maths and physics led to better panoramic sights allowing cannons and heavy artillery to be better utilised. Discoveries made by scientists in these times were quickly adapted to suit the battlefield. Towards the end of the scientific revolution came a period of time called “The Age of Enlightenment”. Originally a cultural movement or intellectuals where reason was valued more over faith it also marked the beginning of the industrial revolution and ushered a new age of electricity, automation and machines. By the end of the 1800s weapon manufacturers had a few new toys to play with; perhaps one of the most significant was the mass assembly production line. This not only allowed mass production of weaponry but also of machines, cars and armoured trucks that could be used in war. The invention of the airplane by the wright brothers in 1903 was another huge breakthrough, and it didn’t take long before guns and weapons were being attached to these new manners of machines, adding a whole new element to war. Advances in science made these creations possible, and soon tanks, fighter planes and bombers were standard affair in the wars of the early 1900s.
In the first few decades of the 1900’s, major developments in the understanding of atoms led to a new revolution in physics. The French physicist Pierre Curie discovered that contained in uranium ore a substance called radium emitted large amounts of radiation. This fuelled speculation that elements accessible to us could contain incredible amounts of energy which we could harness. In 1933, the idea of a chain reaction via neutrons, whereby one nuclear reaction causes on average one or more new nuclear reactions to occur was proposed by Leo Szilard. Achieved by either the fusion of light isotopes (e.g. H2 or H3) or the fission of much heavier elements such as Uranium-235, these nuclear reactions would release millions of times more energy than chemical reactions such as those used in gunpowder and artillery. More research was poured into the possibility of nuclear energy and weaponry but abruptly stopped being published on the eve of World War II; this was an act of censorship to stop any breakthroughs from reaching the opposing side of the war.
This all led to arguably the next landmark in terms of the relationship between science and warfare. A research and development program headed in the United States named “The Manhattan Project” begun in 1939 and the end result was a weapon of mass destruction which changed the way wars were fought. First utilised in combat in August 1945 with the bombing of Hiroshima, Japan, the A-bomb was a weapon of the nuclear age, with far more destructive capabilities than anything that had come before it. Over coming decades, the very existence of these terrifying devices led to a Cold War, a huge arms race between the United States and the Soviet Union in which over 60,000 nuclear warheads were built. This rivalry between two superpowers had a profound effect on science as by now both countries leaders had begun to recognise how science could give them the upper hand when it came to conflict. Billions of dollars and roubles were poured into technological advancement, the most prominent being that of space travel. The advancements made by these huge investments had the effect of driving forward military technology; NASA for example pioneered many technologies: Intelligent Flight Control Systems, Composite Material Structures and Vertical Take off & Landing being just a few of them. All three are now widely used in the military, having first been designed and invented as a means to fly through space. As we move onto future warfare, we will see how important pushing the boundaries of our technology still really is.
In 2008, the US military accelerated a 3.2kg object to 2415ms-1 in a device called a Railgun (so called because of the two conductive rails it uses to fire the projectile). The idea for a gun that uses a magnetic field to propel bullets had been around since the early 1900’s. However up until recently the theory was practically unfeasible due to power requirements, with reports showing that each gun would “need the same amount of power needed to illuminate half of Chicago.” A railgun is made up of two parallel rails, usually between 1-10 meters, that are connected to a power supply. When a conductive projectile is placed between the rails, it allows current to flow from one rail to another. Current flowing through the rails induces a magnetic field, circular around the rails, the projectile then experiences a Lorentz force, pushing the projectile in a direction parallel to the rails and out of the barrel. Once the projectile has left
the barrel, there is no conductor between the rails and current stops flowing. There are a few advantages to a railgun, the first that it doesn’t involve any explosive materials that could be hazardous when stored; the second is that it can fire projectiles much faster than conventional gunpowder can. Projectiles propelled by gunpowder are usually limited to around 1219ms-1, half that of the experimental navy railgun test. There are problems with the railgun though, first it needs a colossal amount of energy to propel slugs to a high speed, we can use the Biot-Savart Law and the Lorentz Force to determine the power needed to propel projectiles at a high speed, the recent navy experiments used thousands of mega joules for their tests. The other problems involved with railguns include the melting of the rails, when projectiles are forced down the rails with such speed the rails experience frictional heating, and the flow of current through the rails, especially at such high currents provides a resistive heating effect. The next major problem that railguns face is the face that the current in each rail flows in opposite directions, this means that the railguns are repelled from each other and at such high powers this repulsive force can cause wear and tear. A similar type of device is called a Coilgun or Gauss Cannon. This works by firing a projectile up a barrel which is surrounded by conducting coils. These coils provide a propulsive force on the projectile and speeds it up faster than conventional projectiles.
The Mosquito is a device used all around shops and malls in England, a loudspeaker that produces a high pitch noise (around 17.4 kHz at 108dB). The idea is that this screeching sound can only be heard by people under the age of 25, in tests it has proved successful and while there are many ethical issues surrounding its usage, it is an excellent example of how sound can be used as a weapon or deterrent. Ultra Sonic Weapons are currently in limited use in military and law enforcement agencies, while they would generally be classified as non-lethal, these weapons are still capable of killing under certain conditions. It is possible for high power sound waves to vibrate and destroy eardrums, causing severe pain to a target; this has been demonstrated in both counter-terrorist exercises and crowd control. More experimentation has also been done on the resonant frequencies of other body parts. Research has shown that at some frequencies around 0-20Hz, a human’s eyeball would vibrate at resonance, causing distortions to vision. Click link to see Use of sonic cannon.
Unmanned vehicles have been in use for decades, and they range from aerial vehicles used to scout and spy to remote controlled cars
that can be used to investigate and disarm unexploded bombs. The future of robots in the military though goes way beyond scouting and exploring however, plans have been made to introduce more and more autonomous infantry and support into war situations. These initiatives range from autonomous sniper systems, where a computer is hooked up to rifles on a moving helicopter, to TAC, Tactical Autonomous Combatant, robot infantry straight out of a terminator film that could be used in place of human foot soldiers. There are many moral and ethical dilemmas involving the use of robots on the battlefield, but the advantages are great. Conflicts in the future could have literally no loss of human life, and robots unlike humans are not prone to getting tired or feeling fear. What is important is that as robots become more and more complex, greater interest must be put into investigating the implications of their ability to make autonomous decisions.
Technological advances in physics and science has been the catalyst for hundreds of new techniques and tools in weaponry. It is important to remember that these scientific discoveries were not made becausewe could the convert them into weapons, but rather that weaponry was just one way of applying our new found knowledge. All of the technologies I have talked about in this essay exist in real life, but there are many others that while for the moment exist only in science fiction, could one day be used in the military. You only have to look as far as popular films and TV series, the ICARUS cannon seen in James Bond: Die Another Day, focusing the sun’s rays to a point meters in diameter, or the lightsabres and droids used in Star Wars to see that when it comes to weaponry human imagination has few limits, and as long as scientific advancements lead to more power, new materials, new theories, that weapons development won’t be too far behind.