Ok thet title not necessarily true… Actually it is meant to say “Change the Universe… by clicking your fingers”. Well, again that’s not entirely correct either; it should be “Change the Universe… By doing anything at all” and that includes simply existing. We must start by asking a tricky question: how do atoms exist?
Water molecules are made up from oxygen and hydrogen atoms. Atoms are made up of a positively charged nucleus and a negatively charged electron cloud, these two components are held together by having opposite charges, like magnets with opposite poles. But what stops the electron cloud from collapsing onto the nucleus?
Well to start off with, the Universe is a lot simpler than you might have learnt at school. There are actually only 16 fundamental particles in the Universe, not the 110 elements you learn in education. These together form what is called the Standard Model, a 4 by 4 table which makes up anything you see around you, even yourself and even light. Here is the answer to the question of why electrons don’t collapse into the nucleus of atoms.
The answer came from the capital of the Austrian-Hungarian Empire: Vienna. One of the youngest physicists that ever lived, Wolfgang Pauli, answered the question using what is called today “The Pauli Exclusion Principle”. This physicist was only 23 years old and he had already began lecturing on physics.
The 16 particles proposed by the standard model have some intrinsic properties. We have already talked about one of them, charge, but there are others like mass and more importantly spin. This is something that was first hypothesised by Pauli. It is one of those difficult things to explain from the quantum theory, but analogies to geometry should make the answer more clear.
Think of a kite. How many complete revolutions would you need for it to look the same as when you first started? You have to spin a kite 360˚ for it to look the same; therefore you need one complete revolution so it has a quantum spin of 1. Contrastingly, think of a square and try to spin that. Unlike the kite, by just doing a quarter of a spin (90˚) it will look the same. This means that a square has a spin of 4. 1 and 4 are both whole numbers, or as you say in mathematics and physics, they’re both integers. Anything which has an integer spin is called a Boson.
A boson cannot be told apart from another boson very easily, for example photons (light particles) are interchangeable with each other because they’re like squares. If you had four squares which had been spun 90˚, 180˚, 270˚ and a last one at 360˚ you wouldn’t be able to tell the difference between them. More importantly, it wouldn’t matter which one is which. You could use them interchangeably. This is what is so important about particles with integer spin.
Now, try to think of something which needs to be turned around twice (720˚) for it to look the same. Here simple geometry analogies fail, but your imagination should be able to follow. If it needs to be spun twice to look the same, we say it has a 1/2 spin, and if it needs to be spun 3 times it has a 1/3 spin and so forth. Anything that has a fractional spin is called a fermion.
Fermions look different all the time, even if you spin them around completely. They, as a general rule, cannot be interchanged because they’re so different. It would be like swapping the pope for Stephen Hawking – things would get problematic. Though, this is an interesting experiment and if you are in contact with either party, perhaps you would consider setting it up?
The reason all of this about spin is so important is because the Pauli Exclusion Principle only works on fermions: bosons are unaffected. Moreover, it just so happens that 12 out of the 16 fundamental particles of the standard model are fermions. The most significant of these is the electron, which underpins all of chemistry and was the stimulus for this question on collapsing atoms.
If you took all the different qualities of a fundamental particle from the standard model you could understand its state. This is essentially all the different factors which makes a particle special i.e. its momentum, energy, mass etc. and even its spin phase (how much it has been spun). Simply stated, the Pauli Exclusion Principle says that no two fermions, anywhere in the Universe, can have the same quantum state.
So, returning to the water molecules and the hydrogen and oxygen atoms. The distance of the electrons from the nucleus determines its energy, velocity and so forth. In other words: its quantum state. So the cloud of electrons cannot collapse onto the nucleus because then all of them would have a lower energy and they would occupy the same quantum state which is illegal in the Universe. Simply because electrons are fermions, atoms, and you, can exist.
So how does this relate with changing the Universe? The answer lies in giving electrons more energy. When you heat up something, you are giving the electrons energy. This makes them move into a different state (it is part of what defines a state). There are 1 billion billion billion billion billion billion billion electrons in the Universe, so another electron will probably already have been in that ‘new’ state. Now this electron, which could be anywhere, has to change state because your electrons have changed their quantum state. This is how the Pauli Exclusion Principle works.
When you click your fingers, you give the electrons in your hand a little bit of energy, the above process does happen. However, what if that electron moved into a quantum state occupied by a third electron? A chain reaction occurs and across the Universe right in the heart of the Andromeda galaxy and in the centre of our sun electrons moving, just because you clicked your fingers.
–Alexander V. Gheorghiu
Take a cat and think about what it is made up from. You will probably come to the conclusion that it is composed of little bits of things called atoms. If you were to go further you might even conclude that those atoms are made from electrons revolving around a nucleus. Look deeper down and you’ll see that the tiny nucleus is made up from protons and neutrons. What would happen if you tried to split the proton or the neutron? Well, you would simply get smaller things.
There are 110 different elements; together they make up everything around you, including you yourself. But where is an electron on the periodic table? And where is a proton? If light is a particle, then how do we categorise it? What holds the nucleus of atoms together? The fact of the matter is that the Periodic Table of elements is a simplification of just the normal things we see every day. Actually, it is an over complication because in the world there is actually just 16 things – everything is made from different combinations of these things.
We call these sixteen things the Standard Model. There are three different categories: The Gauge Bosons, the Leptons and the Quarks. The gauge bosons are the fundamental forces of the universe, like magnetism. The quarks and the leptons are the things that stuff is made from – the actually matter.
There is a pervading rule in the Universe that everything must have a tiniest bit – even time. So you may be familiar with magnetic field, but you will probably not be familiar with how the fact that there is a tiniest bit of a magnetic field called a photon. Incidentally, a photon is also the tiniest pocket of light there is, so the force which holds magnets together is actually just light. There are only three other Gauge Bosons, they are the: Photon, Gluon, W± and Z0 particles.
The photon is what holds electrons to the nucleus of an atom. Electrons have a negative change and the nucleus has a positive one, opposites attract like two magnets with north and south poles coming together. This magnetic force is all due to the photon – light is what holds the electrons of an atom to the nucleus. Light is what holds two magnets together or pushes them apart. However, what are the protons and neutrons and electrons? They are your quarks and your leptons.
Anything which is made up of a collection of quarks is called a Hadron. Like magnets are held together because of the photon, quarks are held together because of the strong nuclear force AKA the Gluon.
Hadrons are broken down into two groups: Baryons and Mesons. A baryon is anything made up of three quarks. A meson is something made up from a matter quark and an antimatter quark, but we will get to antimatter in another article. It is worth noting that Baryons are very strong and stable, whereas mesons are very weak and will fall apart relatively quickly.
Protons and neutrons are both Baryons. They are formed by holding together 2 up quarks and 1 down quark; each has a respective charge of +2/3 and -1/3 so the net charge of a proton is +1. Neutrons are made up from 1 up quark and two down quarks; it has a total charge of zero. That is the only difference between the protons and the neutrons in the nucleus of an atom. So what makes these protons and neutrons stick together?
Imagine trying to hold two really powerful magnets to close to each other when you are putting both the north sides together, this is synonymous to getting two positively charged protons together. You would need a lot of energy, or force, to overcome the magnetic repulsion between them. If you can do that, you can fuse protons and neutrons to make any element you want – including gold and platinum. Where can you get it from? Stars.
Stars are massive objects that can use their enormous weight to push the magnets, or rather protons together. So close that the attractive strong nuclear force takes over from the electromagnetic force (photon) between the two powerful charges. The stars are the furnaces of the Universe; to fuse nuclei together you would need phenomenal energy on Earth.
Now that you have the nucleus all that is left is to take the negative electron, which is a fundamental particle in the Lepton series, and use the electromagnetic force, the photon, to make it be attracted to the positive charge of the nucleus (proton). Et Voila! You have an atom. So if you had a few billion up quarks and down quarks, some gluons, a lot of light and trillions of electrons you could built the cat you took apart at the very start of this article.
To summarise: everything you see around you is made up of atoms. In turn, atoms are made up from three things: protons, neutrons and electrons. Which are made up of three things: up quarks, down quarks and gluons. Yet this doesn’t even cover half of the fundamental particles, the 16 things shown at the bottom.
If you could consider all of the 16 as part of the Universe, there are only two things you’d miss: mass and gravity. Arguably the most important things there are. They are what modern physicists are trying to discover using things like the Large Hadron Collider (LHC) at CERN in Geneva which require incredible amounts energy just to smash together particles.
So with 18 fundamental things and a bit of maths, you can explain everything there is in the entire Universe, is that amazing?
–Alexander V. Gheorghiu
Richard P. Feynman was raised in New York by parents of jewish origin. His Father encouraged him to think in an unorthodox way about problems, a trait which not only stuck with him, but defined him as a scientist. He went through M.I.T and Princeton to gain his bachelors degree and his PhD.
At Los Alamos, Feynman worked with vigour on the Manhattan project; the United States’ successful endeavour to create a nuclear bomb. Having been persuade by the Nazi’s own alleged attempts to create a bomb, Feynman was convinced to go to work as one of many human computers working on the project. While working on the project, Feynman was hunted down by Niels Bohr, who took a shine to him as he was the only man there with the audacity to argue with him on various physical ideas. Due to the secreted nature of the project, Los Alamos wasn’t a particularly vibrant place, however Feynman managed to keep himself entertained by picking locks and moving secret notes around to scare other physicists into thinking they were being spied on.
After leaving the Manhattan project, Feynman realised the scale of the work he had been doing and fell into a depression, convinced that what he had been working on would be the end of the world. Fortunately, his prediction was not to come true and he thus continued his work on physics. His most notable contributions to his most beloved topic were in the fields of quantum electrodynamics, however he is also renowned for his work relating to the superfluidity of supercooled helium as well as, obviously, the Feynman diagrams.
His work on quantum electrodynamics was revolutionary, and it won him the Nobel prize in Physics in 1965. one of the main components of this work was the path integral formulations which he developed at Caltech.
The path integral formulation is more commonly referred to as the sum over histories, it is one of the strange results of quantum theory. Kick a ball from point A to point a B 10 meters away, at a velocity of 5m/s in a simple application of knowledge you know that in 2 seconds the ball will have reached B. However if this was a quantum ball you wouldn’t be so sure due to the erratic behavior of quantum objects.
Feynman realised that you must consider all possibilities for the ball travelling from A to B. Not only the boring straight-line approach, but also the possibility of the ball going through the Andromeda Galaxy and returning and any other insane path you believe is insane. Additionally, you cannot say how the velocity of the ball will change during its path which adds a few new possibilities. In short, take into account all ways of travelling from A to B, however outlandish they may seem, and you will undoubtedly reach an infinity of cases. Next thing to do is to associate a special kind of physics number with each of these possibilities. The interesting bit happens when the numbers associated with all possibilities are added up; some parts of the sum will cancel each other like a positive and a negative, others will add up – this is called an interference phenomenon. The resulting sum tells us the probability of detecting the particle that started out at A at the location B at the specified time i.e. two seconds away. It is a key point of quantum theory to understand how to deduce the chance of discovering a certain particle at a certain point.
After the Challenger disaster in 1986, Feynman was invited to take up a seat on the presidential commission investigating the cause of the incident. Initially uneasy about the prospect – Feynman had a long term dislike for both the military (who were heavily involved in space development) and for Washington itself – he was convinced by his wife and close friends that he was the only potentially independent mind on the panel. Feynman was tipped off that the O-ring component on the spacecraft was subject to warping in extremely cold weather, much like that which was seen on the day of launch. Feynman, although discouraged by the head of commission William Rodgers, proceeded to demonstrate this phenomena before both the commission and a substantial number of TV viewers. Having shown the dangerous nature of the component, Feynman set about writing his own appendix to the presidential report detailing the mechanical failure of the O-ring, and the Human failure of NASA and their contractor Morton Thiokol. His appendix was included after Feynman threatened not sign the report as a matter of principle.
Besides his substantial scientific achievements, Feynman was also a great teacher. Known by many as ‘The Great Explainer’; Feynman spent many years working and teaching at various universities across America, as well as giving numerous popular public lecture series’ such as his famous ‘The Character of Physical Law’ series. He was known by his students for his charismatic teaching style and his ability to explain with lucidity the most complex physical truths in nature. What is left of him in his books, in particular his legendary ‘Feynman Lectures’, will no doubt be treasured for decades as cornerstones for the study of fundamental physics by the students of the future, just as we treasure the writings of Einstein and Newton.
He was a peculiar character, often completing complex mathematical problems whilst frequenting strip clubs and playing the bongo drums. He was not only a physicist, but also an excellent Artist and, at least for a year, a Biologist. He also wanted to travel to Tuva in Russia to experience and learn the indigenous peoples unique style of throat singing. sadly, Feynman’s last adventure was never to be realised as the travel permits arrived a short time after his death from two very rare kinds of cancer.
Feynman’s brilliant life and science is perhaps better explained by the man himself, as well as his family and friends in the brilliant Horizon documentaries ‘the pleasure of finding things out’ and ‘no ordinary genius.’
“I have a friend who’s an artist and has sometimes taken a view which I don’t agree with very well. He’ll hold up a flower and say “look how beautiful it is,” and I’ll agree. Then he says “I as an artist can see how beautiful this is but you as a scientist take this all apart and it becomes a dull thing,” and I think that he’s kind of nutty. First of all, the beauty that he sees is available to other people and to me too, I believe. Although I may not be quite as refined aesthetically as he is … I can appreciate the beauty of a flower. At the same time, I see much more about the flower than he sees. I could imagine the cells in there, the complicated actions inside, which also have a beauty. I mean it’s not just beauty at this dimension, at one centimeter; there’s also beauty at smaller dimensions, the inner structure, also the processes. The fact that the colors in the flower evolved in order to attract insects to pollinate it is interesting; it means that insects can see the color. It adds a question: does this aesthetic sense also exist in the lower forms? Why is it aesthetic? All kinds of interesting questions which the science knowledge only adds to the excitement, the mystery and the awe of a flower. It only adds. I don’t understand how it subtracts.”
-Richard. P. Feynman
Man loves speed. It gives us an unparalleled biological thrill that we have strived to fulfill for a century. But behind the biology, comes physics.
Formula 1 is perhaps the sport that uses physics the most, answering the question: how fast can I make this car go through that corner while still hitting maximum speed on the straights? unfortunately, this question is very hard to satisfactorily put into practice, which is why the top F1 teams spend tens of millions of pound in Research and Development before the car even turns a wheel in anger.
In this very brief explanation, you may get a sense of how complicated the workings of a F1 car are. The aerodynamics of the car are perhaps the most crucial element to a fast lap time. The image of the coloured car is a simulation run on a CFD computer. It shows the various pressures exerted on the car due to the airflow over it. To understand this, we must first understand the properties of air. Although we see air as very light, its properties change as velocity increases. At 160 km/h, air causes a lot of friction. It’s a bit like driving through soup. At 321 km/h, air is more like thick treacle that the car has to force its way through. At this speed, the airflow over the front wing of the car is equivalent to having 8 fully grown men stand on each endplate. That is why modern F1 cars have multi tiered front wings. Every little wing section is designed to: a) force the front tires into the road to stop the car understeering or taking off faster than Gangnam Style and, b) manipulate the airflow into the brake ducts (to cool the brakes) or into the main engine sidepods that cool the engine. In fact, so much air is needed to cool a F1 engine revving at 18,000 rpm that a stationary F1 car will overheat its engine in about 2 minutes. The air also flows over the car to the rear wing. The rear wing is an amazing bit of kit. It’s essentially an upside-down aerofoil that, instead of creating lift, creates downforce. This pushes the car into the track, creating better grip through the corners and better traction out of them.
However, as the diagram shows, the rear wing creates enormous turbulence in the air. You can see how it is disrupted and looks like part confetti. A more realistic representation can be seen with the image of Lewis Hamilton’s McLaren
Now, although the downforce created by the rear wing and the diffuser (underneath the car’s rear suspension) is good for fast corners, it is damaging on the straights. To make a car go like a stunned gazelle, the airflow over the car needs to be as smooth and as uninterrupted as possible. To ensure speed in both sections, all aerodynamic parts are fully adjustable. For a track like Monza, where the cars nudge 220mph on about 4 occasions, the engineers may choose for a low wing setting, thus causing less interference with the airflow. However, for a track like Silverstone, where the cars are expected to do maniacal direction changes in 150 mph corners where the drivers pull nearly 6G in lateral G-Force, it is much better to opt for a higher wing setting to generate the grip needed. However, the choice between high and low wing settings becomes more convoluted at tracks with long straights and fast corners, such as China or India. This is where aerodynamic efficiency is the buzz word. The fastest car over the last few years, the Red Bull, has perfected this more than any other car on the grid – and no-one really definitively knows why.
The physical properties of air are still allowing huge change in aerodynamic development that is designed to make the cars more efficient. Although part of a sport, this area of physics has come on leaps and bounds over the last 50 years, as the cars now look more like fighter jets than the 60s style metal cylinders as shown in the below picture. The trouble is, this technology costs about as much as the Olympic Stadium to research, develop, build and apply to the car while constantly trying to improve the design throughout the season and propel a multi million dollar sports star to a race win.
– S. J. Smith
English, the language we take for granted everywhere in the world, even complain is spoken too much, has a rich, confusing and fascinating history. This article details the rise of Old English, the first direct ancestor of our modern-day tongue.
Here’s a small timeline of the events I will mention:
The years 55AD – 410AD were spent, for England, under Roman rule. Before that, a Celtic language, a relative of Welsh, was spoken in the majority of England. This was the earliest precursor, or ancestor, of Old English. Pre-Roman people in England were completely illiterate, other than ancient runes used only as inscriptions. The years under Roman rule gave Britain the alphabet, and therefore our historical record of language in England begins near the end of this 400-year period, as people became accustomed to visually recording language. The language they recorded slowly morphed into Old English (the earliest clear ancestor of our Modern English), under the later Anglo-Saxon rule.
Although the Latin alphabet made up the main body of Old English’s new written form, the native speakers made a few adjustments over time, adding a few Saxon and Old Irish characters. Some of the letters they added are still part of the Icelandic language to this day, so connected were the existing alphabets of the time. Examples of these are ‘eth’, Ð/ð (the ‘th’ in neither) and ‘thorn’ Þ/þ (the ‘th’ in thesaurus).
This new written system of the language of the British Isles was developed, in the beginning, only as far as being a phonetic record of spoken language. This meant that how a certain word, phrase or sentence would be represented on the page depended massively on the dialect of the speaker/writer. In Old English (700AD – 1100AD), the four main dialects were Northumbrian, Mercian, West Saxon and Kentish. The West Saxon dialect comes from the area labelled ‘Wessex’, and was the language of Alfred the Great – and therefore held great importance between the years of 871AD and 899AD, during his reign.
Each dialect differed greatly from the others, much more so than the ways that contemporary language does between the regions marked on the map. The dialects portrayed by the areas in this map could be better compared to the Scandinavian languages of today, and their similarities and relationships, than to Modern English itself.
This image is labelled “Anglo-Saxon England”, after the people that lived here for almost the entire duration of the existence of Old English. For this reason, Old English is often referred to as Anglo-Saxon. ‘Anglo-Saxon’ is the name we give, collectively, to the ethnicity of the several small kingdoms formed after the invasion of three Scandinavian tribes; the Angles, Saxons and Jutes. The Jutes were from modern-day mainland Denmark (the peninsula which is still called Jutland), the Angles from the peninsula too, but just South of the Denmark/Germany border, and the Saxons just South of the Angles, in Northern Germany:
The Jutes invaded the small area later known as Kent, and gave rise to the traditions and variation of language that were present there for several centuries hence. As they obviously had the smallest effect on ‘England’ after their invasion, it makes sense that they are not included in the title ‘Anglo-Saxon’. The Angles invaded later-known Northumbria, and the centre of the island, later known as Mercia, and the Saxons created Wessex and its ways.
These invasions began around a century before the Romans left, but weren’t truly ‘finished’ until around 700AD, when the areas on the first image were properly formed, and the language and civilisations of each had been properly established. 700AD is when, from observation of surviving records, we can say that Old English officially began to exist.
-Sarah E. Wallace
What is everything made from, and where does it all come from? This is one of those pillars of science which has driven progress to continue, it has been the force accelerating our knowledge to the place that it is now. So what is the answer?
You may remember that in the Universe everything is composed of three things: Solid, Liquid and Gas. This is already an over simplification. There are actually a total of nine states including the three already mentioned. However these are the states of matter, but they are not actually matter, the true answer to what stuff is made from is much deeper.
Atoms. You will probably already be familiar with this idea that you can split everything into a small little ball called an atom. The word literally comes from the Greek of “indivisible” meaning there is nothing smaller, you cannot split an atom. This theory has been with the world since the ancient Greek Democritus and it held true as far as anyone could see… then a New Zealander Physicists called Rutherford ruined the elegant theory by splitting the atom in 1917.
Rutherford used a nuclear reaction between a nitrogen atom and an alpha particle and showed that there is something smaller than an atom. Between the years 1897 and 1932 three discoveries had been made in physics by JJ Thomson, Rutherford and Chadwick in chronological order. The discoveries were the electron, the proton and the neutron respectively: these are the three fundamental components that make up the atom.
The current model, the atomic model, is what you will have hopefully learnt at school. An atom is made up of a tiny nucleus composed of positively charged protons and neutrally charged neutrons with a cloud of negatively charged electron floating around it. This is what makes up every element in the Universe, all the way from Hydrogen to Ununnilium (the largest atom there is).
The only difference between one element and the other is the number of protons it has in its nucleus, for example hydrogen has one proton in the nucleus and helium has two – yet the highly inactive helium has completely different properties from the explosive hydrogen of Hindenburg flame… I mean fame.
All atoms have the same number of protons as electrons, so their total charge is zero. However, you may be familiar with the term “charged particles”. This is a case where the number of electrons doesn’t equal the amount of protons, for example a helium particle (2 protons) with 1 or 3 etc. electrons. In science a charged particle is called an ion.
An alpha particle is simply a helium nucleus with no electrons whatsoever: just two protons and to two neutrons held together giving it a total positive charge of 2. A positive hydrogen ion is just a proton floating around.
So what is the point of neutrons? Well not much… except that they’re what stop atoms and ions from falling apart. Take a hydrogen atom: one electron and one proton with no neutrons. This is the most common way hydrogen exists in the Universe; it is its most stable form, as in it will stay as an atom for a loooong time. However, if you add a neutron to the mix you get a deuterium particle, or a heavy hydrogen. In science you call this change of neutrons in the nucleus of an element an isotope.
Being an isotope makes the particle unstable and so it will literally fall apart – take uranium-235 (92 protons and 143 neutrons) or yellow cake as it is more commonly called. This is used to create nuclear fission reactions where elements fall apart releasing huge amounts energy which power electric generators or bombs. The energy released is so incredible one kilogram of unstable, or fissile, uranium could power a city for a year… or destroy one in a second as happened in the Second World War. This energy is similar to what fuels the stars, like our sun. They are powered by the fusion of elements rather than the tearing apart of them.
Imagine a cloud of gas somewhere in space.This is what the picture at the top is off. The cloud begins to spin, faster and faster and move closer and closer toward a single point. Gravity has taken over and the cloud of atoms is collapsing in on its own weight. A ball of hydrogen collapsing due to gravity has formed has formed, this is a star.
Yet gravity is relentless and the ball keeps collapsing in on itself; it squeezes the hydrogen so tight that some of them begin to merge together, releasing tons of energy to counteract its own weight so it can stay as a ball. Each hydrogen proton nucleus merges with another forming a helium isotope (two protons and no neutrons). However it is too unstable and so on of the protons becomes a neutron by releasing beta radiation, thus forming heavy hydrogen (1p +1N).
Eventually, all the hydrogen is fused into heavy hydrogen. After the fusion of hydrogen the star expands exponentially and becomes red/orange, our sun would grow as large as to engulf the Earth: this Red Giant. It continues to fuse nuclei together to form heavier elements like helium and oxygen.
However, once it gets to fusing Iron atoms together, the energy it releases is insufficient to fight its own gravity. It will collapse onto a single point. The star, like our sun, implodes by crushing itself onto a single point which then bounces back with super high energy. This implosion is called a Super Nova and it is where all the heavier things than iron are formed in the cosmos, such as copper and gold.
This is how a star lives; our sun simply exists by crushing atoms together to form heavier elements and release energy to fight its own weight. It is from this explosion of a star, the death of a sun, that things like the earth and the material which makes up your monitor comes from.
The world and everything around you, including you yourself, is made from electrons, neutrons and proton… well that’s not strictly true, come back next week and find out why. For now think about this: A star died so you could live. For all intents and purposes, you are star matter.
–Alexander V. Gheorghiu