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chapter/antimatter.html
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<h1>Antimatter</h1> <h1>Antimatter</h1>
<p>Every particle[ref] that we have met so far has a corresponding <p class="abstract">Every particle[ref] that we have met so far has a
anti-particle. These antiparticles have exactly the same mass[ref] as corresponding anti-particle. These antiparticles have exactly the same
the particle, but opposite charge[ref], and their lifetime and mass[ref] as the particle, but opposite charge[ref], and their
stability are the same. When a particle, for example the electron, lifetime and stability are the same. When a particle, for example the
meets its antiparticle, an anti-electron (or positron), they will electron, meets its antiparticle, an anti-electron (or positron), they
annihilate each other. This means that both particles disappear and will annihilate each other. This means that both particles disappear
produce a huge amount of energy[ref]. This annihilation will only and produce a huge amount of energy[ref]. This annihilation will only
occur when an antiparticle meets its matching partner. For example, an occur when an antiparticle meets its matching partner. For example, an
antimuon will not annihilate with an electron. However, because there antimuon will not annihilate with an electron. However, because there
is a lot more matter in our universe than antimatter, it is much more is a lot more matter in our universe than antimatter, it is much more

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chapter/the_electromagnetic_interaction.html
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<h1>The Electromagnetic Interaction</h1> <h1>The Electromagnetic Interaction</h1>
<p>The electromagnetic force is the force affecting electrically charged <p class="abstract">The electromagnetic force is the force affecting
particles. This is the force that keeps the electrons close to the electrically charged particles. This is the force that keeps the
nucleus of an atom. How do the charged particles communicate with each electrons close to the nucleus of an atom. How do the charged
other? They exchange a certain type of particle, called the particles communicate with each other? They exchange a certain type of
photon. This is the same particle that makes up light! Visible light, particle, called the photon. This is the same particle that makes up
X-rays, microwaves and radio waves are all photons, with different light! Visible light, X-rays, microwaves and radio waves are all
energies.</p> photons, with different energies.</p>

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chapter/the_higgs.html
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<h1>The Higgs</h1> <h1>The Higgs</h1>
<p>On July 4th 2012, the two LHC experiments ATLAS and CMS announced <p class="abstract">On July 4th 2012, the two LHC experiments ATLAS
the discovery of a new boson, which is likely to be the Higgs and CMS announced the discovery of a new boson, which is likely to be
boson. It has been the missing piece of the Standard Model for many the Higgs boson. It has been the missing piece of the Standard Model
years, and its discovery is one of the most amazing successes of for many years, and its discovery is one of the most amazing successes
physics. In this chapter, we will explain the Higgs mechanism, that of physics. In this chapter, we will explain the Higgs mechanism, that
gives mass to all the particles we know by now.</p> gives mass to all the particles we know by now.</p>

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chapter/the_strong_interaction.html
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<h1>The Strong Interaction</h1> <h1>The Strong Interaction</h1>
<p>There must be some kind of force that glues together the quarks in the <p class="abstract">There must be some kind of force that glues together the quarks in the
proton, just like the electromagnetic force attaches the electron to proton, just like the electromagnetic force attaches the electron to
the atomic nucleus. And like for electromagnetism, there must be the atomic nucleus. And like for electromagnetism, there must be
messenger particle of this force, and also a kind of “charge”, called messenger particle of this force, and also a kind of “charge”, called
@ -12,10 +12,10 @@ messenger particles of this interaction are called gluons, and they
themselves carry color, so they cannot exist freely either.</p> themselves carry color, so they cannot exist freely either.</p>
<p>Looking at the proton, we see that there are three quarks glued <p class="abstract">Looking at the proton, we see that there are three
together - unlike in the hydrogen atom, where there are only two quarks glued together - unlike in the hydrogen atom, where there are
partners: the proton and the electron. Hence, something must be only two partners: the proton and the electron. Hence, something must
different about this strong, nuclear force, that glues together the be different about this strong, nuclear force, that glues together the
quarks. There are three different kinds of "charge", as opposed to quarks. There are three different kinds of "charge", as opposed to
electromagnetism, where there are only two, which we call positive and electromagnetism, where there are only two, which we call positive and
negative. For the strong force, the "charge" is called color.</p> negative. For the strong force, the "charge" is called color.</p>

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chapter/the_weak_interaction.html
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<h1>The Weak Interaction</h1> <h1>The Weak Interaction</h1>
<p>Some nuclear decays cannot be explained with only the strong and <p class="abstract">Some nuclear decays cannot be explained with only
the electromagnetic interactions, another interaction is the strong and the electromagnetic interactions, another interaction
required. These decays are called beta decays (β-decay), and turn a is required. These decays are called beta decays (β-decay), and turn a
neutron into a proton (or the other way around) and emit an electron neutron into a proton (or the other way around) and emit an electron
and a new particle, the neutrino [or a positron (an and a new particle, the neutrino [or a positron (an
antielectron)]. They are rare and very different from the other types antielectron)]. They are rare and very different from the other types

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chapter/three_generations.html
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<h1>The Three Generations of Matter</h1> <h1>The Three Generations of Matter</h1>
So far we have met the particles that make up most of the matter we <p class="abstract">So far we have met the particles that make up most
see all around us - the up quark, the down quark and the electron. We of the matter we see all around us - the up quark, the down quark and
have also met the electron neutrino, which is emitted during the electron. We have also met the electron neutrino, which is emitted
radioactive decay. It seems like these four particles, along with the during radioactive decay. It seems like these four particles, along
particles that carry forces, are enough to explain everything. with the particles that carry forces, are enough to explain
everything.</p>
<p class="abstract">It turns out that each of the matter particles has
<p>It turns out that each of the matter particles has two "big two "big brothers" - new particles that are identical except for their
brothers" – new particles that are identical except for their larger larger mass. Physicists talk about "three generations" (sometimes
mass. Physicists talk about "three generations" (sometimes called called families instead) of matter. The first generation is the
families instead) of matter. The first generation is the particles we particles we have met already. The second generation contains the
have met already. The second generation contains the charm quark (the charm quark (the big brother of the up quark), the strange quark (the
big brother of the up quark), the strange quark (the big brother of big brother of the down quark), the muon (the big brother of the
the down quark), the muon (the big brother of the electron) and the electron) and the muon neutrino (the big brother of the electron
muon neutrino (the big brother of the electron neutrino). The third neutrino). The third generation is the top quark, the bottom quark
generation is the top quark, the bottom quark (this is sometimes also (this is sometimes also called the beauty quark), the tau lepton and
called the beauty quark), the tau lepton and the tau neutrino.</p> the tau neutrino.</p>

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chapter/what_is_the_world_made_of.html
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<h1>What is the World made of?</h1> <h1>What is the World made of?</h1>
<p>The world around us, everything we see, touch, smell and taste, is <p class="abstract">The world around us, everything we see, touch,
made of matter. Everything from the device you are reading this smell and taste, is made of matter. Everything from the device you are
webpage on and the ground that you are standing on to your body and reading this webpage on and the ground that you are standing on to
the air you breathe - all consist of matter. But what is "matter"? your body and the air you breathe - all consist of matter. But what is
People have been puzzling over this question for generations. In the "matter"? People have been puzzling over this question for
early 20th century, it was believed that the smallest unit of matter generations. In the early 20th century, it was believed that the
was the atom (from greek atomos, meaning indivisible). It was known smallest unit of matter was the atom (from greek atomos, meaning
that atoms of different types have different properties and cannot be indivisible). It was known that atoms of different types have
transformed into one another. However, today we know what atoms are different properties and cannot be transformed into one
made up of and why the different atoms have different properties. </p> another. However, today we know what atoms are made up of and why the
different atoms have different properties. </p>

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that it is made of a proton with electric charge +1 and an electron that it is made of a proton with electric charge +1 and an electron
with charge -1. Particles with opposite electric charge attract each with charge -1. Particles with opposite electric charge attract each
other just like magnets. This is an example of the electromagnetic other just like magnets. This is an example of the electromagnetic
force, or “the electromagnetic interaction”. </p> What is interaction? force, or "the electromagnetic interaction".
<h2>What is interaction?</h2>
<p>How do the proton and the electron know about each other? How do <p>How do the proton and the electron know about each other? How do
they “interact”, and what do we mean by “interaction”? Particles they "interact", and what do we mean by “interaction”? Particles
interact with each other by exchanging other particles. How does this interact with each other by exchanging other particles. How does this
work?</p> work?</p>
@ -23,7 +25,7 @@ receive the tools momentum, carrying him in the direction of
flight. What happened? The two astronauts are now floating away from flight. What happened? The two astronauts are now floating away from
each other, whereas they were approaching each other before. They each other, whereas they were approaching each other before. They
exchanged a tool, and transmitted momentum from one another, a process exchanged a tool, and transmitted momentum from one another, a process
particle physicists call “scattering”. Sadly, this example only works particle physicists call "scattering". Sadly, this example only works
for a repelling interaction. However, there is a similar example, that for a repelling interaction. However, there is a similar example, that
also works for an attractive interaction, which is a little more also works for an attractive interaction, which is a little more
complicated.</p> complicated.</p>
@ -101,10 +103,10 @@ called fermions (all particles with half-integer spin are fermions).</p>
Like all other bosons, photons can - given that sufficient energy is <p>Like all other bosons, photons can - given that sufficient energy is
available - be produced out of nowhere and can also vanish into available - be produced out of nowhere and can also vanish into
nothingness, leaving behind nothing but energy. Therefore, the nothingness, leaving behind nothing but energy. Therefore, the
electrons and protons in the atoms - as oppo<p>sed to the persons in electrons and protons in the atoms - as opposed to the persons in
the boats we used as an analogy earlier - do not need to carry around the boats we used as an analogy earlier - do not need to carry around
their messengers (in our case photons), as they can simply be produced their messengers (in our case photons), as they can simply be produced
by all particles that carry charge. </p> by all particles that carry charge. </p>
@ -112,7 +114,7 @@ by all particles that carry charge. </p>
<h2>Outlook</h2> <h2>Outlook</h2>
<p>The exchange of photons between particles is what we call <p>The exchange of photons between particles is what we call
“electromagnetic interaction”, The photon can create either attraction "electromagnetic interaction", The photon can create either attraction
or repulsion between particles and transport momentum as well as or repulsion between particles and transport momentum as well as
energy. Now we know what binds together the electron and the nucleus energy. Now we know what binds together the electron and the nucleus
to form atoms, such as the Hydrogen atom or the Helium atom that we to form atoms, such as the Hydrogen atom or the Helium atom that we