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An Elementary particle then is a fundamental  constituent of matter

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whose substructure is unknown so far.

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Take as an example the electrons in the atoms or the quarks in the protons.

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The rest of the particles are obviously not elementary particles,

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but are constitued by them, electrones and quarks.

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So, for instance: a proton is made up by 3 quarks.

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This is clearly a really interesting field, because if it is true that all the matter is

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constitued by these kinds of elementary particles we could have

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a wider understanding of the universe by being aware of them and their interactions.

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There is a really important factor in Particle physics,

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called "wave-particle duality", which means that a particle

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is not only a corpuscle but that it also has a wave nature.

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We all have waves around us, so we know intuitively what a wave is.

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Well, it turns out that a particle does not only behave as matter does,

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(as we usually think)but also as waves do.

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In this picture, (which is a real image) you can see that I clearly

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exemplified the images of the waves produced by the effect

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of two electrons in the surface of a crystal of copper,

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merely to explain that an electron (a particle) produces a wave-like effect

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in its surroundings when it moves in a surface. In other words

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it can also be seen as a wave. It is actually this property,

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when particles behave as waves do, what

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allows us to understand this very important issue of Fundamental physics:

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the relation between distance and energy.

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Once we have identified this duality in a particle,

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it is necessary to establish a connection between the inherent

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properties to the particle and the ones inherent to the wave.

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For instance, we know that a particle is characterized by a

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determined mass and speed. Just like when we move,

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we have mass and speed, well the same happens with a particle.

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As I have just explained, a wave is characterized by a determined

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wave-length and frequency, right? Well, when I study a particle in

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its duality, as a wave and as a particle at the same time,

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there will logically be a relation among these numbers, ok?

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You can see this relation there, but it is basically

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what I've already said: when the particle moves

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at a high speed, it will have a small wave-length.

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This is the speed in the denominator and this means "short wave-length".

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In other words, this is a particle with high energy and speed,

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but when this energy is studied for its wave behaviour,

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it will have a short wave length (If we were considering that it had high energy).

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To sum up, this is key in Quantum mechanics.

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When high energy is reached, when we

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considerably accelerate a particle, when it is full of energy,

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What can we do? Well, we try to find

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another particle in the way, which can be accelerated or at rest,

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in order to make them collide so the energy of the first particle

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is able, just as a microscope, to go to really tiny discances.

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A big deal of the energy of this particle will look at really tiny distances

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(in a quantic level) of the other particle. That is the

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"Quantum key distribution". So, again, the summary would be that

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we considerably accelerate the particles, we make them collide against

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whatever we would like to study, it is like a microscope that will

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get closer each time, so the more energetic the particle,

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the smaller the distance covered: we would see

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in more detail the hair of a fly, so to speak.

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Therefore, particle accelerators are very poweruful microscopes.

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Excerpt from the conference held

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November 15th, 2013, at the Residencia de  Estudiantes,

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during the sessions "Las fronteras de la Física Fundamental".

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Full video available at: www.eddaddeplata.org