# Recap di Fisica Moderna

Dal momento che la serie di post su Particelle e interazioni è diventato un po 'più a lungo di quanto avrei voluto, Ho pensato di disgregare. Cominciamo con un riassunto della fisica moderna che è necessario comprendere la struttura della materia.

# Interpretation of Special Relativity

When we looked at Quantum Mechanics, we talked about its various interpretations. The reason we have such interpretations, Ho detto, is that QM deals with a reality that we have no access to, through our sensory and perceptual apparatuses. D'altronde, Special Relativity is about macro objects in motion, and we have no problem imagining such things. So why would we need to have an interpretation? The answer is a subtle one.
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# Velocità della luce

The speed of light being a constant sounds like a simple statement. But there is more to it, quite a bit more. Let’s look at what this constancy really means. A prima vista, it says that if you are standing somewhere, and there is a ray of light going from your right to left, it has a speed c. And another ray of light going from left to right also has a speed c. So far, so good. Now let’s say you are in a rocket ship, come mostrato in figura, moving from right to left.

# Teoria della Relatività

Quando sentiamo parlare di Einstein e la relatività speciale (o la teoria della relatività, di utilizzare il nome reale), pensiamo al famoso $E = mc^2$ equazione, e cose strane come il paradosso dei gemelli. Mentre queste cose sono tutte vere e importanti, il problema SR cerca di risolvere è uno completamente diverso. È un tentativo di difendere un principio fondamentale in fisica.
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# Quantum Mechanics – Interpretations

Whenever we talk about Quantum Mechanics, one of the first questions would be, “What about the cat?” This question, davvero, is about the interpretations of Quantum Mechanics. The standard interpretation, the so-called Copenhagen interpretation, leads to the famous Schrodinger’s cat.
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# Quantum Field Theory

In this post on Quantum Mechanics (QM), we will go a bit beyond it and touch upon Quantum Field Theory – the way it is used in particle physics. In the last couple of posts, I outlined a philosophical introduction to QM, as well as its historical origin – how it came about as an ad-hoc explanation of the blackbody radiation, and a brilliant description of the photoelectric effect.
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# Historical Origin of Quantum Mechanics

In questa sezione, we will try to look at the historical origin of Quantum Mechanics, which is usually presented succinctly using scary looking mathematical formulas. The role of mathematics in physics, as Richard Feynman explains (in his lectures on QED given in Auckland, New Zealand in 1979, available on YouTube, but as poor quality recordings) is purely utilitarian.
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# Meccanica Quantistica

Meccanica Quantistica (QM) is the physics of small things. How do they behave and how do they interact with each other? Conspicuously absent from this framework of QM is why. Why small things do what they do is a question QM leaves alone. E, if you are to make any headway into this subject, your best bet is to curb your urge to ask why. Nature is what she is. Our job is to understand the rules by which she plays the game of reality, and do our best to make use of those rules to our advantage in experiments and technologies. Ours is not to reason why. Davvero.

# Classical Physics

The main difficulty in describing particle physics to general public is the fact that it is built on modern physics. Even if you are physics aficionado and did extremely well in your high school physics, what you have learned and loved is classical physics. The difference between classical physics and modern physics is not just more physics, but a completely new way of looking at the reality around us.
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