User:Ludovico Mazzocchi

Particle Physics Every particle belongs to quantum mechanics. The minuscule world of science is where relativity starts to become wonky. Every particle is a field quanta is an underlying physical field. There are two different class of particle, fermion and boson. A fermion is a particle with half integer spin like the electron and the boson is any particle without spin. Therefore every particle is an excitation in an underlying physical field or matter field. For instance a electron has spin. This evolution of the electron is called chirality. The electron can possess either a right of left handedness due to this spin. The lepton family interacts with the electromagnetic force and that only but the electron can possess both handedness simultaneously. Left handedness gives the electron the ability to interact using the week interaction, a phenomenon called weak hyper charge. The reason the electron can use both handedness’s simultaneously is due to quantum superposition. This when multiple quantum states combine to form another valid quantum state. What makes the electron unique to the photon is that the electron is hindered to travel at the speed of light by the Higgs field. The photon however is a boson and therefore is a transmitter of forces. The Infinite problem regards the photon as a force transmitter but that assumption leads physicists to multiple infinities. The discovery of the W and Z boson cancelled out these infinities. Therefore the photon remains massless and it does not evolve yet the electron does.

Another principle called the Uncertainty principle states that if a certain quantum object has a certain momentum or position one or the other will be very or almost impossibly uncertain. This is a phenomenon that is key in the formation of black holes. To understand how black holes are formed we need to use a type of spacetime by the name of Quantum Phase space (6-D space). This phase space defines position an d momentum and is governed by the Uncertainty principle and the Pauli Exclusion principle. Lets take a neutron star. When a star accretes into a neutron star the position of the particles is highly certain. The phenomena that will prevent this neutron star from collapsing inward towards at the singularity is the Pauli Exclusion principle. This states that two fermions cannot occupy the same quantum state simultaneously. Also degeneracy pressure, the pressure that keeps electrons in their stable orbits.

This Report will be overlooking the different Quantum beliefs for the Double slit experiment and furthermore. First we will remind ourselves about the Double slit experiment. This experiment was used to identify the behaviour of quantum particles. Sending a conventional water or sound wave through the two slits created a series of constructive and destructive interference. Constructive interference is when the troughs and crests of the waves line up to form a higher amplitude wave and Destructive interference occurs when the crest meets with the trough of another wave and the waves cancel each other out. But sending individual particles through the slits, these interference pattens still occur yet they are just particles. This led to the birth of the wave function. This is a description of the quantum state of a system. It is a Complex numbered Probability amplitude used to make a relationship between the wave function and the results of observations of that system. So, the particles journey is a superposition of all possible states. It simultaneously takes all possible paths and later converges into one single result. These different superposed histories converge on that single outcome. One interpretation of the Double slit experiment was called the Copenhagen Interpretation. It stated that the act of measurement collapsed the wave function into a single reality. That collapse signified the collapse of the quantum realm into the classical realm. This led to the explanation for Schrodinger’s cat. This was a thought experiment which went as follows: A cat is in a box with a flask of poison. A radioactive element is set to decay and poison the cat. The Cat would die. But this process is purely quantum physical and is both decayed and not decayed. This means that the cat is both alive and dead before we open the box. This decay exists in a superposition of states. But you would think, why can the cat not collapse its own wave function. His equation describes the evolution of particles to be probabilistic and how their wave functions evolve. His description counteracting the Copenhagen interpretation uses the Many Worlds Theorem of Quantum Mechanics. This was proposed sensible ideas of Quantum decoherence. This superposition of states does not extend to macroscopic scales. It disappears when two quantum scale histories diverge. This is called Quantum decoherence. It relation to the Double slit experiment, when waves overlap sufficiently, a system is said to be coherent. When the wave functions, describing quantum systems, overlap sufficiently, in other words are coherent, you can get interference patterns and weirdly corresponding quantum entanglement measurements. As long as there exists a definite phase relation between different states, the system is said to be coherent. But if these systems interact with their environment, coherence will decay over time. This is when parallel histories cannot interact so coherence is lost. Another important factor of quantum mechanics is quantum tunnelling. Every quantum particle has a De Broglie wavelength, or in other words a matter wave. This is a probability cloud similar to the Heseinberg uncertainty principle. It states that nothing in the universe has a definite position, so instead an object is defined distribution of possible states of being. This is true until another quantum object interacts with it, in which then it is more likely that position. This distribution of possibilities is encoded in the wave function of that object. A higher De Broglie wavelength means there is a increased uncertainty, but a short one is very certain. A De Broglie wavelength depends on ones momentum, higher momentum means a smaller wavelength. If we look at an alpha particle, bound into a heavier atomic nucleus by the strong nuclear force, we can see it is a quantum object. This means its position is not well defined. When it approaches the force barrier of the nucleus its De Broglie wavelength is reflected. But the possibility space of the particle does not suddenly end at the force barrier, it extends outside of its condo. But thus extension is very slight and does not obtain large amounts of energy. This therefore means that the particle has a very small chance of tunnelling out of the nucleus. This is called Quantum tunnelling. This is when a particle tunnels through a barrier it conventionally could not surpass. These Quantum Tunnelling techniques help stars fuse hydrogen into heavier nuclei, are used in various particle capture phenomena and now modern transistors rely on Quantum tunnelling to function. But how long does it take to Quantum tunnel through a barrier. Well, studies suggest that it is a faster than the speed of light transaction. This is very problematic as it tinkers with causality. But we cannot test such a phenomena as our clocks are not precise enough to measure a speed as fast as that of Quantum tunnelling. To test Quantum tunnelling we can send individual photons at a reflective barrier. If all the photons are reflected 100% of the time, then Quantum tunnelling is a hoax. We have tested it and the photons are not always reflected. If Quantum tunnelling is faster than light then the impeded photon path should arrive before the untouched one. In other words, the De Broglie wavelengths would not line up. Although, for this to work, the path lengths of the interferometer must be very equal. For that to work, a second stage of quantum mechanics is needed, Quantum Entanglement. If you tune the interferometer paths to be extremely similar, quantum entanglement weirdness will start to show. The faster than light speed is true, but only to microscopic quantum realms, not to relativistic, macroscopic scales.