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Quantum Physics - Overview Classical Physics Daily life Macrocosmos (universe) Quantum Physics Microcosmos (atom)
Quantum Physics What is Quantum Physics? In physics, a quantum is the minimum of any physical entity involved in an interaction. Fundamental physical property may be ’quantized’. Quantum Physics is a branch of physics providing a mathematical description of microcosmos (atoms, elementary particles, …) Microcosmos (atom)
Quantum Physics Microcosmos 1000*distance earth/sun Atom Diameter = 1 km 99. 999999 % of the atom is empty space
Quantum Physics Microcosmos in our daily life
Quantum Physics Microcosmos in our daily life - Future Quantum Computer A quantum computer is a device for computation that makes direct use of quantum physical phenomena, such as superposition and entanglement to perform operations on data. Quantum computers are different from traditional computers based on transistors. The basic principle behind quantum computation is that quantum properties can be used to represent data and perform operations on these data. Experiments have been carried out where quantum computational operations were executed on number of qubits (quantum bits).
Quantum Physics Microcosmos in our daily life - Future Quantum Cryptograhpy Cryptography is the practice and study of hiding information. Modern crypthography intersects the disciplines of mathematics, computer science and electrical engineering. Quantum cryptography describes the use of quantum physics effects. Well-known examples of quantum cryptography are the use of quantum communication to securely exchange a key (quantum key distribution). The advantage of quantum cryptography lies in the fact that it allows the completions of various cryptographic tasks that er proven to be impossible using only classical communications. In particular, quantum physics guarantees that measuring quantum data disturbs the data, this can be used to detect an adversary’s interference with a message.
Quantum Physics Microcosmos in our daily life - Future Quantum secured bank transfer
Quantum Physics - History 2000 . . . . Quantum physics Theory of relativity 1900 Microcosmos Electromagnetism Thermophysics Planetary motion Mechanics.
Quantum Physics Planck’s law of blackbody radiation Quantum of Energy
Quantum Physics Photoelectric Effect Light cannot be explained purely as a wave phenomenon
Quantum Physics Compton scattering Light cannot be explained purely as a wave phenomenon
Quantum Physics Double Slit Experiment
Quantum Physics Mach-Zhender interferometer Out 2 R 2 4 S 2 6 4 -6 5 Out 1 2 -4 S 1 S 2 4 -5 5 0. 25 0. 5 3 -5 5 0. 25 3 -6 6 0. 25 In 1 S 2 3 S 1 1 R 1 0. 25 0. 5 1 -3 2 6 Classical physics Out 1 : Out 2 : 3 -5 + 4 -5 = 0. 25 + 0. 25 = 0. 5 3 -6 + 4 -6 = 0. 25 + 0. 25 = 0. 5 Quantum physics Out 1 : Out 2 : 1 0
Quantum Physics Entanglement Quantum entanglement is a physical resource (in a way like energy) associated with the nonclassical correlations that are possible between separated quantum systems. A pair of quantum systems in an entangled state can be used as a quantum information channel to perform computational and cryptographic tasks that are impossible for classical systems.
Quantum Physics x-ray
Quantum Physics Strange Questions An apple is laying on a table. You measure the position of the apple on the table. Question: Where was the apple just before your measurement? Question: Is it possible for a person to be at two different places at the same time? Question: Is it possible for two persons to interact without any kind of communication?
Quantum Physics Understanding The mankind has all time been thinking of beeing in the centre of the world, the earth, the planetary system, Milky Way, … How can we imagine we are seeing almost the whole world, we are only seeing a little part of the electromagnetic spectrum. In microcosmos we have to learn again almost everything, we almost have no models / pictures / conceptions, common sense, …
Quantum Physics Relativity - Addition of velocities Classic: Relativity: The velocity of the person relative to the earth The velocity of the person relative to the train The velocity of the train relative to the earth
Quantum Physics GPS - Relativity Because of the high speed, the time moves more slowly in the satellites. Because we are closer to the center of the earth, the time moves more slowly on the earth. The last effect is greater, therefore the time goes more slowly on the earth than in the satellite. We have to use Einstein’s theory of relativity to adjust the time. If not, the GPS would give a result several kilometers out of position.
Quantum Physics Strange situations in microcosmos A measurement of a system cause a change of the state of the system Measuring the door makes the door smaller A system can be in a superposition of different states at the same time Going through two doors at the same time Two different systems far away from each other can affect each other momentarily though no communication Changing spin of one of the two particles change spin of the other though no communication
Quantum Physics Classical Physics Quantum Physics Strange situations in daily life that happens in micro cosmos [1/2] You have parked your car. If you know your car is parked (zero velocity), it’s impossible to find it, it can be anywhere.
Quantum Physics Classical Physics Quantum Physics Strange situations in daily life that happens in micro cosmos [2/2] . . . . The laser changes the speed of the car. It’s the laser control that gives the car it’s speed. The measuring changes the high of the car so it cannot pass the tunnel. Always different colors of clothes though they don’t communicate. The cat is both dead and alive until something controls it.
Quantum Physics Quotation Niels Bohr: If you are not confused by quantum physics then you haven’t really understood it. Richard Feynman: I think I can safely say that nobody understands quantum physics. J. B: Haldane: The universe is not only more strange than we suppose, but more strange that we are able to suppose. Daniel Greenberger: Einstein said that if quantum physics were correct, then the world would be crazy. Einstein was right, the world is crazy. William D. Phillips: Entanglements, along with the superposition states, is the strangest thing about quantum physics. Davied Bohm: The most fundamental theory now available is probabilistic in form, not deterministic.
Kvantefysikk Innføring Fysikk Matematikk 0 1 2 3 … 0 1
Quantum Physics Statistics - Discrete Variables - Continuous Variables Discrete Variables Probability density Total probability Expectation value Variance Standard deviation Continuous Variables
Kvantefysikk: Størrelser som inngår i beskrivelse av materien og dens vekselvirkning kan bare anta bestemte, kvantiserte, verdier og ikke forandre seg kontinuerlig fra en verdi til en annen. 1900 Plancks strålingslov 1905 Einstein fotoelektrisk effekt En energimengde E = hf svarende til hver frekvens f. Lys som fotoner eller energikvanter med energi E = hf h Plancks konstant 6. 626 10 -34 Js. Usikkerhetsrelasjon (uskarphetsrelasjon):