This course follows on to Understanding Quantum 1. In this course we apply the concepts introduced in the previous one. The power of visual communication is used to make the complex mathematical models of quantum a little more comprehensible.
When two particles are entangles their spins are correlated. When one has spin up the other with have spin down. Standard quantum mechanics says that this state is only reached when one of the particles is measured. The other particle will then take on the opposite spin. This happens instantaneously. In 1935 Einstein, Podolsky and Rosen (EPR) did not like this concept, and assumed quantum mechanics to be incomplete. By assuming an enhanced spin state the EPR team proposed that the spins of the particles were correlated from the point of creation. The experimental outcome would be the same for standard quantum mechanics and the EPR explanation. There seemed to be no way to distinguish between the two description.
In 1964 John Bell proposed that it is experimentally possible to distinguish between the two description. The experiment was performed in the mid 1970s. The results favoured standard quantum mechanics. This implied that the state of a particle's spin would instantaneously correlate on the measurement of other. "Spooky action at a distance" as Einstein famously referred to it.
In this presentation we look at Bell's theorem.
A wonderful example of the magic and mystery of quantum mechanics is hidden in the details of how simple optics work. Even in the simple reflection of a flat mirror quantum mechanics offers a bizarre description of what is happening. All the mirror must be taken into account to explain where a photon may end up.
In this presentation we apply our wavefunction depiction to simple optics and explain the rainbow you see in a CD, in the colours of some butterfly wings, how a lens makes an image and the limitations of optics. The uncertainty principle explains why there is a limit to the amount of detail we can expect to see in an optical image.
One of the greatest achievements of quantum mechanics is its ability to describe the inner workings of the atom. Even some of the simplest properties of an atom can not be explained by classical physics, like the size of an atom or why an atom does not collapse. Quantum mechanics provided an explanation.
Even the nucleus has a quantum mechanical description which is very much in a developmental stage. Without a quantum explanation of the nucleus we would not understand how stars exist.
In this presentation we look at how quantum mechanics describe the atom and the rules it defines that constrains the characters of all the different elements.
It was the spectrum of hydrogen that led Neils Bohr to a quantum description of the hydrogen atom. Observing and creating spectra in one of the most powerful applications of quantum mechanics. Astronomy would be a very disabled science without the quantum interpretation of spectra. The generation of photons from shell transitions of electrons, to changing rotational and vibrational states of molecules has given us the means by which we can measure the composition and properties of the universe.
This presentation is all about colour and the information hidden in the electromagnetic spectrum and what it tells us about the atom.
More Applications of Quantum Mechanics
We are exposed to the application of quantum mechanical effects on a daily basis. Some are more sophisticated than others, such as an MRI scan. Nature also seems to have evolved some amazing application of quantum effects. One of the fastest growing fields is quantum computing. Still very much in its infancy quantum computing promises to solve problems that are well beyond the capabilities of modern conventional computers.
In this last presentation we look at how quantum mechanics is helping us today and where it may take us in the future.