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“It is the only physical theory of universal content, which I am convinced, that within the framework of applicability of its basic concepts will never be overthrown.”
Albert Einstein
We used videos illustrating Conway’s game of life from:
https://playgameoflife.com, https://www.youtube.com/watch?v=3NDAZ..., https://www.youtube.com/watch?v=xP5-i...
A variety of photos and gif files were taken from wikipedia, wikimedia and online open sources.
Majbrasa: Traditional Swedish fire to commemorate the beginning of spring. The picture is from Gamla Uppsala celebration, 30th April 2022.
In ancient civilisations, people believed that fire consists of fire elements and vapour/liquid/solid consists of vapour/liquid/solid elements. While it is a bit true for fire (molecules are partially ionised), we know these days that this is fundamentally wrong for the other states of matter: It is not what molecules are but how they organise that determines which phase of the matter shall be.
You probably learned that red is a hot colour and blue is a cold colour. In fact, it is the opposite in physics! Any body emits thermal radiation which is just invisible to us unless the body is hot. The body should be as hot as fire for the radiation to become visible, and it will be of red and then yellow colour which you see in the picture. If we raise the temperature further, the colour of the radiation shifts from red to blue. So blue is actually much hotter than red!
Our Sun is not yellow but white (a mixture of all colours corresponding to its surface temperature above 5000 degrees), we see it as yellow/red on the Earth's surface for a different reason: Light scatters in the atmosphere, and blue colours scatter more while yellowish colours follow a more straight path. This also explains why the sky is blue.
Phases of matter and thermal radiation are topics explained by statistical physics.
Another interesting question is why the sky is dark at night (so-called Olbers' paradox). In reality it is not, just it is so low-temperature radiation (-270 degrees Celcius) that we don't see it with the naked eye. Scientists can measure it though and even launched Planck telescope to space to study it. This radiation tells us about the history of the Universe, and we shall discuss it during other lectures: about Gravity and Cosmology.
Brief description
When there are too many things, we'd better give up any attempt at a detailed description and resort to the idea of getting the most probable outcome. That's the world of statistical physics. At first glance, everything looks chaotic. However, behind this chaos, there are universal laws which work independently of how the system looks at the microscopic level.
To quantify the concepts of order and chaos we should introduce the mathematically meaningful idea of information. The lack of information--entropy--is notorious for being the one that is constantly increasing. Microscopic laws of Nature are essentially reversible in time, and it is hard to understand how something irreversible can exist. One opinion is that time exists only in human perception and the irreversible process of the entropy increase defines for us the feeling of the time flow.
Another interesting question is how much information can we store in a given volume. A surprise comes that the maximal amount of information is proportional not to the volume but to its surface area which leads to the idea that the Universe is just a holographic image of something stored on its boundary.
Brief plan of the lecture:
Part I: Chaos, order, and statistical laws
Deterministic choas in relatively small systems. Butterfly effect. Why predicting weather is hard.
Laws of large numbers
Statistical analysis of elections: scientific indicators of falcified votes
Organisation at large scales: regular structures from chaos, and different phases of matter
Exotic materials
Conway's game of life
Part II: Information
Sending and coding signals. Shannon entropy
Information and entropy. 2nd law. Examples and computer simulations when entropy does decrease!
Arrow of time
Maxwell daemon and other paradoxes
Bounds on storing information
World as a hologram
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