CP/M (Control Program for Microcomputers) is an early operating system that was widely used in the late 1970s and early 1980s for personal computers. Developed by Digital Research, CP/M became a standard platform for microcomputers, especially those based on the Intel 8080 and Zilog Z80 CPUs. Over time, various variants of CP/M were created to serve different hardware architectures and user needs.

Renée Hložek is an astrophysicist known for her work in the field of cosmology, particularly in studying the large-scale structure of the universe, dark energy, and gravitational waves. She is an associate professor at the University of Toronto. Hložek has contributed to significant research projects and collaborations that aim to deepen our understanding of the universe and its underlying mechanisms. She has also been active in promoting diversity and inclusion in the sciences.

A creation myth is a symbolic narrative or story that explains how the universe, the world, and life began. These myths often convey the beliefs, values, and cultural identity of the people who tell them. Creation myths can vary widely among different cultures and religions, but they typically address fundamental questions about existence and the origin of humanity.

Most important application: produce X-rays for X-ray crystallography.

Note however that the big experiments at CERN, like the Large Hadron Collider, are also synchrotrons.

List of facilities: en.wikipedia.org/wiki/List_of_synchrotron_radiation_facilities

**Cosmographia** is a notable work written by the 12th-century philosopher and poet Bernardus Silvestris, also known as Bernard of Silvestre. This poem is one of the earliest examples of allegorical cosmology in medieval literature. The **Cosmographia** is structured as an epic poem and consists of seven books that explore the nature of the universe, integrating both Aristotelian philosophy and Christian theology.

Mammals and a bunch of extinct animals that look more like mammals than reptiles.

TODO name: Wikipedia says "being with a fused arch" but what does that mean???

"A Universe from Nothing" is a concept and a title of a popular book written by physicist Lawrence M. Krauss. The book, published in 2012, explores the idea that the universe could arise from a state of "nothing." Krauss argues that the laws of physics, particularly quantum mechanics, allow for the spontaneous creation of particles and, by extension, entire universes from a vacuum state that is devoid of matter.

Creation myths are traditional stories or narratives that explain how the universe, the Earth, and humanity came into existence. These myths are often foundational to the beliefs and cultures of various societies and can serve various purposes, such as providing a sense of identity, explaining natural phenomena, or establishing moral and social order.

www2.physics.ox.ac.uk/students/course-materials/symmetry-in-condensed-matter-physics# Archive: web.archive.org/web/20230804204137/https://www2.physics.ox.ac.uk/students/course-materials/symmetry-in-condensed-matter-physics Lecture notes from 2019.

Professor: Radu Coldea

A matrix that equals its transpose:

Can represent a symmetric bilinear form as shown at matrix representation of a symmetric bilinear form, or a quadratic form.

In cosmogony, "Chaos" refers to a primordial state of existence from which the universe and all things within it arise. This concept appears in various mythologies and philosophical systems, often representing a formless or void-like condition that precedes the creation of order and structure in the cosmos. In ancient Greek mythology, for example, Chaos is often depicted as a yawning void or a primal state of nothingness, from which the first deities and elements emerged.

The "Oh-My-God particle" refers to an extremely high-energy cosmic ray particle that was detected in 1991. Specifically, it was observed by the Fly's Eye observatory in Utah, USA. This particle, with an energy of about 3.2 x 10²⁰ electronvolts (eV), is significantly more energetic than any particles produced in terrestrial particle accelerators, such as the Large Hadron Collider.

Group of all permutations.

The main interest of this theorem is in classifying the indefinite orthogonal groups, which in turn is fundamental because the Lorentz group is an indefinite orthogonal groups, see: all indefinite orthogonal groups of matrices of equal metric signature are isomorphic.

It also tells us that a change of basis does not the alter the metric signature of a bilinear form, see matrix congruence can be seen as the change of basis of a bilinear form.

The theorem states that the number of 0, 1 and -1 in the metric signature is the same for two symmetric matrices that are congruent matrices.

For example, consider:

The eigenvalues of $A$ are $1$ and $4$, and the associated eigenvectors are:symPy code:and from the eigendecomposition of a real symmetric matrix we know that:

Now, instead of $P$, we could use $PE$, where $E$ is an arbitrary diagonal matrix of type:With this, would reach a new matrix $B$:Therefore, with this congruence, we are able to multiply the eigenvalues of $A$ by any positive number $e_1^2$ and $e_2^2$. Since we are multiplying by two arbitrary positive numbers, we cannot change the signs of the original eigenvalues, and so the metric signature is maintained, but respecting that any value can be reached.

Note that the matrix congruence relation looks a bit like the eigendecomposition of a matrix:but note that $D$ does not have to contain eigenvalues, unlike the eigendecomposition of a matrix. This is because here $S$ is not fixed to having eigenvectors in its columns.

But because the matrix is symmetric however, we could always choose $S$ to actually diagonalize as mentioned at eigendecomposition of a real symmetric matrix. Therefore, the metric signature can be seen directly from eigenvalues.

Also, because $D$ is a diagonal matrix, and thus symmetric, it must be that:

What this does represent, is a general change of basis that maintains the matrix a symmetric matrix.

Related:

OREOcube is a concept or product developed by Nabisco, which is a brand of Mondelēz International, known for producing Oreo cookies. The OREOcube is essentially a three-dimensional cube made up of Oreo cookie elements that can be manipulated and assembled in various ways, often focusing on creativity, construction, and play. While the specifics may vary, the OREOcube is typically aimed at both adults and children, combining the familiar enjoyment of Oreos with an interactive experience.

TODO freely licensed image of sycees presented on a plate. This is how gifts/prizes would be formally handed in ancient China, possibly wrapped in silk to make it more discrete.