The first image of a black hole was captured in 2019 by the Event Horizon Telescope (EHT) collaboration. Before that, the first observational evidence was discovered in 1964 with the detection of the X-ray source Cygnus X-1, which was later interpreted as material accreting onto a black hole from a companion star. In 1971, Cygnus […]
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General Relativity incorporated gravity into the mix. It describes gravity not as a force, but as the curvature of spacetime caused by massive objects. According to General Relativity, the curvature of spacetime around an object like the Earth causes objects to fall towards its center, which we experience as gravity. In November 1915, Einstein expanded
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30 Phil, Chapter 21, Galileo, Touchstone 52: Relativity Principle. The Relativity Principle states that the laws of physics are the same for all observers in uniform motion relative to one another. This means that the passage of time, the length of objects, and the speed of light are the same for everyone, regardless of their
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Special Relativity explains the relationship between space, time, mass, and energy. It shows that time and space are not separate entities but are connected as a single entity called spacetime. Additionally, it introduced the famous equation E=mc², which demonstrates that mass is engergy, energy is mass. They are equivalent and can be converted into each
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In 1965, Arno Penzias and Robert Wilson, two radio astronomers at Bell Telephone Laboratories, stumbled upon a mysterious and persistent background noise that pervaded their radio telescope. After much investigation and the elimination of potential terrestrial and instrumental sources, they concluded that this noise was cosmic in origin. Their findings, published on May 20, 1965,
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In 1848,French physicist Hippolyte Fizeau observed a shift in the spectral lines of stars, hinting at a similar effect for light waves.
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By 1929, an important time in cosmology, Edwin Hubble used the spiral nebulae data collected by Vesto Slipher from 1912 to 1925 to introduce the world to galaxies. Prior to the 20th century, astronomers debated whether spiral nebulae were merely gaseous clouds within the Milky Way, possibly forming solar systems. This view changed dramatically following
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The Doppler effect is the apparent difference between the frequency at which sound or light waves leave a source and that at which they reach an observer, caused by relative motion of the observer and the wave source. The Doppler effect for sound was first described by the Austrian physicist Christian Doppler in 1842. He
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30 Phil, Chapter 3 Touchstone 8: Holism. Holism views things as a whole, emphasizing interconnectedness and interdependence, and values unity and synthesis. It is essential for fully understanding complex systems like living organisms and ecosystems. This notion of an underlying, unifying essence mirrors the intricacies of the natural world, where each element, though distinct, harmoniously contributes
30 Phil, Chapter 3 Touchstone 7: Ontology. Ontology: When we’re alive, life feels endless, stretching beyond the horizon of our imagination. The realization that it must end is not easily accepted. We’re not just sentient beings; we are self-aware. For many, the notion that we cease to exist after death is unbearable. We can’t help
30 Phil, Chapter 2 Touchstone 6: Philosophy. Philosophy is the systematic study of fundamental questions concerning existence, knowledge, values, and meaning. It’s a discipline guided by reason and the evaluation of evidence. A central question is “How should we live?” While there is a general agreement on overarching principles, as always, the devil is in the
30 Phil, Chapter 2 Touchstone 5: Knowledge Framework. In philosophy, the study of knowledge is called epistemology. It’s important because knowledge describes reality, and understanding how we craft knowledge brings philosophical clarity. Each of us maintains a personal knowledge framework that arranges the knowledge we accumulate. You can think of it as a personalized dictionary. But
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30 Phil, Chapter 1 Touchstone 4: Cultural Transmission. Cultural transmission, perhaps more than any other trait, sets humans apart from other animals. It’s the ability to pass behaviors, traditions, and knowledge to the next generation. Cultural transmission has likely been a feature of our direct-line hominin mind for millions of years. Returning to what we
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30 Phil, Chapter 1 Touchstone 3: Evolution. In 1859, the naturalist Charles Darwin revolutionized the scientific world with his seminal publication, “On the Origin of Species.” In it he formulated his scientific theory of evolution by natural selection. The process by which new species arise is well-understood. It proposed that changes in species occur gradually over time. With each generation,
30 Phil, Chapter 1 Touchstone 2: Free Will. There are two basic types of Free Will. Determinism says everything that happens is set in stone and can’t be changed; in contrast, indeterminism says people and animals make choices. There are four basic types: scientific determinism, scientific indeterminism, fatalism, and providence.
While speculative, it is reasonable to position the occassional use of proto-medicine as emerging in the great apes sometime around 18 million years ago. Modern orangutans, apes, and chimpanzees treat wounds, digestive issues, and even use insect repellant. The Great Apes LCA lived around 18 million years ago, so using the Occam Approach, this implies
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The ancient site of Çatalhöyük was not continuously known through historical records and was rediscovered in the modern era. It was first excavated by James Mellaart in 1958, who conducted major excavations between 1961 and 1965. These excavations revealed a wealth of information about Neolithic life and brought significant attention to the site. Its discovery
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The earliest known use of plaster dates back to around 9000 BCE, with evidence from the ancient site of Çatalhöyük in modern-day Turkey. Here, Neolithic inhabitants utilized plaster made from lime to coat the floors, walls, and even ceilings of their mud-brick houses. This early application of plaster represents a significant technological innovation, indicating a
In the tropical rainforests of Mesoamerica, the ancient Olmecs unlock the secrets of the cacao pod. By fermenting, roasting, and grinding the seeds, they create the bitter beverage chocolate. This divine elixir lays the foundation for chocolate’s enduring legacy, cherished by the Mayans and Aztecs as a ceremonial drink, a currency, and a medicine.
In the highlands of Mexico, the story of maize, or corn, begins with its ancestor, teosinte. Through centuries of selective breeding, Indigenous peoples transform this humble grass into corn.
