IB Astrophysics - cosmology - Flippingphysics by nothingnerdyNothingnerdyThe document summarizes key concepts in cosmology, including Olbers' paradox, the expanding universe, the Big Bang theory, and evidence like the cosmic microwave background radiation. It discusses how the universe originated approximately 13.7 billion years ago in a massive expansion from a single point. The universe is still expanding today, and its fate depends on whether it has a flat, closed, or open geometry based on its total mass density. While most mass is dark matter and dark energy, their exact nature remains unknown. International space projects seek to further understand these cosmological questions through observation and research.
Ernest Sosa’s A Virtue Epistemology” (Lecture 2) TanaMaeskmErnest Sosa's lecture outlines a virtue epistemology that distinguishes between animal knowledge (apt belief requiring competence) and reflective knowledge (apt belief with defensibility). He explores concepts of safety and sensitivity in belief, addressing skepticism, particularly the dream problem, and concluding that knowledge doesn't require belief safety, as beliefs can remain apt despite being unsafe. The analysis culminates in a distinction between having definitions of knowledge and the criteria for attributing credit for performances or beliefs.
RedshiftHassaan SaleemCosmological redshift refers to the phenomenon where the wavelength of light from distant astronomical objects like galaxies is longer than the wavelength emitted. There are two main reasons for this - the relativistic Doppler shift due to the objects moving away from us due to the expansion of space, and the expansion of space itself increasing the wavelength as the light travels. Edwin Hubble discovered that more distant galaxies had a greater redshift, establishing the relationship between distance and velocity known as Hubble's law, which provided evidence that the universe is expanding. A few nearby galaxies instead show a blueshift due to their relative motion.
Electric Field, Electric Circuit and Electric Currentsalvie alvaroThis document defines and describes electric fields, electric current, and electrical circuits. It discusses how electric fields create forces on charged particles, how current is the flow of electric charge in a circuit, and how circuits can be connected in series or parallel. Components like batteries, bulbs, switches, and wires are explained. Diagrams illustrate key concepts like open versus closed circuits, series versus parallel connections, and circuit symbols.
042416 week7 electricity magnetismSubas NandyThis document outlines key concepts from Chapter 6a and 6b on electricity and magnetism. It covers topics such as positive and negative charge, Coulomb's law, conductors and insulators, Ohm's law, electromagnets, electromagnetic induction, and transformers. The main points are that opposite charges attract and like charges repel, Coulomb's law describes the electrostatic force between two charged particles, conductors allow electric charge to flow easily while insulators do not, and electromagnetic induction produces an electric current from a changing magnetic field.
Higgs bosonAbhijeet DasThe document discusses the Higgs boson, a particle predicted by the Standard Model of particle physics, which explains the masses of gauge bosons and the fundamental forces of nature. The existence of the Higgs boson was confirmed on April 4, 2012, by ATLAS and CMS detectors at CERN's Large Hadron Collider. It highlights the significance of the Higgs mechanism and the ongoing research in particle physics to understand the fundamental constituents of matter and their interactions.
10608486.pptmustafaalasady8Magnetic fields can confine charged plasma particles by restricting their motion across field lines while allowing motion along field lines. However, external forces or gradients in the magnetic field can cause particles to drift across field lines, breaking confinement. The Earth's magnetic field confines plasma in its magnetosphere and uses this confinement to deflect harmful solar particles, while planetary magnetic fields or artificial magnetic fields can be used to confine fusion plasma or create miniature magnetospheres for planetary protection.
042416 week7 electricity magnetismSubas NandyThis document outlines key concepts from Chapter 6a and 6b on electricity and magnetism. It covers topics such as positive and negative charge, Coulomb's law, conductors and insulators, Ohm's law, electromagnets, electromagnetic induction, and transformers. The main points are that opposite charges attract and like charges repel, Coulomb's law describes the electrostatic force between two charged particles, conductors allow electric charge to flow easily while insulators do not, and electromagnetic induction produces an electric current from a changing magnetic field.
Higgs bosonAbhijeet DasThe document discusses the Higgs boson, a particle predicted by the Standard Model of particle physics, which explains the masses of gauge bosons and the fundamental forces of nature. The existence of the Higgs boson was confirmed on April 4, 2012, by ATLAS and CMS detectors at CERN's Large Hadron Collider. It highlights the significance of the Higgs mechanism and the ongoing research in particle physics to understand the fundamental constituents of matter and their interactions.
10608486.pptmustafaalasady8Magnetic fields can confine charged plasma particles by restricting their motion across field lines while allowing motion along field lines. However, external forces or gradients in the magnetic field can cause particles to drift across field lines, breaking confinement. The Earth's magnetic field confines plasma in its magnetosphere and uses this confinement to deflect harmful solar particles, while planetary magnetic fields or artificial magnetic fields can be used to confine fusion plasma or create miniature magnetospheres for planetary protection.