Hyperbolic geometry | Surfaces | Spheres | Differential geometry
In geometry, a pseudosphere is a surface with constant negative Gaussian curvature. A pseudosphere of radius R is a surface in having curvature −1/R2 in each point. Its name comes from the analogy with the sphere of radius R, which is a surface of curvature 1/R2. The term was introduced by Eugenio Beltrami in his 1868 paper on models of hyperbolic geometry. (Wikipedia).
Teach Astronomy - Pseudoscience
http://www.teachastronomy.com/ A pseudoscience is something that pretends to be scientific but is not. Science follows a rigorous method which relies on the sharing of data, the basis in observations, and the fact that any scientist can assert something, but it has to be supported by evid
From playlist 01. Fundamentals of Science and Astronomy
Differences Between Natural & Artificial Ecosystems | Ecology & Environment | Biology | FuseSchool
An ecosystem can be defined as a large, highly interconnected area of the planet that is composed of several different biotic and abiotic components. A good example of an ecosystem would be an entire forest or mountain range. A natural ecosystem is made of all the plants, animals, and en
From playlist BIOLOGY: Ecology & Environment
Ken Brecher – Pseudosphere Rolling Uphill – March 23, 2014
The “Uphill Roller” is a beautiful (and counterintuitive) physics demonstration. English mathematician William Leybourn first reported it in 1694. In the original version, a double cone placed on two divergent inclined ramps appears to roll “uphill”, apparently violating the laws of physi
From playlist Illusions
Illuminating hyperbolic geometry
Joint work with Saul Schleimer. In this short video we show how various models of hyperbolic geometry can be obtained from the hemisphere model via stereographic and orthogonal projection. 2D figure credits: 4:09 Cannon, Floyd, Kenyon, Parry. 0:49, 1:20, 1:31, 2:12, Roice Nelson. We th
From playlist 3D printing
We (could) live on a 4D Pringle (Non-Euclidean Geometry and the shape of the Universe)
Everything we were taught in geometry falls apart if our universe is curved. This video is a friendly introduction to non-Euclidean geometry and how cosmologists used the Cosmic Microwave Background to calculate the curvature of our universe. See Part Two of the shape of the universe duo
From playlist Summer of Math Exposition 2 videos
Life in the Clouds | bioGraphic
Scientists are looking skyward to explore one of biology’s last frontiers and discovering arich diversity of microbial life high above our heads. Learn more: http://www.biographic.com/posts/sto/invisible-nature-life-in-the-clouds (Video by Flora Lichtman) --- Discover more beautiful and
From playlist American Museum of Natural History's Wonders of Nature
Supported by Patreon! https://www.patreon.com/vihart Shirts: https://store.dftba.com/collections/vi-hart/products/tau-day-shirt Especially thank you to: Caleb Wright, Albert Wenger, Pat Devlin, Jack Heidrick, Jade Bilkey, David Perryman, Chris Pierik, Donald "Chronos" King, Carol Ghiorsi
From playlist Recreational Math Videos
Check out my newest video over on @FlammysWood where I started the Series "Mathematics for Woodworkers"! :) https://youtu.be/e7gFloGdKxs 6.9% off all Handcrafted products, puzzles and more! :0 https://stemerch.eu/collections/handmade-by-stemerch-eu 10-15% off ALL my Merch using the code SI
From playlist Advent Calendar 2021
Wolfgang Schief: A canonical discrete analogue of classical circular cross sections of ellipsoids
Abstract: Two classical but perhaps little known facts of "elementary" geometry are that an ellipsoid may be sliced into two one-parameter families of circles and that ellipsoids may be deformed into each other in such a manner that these circles are preserved. In fact, as an illustration
From playlist Integrable Systems 9th Workshop
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From playlist Science Unplugged: General Relativity
Is There A Shadow Biosphere? Searching For Life On Earth That Isn't Related To Us
Whenever I talk about the search for life in the Universe and its emphasis on water, I get comments that scientists aren’t being creative enough. Why does life rely on water? Couldn’t there be lifeforms which are completely different from life on Earth? Isn’t that the textbook definition o
From playlist Guide to Space
Astronomy - Ch. 9.1: Earth's Atmosphere (25 of 46) What is the Greenhouse Effect?
Visit http://ilectureonline.com for more math and science lectures! In this video I will explain what is the greenhouse effect by relating our troposphere to an actual greenhouse, and a person sleeping in a sleeping bag. Next video in this series can be seen at: https://youtu.be/3dnpLIqQ
From playlist THE GREENHOUSE EFFECT
The Universe is always surprising us with how little we know about... the Universe. It's continuously presenting us with stuff we never imagined, or even thought possible. The search for extrasolar planets is a great example. Since we started, astronomers have turned up over a thousand
From playlist Planets and Moons
What is the difference between theoretical and experimental physics?
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From playlist Science Unplugged: Physics
The Extraordinary Theorems of John Nash - with Cédric Villani
Fields medal winner Cédric Villani takes us through the very special world of mathematical creation of John Nash, who founded several new chapters of game theory and geometric analysis in just a few revolutionary contributions that seemed to come from nowhere. Subscribe for regular scienc
From playlist Mathematics
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From playlist Science Unplugged: Parallel Universes
What the heck is a Multiverse?
The idea of a multiverse (short for multiple universes) can seem absurd. After all, the definition of universe means everything, so what does it mean to have multiple universes? In this video, Fermilab’s Dr. Don Lincoln lists a couple possible definitions for a multiverse. The reality in
From playlist Speculative Physics
First-order rigidity, bi-interpretability, and congruence subgroups - Nir Avni
Arithmetic Groups Topic: First-order rigidity, bi-interpretability, and congruence subgroups Speaker: Nir Avni Affiliation: Northwestern University Date: October 13, 2021 I'll describe a method for analyzing the first-order theory of an arithmetic group using its congruence quotients. W
From playlist Mathematics