Thanks to observations of galaxy redshifts, we can tell that the universe is EXPANDING! Knowing that the universe is expanding and how quickly its expanding ...
The majority of the universe is made up of a currently mysterious entity that pervades space: dark energy. We don't know exactly what it is, but we do know that ...
Our unit on the philosophy of religion and the existence of god continues with Thomas Aquinas. Today, we consider his first four arguments: the cosmological ...
Today on Crash Course Astronomy, Phil dives into some very dark matters. The stuff we can actually observe in the universe isn't all there is. Galaxies and other ...
In which John Green, Hank Green, and Emily Graslie teach you about what happened in the Universe after the big bang. They'll teach you about cosmic ...
The Milky Way is our neighborhood in the universe. It's a galaxy and there are many others out there. Galaxies contain gas, dust, and billions of stars or more.
In which John Green, Hank Green, and Emily Graslie teach you about, well, everything. Big History is the history of everything. We're going to start with the Big ...
Last week we introduced Thomas Aquinas's four cosmological arguments for the existence of god; today we introduce his fifth argument: the teleological ...
As we approach the end of Crash Course Astronomy, it's time now to acknowledge that our Universe's days are numbered. Stars will die out after a few trillion ...
Gamma-ray bursts are not only incredible to study, but their discovery has an epic story all its own. Today Phil takes you through some Cold War history and then ...
In the aftermath of a 8 – 20 solar mass star's demise we find a weird little object known as a neutron star. Neutrons stars are incredibly dense, spin rapidly, and ...
How do astronomers make sense out of the vastness of space? How do they study things so far away? Today Phil talks about distances, going back to early ...
In today's Crash Course Astronomy, Phil takes a look at the explosive history of our cosmic backyard. We explore how we went from a giant ball of gas to the ...
Active galaxies pour out lots of energy, due to their central supermassive black holes gobbling down matter. Galaxies tend not to be loners, but instead exist in ...
Welcome to the first episode of Crash Course Astronomy. Your host for this intergalactic adventure is the Bad Astronomer himself, Phil Plait. We begin with ...
In order to understand how we study the universe, we need to talk a little bit about light. Light is a form of energy. Its wavelength tells us its energy and color.
Cosmic Background Radiation. Created by Sal Khan. Watch the next lesson: ...
Aristotle was the master of virtues. If you like our films, take a look at our shop (we ship worldwide): https://goo.gl/OD73do FURTHER READING “Aristotle was ...
"A cosmic tempo based on Sacred Geometry, encoded in myth & mystical architecture throughout the Earth governs the unfolding of world ages, the rise and fall ...
Another version of the stellar parallax introduction. Created by Sal Khan. Watch the next lesson: ...
Thomas Malthus's views on population. Malthusian limits. Created by Sal Khan. Watch the next lesson: ...
Here it is, folks: the end. In our final episode of Crash Course Astronomy, Phil gives the course a send off with a look at some of his favorite topics and the big ...
Thanks to the wonders of physics, astronomers can map a timeline of the universe's history. Today, Phil's going to give you an overview of those first few minutes ...
One of the greatest inventions is the steam engine. But why? What makes it so useful? And how does it work? In this episode of Crash Course Physics, Shini ...
S-waves and P-waves. Created by Sal Khan. Watch the next lesson: ...
Phil starts the planet-by-planet tour of the solar system right here at home, Earth. -- Table of Contents Earth is a Planet 0:03 Layers of Earth 1:25 The Magnetic ...
String theory In physics, string theory is a theoretical framework in which the point-like particles of particle physics are replaced by one-dimensional objects ...
In this video we debunk the Kalam cosmological argument (commonly used by Dr William Lane Craig). The cosmological argument is commonly used by ...
Astronomers study a lot of gorgeous things, but nebulae might be the most breathtakingly beautiful of them all. Nebulae are clouds of gas and dust in space.
Today we're talking about our galactic neighborhood: The Milky Way. It's a disk galaxy, a collection of dust, gas, and hundreds of billions of stars, with the Sun ...
How changes in Earth's rotation can effect Earth's seasons and climate. Created by Sal Khan. Watch the next lesson: ...
Now that we've finished our tour of the planets, we're headed back to the asteroid belt. Asteroids are chunks of rock, metal, or both that were once part of ...
In today's episode, Phil looks at how gravity plays out across the universe. This episode is sponsored by Squarespace: ...
Today Phil explains that YES, there are other planets out there and astonomers have a lot of methods for detecting them. Nearly 2000 have been found so far.
We've covered a lot of incredible stuff, but this week we're talking about the weirdest objects in space: BLACK HOLES. Stellar mass black holes form when a ...
Saturn is the crown jewel of the solar system, beautiful and fascinating. It is a gas giant, and has a broad set of rings made of ice particles. Moons create gaps in ...