Considering how massive our universe is, we know the distances to cosmic objects surprisingly well. What tools and clues do scientists use to measure distances that are so enormous they sound like made-up numbers?

In the late 16th century, Tycho Brahe built an observatory on an island and collecting some of the most accurate data ever. He also lost his nose in a duel with a classmate -- over who was the better mathematician.

It's School of YouTube Week! Comic Relief and YouTube are partnering to send students to school! The Bad Astronomer Phil Plait teaches Hank how to measure the distance to the stars.

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 astronomy. Ancient Greeks were able to find the size of the Earth, and from that the...

Welcome to the first episode of a new format for Bizarre Beasts, which we’re calling Season Zero. Over the next year, we will be remastering episodes of Bizarre Beasts that were originally created for vlogbrothers.

First up: the...

Discover how parallax can be used to measure distances, and how early astronomers used it to find the distance of stars from Earth. Maths - Space A Twig Math Film. Reinforce and extend the learning required by the curriculum. Twig’s math...

In this introductory free-fall acceleration problem we analyze a video of a medicine ball being dropped to determine the final velocity and the time in free-fall. Included are three common mistakes students make. "Why include...

Holograms are photographic recordings of 3D scenes. Unlike a camera, which captures one view through a small viewer focused by a lens, holograms capture an entire light field which allows them to recreate the 3D scene. Shimmery 2D...

Technology that could one day result in glasses-free 3D movies at theaters is being developed by researchers at Seoul National University. Two different techniques, one using a parallax barrier and the other using a pinhole array, are...

This tutorial demonstrates how to create a popular parallax effect in Microsoft PowerPoint, where content and background images move at different speeds to create a sense of depth and immersion. Using simple steps like cropping images,...

We can't use tape measures, rulers or lasers to measure the astronomical distances to stars and galaxies, so how do we do it?

Once it was determined that the Earth is round, the next step was to decipher the geometry of the solar system. Does everything rotate around the Earth, like in the geocentric model of Ptolemy? We thought so for thousands of years, but...