Measuring the Universe
About this video
Determining the distance of the stars in an expanding universe.
Dr. Olivia Johnson from the University of Nottingham explains how astronomers have built upon systems of measurement to calculate the distance of the furthest stars in an expanding universe.
The quirky animation leads us through a variety of techniques for calculating the distance of moving celestial objects — from parallax and standard candles (objects with known luminosity) to measuring the different wavelengths of light emitted from a star.
"It's only by knowing the scale of our Solar System — the distance between the Earth and Sun — that we're able to measure the distances to nearby stars using parallax.
If we can find out how far it is to some nearby standard candles using parallax, we can then use parallels between standard candles to measure the distances to further stars and galaxies.
Finally, by studying the motion of galaxies with standard candles, we learn we can use red shift to measure distances throughout our expanding universe."
Created by animators Robert Milne, Kwok Fung Lam and Ross Phillips the film forms part of the Royal Observatory’s micro exhibition 'Measuring the Universe: from the transit of Venus to the edge of the cosmos'. Admission is free until the end of September 2012.
Licence: © Royal Observatory Greenwich