Visit Your Local PBS Station PBS Home PBS Home Programs A-Z TV Schedules Watch Video Support PBS Shop PBS Search PBS
 
 
GIOVANNI DOMENICO CASSINI
GIOVANNI DOMENICO CASSINI
Genoa, Italy (1625 - 1712)
Giovanni Domenico Cassini was an Italian mathematician, astronomer, engineer, and astrologer. Cassini was an astronomer at the Panzano Observatory, from 1648 to 1669, professor of astronomy at the University of Bologna and became, in 1671, director of the Paris Observatory. Along with Robert Hooke, Cassini is given credit for the discovery of the Great Red Spot on Jupiter (ca. 1665). Cassini was the first to observe four of Saturn's moons, which he called Sidera Lodoicea. Around 1690, Cassini was the first to observe differential rotation within Jupiter's atmosphere.
 

Enjoy these insightful and educational video clips drawn from over 70 hours of interviews with the world's leading figures in astronomy, shot during the filming of 400 Years of the Telescope.

Search the catalog GO     FIND ALL     Display 5 10 25 Clips.

Find all clips by name:

Butler Burton

Locating a radio observatory
Butler Burton - NRAO, Green Bank

When a site is sought for an optical telescope you want a site which is dark. That means far from cities, far from city lights. When a site is sought for a radio telescope you want the sky also to be dark. Darkness in radio terms means free from interference.

PLAY VIDEO | VIEW TRANSCRIPT

Butler Burton

New frontiers in radio astronomy
Butler Burton - NRAO, Green Bank

Radioastronomy was the opening of a new scientific window. Whenever you open a new window you’re bound to be surprised. It can’t be otherwise. Serendipitous discoveries, surprises, are what happens.

PLAY VIDEO | VIEW TRANSCRIPT

Butler Burton

Optical versus radio telescopes
Butler Burton - NRAO, Green Bank

An optical telescope has a mirror, which reflects the incoming radiation to focus, which is a camera, an electronic camera. A radio telescope has a parabolic surface which reflects the incoming radio radiation to focus which is collected by a radio camera, a receiver, and it further processes the images from that reception.

PLAY VIDEO | VIEW TRANSCRIPT

Butler Burton

Collecting radio signals from space
Butler Burton - NRAO, Green Bank

The signals from space enters the Earth’s vicinity and those that are lucky enough to land on the surface of the GBT are reflected up to the focus. At the focus there’s a collection of receivers depending on which wavelength the astronomer wants to observe.

PLAY VIDEO | VIEW TRANSCRIPT

Butler Burton

Serendipitous radio discoveries
Butler Burton - NRAO, Green Bank

In all branches of science, serendipitous discoveries occur. They can’t be predicted but they have certain things in common, and one is that, like Jansky, the people understand the equipment they’re dealing with and are prepared to accept the unexpected.

PLAY VIDEO | VIEW TRANSCRIPT

« 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 »

The Film | Video | For Teachers | Schedule | News | Planetarium Program
Newsletter | IYA Calendar | Resources | Glossary | Contact Us | Site Map

© 2009 Interstellar Studios. All rights reserved.