Season
- Season 0 1966-12-25
- Season 1 1964-02-04
- Season 2 1965-01-06
- Season 3 1966-01-02
- Season 4 1967-01-17
- Season 5 1968-01-02
- Season 6 1969-01-02
- Season 7 1970-01-05
- Season 8 1971-01-04
- Season 9 1972-01-03
- Season 10 1973-01-04
- Season 11 1974-01-07
- Season 12 1975-01-20
- Season 13 1976-01-05
- Season 14 1977-01-07
- Season 15 1978-01-06
- Season 16 1979-02-26
- Season 17 1980-01-14
- Season 18 1981-01-05
- Season 19 1982-01-11
- Season 20 1983-01-10
- Season 21 1984-01-09
- Season 22 1985-01-07
- Season 23 1986-01-06
- Season 24 1987-01-05
- Season 25 1988-01-04
- Season 26 1989-01-09
- Season 27 1990-01-08
- Season 28 1991-01-07
- Season 29 1992-01-06
- Season 30 1993-01-04
- Season 31 1994-01-10
- Season 32 1995-01-09
- Season 33 1996-01-08
- Season 34 1997-02-27
- Season 35 1998-02-19
- Season 36 1999-01-28
- Season 37 2000-01-12
- Season 38 2001-01-25
- Season 39 2002-01-10
- Season 40 2003-01-09
- Season 41 2004-01-08
- Season 42 2005-01-13
- Season 43 2006-01-12
- Season 44 2007-03-13
- Season 45 2008-01-15
- Season 46 2009-01-26
- Season 47 2009-10-13
- Season 48 2010-09-27
- Season 49 2011-08-08
- Season 50 2012-07-23
- Season 51 2013-08-12
- Season 52 2014-08-18
- Season 53 2016-03-16
- Season 54 2017-01-19
- Season 55 2018-02-05
- Season 56 2019-01-23
- Season 57 2020-01-16
- Season 58 2021-01-04
- Season 59 2022-03-31
- Season 60 2024-07-22
Season 60 Episode
- Season 2 Learning from Machines
- Season 2 The Technique of Change
- Season 2 Star Gazers
- Season 2 Science and Art
- Season 2 The Great Computer Scandal / H-Bomb Detectors
- Season 2 Forbidden Events / I am a Madman
- Season 2 Restless Genius / Faster, Farther, Higher
- Season 2 The Other Side of the Pill
- Season 2 The Big Smoke / The Model Makers
- Season 2 The Long Slide / Men with Gills
- Season 2 Men and Sharks / Sir Henry Dale, OM, FRS
- Season 2 The Brain Gain / The Sudden Night / Learning to Speak
- Season 2 Dr. Joseph Needham / Mariner IV
- Season 2 Science Fiction : Science Fact? / Alone and Unarmed
- Season 2 Certain of Uncertainty / State of Nature
- Season 2 Time Stood Still / Weighty Matters
- Season 2 Fuel for the Future / Collector's Piece
- Season 2 Let Newton Be
- Season 2 Special Senses / Toil, Sweat & Tears
- Season 2 An Affair of the Heart
- Season 2 10,000 Tombs
- Season 2 Albert Szent-Györgyi M.D., Ph.D., D.h.c.
- Season 2 The Big Dishes / The Living Stream
- Season 2 Boys on Bubbles / Problems and Puzzles
Horizon - Season 2 Episode 9 The Big Smoke / The Model Makers
7.30 60 minutes Nine years after the passing of the Clean Air Act, where do we stand? Scientists are gradually finding out why dirty air Is so harmful to ill persons with Dr. P. J. Lawther of Air Pollution Research Centre at St. Bartholomew's Hospital.
Whenever the things they study are too big, too far off, or too hot to handle, scientists can make a model of these-but can they be sure their models truly represent reality?
