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 61 2025-08-18
Season 61 Episode
- Season 41 Episode 1
- Season 41 Episode 2
- Season 41 Episode 3
- Season 41 Episode 4
- Season 41 Episode 5
- Season 41 Episode 6
- Season 41 Episode 7
- Season 41 Episode 8
- Season 41 Episode 9
- Season 41 Episode 10
- Season 41 Episode 11
- Season 41 Episode 12
- Season 41 Episode 13
- Season 41 Episode 14
- Season 41 Episode 15
- Season 41 Episode 16
- Season 41 Episode 17
- Season 41 Episode 18
Horizon - Season 41 Episode 9 Project Poltergeist
7.40 60 minutes This is the story of two genuine scientific heroes. For forty years, John Bahcall and Ray Davis were engaged in a single extraordinary experiment - to find out why the Sun shines. In the end they would triumph. Davis would win the Nobel Prize and, thanks to their work, a whole new theory about how the universe is put together may have to be created.
At the heart of this story is a tiny, utterly mysterious thing called a neutrino. Trillions of them pass through your body every second, touching nothing, leaving no trace. Yet neutrinos are one of a handful of fundamental particles in the universe, essential to every atom in existence and clues to what makes the Sun work. But their ghost-like quality made trapping and understanding them immensely difficult.
What then followed was a bizarre series of experiments. They led from a vat containing 600 tons of cleaning fluid, to a vast cavern in a Japanese mountain, to a hole in the ground in Canada two kilometres deep.
What they would reveal would stun the world of science. It seems that neutrinos may be our parents. They may be the reason why everything, including us, exists.
