Below is a list of the guests from episodes that were first aired or last repeated in 2006. To listen, click on the episode title to go to that episode’s page.
| Name | Discipline/Profession | Episode Title | Episode Date | Last Aired |
|---|---|---|---|---|
| Najib Abboud | Law | Skeptical Sunday: 9/11 Conspiracy | 11/28/2006 | 11/28/2006 |
| Nancy Ellen Abrams | Author | The Universe in Theory | 7/11/2006 | 7/11/2006 |
| Joel Achenbach | Journalism/Technical Writing | Look! Up in the Sky! | 5/23/2006 | 5/23/2006 |
| Michael Archer | Education | Dinos and Carnivorous Kangaroos | 7/25/2006 | 7/25/2006 |
| Ken Alder | History | How the Universe Measures Up | 9/19/2006 | 9/19/2006 |
| Richard Alley | Geology | Waking the Giant | 10/24/2006 | 10/24/2006 |
| Abby Alwood | Geology | When Life Began | 7/18/2006 | 7/18/2006 |
| Robyn Asimov | Other | Robot Uprising | 5/2/2006 | 5/2/2006 |
| Tibor Balant | Astronomy | These Planets are a Gas | 3/28/2006 | 3/28/2006 |
| Ray Bamberry | Astronomy | Rubble Trouble | 9/5/2006 | 9/5/2006 |
| Christopher Bazinet | Biology | Sex: What is it Good For? | 8/8/2006 | 8/8/2006 |
| Bernie Beanstalk | Physics | The Horrendous Space Kablooie | 3/7/2006 | 3/7/2006 |
| Greg Bear | Author | To Boldly Go… Star Trek’s Legacy | 9/26/2006 | 9/26/2006 |
| Luann Becker | Chemistry | Dinos and Carnivorous Kangaroos | 7/25/2006 | 7/25/2006 |
| James Bennett | Author | Skeptical Sunday: 9/11 Conspiracy | 11/28/2006 | 11/28/2006 |
| Charles Bentley | Geology | Not So Cool | 4/25/2006 | 4/25/2006 |
| Michael Berger | Other | Skeptical Sunday: 9/11 Conspiracy | 11/28/2006 | 11/28/2006 |
| William Berger | Biology | Sex: What is it Good For? | 8/8/2006 | 8/8/2006 |
| William E. Burrows | Journalism/Technical Writing | Rubble Trouble | 9/5/2006 | 9/5/2006 |
| Douglas Caldwell | Astrobiology | Not So Cool | 4/25/2006 | 4/25/2006 |
| George Camps | Other | No Free Launch | 6/27/2006 | 6/27/2006 |
| Keith Chang | Genetics/Genomics | The Horrendous Space Kablooie | 3/7/2006 | 3/7/2006 |
| Marcus Chown | Journalism/Technical Writing | The Universe in Theory | 7/11/2006 | 7/11/2006 |
| Sharon Cisneros | Industry | Lost and Found Astronomy | 8/22/2006 | 8/22/2006 |
| Neil Clark | Biology | Skeptical Sunday: The Gospel According to SETI | 5/16/2006 | 5/16/2006 |
| Carol Cleland | Philosphy | Don’t Be a Chimp | 3/21/2006 | 3/21/2006 |
| Elizabeth Colbert | Journalism/Technical Writing | Not So Cool | 4/25/2006 | 4/25/2006 |
| Anthony Coloprete | Planetary Science | No Free Launch | 6/27/2006 | 6/27/2006 |
| David Coltman | Genetics/Genomics | Skeptical Sunday: Sleight of Hand | 4/4/2006 | 4/4/2006 |
| Martin Cooper | Industry | To Boldly Go… Star Trek’s Legacy | 9/26/2006 | 9/26/2006 |
| Dale Cruikshank | Planetary Science | Rubble Trouble | 9/5/2006 | 9/5/2006 |
| David Darling | Astronomy | These Planets are a Gas | 3/28/2006 | 3/28/2006 |
| David Darling | Astronomy | Skeptical Sunday: The Gospel According to SETI | 5/16/2006 | 5/16/2006 |
| Eric Davidson | Biology | That Last 2% | 12/12/2006 | 12/12/2006 |
| Paul Davies | Futurist | The Universe in Theory | 7/11/2006 | 7/11/2006 |
| Richard Dawkins | Biology | Don’t Be a Chimp | 3/21/2006 | 3/21/2006 |
| Frans de Waal | Biology | That Last 2% | 12/12/2006 | 12/12/2006 |
| Scott Diddams | Physics | How the Universe Measures Up | 9/19/2006 | 9/19/2006 |
| Dale Dougherty | Journalism/Technical Writing | F is for Science | 5/30/2006 | 5/30/2006 |
| Eric Dregni | Author | The End of Science: A New Beginning | 10/31/2006 | 10/31/2006 |
| Jonathan Dregni | Author | The End of Science: A New Beginning | 10/31/2006 | 10/31/2006 |
| Celia Edwards | Education | F is for Science | 5/30/2006 | 5/30/2006 |
| Ron Ekers | Astronomy | Lost and Found Astronomy | 8/22/2006 | 8/22/2006 |
| Jack Farmer | Geology | When Life Began | 7/18/2006 | 7/18/2006 |
| Ken Feder | Anthropology | Skeptical Sunday: There’s Noah Counting | 10/17/2006 | 10/17/2006 |
| Mark Fenster | Law | Skeptical Sunday: 9/11 Conspiracy | 11/28/2006 | 11/28/2006 |
| Matthew Fenton | Author | Skeptical Sunday: Exploring the Unexplained | 12/19/2006 | 12/19/2006 |
| Anne Foerst | Theology | Robot Uprising | 5/2/2006 | 5/2/2006 |
| Andrew Fraknoi | Astronomy | Skeptical Sunday: There’s Noah Counting | 10/17/2006 | 10/17/2006 |
| Andrew Fraknoi | Astronomy | Lost and Found Astronomy | 8/22/2006 | 8/22/2006 |
| Brett Gladman | Planetary Science | When Life Began | 7/18/2006 | 7/18/2006 |
| Robert Gold | Physics | The Horrendous Space Kablooie | 3/7/2006 | 3/7/2006 |
| Mariana Gosnell | Author | Not So Cool | 4/25/2006 | 4/25/2006 |
| Ronald Green | Biology | Neanderthals Return | 10/3/2006 | 10/3/2006 |
| Michael Griffin | Aeronautics/Space | A Trip Through the Solar System… But How Do You Planet? | 3/14/2006 | 3/14/2006 |
| Bud Gundy | Journalism/Technical Writing | The Horrendous Space Kablooie | 3/7/2006 | 3/7/2006 |
| Andrew Hamilton | Physics | Quantum Universe | 6/6/2006 | 6/6/2006 |
| Brian Hare | Biology | That Last 2% | 12/12/2006 | 12/12/2006 |
| Theona Harrison | Astrophysics | No Free Launch | 6/27/2006 | 6/27/2006 |
| Blair Hedges | Biology | Monsters and Mutations | 7/4/2006 | 7/4/2006 |
| Jörn Helbert | Planetary Science | Not So Cool | 4/25/2006 | 4/25/2006 |
| Trenton Holliday | Anthropology | Neanderthals Return | 10/3/2006 | 10/3/2006 |
| John Horgan | Journalism/Technical Writing | The End of Science: A New Beginning | 10/31/2006 | 10/31/2006 |
| Christine Huffard | Biology | Don’t Be a Chimp | 3/21/2006 | 3/21/2006 |
| David Itzkoff | Journalism/Technical Writing | Aliens Ready for Their Close-Up | 4/11/2006 | 4/11/2006 |
| Peter Jenniskens | Planetary Science | Skeptical Sunday: The Gospel According to SETI | 5/16/2006 | 5/16/2006 |
| Peter Jenniskens | Planetary Science | Look! Up in the Sky! | 5/23/2006 | 5/23/2006 |
| George Johnson | Journalism/Technical Writing | Quantum Universe | 6/6/2006 | 6/6/2006 |
| Steve Jones | Other | No Free Launch | 6/27/2006 | 6/27/2006 |
| Jane Jordan | Astrobiology | The Horrendous Space Kablooie | 3/7/2006 | 3/7/2006 |
| Tom Kilsdonk | Astrobiology | The Horrendous Space Kablooie | 3/7/2006 | 3/7/2006 |
| Paul Knauth | Geology | A Trip Through the Solar System… But How Do You Planet? | 3/14/2006 | 3/14/2006 |
| Walter Koenig | Entertainment | To Boldly Go… Star Trek’s Legacy | 9/26/2006 | 9/26/2006 |
| Lawrence Krauss | Physics | Aliens Ready for Their Close-Up | 4/11/2006 | 4/11/2006 |
| Lawrence Krauss | Physics | To Boldly Go… Star Trek’s Legacy | 9/26/2006 | 9/26/2006 |
| Joanna Kunis | Education | F is for Science | 5/30/2006 | 5/30/2006 |
| Kara Kunni | History | Skeptical Sunday: Curses! | 6/13/2006 | 6/13/2006 |
| Jane Lawson | Education | F is for Science | 5/30/2006 | 5/30/2006 |
| Leon Lederman | Physics | It’s Elemental | 11/21/2006 | 11/21/2006 |
| Nicolas Lemann | Journalism/Technical Writing | Skeptical Sunday: 9/11 Conspiracy | 11/28/2006 | 11/28/2006 |
| Michael Lemonick | Journalism/Technical Writing | F is for Science | 5/30/2006 | 5/30/2006 |
| John Lindsey | Planetary Science | When Life Began | 7/18/2006 | 7/18/2006 |
| Seth Lloyd | Engineering | Quantum Universe | 6/6/2006 | 6/6/2006 |
| John Logsdon | Aeronautics/Space | Lost and Found Astronomy | 8/22/2006 | 8/22/2006 |
| James Mallett | Biology | Monsters and Mutations | 7/4/2006 | 7/4/2006 |
| Rocco Mancinelli | Biology | When Life Began | 7/18/2006 | 7/18/2006 |
| Rocco Mancinelli | Biology | Skeptical Sunday: Meet a Psychic | 8/1/2006 | 8/1/2006 |
| Lori Marino | Evolutionary Science | Monsters and Mutations | 7/4/2006 | 7/4/2006 |
| Jessica Marshall | Journalism/Technical Writing | Don’t Be a Chimp | 3/21/2006 | 3/21/2006 |
| Thomas McCollum | Geology | A Trip Through the Solar System… But How Do You Planet? | 3/14/2006 | 3/14/2006 |
| Ralph McNutt | Physics | The Horrendous Space Kablooie | 3/7/2006 | 3/7/2006 |
| Rich McCray | Biology | Dinos and Carnivorous Kangaroos | 7/25/2006 | 7/25/2006 |
| Karen Meech | Genetics/Genomics | The Horrendous Space Kablooie | 3/7/2006 | 3/7/2006 |
| Michael Millane | Aeronautics/Space | No Free Launch | 6/27/2006 | 6/27/2006 |
| Geoffrey Miller | Psychology | It’s Elemental | 11/21/2006 | 11/21/2006 |
| Joe Miller | Biology | These Planets are a Gas | 3/28/2006 | 3/28/2006 |
| Steven Mithin | History | Neanderthals Return | 10/3/2006 | 10/3/2006 |
| Read Montague | Neuroscience | The End of Science: A New Beginning | 10/31/2006 | 10/31/2006 |
| David Morrison | Planetary Science | Rubble Trouble | 9/5/2006 | 9/5/2006 |
| Karim Nayernia | Biology | Sex: What is it Good For? | 8/8/2006 | 8/8/2006 |
| Darren Owens | Other | Skeptical Sunday: Meet a Psychic | 8/1/2006 | 8/1/2006 |
| Svante Pääbo | Evolutionary Sciences | Neanderthals Return | 10/3/2006 | 10/3/2006 |
| Roland Pease | Journalism/Technical Writing | These Planets are a Gas | 3/28/2006 | 3/28/2006 |
| Cynthia Phillips | Planetary Science | These Planets are a Gas | 3/28/2006 | 3/28/2006 |
| Ramond Pierrehumbert | Physics | Waking the Giant | 10/24/2006 | 10/24/2006 |
| Tom Pierson | Industry | F is for Science | 5/30/2006 | 5/30/2006 |
| Phil Plait | Astronomy | Don’t Be a Chimp | 3/21/2006 | 3/21/2006 |
| Phil Plait | Astronomy | Skeptical Sunday: Sleight of Hand | 4/4/2006 | 4/4/2006 |
| Phil Plait | Astronomy | Skeptical Sunday: The Gospel According to SETI | 5/16/2006 | 5/16/2006 |
| Phil Plait | Astronomy | Skeptical Sunday: Curses! | 6/13/2006 | 6/13/2006 |
| Phil Plait | Astronomy | Monsters and Mutations | 7/4/2006 | 7/4/2006 |
| Phil Plait | Astronomy | Skeptical Sunday: Meet a Psychic | 8/1/2006 | 8/1/2006 |
| Phil Plait | Astronomy | Skeptical Sunday: There’s Noah Counting | 10/17/2006 | 10/17/2006 |
| Phil Plait | Astronomy | Skeptical Sunday: 9/11 Conspiracy | 11/28/2006 | 11/28/2006 |
| Phil Plait | Astronomy | Skeptical Sunday: Exploring the Unexplained | 12/19/2006 | 12/19/2006 |
| Katherine Pollard | Biology | That Last 2% | 12/12/2006 | 12/12/2006 |
| Carolyn Porco | Planetary Science | These Planets are a Gas | 3/28/2006 | 3/28/2006 |
| Joel Primack | Physics | The Universe in Theory | 7/11/2006 | 7/11/2006 |
| Lawrence Principe | History | Lost and Found Astronomy | 8/22/2006 | 8/22/2006 |
| Jeffrey Rudsky | Psychology | Skeptical Sunday: Curses! | 6/13/2006 | 6/13/2006 |
| Joan Ruthgarden | Biology | Sex: What is it Good For? | 8/8/2006 | 8/8/2006 |
| Andy Saunders | Chemistry | Dinos and Carnivorous Kangaroos | 7/25/2006 | 7/25/2006 |
| Kathy Sawyer | Author | Look! Up in the Sky! | 5/23/2006 | 5/23/2006 |
| Steven Schuster | Genetics/Genomics | Monsters and Mutations | 7/4/2006 | 7/4/2006 |
| Rusty Schweickart | Aeronautics/Space | Rubble Trouble | 9/5/2006 | 9/5/2006 |
| Michael Shermer | Journalism/Technical Writing | Don’t Be a Chimp | 3/21/2006 | 3/21/2006 |
| Donna Shirley | Aeronautics/Space | Aliens Ready for Their Close-Up | 4/11/2006 | 4/11/2006 |
| Seth Shostak | Astronomy | Look! Up in the Sky! | 5/23/2006 | 5/23/2006 |
| Seth Shostak | Astronomy | When Life Began | 7/18/2006 | 7/18/2006 |
| Seth Shostak | Astronomy | Skeptical Sunday: Meet a Psychic | 8/1/2006 | 8/1/2006 |
| Mark Showalter | Planetary Science | A Trip Through the Solar System… But How Do You Planet? | 3/14/2006 | 3/14/2006 |
| Simon Singh | Journalism/Technical Writing | The Horrendous Space Kablooie | 3/7/2006 | 3/7/2006 |
| Mickey Sklar | Computer Science | Robot Uprising | 5/2/2006 | 5/2/2006 |
| Gordy Slack | Journalism/Technical Writing | Don’t Be a Chimp | 3/21/2006 | 3/21/2006 |
| Gordy Slack | Journalism/Technical Writing | Skeptical Sunday: Sleight of Hand | 4/4/2006 | 4/4/2006 |
| Gordy Slack | Journalism/Technical Writing | Skeptical Sunday: The Gospel According to SETI | 5/16/2006 | 5/16/2006 |
| David Smith | Engineering | It’s Elemental | 11/21/2006 | 11/21/2006 |
| Lamar Smith | Law | F is for Science | 5/30/2006 | 5/30/2006 |
| Dava Sobel | Author | A Trip Through the Solar System… But How Do You Planet? | 3/14/2006 | 3/14/2006 |
| Erica Sondergren | Genetics/Genomics | That Last 2% | 12/12/2006 | 12/12/2006 |
| Steve Squyers | Astronomy | A Trip Through the Solar System… But How Do You Planet? | 3/14/2006 | 3/14/2006 |
| Kris Stanek | Astronomy | How the Universe Measures Up | 9/19/2006 | 9/19/2006 |
| Phil Stevens | Anthropology | Skeptical Sunday: Curses! | 6/13/2006 | 6/13/2006 |
| Jill Tarter | Astronomy | Skeptical Sunday: The Gospel According to SETI | 5/16/2006 | 5/16/2006 |
| Ed Tarvyd | Biology | Skeptical Sunday: There’s Noah Counting | 10/17/2006 | 10/17/2006 |
| James Underdown | Sociolology | Skeptical Sunday: Sleight of Hand | 4/4/2006 | 4/4/2006 |
| James Underdown | Sociology | Skeptical Sunday: Curses! | 6/13/2006 | 6/13/2006 |
| James Underdown | Sociology | Skeptical Sunday: Meet a Psychic | 8/1/2006 | 8/1/2006 |
| James Underdown | Sociology | Skeptical Sunday: There’s Noah Counting | 10/17/2006 | 10/17/2006 |
| Francisco Valero | Physics | No Free Launch | 6/27/2006 | 6/27/2006 |
| Verner Vinge | Computer Science | Robot Uprising | 5/2/2006 | 5/2/2006 |
| Malcolm Walter | Astrobiology | When Life Began | 7/18/2006 | 7/18/2006 |
| Sheila Watt-Cloutier | Other | Waking the Giant | 10/24/2006 | 10/24/2006 |
| George Weinstock | Biology | That Last 2% | 12/12/2006 | 12/12/2006 |
| Eric Weygrin | Astronomy | When Life Began | 7/18/2006 | 7/18/2006 |
| Daniel Wilson | Author | Robot Uprising | 5/2/2006 | 5/2/2006 |
| Ian Wilson | Biology | Monsters and Mutations | 7/4/2006 | 7/4/2006 |
| Richard Wiseman | Psychology | Skeptical Sunday: Sleight of Hand | 4/4/2006 | 4/4/2006 |
| Peter Woit | Mathematics | How the Universe Measures Up | 9/19/2006 | 9/19/2006 |
| Lucy Ziurys | Astronomy | Look! Up in the Sky! | 5/23/2006 | 5/23/2006 |
