Writer and comedic actor Lucas Kavner (@lucaskavner) joins Andy and Matt to talk about rebooted shows, reporting on robots, dog and wolf sharing, how breakfast affects benevolence, Einstein's impossible experiment finally performed, gut bacteria and dinosaur sex.

Comedian Curtis Cook (@Curtis_Cook) writes with Matt on The Jim Jefferies Show, and he sits down to discuss fancy premiere parties and imposter syndrome, catapult-making, how depressing the first Peanuts comic strip is, how AI will beat humans at everything by 2060, Moravec’s paradox, dino feathers and scales, getting re-upped on your vaccines, rust getting unfairly blamed for tetanus and parasitic worm healing.

Renee Colvert (@ReneeColvert) of the hit podcast Can I Pet Your Dog? joins Matt and Andy to discuss Paris disagreements, dog podcasting, universal healthcare, Savage/Soundgarden, Australian healthcare, another LIGO victory, Janna Levin's book, the Parker Solar Probe, the monkey mafia who steal your stuff and sell it back to you for a cracker, measuring sheep pain, and hand-washing rules.

Comedian and Jim Jefferies Show writer Subhah Agarwal (@Subhah) joins co-writer Matt and Andy to talk about actuarial tables and suicide, copying comics, asteroid timing, river meandering, a perfect dino, stable flamingos, Italian vaccines, mussel gloop for scarring, pretty pics of Saturn's rings and a puffy styrofoam planet.

Neil deGrasse Tyson (@neiltyson), astrophysicist, science communicator and author of the fantastic new book Astrophysics for People in a Hurry, joins Matt and Andy for a Definitely Science episode, discussing, well, the entire universe: Its origins, the forces that govern it, general relativity, the multiverse, dark matter, dark energy, the fact that the universe is under no obligation to make sense to you, and the questions that Neil would ask a physicist in the year 2317. This episode is brought to you by Parachute; visit parachutehome.com/science for free shipping and returns and a no-risk 60-night trial.

Live from the 10th annual Bridgetown Comedy Festival in Portland, Oregon, Matt and Andy welcome Reed College professor and cultural anthropologist specializing in health and medicine in southern Africa Dr. Betsey Brada, anthropologist specializing in bardic song in contemporary Russia Dr. Brian Horne, and the voice of Crow on Mystery Science Theater 3000: The Return Hampton Yount (@hamptonyount).

Comedy powerhouse Russell Howard (@russellhoward) joins Matt and Andy to chat about unintentional rudeness, new spider species, birds of paradise dances, Catalina and gerbil smuggling, more spiders, scaring off mice, artificial wombs and throwing things.

Matt and Andy traveled to downtown LA's Pershing Square and City Hall to take part in the March for Science, along the way speaking with various groups who had set up booths for the event, and even a neuroscientist listener who took the time to chat about her work giving cocaine to mice. Don't forget that Probably Science (and Andy and Matt individually) will be performing live at Portland's Bridgetown Comedy Festival on May 7th. Get your festival passes now at bridgetowncomedy.com

Married comedians Mary Mack (@marymackcomedy) and Tim Harmston (@timharmston) sit down with Andy and Matt to talk about Frog rockets, orchestral doubling, Army band status, Guy Fawkes, accidentally melting science, dinobirds, kids with beaks, triple yolks, yogurt toppings economics, the book-stacking problem and why shoelaces come untied.

Comedians Bryan Vokey (@BryanVokey), Carmen Morales (@thefunnycarmen) and TJ Chambers (@tjchambersLA) join Andy and Matt to discuss Georgia creationism, sperm-delivered drugs, erogenous T-Rex noses, geological Brexit, Segways on boats, Andy's mathematics puzzle, hamsters on Viagra and how memories are made.

Returning guest Henry Phillips (@henlips) of Punching Henry fame sits down with Matt and Andy to discuss graphene water filtration, a real-life (sort-of) Iron Man, funny foreign names, CT scan risks, CTs vs. MRIs, biologics, dumb/smart interview questions and the probability of rude names happening randomly.  

Comedian MK Paulsen (@mkpaulsen) joins Matt and Andy to talk about Crazy Frog, public policy, October Sky, RIP radioactive boy scout, a heart of spinach, German fake suns, beating cancer and stopping aging, corrections corner, Andy's new swim teammate, strep, the Ten Commandments, tits on Nazis and chimp death rituals.

Comedian Phoebe Bottoms (@phoebebottoms) and returning guest TJ Chambers (@tjchambersLA) join Andy and Matt to discuss the Boaty McBoatface submarine, sirens and pigs, breaking up with your physics teacher, naughty snooping dildos, microphones in your pocket, why avoiding gluten might hurt you, unvaccinated Australians, OCD, which animals you can't keep as pets, why plastic is still bad, why licking video games is no fun anymore, Egg-wina and pee danger.

Hot on the heels of her recent Tonight Show appearance, comedian Candice Thompson (@jokesbyCandice) joins Matt and Andy to talk about Punching Henry, the movie Matt is in with Henry Phillips, ASMR, Richard Simmons, anti-Brit racism, what zoo animals taste like, Neanderthals’ medication, mini-pigs and films about them, iCondoms, 3D printing medical supplies and pizzas, swimming pool pee and dog fMRIs.

Comedian and actor Johnny Pemberton (@johnnypemberton) of Son of Zorn joins Matt and Andy to discuss water shortage solutions and Indiegogo lies, pipe bombs, ulcerative colitis, money you can piss on, a better way to crowdsource, training bees to play with balls, chiropractic, more opinions on cats and toxo, saving polar ice and eating da poo-poo.

Comedian Kate Willett (@katewillett) joins Andy and Matt to talk about NASA's big exoplanet announcement and Episode 70 of our show discussing exoplanet research, the twin paradox, twin astronauts, fake Twitter accounts, a study showing that cats may not make you crazy, and a chiropractor's creative menstrual invention.

Comedians Ever Mainard (@evermainard) and Deborah Etta (@deborah_etta) join Andy and Matt to talk about scientific weirdos and Galois, starfish and STDs and regrowing dicks, finger regrowth, Matt’s awful ex, why whales jump, unethical kitten experiments, science fairs gone wrong, more blood and shit stuff, moon stuff and monkeys and dogs judging cooperation in humans. This episode is brought to you by Audible. For a free 30-day trial, visit audible.com/psp.

Danish comedian Simon Talbot (@simontalbot_) recently relocated to the US, and he joins Matt and Andy to talk about Andy's cold apartment, Jehovah's witnessing, Simon’s weird blood, our no-butthole ancestor, dinosaur protein, Danish traditions, time crystals, ask-a-sociopath, talking viruses and a possible way to reverse antibiotic resistance.

British comic James Acaster (@JamesAcaster) stopped by to talk with Matt and Andy about city rivalries, science marches, conga/flute/didgeridoo combos, Jerusalem Syndrome and Paris Syndrome, human/pig chimeras, cats possibly being as intelligent as dogs, Matt not knowing how big an otter is, giant otter fossils, slowing down light, a light speed sonic boom and James' band Luna Dott Raids the Bee Pigeon.

Podcaster Andrew Ti (@ANDREWTI) of the popular show (and blog) Yo, Is This Racist? joins Andy and Matt to talk about injecting frog neurotoxins in eyes, unethical self-experiments, the EPA vs. Trump, fake news inoculation, a free course on critical reasoning, poop stuff, mouse lasers, dumb psychopaths and who is, in fact, racist.

Comedy writer and improviser Laura Willcox (@Laura_Willcox) and comedian Andy Peters (@andy_peters) join Matt and Andy to talk about famous and not famous namesakes, failing low-level tests, sharks reproducing asexually, dud rockets, rhino shit as social media, cat marking and the parasites in it, a massive Venus wave, the truth about lemmings and other potentially dodgy kids' films, plus alchemy.

Actor/author Maggie Rowe (@ThisMaggieRowe) has written for Arrested Development and produced both Hollywood Hell House and Hollywood Purity Ball, and her new book Sin Bravely: A Memoir of Spiritual Disobedience chronicles her early experiences as a born-again Christian and her time spent in an Evangelical psychiatric facility. Maggie joins Matt and Andy to discuss entropy and evolution, false memory and sleep, synaesthesia and lightning strikes, icebergs and global warming, the antimatter story we didn’t cover, the origins of Stouffer's french bread pizza, and radio bursts from a galaxy billions of light years away.

British standup and sketch comic Steve Hall (@stevehallcomedy) happened to be stateside for the holidays, so he stopped by to talk with Matt and Andy about pamphlets and Thomas Paine, the passing of dark matter-discoverer Vera Rubin, ants using tiny sponges to carry honey, new evidence that suggests an iceberg didn't cause the Titanic to sink, why sustainable fishing might not be the best, molten underground rivers, Bill Gates and an effective Ebola vaccine, Dr. Jane Gregory's Cognitive Behave Yourself, inverted farting, Eric Cantona's goal, a pretend city for kids and First Kiss by Steve's sketch group We Are Klang.

Sylvia Tara (@SylviaTaraPhD) holds a PhD in biochemistry, and in her new book The Secret Life of Fat: The Science Behind the Body's Least Understood Organ and What It Means For You she examines the function and behavior of fat, why it's essential to our lives, how our genetics, gender, hormones and microbiomes affect it and much more. Her book is on sale December 27th, and you can pre-order it here or visit thesecretlifeoffat.com for more information. This episode is brought to you by Curiosity Box by Vsauce. To get your mystery box full of geeky science toys and gear along with a FREE Vsauce beanie, visit curiositybox.com/probablyscience.

Comedian and former marine biologist Forrest Shaw (@forrestshaw) joins Matt and Andy to discuss face painting and Mexican fireworks and lax laws, manatee preservation and their removal from storm drains, a bid to save the smallest porpoise, Chinese appetites for rare animals, a feathery dinosaur tail encased in amber, SSREs and the bees of the ocean.

Comedy Central Roast writer Bryan Olsen (@olsen__) and comedian Dominic Harris (@DomComedy) sit down with Matt (@mattkirshen) and Andy (@andytwood) to talk about battery pigs, Dom's lost episode, Saint Bernard and Air Bud, Buzz and Antarctica, Dominic the debutante, dog memory, gut Parkinson’s, fecal transplants again, new elements, the chemistry helpline, uncombable hair syndrome, platypus venom that can help diabetes and Dominic's new album. This episode is brought to you by Curiosity Box by Vsauce. To get your mystery box full of geeky science toys and gear along with a FREE Vsauce beanie, visit curiositybox.com/probablyscience.

Comedian and movie reviewer Cecily Knobler (@Cecilysaysstuff) joins returning guest Auggie Smith (@auggiesmith) and Andy (@andytwood) to discuss hospice humor, intervention critiques, Andy Dick stories, sex addiction getting depathologized, Auggie's issues with addicts, Cecily's neuropsychology background, Myers-Briggs personality types, high school kids undercutting Martin Shkreli's expensive drugs, Google's AI that can lip read better than humans, SNL's Trump responsibility, naming Secretaries of State, Cecily's book and Andy's swim meet.

Comedian Eric Lampaert (@EricLampaert) and returning guest JJ Whitehead (@JJWhitesnake) join Matt and Andy to discuss NASA's Space Poop Challenge, paper bike helmets, an end to zika's global health emergency, the hanging of a shipwrecked monkey and a circus elephant, JJ's new album and two moose found locked together in ice. This episode is brought to you by Curiosity Box by Vsauce. To get your mystery box full of geeky science toys and gear along with a FREE Vsauce beanie, visit curiositybox.com/probablyscience.

Comedian, engineer and outspoken moderate Toby Muresianu (@tobymuresianu) joins Andy and Matt to discuss President-Elect Trump on vaccines, Vice President-Elect Pence on smoking, Macedonian Facebook clickbait, polling methodologies, the supermoon, dog domestication, brain wifi that reverses monkey paralysis and a new type of bond.

Comedian and former environmental scientist Grant Lyon (@grantlyon1) joins Matt and Andy to talk about the Elkhorn Slough Foundation, naked cow science, why reservoirs aren’t all good, surgery farts, nightmare machines, sentencing algorithms, a third hominid and Patient Letter O. This episode is brought to you by Curiosity Box by Vsauce. To get your mystery box full of geeky science toys and gear along with a FREE Vsauce beanie, visit curiositybox.com/probablyscience.

Comedian, podcaster and author Moshe Kasher (@moshekasher) returns to the show, inviting Andy and Matt over to his place to talk about playground games, Moshe’s entomologist stepdad, stealthy spider eaters, mice fall for the same tricks as humans, the rise of renewables, vaccine deniers who accidentally proved the counterargument, conspiracy theories, the AIDS denial mom, the Duesberg hypothesis, an accidental discovery of a way to slow aging in the brain and porn theaters.  

Comedian, musician and bestselling author Greg Behrendt (@gregorybehrendt) joins Matt and Andy to talk about the joys of riding bikes, Laird Hamilton shooting the pier in Malibu, teachers’ penises, cod accents, Nazis on meth, Provigil and sleep, black widow spider viruses, a correction to the intelligence story, Alan Turing music and Dr. Strange.

Writer/comedian extraordinaire Lizzy Cooperman (@lizzycooperman) joins Matt and Andy to talk about Invisalign, fan death, having Lyme disease, Nobel Prizes in chemistry, physics and medicine, self-eating boobs and the end of Rosetta.

Comedian Shawn Pearlman (@shawnpearlman) joins Andy and Matt to talk about Shawn’s early movie effects, budgie rules for not colliding, boning young spiders, amateur turtle surgery, getting intelligence from your mother, a baby with three parents and the most accurate (and adorable) dinosaur renderings yet.

Steele Saunders (@SteeleSaunders), host of I Love Green Guide Letters and Steele Wars, joins Matt and Andy to talk about mice and apologies, more body (not head) transplants. smoke bombs, weed vs. opioids in car crashes, bumper sticker flashing, Australians origins, and giraffes actually being many giraffes.

Matt sits down with returning guest comedian Shane Mauss (@shanecomedy) to talk about his podcast Here We Are, his new tour all about psychedelics called A Good Trip, his early days as a more straightforward standup, his dalliances into evolutionary biology, the state of scientific research into recreational drugs, simulated near-death experiences, and the differences between trying ayahuasca and DMT.

Comedians Christian Duguay (@christianduguay) and Emily Maya Mills (@emilymayamills) join Matt and Andy at Andy's new apartment to talk about screaming at roommates, burning ants, Hitler's disguises, bank robbery, infant simulators that actually increase teen pregnancy, Lucy’s death, a miraculous new painkiller, ecstasy/MDMA, Tasmanian devils developing cancer resistance and the ban on antibacterial soap.

Comedians Ahmed Bharoocha (@ahmedbharoocha) and Auggie Smith (@auggiesmith) join Matt and Andy for the final recording from Bluebell Ranch, which happens to coincide with an apocalyptic forest fire in the area, and the crew discuss topics including bouncy castle economics, zorbs in Russia, a new hard material, the Mohs hardness scale, Pliny the Elder, the Randi paranormal challenge, new brain areas, listening to music while drinking, a new biohybrid creature, a Mars laser with free will, artwork damagers and what to call Ahmed’s album.

Science teacher-turned-comedian Al Jackson (@aljackson) joins Matt and Andy for one of the final Bluebell recordings (also video streamed on Facebook here) to talk about ball-boiling as contraception, why flossing may not help you, steroids in sports, Al's research, stomach taps, old cars vs. new cars, firefighting equipment sharing and fire in space.

Dr. Farah Alibay, a systems engineer at NASA's Jet Propulsion Laboratory, invited Matt and Andy to her home in Highland Park to talk about her work on a real-world Armageddon mission to redirect an asteroid, CubeSats, giant geysers on Saturn's moon Enceladus, the importance of planetary protection and upcoming solar system exploration missions.

Pacific Northwest comics Derek Sheen (@dereksheen) and Sean Jordan (@SeanSJordan) join Andy and Matt back at Bluebell to talk about going to a Scientology boarding school, non-ice cream heir Tony Robbins, amateur Australian ball surgery, Juno's pics of Jupiter, AIDS ceasing to be an epidemic in Australia, good news on the ozone hole's healing, and even more good news about finding new reserves of helium.

Professor Sophie Scott (@sophiescott) of University College London's Institute of Cognitive Neuroscience welcomes Matt and past guest Nick Doody (@NickDoody) to her office to discuss her research on the neural basis of human speech processing, and specifically her study of laughter.

Podcaster, host and science communicator Alie Ward (@alieward) appears with Matt and Andy on Science Channel's upcoming How To Build Everything (premiering June 22nd at 10pm) and she makes her first appearance on the podcast to discuss supernumerary nipples, McNuggetinis, owl pellet mouse skeletons, a third lizard sex, an inflatable space station room, Alie’s aeronautic training, antibiotic-resistant bacteria, MRSA, wrestling bugs and swimming pool pee.

Software engineer and Google employee John Eric Hoffman welcomes Matt and Andy to his house (next door to Todd Glass's, coincidentally) to talk about machine learning, neural networks, Maxwell's Demon, DeepDream, natural language processing and the recent short sci-fi film written by AI (and co-starring past guest Humphrey Ker).

This episode was taped live at the 2016 Bridgetown Comedy Festival in Portland, Oregon, with Matt and Andy welcoming comedian/environmental engineer Ella Gale (@hellakale) and author/podcaster/@BitchMedia editor Sarah Mirk (@sarahmirk) to discuss gender biases in science reporting, women in science (and comedy) and why it's hard to make bagels when it's hot outside.

Popular science author Mary Roach's (@mary_roach) books have tackled a wide variety of topics including sex, the afterlife, digestion and space travel. In her soon-to-be-released book Grunt, she takes on the curious science of humans at war, delving into combat medic training, stink bombs, genital transplant surgery, the war on heat, shark repellant and diarrhea as a threat to national security. Pre-order your copy of Grunt now!

Comedian/rapper/writer Zach Sherwin (@ZachSherwin) can be seen on Epic Rap Battles of History, among many other places, and he joins Matt and Andy to talk about writing a JAP battle rap battle on Crazy Ex-Girlfriend, p-branes, playing Einstein, the new Ghostbusters script, Andy’s bidet, magician hacks and Joel Hodgson's ventriloquism mask invention, Shy Tony, silver underwear, John Oliver’s science story, a teen's Mayan discovery that may not be what it seems, everyone yells air ball at the same pitch, diving robots, being bepenised, and long-lasting batteries.

Fahim Anwar (@fahimanwar) recently made his first appearance on Conan as well as the Tina Fey movie Whiskey Tango Foxtrot, and he joins Matt and Andy to discuss birthday escape rooms, engineering degrees to subsidize comedy, bringing people back from the dead, more head transplant news, archaeology vs. paleontology, another EM Drive debunking from Sean Carroll, tons of oral spider sex, enzyme corrections, 3D-printed fake rhino horns, breast cancer gene mapping and where to find Fahim Anwar performances.