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.