Aristotle thought babies became human beings only once they laughed for the first time. He also decided that this should happen around their 40th day. Conventional wisdom now puts it at about the 90th day—but we’re probably not as funny as the ancient Greeks.

The use of fetal cells in science has become quite controversial. There was an interesting moment in an interview between Radio Lab co-host, Jad Abumrad. and scientist Dr. Leonard Hayflick on this topic when we were making the show Mortality. Dr. Hayflick grew millions of cells from one aborted fetus and pioneered the use of fetal cells for research and the creation of vaccines.

Last summer we traveled to Tanzania in our Laughter show to investigate a 1962 epidemic of contagious laughter. Well, it turns out these sorts of episodes still happen, and not just with laughter.

We're looking into a possible story on thymic irradiation. What's that you ask? It's when your thymus is treated with x-ray therapy - in most cases to reduce its size. But, while it was a popular procedure for kids with respiratory ailments in the twenties, the thirties and even up through the fifties it doesn't happen so much anymore. So now we're hoping you can help.

“Laughter,” wrote Thomas Hobbes, “is nothing else but sudden glory arising from some sudden conception of some eminency in ourselves, by comparison with the infirmity of others, or with our own formerly.”

Here at Radiolab we’ve been known to tinker with sound.... cutting music, ambi, and big ideas all together to get the point across in the most fun, interesting and understandable way. It’s not your typical public radio interview. Recently, we decided to check in with some of the guests on past episodes to see what they thought. Were they over-edited? Mis-represented? Did they love the show? Hate it?

Here at Radiolab we’ve been known to tinker with sound.... cutting music, ambi, and big ideas all together to get the point across in the most fun, interesting and understandable way. It’s not your typical public radio interview. Recently, we decided to check in with some of the guests on past episodes to see what they thought. Were they over-edited? Mis-represented? Did they love the show? Hate it?

We want your two cents. Give us your best argument for or against calling Radiolab a science show. Is it a show about science? Is it scientific in its approach? How would you describe it to a friend who's never heard an episode? Are there limitations to classifying it as a science show?

Yet another listener has sent in a youtube that makes us stop what we're doing and gather around ye olde computer screen to gaze upon its offerings. Darn you, Ross Bennett, for indulging our desire to procrastinate! You want to us to finish Season 5, don't you? Alas. This one's too good not to pass along.

Hey folks, we're considering putting out a Best of Radiolab CD in the fall and we're looking for a few suggestions for what to include. Imagine if you could only play one story -- not a whole show, but something a little smaller -- which one would it be?

Here at Radiolab we’ve been known to tinker with sound... cutting music, ambi, and big ideas all together to get the point across in the most fun, interesting and understandable way. It’s not your typical public radio interview. Recently, we decided to check in with some of the guests on past episodes to see what they thought. Were they over-edited? Mis-represented? Did they love the show? Hate it?

The excellent Brooklyn-based quarterly Cabinet dedicated its Spring ‘05 issue to laughter. You’re just going to have to buy a copy, because only a very small portion is available online…including this fine essay by Chris Turner on the fluid boundary between laughing and crying:

Hydrogen sulfide stinks, but you knew that already, didn't you. Hydrogen sulfide is flammable, but you probably knew that too (and I won't ask how). But did you know hydrogen sulfide lowers blood pressure? and might protect the body from injury?

We've gotten a lot of great responses to our show Laughter. Tom was so inspired that he changed his voicemail: 'I was so excited that when I got to work I changed the end of my daily telephone greeting to '...make it a groovy day.' For some reason I then decided to start laughing like the laugh track people on your show.

Last week, the band Neurotic and the PVCs brought new meaning to the idea of cultivating an audience. The band played to a crowd of human fans and a set of three robots. The robots are rigged with "neural networks" based on human neurology that allow them to make their own neural connections...and therefore develop a taste for music.

Helene Meyer Tvinnereim and a team of Norwegian scientists are collecting milk teeth from 100,000 kids to create what may be the world's largest tooth bank. A dental biomaterials researcher at U Bergen in Norway, Tvinnereim seeks to find links between diseases and prenatal/childhood exposure to chemicals. The normally discarded teeth function as a 'black-box' recording of the chemicals children are exposed to, and have excellent shelf-life when dried and stored. Of course, this is a lot easier to do when you have a streamlined national health-care and record keeping system.

A listener recently sent us an email alerting us to a new dietary supplement released in June called Obecalp. Obecalp, which is Placebo spelled backwards, is a cherry-flavored chewable dextrose pill meant to trick children into believing they are getting a medicine that will make them feel better.

In the early 1940s, Esmond Emerson Snell (1914-2003) was trying to figure out why baby chicks who were fed raw egg whites (I know.. how cruel..) showed symptoms of biotin deficiency despite having plenty of it in the diet.

'Have you quantified that?' Answering 'no' to this question will usually trigger a collective humph from the crowd at a scientific meeting. We don't want to know that there's more or less of some biological activity unless you can say exactly how much different it is from normal.