People are surprisingly off put just by saliva, the substance that you carry around in your mouth. You swallow it. You have no objection to it. But then it leaves your body, and you're just revolted. So it - that - just that right there to me is a fascinating thing.

There are three kinds of people in this world: 1) People who make lists, 2) People who don't make lists, and 3) People who carve tiny Nativity scenes out of pecan hulls. I'm sorry, there isn't really a third category; it's just that a workable list needs a minimum of three items, I feel.

There are people who would love to spend their last ten years, or five years, or whatever it is, on the surface of Mars.

We exist in this weirdly schizo culture, where sex is everywhere in the media, and yet, at the same time, you don't sit down and have a conversation about what you did in bed last night with your friends. Despite the ubiquity of sex, it's still a taboo when it comes to day-to-day conversation.

The broader the topic, the easier it is, not only to fill a book, but to set the bar pretty high for really great stuff.

Most of the people who are engaged in the subjects that I look into are pretty interesting. Whether its sex researchers or someone who's devoted their career to saliva or somebody who does research with cadavers, there's an inherent fascination in the subject matter of their work.

If you get a colonoscopy, you should really insist they give you no drugs - then you do get to see what it's like to swim through your own intestines.

Any time you can take a book a little beyond the realm of pure entertainment, I think it's a good thing. But I don't really have it on my to-do list when I write a book. It just evolves naturally during the process of immersing yourself in a subject.

Animals' taste systems are specialized for the niche they occupy in the environment. That includes us. As hunters and foragers of the dry savannah, our earliest forebears evolved a taste for important but scarce nutrients: salt and high-energy fats and sugars. That, in a nutshell, explains the widespread popularity of junk food.

Weightlessness was unbelievable. It's physical euphoria: Nothing about you has any weight. You don't realize that you are weighed down all the time by yourself, and your organs, and your head. Your arms weigh down your shoulders. In space simulation, you get to fly like Superman! You're hanging in the air! It's the coolest thing.

I have not eaten a lot of insects. I ate a termite in Africa, but it was on a bet. It was a soldier termite. It was alive, and I don't really recommend the live soldier termite as something you want to start with if you're going to start exploring eating insects.

My books are not really books; they're endless chains of distraction shoved inside a cover. Many of them begin at the search box of Pub Med, an Internet database of medical journal articles.

Literally thousands of e-mails over the course of a book go out to people I've never met, people who might end up being the focus of a chapter.

To me, NASA is kind of the magical kingdom. I was sort of a geek, and you go there, and there are just these wondrously strange things and people.

LOL is rarely OL, or even really L. A real out-loud laugh - not the forced social variety, which is closer to barking than laughing - is uncommon among adults.

I spend a lot of my time on the phone, pestering people. 'What's new in your lab? Can I come visit your lab? When can I come visit your lab?' I'm basically a professional pesterer.

Ultimately, the problem is that sex is perceived as a personal, intimate thing, not in the realm of science. But that's not true. It's physiology; it's anatomy. It deserves to be studied.

Saliva has antibacterial properties. It also has things called nerve growth factor, skin growth factor, histatins which help with wound closure. So when you see an animal licking a wound or even a mom kissing a child's boo-boo, there's some, there's some good science behind why one might do this.

Dead people never seem to address the obvious - the things you'd think they'd be bursting to talk about, and the things all of us not-yet-dead are madly curious about. Such as: 'Hey, where are you now? What do you do all day? What's it feel like being dead? Can you see me? Even when I'm on the toilet? Would you cut that out?'

I think by and large, humans prefer to think of themselves as minds from the neck up. We don't really like to think of ourselves as another animal, another digesting, excreting, mating, snoring, sleeping kind of sack of guts. I don't think we like that. I think we'd rather not be reminded of it.

To me, death is dark, pain, grief.

A space station is a rangy monstrosity, a giant erector set built by a madman.

I didn't really realize that writing... would be fun and people would pay you to do it. Being an astronaut is a glory profession, and so is writing, in a way.

When I was a kid, I hated everything. I was really skinny, and I'd have a milkshake with an egg in it. Growing up, I ate, like, five different foods. I was not an adventurous eater. But as soon as I left home, that all changed and from that point on, I've been a pretty enthusiastic eater of new and strange food.