Jonathan Eig is best-known as the biographer of Al Capone, Lou Gehrig and Jackie Robinson, but his latest book breaks new ground.In “The Birth of the Pill: How Four Crusaders Reinvented Sex and Launched a Revolution,” Eig chronicles the history of birth control pill in a book the L.A. Times calls "a deft study of revolution."In this edition of The Big Questions podcast, Eig talks about the development of the pill, Hugh Hefner and how birth control fundamentally changed sex. Below is an excerpt of our conversation, but you can listen to the full episode on iTunes, SoundCloud and YouTube.On how the pill changed sex:Sex before the pill was very different. You might become a mother and your life is going to change dramatically. Sex after the pill ... becomes something that you can really do for fun. It completely changes the nature of the act, it completely changes the relationship dynamics. It changes dating. It changes what it means to be a man and a woman and a couple and in love. What can you think of that is bigger than that? What invention can you think of that changed what it means to be in love? That's the pill. The pill did that.On the development of the birth control pill:The Republicans should love this, because it is all like bootstrap stuff with no government funding. These are entrepreneurs, basically. And because birth control was illegal in much of the country, so you couldn't say, “Hey, we're going to run a test on this new birth control drug and we're going to give it to women in Massachusetts”—because you would have been breaking the law. So the fact that they were operating like this, is like these guerrilla warriors. Really was the only way they could have gotten it done.On why there isn’t a pill for men:It was a lot easier for these male scientists to tolerate the side effects as long as they were happening to women. There was really little tolerance for male side effects.But I should also say in their defense — Margaret Sanger and Katharine McCormick — the women who were really behind this effort to invent the birth control pill, the people who had the idea and were funding this, they said this had to be something for women, because women needed to be able to take control of their bodies.And if it was something that they had to count on men for, it wasn't going to work. Because men would decide when women would get pregnant, and that was not something they were willing to put up with. They absolutely insisted that this should be a pill for women; that women could take secretly if necessary, that they could stop taking when they wanted to have children again. For Margaret Sanger, the key word was control, when she talked about birth control.On the pill, the sexual revolution and Playboy founder Hugh Hefner:It’s not completely responsible for the sexual revolution. There were a lot of other factors involved, including LSD and Hugh Hefner and so many other things. But the pill made it possible, as one of the key ingredients.It was approved in '57 just for menstrual disorders, but women figured out what it really did. By 1960 it was approved as birth control. I asked Hefner, "Who is the first woman you ever slept with who was on the pill?"And he goes, "Ah, geeze I don't remember the first. But I know that once it was out there on the market, every women I was sleeping with was on it." And that was the best thing that ever could have happened to him.He likes to portray himself as an advocate for women's power, for women's equality, and for sex and for pleasure, obviously. But he says that he wrote editorials and columns very early on — before even a lot of feminists were picking up on this — that the birth control pill was a tool for women to gain power and to gain equality. He certainly enjoyed the fact that it spread pleasure across the land and he was the king of that movement.On what he learned from writing the book:As I got into it I realized: I take birth control for granted. I don't want to have to use a condom. So what are you going to do? And what men always assume after they declare that they don't use condoms is that the woman will take care of it. It's her responsibility. It's her body. She’s the one who has to get pregnant and carry the child. So, she should have to make the call here and take on that burden.But that's really not fair and it's something that we need to talk about more. Like a lot of men, I didn't have that conversation. I just let it go and figured we'd work it out somehow and it would all get taken care of. And writing this book has made me aware of the fact that I was not really carrying my end of the burden. That I wasn't being as thoughtful as I could have been. And men and women need to talk about it. I think that is the bottom line.