By the mid-17th century, telescopes had improved enough to make visible the seasonally growing and shrinking polar ice caps on Mars, and features such as Syrtis Major, a dark patch thought to be a shallow sea.

Professionalism in art has this difficulty: To be professional is to be dependable, to be dependable is to be predictable, and predictability is esthetically boring - an anti-virtue in a field where we hope to be astonished and startled and at some deep level refreshed.

I don't write about too many male businessmen, and I'm not apt to write about too many female businessmen.

For male and female alike, the bodies of the other sex are messages signaling what we must do, they are glowing signifiers of our own necessities.

In villages across the developing world, governments have provided reasonable enough latrines that have again and again been turned into storage spaces or simply abandoned. In India alone, millions of government-funded latrines have become goat-sheds. Some had been built near kitchens, a taboo in Indian households.

When private sector, government, social, and philanthropic leaders apply innovative partnerships and technologies to address social challenges and build sustainable communities, the impact is multiplied.

I think bad politics are incredibly dangerous, so it's important to make sure that people are communicating well. Culture and morale are super important. It's best to not force it, but let it happen organically and genuinely.

My number one objective continues to be to defund or delay the implementation of Obamacare. But as long as any piece of this law is standing, it needs to apply to all Americans equally, and that includes members of Congress and our staff.