Tonmay Saha

They begin as leftovers, which is the universe’s favorite way to build masterpieces. Before Earth had oceans or names or anyone to be terrified of the dark, the solar system was a loud, dusty argument. Roughly 4.6 billion years ago, a disk of gas and grit swirled around a newborn Sun. Most of that material learned to settle down and become planets. Some of it refused. Some of it never got the chance. Those holdouts are comets and asteroids, the unspent change in the pocket of creation, still...

Stephen Hawking at his time travelers' party In 2009, Stephen Hawking hosted a party for time travelers and mailed the invitations after it ended. Nobody showed up. If you like your science with a clean punchline, you could stop there. Case closed: no guests, no time travel. But physics rarely gives you a satisfying ending on the first page. Hawking’s stunt is better read as a thesis statement: if time travel exists, it is not going to behave like a tourist attraction. It is going to be...

To walk across the Earth is to walk across a battlefield. We tend to view our planet as a static stage—solid rock, immovable mountains, permanent coastlines. But this is an illusion of time. To a geologist, the Earth is a churning, volatile entity caught in a state of  dynamic equilibrium . Every valley and peak you see is the result of an ancient, silent war between two colossal forces. From below, endogenic forces (driven by the planet’s internal heat) shove the crust upward. From above,...