Fifty years ago black holes were science fiction. Today they are observational physics and what we see is stranger than fiction. They send us messages about space and time. Black holes form when the matter of a star more massive than our Sun collapses under its own gravity. Other black holes may have formed in […]
Twin mysteries arose around 1937 when Italian theoretical physicist Ettore Majorana suggested neutrinos are their own antiparticles. Soon afterward he took the night ferry from Palermo to Napoli and vanished, leaving us to ask: What happened to him; and was he right? The Standard Model has a place for every known elementary particle. It says […]
Vera Rubin was a very rare bird forty years ago: a female astronomer. Galaxies were her life’s work. In her day the notion that there are many galaxies outside our own was only a few decades old. Inspired by her ‘just plain old curiosity’, her PhD thesis suggested galaxies are not scattered randomly: they come […]
Physicists have a mental image of the way the universe works. Most think of it as driven by energy. Even leading British physicist Sir Roger Penrose falls for this. He should know better. The conventional wisdom begins with all mass of the universe exploding out in the Big Bang. No-one knows why it would do […]
Planck-scale physics is not yet in its infancy. It is in gestation. Arranging a successful birth requires a strategic discipline. Walk before you try to run! For some reason (we will get to that) physicists seem doomed to run. Indeed—to milk the metaphor for maybe more than it is worth—they essay hundred-meter sprints before they […]
Why does our universe have three space dimensions? As if that question is not tough enough, string theory says that it has nine. So why do we see three? Some say there will never be an explanation, that it is just a “brute fact”. Others say this is one of the ultimate questions and that […]
The universe burst into existence some 13,799,000,000 years ago. Why did it become this universe? Why does it have quarks and electrons; and elements including carbon, hydrogen, nitrogen and oxygen; and gravity to grow galaxies; and planets orbiting vast numbers of stars; and all of the ingredients that lead to life? Doing this required many […]
Of all questions the most fundamental is: What was the initial condition of the universe? It is fundamental for philosophy and religion. It is even more fundamental for physics. Unfortunately it is a realm where physics fears to tread. Yet we may need to tread this realm to find the much-sought Theory of Everything or […]
Physics has two great theories, general relativity and quantum mechanics. Each does very well in its domain. That is nice but plainly isn’t real. Each is fundamentally at odds with the other. And neither of them works at all with the conditions that existed when the universe began. How can we find a single theory […]