Physical Science

“It suddenly struck me that that tiny pea, pretty and blue, was the Earth. I put up my thumb and shut one eye, and my thumb blotted out the planet Earth. I didn’t feel like a giant. I felt very, very small.” -Neil Armstrong This past week saw a whole lot of interesting things happen, including…

“Youth is the gift of nature, but age is a work of art.” –Stanislaw Jerzy Lec You’ve heard it said many times here: the Universe, since the Big Bang, is 13.8 billion years old. But how do we know this to be true? Moreover, how many different lines of evidence do we have that leads…

It is a mystery no more: A physical model can explain how a bunch of ants are able, with no visible leader (or highly-developed brains, for that matter) to drag that oversized cake crumb or leaf all the way across your floor to their nest. It turns out that there are, indeed, leaders, of a…

“To be is to be the value of a variable.” –Willard Van Orman Quine Those constant, fixed points of light in the night sky — the stars — turn out not to be so constant if you looked with great precision at them. A star like our Sun varies in brightness, periodically, by about 0.1% over the…

Pluto, King of the Underworlds

New measurements from NASA’s New Horizons spacecraft revealed that Pluto, named for the Greco-Roman god once called Hades, is a little more swollen with ice than previously thought, making it the biggest trans-Neptunian object—more voluminous than rival dwarf planet Eris, which is nevertheless more massive. Greg Laden explains why these orbs are not considered full-fledged…

On the Road Again

I’m writing this from my New Jersey office, which is to say that I am visiting the ‘rents. But it’s a very short visit. In fact, I’m mostly just using them for their garage. I’m stashing my car there for a few days while I go galavanting around to various math conferences, with a little…

“A cosmic mystery of immense proportions, once seemingly on the verge of solution, has deepened and left astronomers and astrophysicists more baffled than ever. The crux… is that the vast majority of mass of the universe seems to be missing.” –William J. Broad When we look out at the Universe, the other things we see…

When it comes to dark matter, the mysterious substance that makes up the vast majority of the mass in the Universe, there’s a whole lot we don’t understand or know about it. You might think that there are so many unknowns that are so huge that — quite reasonably — perhaps it doesn’t exist at all,…

When you close your eyes and picture a galaxy, what pops into your mind? For most people, it’s a beautiful, spiral shape, where a bright central region fans out with arms that wind around and around, over and over, littered with brilliant, glittering stars. And in almost all the pictures you see, there are two…

“Our knowledge of stars and interstellar matter must be based primarily on the electromagnetic radiation which reaches us. Nature has thoughtfully provided us with a universe in which radiant energy of almost all wave lengths travels in straight lines over enormous distances with usually rather negligible absorption.” –Lyman Spitzer, Jr. There’s nothing quite like looking…