My blog.
Seeing without looking On the crispest, sunniest mornings, Massachusetts Avenue shines as if made of flowing gold. When I bike to work from Harvard to MIT, I ride straight into the sun: squinting into the brightness, holding up my gloved hand to shade my eyes. When I come to traffic lights I look down, dazed, and wait for my vision to adjust. I stare at my bike’s front wheel through a hole in my…
The world is like an apple whirring silently through space After a chance conversation at our lab retreat, I got curious about what tides “sound” like. I downloaded the NOAA’s water level data for Boston Harbor from the start of my PhD until today and sped it up by a factor of about 200 million. You can clearly hear the tone representing the daily tides (pleasingly, it’s tuned to “middle C”… get…
Faces that you can only see without looking I work in a dense urban campus, and the view from my building looks into the windows of the next building over. Sometimes, when I meet with my advisor, I sit at a table facing that window. On these days, a strange thing happens. When I look up at my advisor, I get the eerie sensation in the corner of my eye that there is a face in that window watching…
How to pretend like you have a biased coin Suppose two Bayesians, Alice and Bob, put on a variety show where they take turns tossing a biased coin and announcing outcomes to a live studio audience. (Bayesians love this kind of thing—it keeps them entertained for hours…) Unfortunately, just as Alice goes on stage, she realizes with dread that she forgot to bring the coin. Thinking on her feet, she…
Thinking about a streetlight’s wooden halo Have you noticed the way streetlights shine through the bare branches of trees on cold winter nights? Walking home from work tonight I was struck by the almost overwhelming beauty of the scene. The light creates a perfect, glittering halo around itself, like the moon in a Van Gogh painting. The tree in turn all but reaches its fingers out to grasp the…
Investigating the stability of honey containers I knocked over a tall jar of honey. Clumsy, clumsy! But the jar was nearly empty; jars tend to fall when they are nearly empty. But jars also tend to fall when they are full, which got me thinking: for both full and empty jars, we can argue by symmetry that their center of mass is halfway up. By Rolle’s Theorem, then, at some point when the jar is…
Can stirring more ever lead to worse outcomes? Suppose you are cooking tofu, cut into tasty 1-inch cubes. On your stove it takes each cube-face 10 minutes to cook. You could cook each of the 6 faces of each cube in one hour (60 minutes) by rotating the cube to an uncooked face every 10 minutes–but this is clearly tedious and suboptimal. A better idea is stirring: instead of carefully rotating each…
Thoughts on a blue and yellow photograph I took this summer This summer I was briefly in Vancouver, and after dinner on my last day I found myself walking several blocks back to my hotel. The night was dark but the sidewalk was brightly lit and it was a lovely journey. Along the way, I took this picture: What struck me is how the streetlight casts two shadows, blue and yellow, and moreover those…
A low-power deep learning inference mechanism inspired by flush toilets The other day my toilet broke and I involuntarily learned a lot about how flushing works. My friend suggested an analogy for me: flushing toilets is like a neuron’s activation: once a critical threshold is met, there’s an “all-at-once” response. That got me thinking, could we implement deep neural networks in plumbing? It…
What is it about birds? Toni Morrison, Nobel Lecture Speculation on what (other than its own frail body) that bird-in-the-hand might signify has always been attractive to me, but especially so now thinking, as I have been, about the work I do that has brought me to this company. (full) Richard Siken, “The Language of the Birds” And just because you want to paint a bird, do actually paint a bird,…