My comment policy at the Loom can be summed up with three words: light but firm.

Science writing often triggers intense reactions in readers–whether the subject is evolution, the biology of the brain, global warming, or genetic engineering. I believe readers should feel free to express those reactions–within reason–on my blog.

I actually find many of these comments useful to my own work. Sometimes people fact-check me and show me where I’ve made a mistake. Other times, they point me to a line of research that’s new to me. I’ve actually ended up writing magazine articles based on those helpful suggestions. (There is no copy-editor looking at this blog, so I appreciate notes about typos, which I will remedy quickly.)

Continue reading “The Loom’s Comment Policy” →

When things get small–like millionths-of-an-inch small–they get very interesting. The ordinary rules of physics we’re used to fade back as the oddness of quantum physics looms large. Engineers have taken advantage of this fact by fashioning tiny bits of matter, known as quantum dots, that behave in all sorts of useful ways. For example, quantum dots made from cadmium telluride will respond to ultraviolet light by giving off a flash of visible light–the color depending on their size. If you attach certain molecules to cadmium telluride quantum dots, they will latch onto certain targets, making it possible to detect trace amounts of substances ranging from pesticides to cancer cells.

As versatile as cadmium telluride quantum dots are, however, they’re not easy to make. It’s especially tedious to fashion them so that they’re not toxic to living cells, since both cadmium and tellurium are nasty metals. In the latest issue of Nature Nanotechnology, a group of scientists at Kings College London offer a remarkably easy way to make them.

Continue reading “The Quantum Earthworm” →

A few years back, I noticed a DNA tattoo on the arm of a neuroscientist. He informed me that it spelled out his wife’s initials according to the genetic code. And that enchanting discovery turned me, much to my own surprise, into an amateur anthropologist of scientist body art and the author of Science Ink: Tattoos of the Science Obsessed. (Reviews)

I’ve archived the ~300 tattoos here at National Geographic so that future generations of researchers can analyze them for clues to the folkways of scientists and the scientifically-minded in the early twenty-first century. And I’m still getting fresh ink via email. I will continue to post them here on Saturdays. (The tattoo-averse can thus safely continue reading the Loom while avoiding a scorch of their retinas.)

Continue reading “The Return of the Science Tattoo Emporium” →

We’ve been tinkering with the DNA of other species for thousands of years. We just didn’t know what we were doing.

Starting about ten thousand years ago, humans began to steer the evolution of animals and plants. Our ancestors collected certain seeds instead of others, started to plant them in gardens, and gradually produced domesticated crops. They didn’t know which genetic variants they were choosing, or how those genes helped build new kinds of plants. All they knew was that some plants were better than others. Over thousands of years, for example, an innocuous bush called teosinte turned into tall stalks with gargantuan seeds–otherwise known as corn.

Continue reading “The Evolution of Cavities” →

In 1837, Charles Darwin scribbled a simple tree in a notebook and scrawled above it, “I think.”

That little doodle represented a big idea: that species were descended from common ancestors. They looked different from each other today thanks to the differences that evolved after their lineages split.

Continue reading “Redrawing the Tree of Life” →