For her 7th birthday, my niece received a very special gift — a compound light microscope with a set of slides. As soon as we got it out of the package, she became a diligent young investigator, studying the leg of a fly, dog cardiac muscle and onion epidermal cells. But it wasn’t the prepared slides that captivated her most. She wanted to investigate more familiar things. We plucked hairs from our heads to see what they looked like, and collected dirt from various spots across the yard to compare and contrast. Sitting at the dining room table, she drew big circles on notebook paper and sketched her newfound views. The world she thought she knew was suddenly unexpected.
At one time or another, a similar feeling must have motivated researchers studying the proton. Here’s a basic constituent of matter that, as physics writer Emily Conover writes, makes up stars, planets and people (also, peonies, blue jeans and gelato — a few of my favorite familiar things). The proton has been observed, albeit indirectly, for about a century. Its place at the center of the atom is etched into our minds. Heck, we even control it — smashing protons together at near light-speed in giant particle colliders.
Yet for those who look a little closer, there are many surprises: Protons are made up of more fundamental particles called quarks and gluons. Some of the quarks stick around but others are more ephemeral, popping in and out of existence. Exactly how all the proton’s parts add up to make the whole remains murky, as do some of the proton’s key properties. Scientists don’t know its precise size, nor do they understand its spin. Supposedly the particle should decay over time, but no one has detected a proton’s death. Microscopes aren’t much help, so scientists use souped-up tools with lasers, mirrors and magnets to see in a different way, to become more intimate with the world they thought they knew.
Glass frogs may not be familiar to most of us, but biologists who spent many years’ worth of rainy seasons searching for moms and egg clutches became well-acquainted with these amphibians. Known glass frog caregivers have almost always been dads. But it now appears that by briefly pressing their bellies against the clutches, many moms have an important role, too. As one evolutionary biologist commented: “Parental care is perhaps more common and diverse in animals than we realize…. We just might have to look a bit harder for it.”
And then there are the tropical fang blennies, well-known among home aquarium enthusiasts. New research reveals that the venom of one fang blenny species acts on opioid receptors, probably working as a sedative rather than causing pain. Close investigations with micro-CT scans, chemical analyses and experiments in mice show that these familiar fish have evolved a survival strategy surprisingly different from that of other venomous creatures.
Investigate means to study closely. But looking isn’t sufficient for science. You also have to get to know something well enough to appreciate what you see. By building understanding, recognizing patterns and forming questions, scientists prepare themselves to spot the unexpected. Whether it’s dirt from the front yard or much smaller constituents of matter, there’s always something more to discover.