Last spring, physics writer Andrew Grant reported on the lack of progress by the main U.S. nuclear fusion effort (“Ignition failed,” SN: 4/20/13, p. 26). As the researchers still contend, laser-initiated fusion should work. It works on paper. But in practice, even a set of extremely powerful lasers failed to trigger the fusion of hydrogen nuclei and the concomitant chain reaction and release of net energy expected.
In February, the National Ignition Facility scientists at Lawrence Livermore National Laboratory in California reported a small, if important, breakthrough, as Grant writes in "Step taken toward ignition." By using a different pattern of laser pulses, scientists were able to cajole some hydrogen atoms to fuse, resulting in more than 5,000 trillion fusion reactions before the effect petered out. That created nowhere near the total energy used by the lasers to initiate the reaction, but the event did generate a hairbreadth more energy than what had actually reached the fuel. That’s still very far from actual fusion energy, but it’s progress nonetheless.
Sometimes the devil is in the details, as I’m sure the fusion scientists would agree. As freelance writer Sam Lemonick reports in the feature "Creature Power," those attempting to make a go of fuel cells powered by the body’s own chemistry have definitely found that to be true. The idea, first dreamed up by heart researchers in the 1960s, was to find a way to power medical devices using enzymes. In the last decade, research on biological fuel cells has gained momentum — and has included a menagerie of living power sources, including grapes, lobsters, clams and snails. A major obstacle to getting to a working, body-powered device, however, is the relatively small amount of electricity produced by the fuel cells thus far.
But, as Lemonick relates in his story, scientists are inspired by nanotechnology and other advances to keep trying. The science behind “Quantum timekeeping” is still resolutely on paper, as Grant describes in the cover story. The details haven’t even begun to be fretted about. A global quantum superclock run by entangling atoms and then entangling the clocks themselves is, at this point at least, purely speculative.
But before you can build it, you’ve got to dream it.