7 Big Ideas That Can Change the World
From Wired:
Tesla. Prius. Volt. The auto industry is stocked with radical new
designs that reduce the environmental impact of driving. The airplane
industry has been incrementally improving fuel efficiency for decades,
but it’s maxing out the potential of current designs and will soon need
to come up with a similarly transformative rethink. And it has to move
fast. Air travel is set to explode—more
than double by 2031—as developing nations grow more prosperous. That
growth could eat away at any other improvements we may make from
cleaning up cars or energy grids.
There are a number of ways to tackle the problem. NASA is rethinking
airplane design by sponsoring eye-popping concepts like the MIT D Series—in
which a double-cylinder body allows for rear-mounted engines and an
overall fuel reduction of about 50 percent. (They’re much quieter too.)
Smarter navigation systems could let airlines fly shorter, more direct
flight paths. And small, short-range planes could eventually become
electric: The Slovenian firm Pipistrel
has developed an electric four-seater, with double the mileage of a
similar plane. “All these technologies are converging to produce
capabilities that were not imaginable 10 years ago,” says David Hinton,
NASA’s deputy director of aeronautics research. The sky’s the limit. —Clive Thompson
Harry Gray knows his electrons. In 1982 the Caltech chemist
discovered that electrons “tunnel”—skip across long chains of
molecules—through proteins. This trick turns out to be the animating
breath of life; it’s how living things convert energy into something
they can use, from plants locking the energy of sunlight into their
cells to pretty much every life-form burning fuels such as glucose to
make power. It’s all made possible by hybrid molecules called metalloproteins, which combine the shape-shifting flexibility of proteins with metals’ ability to catalyze chemical reactions.
When Gray figured it out, he was already interested in solar power.
If you were trying to develop a near-infinitely renewable power
generator, he realized, you might try to hijack a metalloprotein-driven
system like photosynthesis. But it wouldn’t work. Biological machinery
is too fragile and inefficient—and has to be resynthesized every few
minutes to work.
If you want a molecular machine that’ll make power efficiently and
reliably, Gray says, you have to build it yourself. He and his
colleagues envision microscale batteries with metal oxides at one end
and silicon at the other, built like metalloprotein arrays in plant cell
membranes. The metal oxides would absorb blue wavelengths of sunlight
and use the energy to split seawater into oxygen and protons, and the
silicon would absorb red light and combine the protons with electrons.
That’s slick, because a proton combined with an electron is actually
hydrogen, which can be used as fuel. Shorter version: free hydrogen from
sunlight. “The whole emphasis of our work is coming up with molecules
or materials that are very robust,” he says, “and will last a long time
in solar fuel plants.”
It might even work. Artificial water splitters are already 10 times
more efficient than natural photosynthesis, though scale-up is still
decades away, as researchers seek new catalysts to drive the chemistry.
(The exotic metals they use today are pricey and toxic.) Still, Gray is
optimistic. “The natural system had to build something that could
actually live,” he says. “All we have to do is make fuel.” Oh, and save
the planet. —Thomas Hayden
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