68 | New Scientist | 21/28 December 2019
It sounds like a steampunk fantasy, but we may
finally have the technology to get vacuum
airships off the ground, finds Philip Ball
I
N 1670, Francesco Lana, a Jesuit
mathematician from Brescia, published
a small volume describing his various
inventions, including a chapter entitled
“A demonstration of the feasibility of
constructing a ship with rudder and sails,
which will sail through the air”. A sketch
showed what it would look like: a typical
wooden sailing boat, except that the vessel
would be suspended below four copper
spheres, each containing a vacuum that,
being lighter than air, would provide lift.
The idea didn’t fly. No one could make
spheres with walls as thin as Lana calculated
he would need – and in any case, they would
have collapsed from external air pressure as
soon as they were evacuated. But maybe Lana
was on to something. There is now renewed
interest in his vision of airships sailing
through the clouds, borne aloft by nothing –
and this time we might have the engineering
solutions to get them off the ground.
Airships have already graced the skies,
of course. The earliest ones featured simple
balloons filled with hydrogen. Their heyday
came in the 1920s, when the familiar elongated
shape of the Zeppelin carried passengers
across the Atlantic in the lap of luxury: the
gondola on the LZ 127 Graf Zeppelin, for