In the late 1960s, Caltech astronomer Fritz Zwicky proposed a novel method of space travel. Instead of using spaceships to go to neighboring stars, he imagined moving the entire solar system.
His idea was that if we could make one side of the sun release more energy than the other, then we could direct the course of its motion. We could steer it towards whatever destination we wanted, with the Earth in tow. He calculated that we could reach Alpha Centauri in 2500 years.
Journeys to the Nearest Stars In the Tow of the Sun
For the purpose of traveling to the nearest stars, Alpha Centauri for instance, at a distance of four light years, rockets do not suffice. A very much more exciting possibility offers itself, however: We remain on the Earth and travel with it as the space vehicle, either alone or with the whole solar system towards our goal. During this journey we may enjoy and use the light from the Sun as always, or if we wish to leave it behind, we can keep warm and provide all of the necessary small and large-scale illumination through the proper use of nuclear fusion energy. Traveling at a speed of 500 km/sec through space, relative to the surrounding stars, we might reach the neighborhood of Alpha Centauri in about 2,500 years.
All of this will become possible once we have mastered nuclear fusion ignition of common materials on the Earth and on the Sun. Physicists in many countries have been attempting during the past fifteen years to induce nuclear fusion reactions in extremely concentrated and high-energy ionic plasmas, without making any use of the release of nuclear fission energy from uranium as it is being used in H-bombs.
Even if these efforts should be successful they would not provide us with any readily usable means for the acceleration of the Sun or of the Earth to velocities of the order of 500 km/sec. I have therefore suggested another approach striving to produce small solid particles with velocities of up to 1,000 km/sec. It is not possible here to go into any details of how this is going to be done. I emphasize only that no fundamental difficulties stand in the way. Particles impacting on dense matter with velocities of the order of 1,000 km/sec will generate the desired temperatures of hundreds of millions of degrees, at which all light elements will be ignited to nuclear fusion reactions.
Launching ultrafast particles against the Sun, local regions on it could be ignited to nuclear fusion. As a consequence of the tremendous release of energy by such reactions, matter would be ejected with velocities of the order of 50,000 km/sec, while the resulting forces of reaction would propel the Sun in the opposite direction. If such processes were applied for a long time, the Sun could eventually be accelerated to the desired velocity with a sacrifice of only a small per cent of its total mass.
Since the planets are held in rein by the Sun's gravitational field, they and the Earth would be carried along on the distant journey. In principle the process and propulsion described could be applied to the Earth alone, which then would detach itself from the solar system and start out on its solitary voyage to the nearest stars.
One of the few analyses of Zwicky's idea that I could find online is at dynamical-systems.org. The author, Oliver Knill, quickly concludes that the idea is completely nuts:
Even if it would be possible to redirect the entire solar wind which ejects 1017 kilogram per year into one direction, this would displace the Sun only 1 meter in one year. On the other hand, the radiation energy produced by the Sun is 4 1033 erg/sec and could in principle be used to accelerate the Sun to a velocity of 100 m/sec in one year, when considering the energy only. By heating and cooling different parts of the Sun and redirect the radiation asymmetrically, a fraction of this energy could in principle be available. But even if the entire radiation could be redirected into one direction, the force would accelerate in one year the Sun only to a speed of 10-3 cm/sec. The reason for this low value is that photons do not carry a lot of momentum.
But even if Zwicky's idea could be made to work, what would happen once our solar system reached the vicinity of Alpha Centauri? How close could our sun approach Alpha Centauri before the two systems became gravitationally bound to each other? What kind of chaos would that wreak on the planets and asteroids within our solar system?
Theoretical physicist Freeman Dyson envisioned our Solar System being explored by "Astrochickens." As described in his 1992 book From Eros to Gaia:
Probably both nanotechnology and genetic engineering will have an important role to play in space science. The two technologies are likely to grow together and ultimately merge, so that it will be difficult to tell which is which. In the end, nanotechnology will give us scientific instruments having the alertness and agility of living creatures, while genetic engineering will give us living creatures having the sensitivity and precision of scientific instruments. The spacecraft of 2018 may well be a hybrid, making use of nanotechnology for its sensors and communications, genetic engineering for its legs, wings, and brain.
Here is a rough sketch of one possible shape that the 2018 spacecraft might take. I call this model the Astrochicken because it is about as big as a chicken and about as smart. It is a product of genetic engineering. It does not look like a chicken. It looks more like a butterfly. It has wide and thin solar sails instead of wings, and a high-resolution spectroscopic imaging system instead of eyes. With its solar sails it flies around the inner solar system as far as the main belt of asteroids. At any one time there will be hundreds of such birds flying, programmed to make specialized observations of Earth, Moon, Sun, planets, and asteroids as well as of the heavens beyond. Other cousins of the Astrochicken will have legs for landing and hopping around on asteroids, or solar-powered ion-jet engines for exploring the outer solar system as far as Pluto.
Wikipedia notes: "As a noted author of essays on the possibilities of science in the future, Dyson's theories, such as the Dyson sphere and the Dyson tree, have become popular in the scientific and science fiction communities. The more whimsically named 'Astrochicken' has not achieved this same level of fame."
In his 1972 documentary, Can You Speak Venusian?, the British astronomer Patrick Moore examined the astronomical theories of various "independent thinkers" — otherwise known as kooks. It's probably now the only footage of most of these odd folks, talking about their odd ideas. Moore released an accompanying book of the same name.
My favorite of his independent thinkers is John Bradbury and his 15-lens telescope, viewable at around the 15:30 mark. His basic idea was that if two lenses are good, then fifteen must be even better. Bradbury claimed his telescope was so powerful that it could show "the actual background casing of the universe."
Black Hole Symphony, which was penned by composer David Ibbett and is due to be performed by an orchestra at the Museum of Science in Boston, Massachusetts, blends real science into the creative mix.
The work cleverly translates cutting-edge research on black holes into an electro-symphonic score with five movements and includes visuals based on images taken by scientific instruments, including the Event Horizon Telescope, a large array made from a global network of radio telescopes, which took the first image of a black hole.
Paul Di Filippo
Paul has been paid to put weird ideas into fictional form for over thirty years, in his career as a noted science fiction writer. He has recently begun blogging on many curious topics with three fellow writers at The Inferior 4+1.