Moving the Solar System

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.

Details can be found in his 1969 book Discovery, Invention, Research Through the Morphological Approach:

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 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?
     Posted By: Alex - Tue Aug 30, 2022
     Category: Spaceflight, Astronautics, and Astronomy

Scientists long ago destroyed any hope of free and easy space travel. Now, we need rockets, escape trajectories, etc. etc. etc.. Before scientists, people could just sail to the edge of the world, drop off, and be in outer space!
Posted by Phideaux on 08/30/22 at 10:18 AM
1. How convenient that: "It is not possible here to go into any details of how this is going to be done." Mastering fusion seems to be one of those things that's always 10 years away.

2. Did this come out on April Fools' Day? For one thing, I'm having trouble believing the name "Fritz Zwicky". Was he in the Bezerkely branch of Caltech?

3. Our world was moved, along with 27 other planets, in Doctor Who episode No. 198, "The Stolen Earth". The Daleks were the perpetrators, led by Davros himself. You'll have to watch it to see how the Doctor put it back, but the method was certainly more elegant than plain old fusion energy.
Posted by Virtual in Carnate on 09/01/22 at 09:53 AM
Virtual -- Zwicky was definitely a real person. Known for being an eccentric. But also a good astronomer. He was one of the first to propose the existence of dark matter.
Posted by Alex on 09/01/22 at 12:40 PM
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