Interplanetary travel

Travelling between stars and planets is called interplanetary travel. It's usually done within one planetary system, like our Solar System. But it's not easy to do. There are many problems, like how far away everything is, how gravity and radiation affect us, and how much it costs to build and run a spaceship.

Maybe quantum physics could help us with some of these problems. Quantum physics is the part of physics that deals with really small things, like atoms and electrons. Quantum physics is weird. It lets some things happen that seem to break the normal rules of physics, like being in two places at once, being connected over long distances, going through walls, and travelling faster than light.

Being in Two Places at Once and Being Connected Over Long Distances

Being in two places at once is called superposition. It means that a quantum thing, like an electron, can be in a mix of two or more states until we look at it. For example, an electron can be spinning up and down at the same time until we measure it. Being connected over long distances is called entanglement. It means that two or more quantum things can share a state and affect each other even when they are far apart. For example, two entangled electrons can have opposite spins no matter how far away they are.

Superposition and entanglement could be useful for interplanetary travel in different ways. One way is to use quantum teleportation, which is when we transfer the state of one thing to another without sending any stuff. This could let us talk to distant spaceships or even move stuff across space. Another way is to use quantum computation, which is when we use quantum things to do calculations that are faster or better than normal computers. This could help us find our way around space, make better decisions, and control our spaceships better.

Going Through Walls and Travelling Faster Than Light

Going through walls is called tunnelling. It means that a quantum thing can go through a barrier that would normally stop it according to normal physics. For example, an electron can go through a thin layer of metal that would otherwise block it. Travelling faster than light is when something moves faster than the speed of light in a vacuum, which is about 300,000 kilometres per second. According to special relativity, nothing can go faster than light in a vacuum, but some solutions of general relativity let us bend space and time to make it possible.

Tunnelling and travelling faster than light could be useful for interplanetary travel in different ways. One way is to use tunnelling to make a shortcut or a wormhole between two points in space. This could let us travel faster or easier between planets or stars. Another way is to use travelling faster than light to go back in time by making a closed time like curve (CTC), which is a path in space and time that goes back to where it started. This could let us explore the past of planets or stars or even change their future.

Problems and Limits

Interplanetary travel using quantum physics is not without its problems and limits. One problem is to make and keep quantum things that are coherent and isolated from outside noise and decoherence, which are things that ruin their quantum properties. This needs advanced technology and engineering that we don't have yet. Another problem is to avoid paradoxes and inconsistencies that might come from travelling faster than light and time travel, like the grandfather paradox or the Novikov self-consistency principle. These need careful analysis and understanding of the physical laws and what they mean.

Another limit is that quantum physics does not really break causality or let us send information or energy faster than light. Some things that look like they are faster than light or superluminal are actually just optical illusions or statistical effects that don't carry any useful information or energy. Also, some solutions of general relativity that let us travel faster than light or time travel might not be realistic or stable. So interplanetary travel using quantum physics might not be possible or practical in all cases.

To Sum Up

Interplanetary travel using quantum physics is a cool topic that looks at how we could use some of the most mysterious and amazing things in nature. Quantum physics gives us some possibilities for getting around some of the problems and limits of normal interplanetary travel, like distance, gravity, radiation, cost, and reliability. But quantum physics also has its own problems and limits, like coherence, decoherence, noise, paradoxes, inconsistencies, causality, and realism. So interplanetary travel using quantum physics is still a guesswork and controversial subject that needs more research and development.