Which method do you think is the most plausable for interstellar travel and why? A generation ship, where large conventionally powered ships designed to support life for 100's of yrs, a ship where the occupants hibernate for long periods, light sails or wormholes?
The method of travel that is most plausible for interstellar journeys is a matter of personal opinion, since all of the proposed methods are still in early stages of research and experimentation. Hibernation, cryogenic freezing, spaceships with light sails, generational starships, and wormholes all have their advantages and disadvantages.
Science fiction stories and films have long explored various methods of interstellar travel. In recent decades, scientists have undertaken serious studies to see whether any of the multitudinous theories that have been proposed are possible. However, since no method has yet been confirmed as the most plausible alternative, we'll explore the advantages and disadvantages of each and leave it to you to draw your own conclusions.
One proposal has been to use propulsion methods that are already known to be feasible and methods such as hibernation or cryogenics to keep humans alive during the long voyage. Animals now existing on Earth have natural hibernation cycles, and scientists theorize that humans would be able to exist in a state of hibernation, or deep sleep in which metabolisms slow down severely, for a journey to the stars. This would depend, of course, on how long humans can sustain a state of hibernation and whether the method of propulsion could get them to their destination within that time frame. A drawback of hibernation is the risk of tissue atrophy and deterioration during long periods in low gravity. This could possibly be offset by inducing artificial gravity in some way and by stimulating the muscles electronically.
An option similar to hibernation is the cryogenic freezing of human passengers during a long space voyage. This would theoretically allow humans to remain in a state of suspension for longer periods of time. However, this method involves a strong risk of cell damage, and the revival of cryogenically frozen people is far beyond our present level of technology.
Light sail-driven ships are a proposed method of interstellar travel that is now in its early stages of research. A project developed by physicist Stephen Hawking, investor Yuri Milner, and Facebook CEO Mark Zuckerberg called Breakthrough Starshot is preparing to send multiple tiny interstellar spacecraft with light sails propelled by lasers to a nearby solar system. As for using light sails, electronic sails, or magnetic sails (all of which have been proposed) to take humans on interstellar voyages, this is all still highly theoretical. A light sail that depended on the light of stars to reach its goal would take hundreds to thousands of years, necessitating a method of preserving humans during this time. Alternatively, advanced laser-driven light sail technology would have to be developed.
Generation ships are spacecraft that would be immense enough to enclose an entire society that would go through multiple generations in the hundreds or thousands of years it would take to reach their destination. Besides the drawback of the inconceivable cost and effort needed to construct such a ship, there is the unknown psychological factor of what would happen to a group of humans closed in together for so long. On the other hand, if it worked, it would be able to contain an entire colony that would be ready to function once it reached its new world.
One of the most speculative ideas about interstellar travel is the concept of Einstein-Rosen Bridges, commonly known as wormholes. These are shortcuts from one place to another in space caused by the warping of spacetime. They bypass the problem of the limiting speed of light because vehicles would enter and exit them below light speed. Wormholes are said to be too unstable to go through, but scientists such as Kip Thorne and Stephen Hawking have said that they could be theoretically stabilized with the proper amount of energy.