It is not man who must go to the stars, but information..

In "Window in Spacetime," Isambard explains why manned space travel in our solar system is useless. The four rocky planets: Mercury, Venus, Mars, and Pluto, are particularly inhospitable to humans, and the remaining gas planets are impossible even to land on. The planets and their moons in our solar system are unsuitable for habitation.

So other stars seem attractive, but that is where the problem begins.

The distances are enormous and are measured in light-years. According to Einstein, nothing with mass can reach the speed of light. You can approach it, but never reach it.

Take the planet Xania (from the book), 52,000 light years away. Suppose a spaceship accelerates constantly at 1 g. After a few years, it approaches 0.99% of the speed of light. But we are not there yet. To avoid shooting past Xania at nearly the speed of light, the ship must begin decelerating years before arrival. That, too, takes several years, assuming a constant deceleration of 1 g.

For the crew, the journey is relatively short. Due to time dilation, they age about twenty years. Meanwhile, more than 52,000 years pass on Earth. Everyone they knew has disappeared, and the world has changed completely. Time dilation means: the faster you move or the stronger gravity, the slower time passes for you.

After that, the return journey still has to begin.

In addition, there are practical problems: food supply, maintenance of the ship, effects on the body, and the reliability of technology over decades.

And this applies only within our Milky Way. Other galaxies are much further away.

Perhaps the future of space travel is not transporting people, but discovering a medium that bridges distances without the limitations of space as we know it.

Want to read more? Discover "Window in Spacetime"