Pathological technologies are typically put forward, promoted, and developed despite the presence of substantial drawbacks or risks that, when considered at all, are commonly dismissed, downplayed, or passed over in silence by proponents. In the case of interstellar travel, the possible payoffs were substantially offset by a roster of downsides, dangers, and existential threats.
One category of risk arose from factors or forces external to the spacecraft—for example, collisions with objects in the interstellar medium. Collisions in space are by no means rare: by the end of the Space Shuttle program, for example, more than 100 shuttle windows had been replaced after impacts with space debris, some objects being as small as the fleck of paint that cracked the front window of STS-7 (the second Challenger mission) in 1983. After a while there had been such a rash of debris impacts that the shuttle, once it reached orbit, was intentionally flown tail-first to minimize the effect of collisions.
It might be thought that the interstellar medium is “empty space,” or a vacuum. To the contrary, the space between the stars contains volumes of interstellar gas and dust, along with cosmic rays, and possibly objects of unknown composition, size, mass, and density. And so it would be difficult to believe that on a journey of at least 4.22 light-years (the distance from Earth to Proxima Centauri) an interstellar spacecraft would meet with no other object whatsoever. But for a starship traveling at relativistic speeds, a collision with even a random small particle, according to Tom W. Gingell of Science Applications International Corporation, who did a study of the subject, would have the effect upon the spacecraft of an H-bomb explosion.
Baloney. Not thinking out of the box. To read more, click here.