This is the original digital file of my poster of an imaginary call for volunteers to experience relativistic time dilation between a future space traveler who would approach the speed of light, c, and his/her fellow humans who would stay behind on Earth.

According to Einstein’s Theory of Relativity, travel at or faster than the speed of light is not physically possible, as mass would become infinite and time would stop. But it remains conceivable for us to approach the speed of light while remaining below it, and begin to experience drastic time dilation.

By accelerating to, and journeying at, 99% of the speed of light (0.99c), time will dilate approximately seven-fold. An astronaut spending one year at such a speed would return home to find his or her twin sibling, and everybody else who stayed on Earth, aged 7 years. This consequence of travel at high relativistic speeds is known in physics as the Twin Paradox.

Achieving the required high relativistic speeds is currently beyond our human civilization’s technological capability, but I wanted to imagine the day when we might create the first 0.99c spacetime transport, and would look for brave volunteers - chrononauts - to try it out.

The spacetime transport depicted is my drawing of the "THE BALL" (ink and pencil on paper, 14 x 11 inches, 22 Mar 1981).

SETI.STX is an imaginary url in which SETI would stand for my home institution, SETI Institute, and STX would mean SpaceTime Exploration.

The warning in small print at the bottom of the poster says:

"WARNING: Hazardous Journey. Safe Return Doubtful. Your Loved Ones Might No Longer Be Alive If/When You Return. Irreversible. Honor And Glory In Case Of Success."

These words of warning were inspired by polar explorer Ernest Shackleton's famous call for volunteers: "MEN WANTED for hazardous journey. Small wages, bitter cold, long months of complete darkness, constant danger. Safe return doubtful. Honour and recognition in case of success."