Grounding Errant Theories on Speed-of-Light Travel

My conviction that we have not been visited by extraterrestrials and that man will never travel to other planets has drawn me into the pit of my own ignorance.

My readers are probably right in suggesting that I quit quoting “experts” who know no more than I do.

David Brin, a science-fiction novelist who is involved with SETI (Search for Extraterrestrial Intelligence), says I have betrayed my public trust by quoting ignoramuses.

Brin complains that the arguments made here by Dr. Nicholas Der are “pure hogwash,” and those of Stephen Mills, who described himself as a Rocketdyne scientist, are “little better.”

Der, you may recall, argued that a man traveling at or near the speed of light would be like a statue, “unable to move or feel, see, smell or hear anything.”

Mills said a space traveler would experience acceleration of several thousand G’s, a force that would melt metals and flatten a human body like a sheet of paper.

From these arguments I concluded that my skepticism about space travel was justified.

Brin says, “All papers on the subject of interstellar flight agree that a steady acceleration at just one gravity would suffice for rapid movement between the stars. There are substantial problems (in) maintaining 1G for great lengths of time, and debate has raged over the practicality of interstellar voyages, but the visceral sensations of such journeys are way down on the list of problems.”

David E. Brahm, a Caltech physicist doing high-energy research, agrees that both Der and Mills are “way off base.” He says, “a spaceship traveling near the speed of light could travel hundreds of light-years in only decades of ‘on-board time.’ To the travelers nothing seems amiss, except that the distance they must travel seems to shorten. They are most emphatically not stuck in some sort of ghoulish statue-like existence.”

He denies Mills’ idea that reaching such a speed would require bone-crushing acceleration. “In fact, at a comfortable 1G (which would feel like standing in your own living room) a spaceship could get close to the speed of light in about a year.”

Brahm agrees that such travel would take tremendous amounts of energy, but means of producing it are on the scientific agenda. “These are just technological fantasies at the moment, but should suffice to show that interstellar travel is at least scientifically plausible.”

Ben Zuckerman of the UCLA department of astronomy agrees that Der and Mills fed me “a ton of rubbish.”

Of Der’s notion about the effects of near speed-of-light travel, he says, “This is 100% rubbish. The inside of the spacecraft would be no different from the inside of your car, unless the spacecraft happened to be unlucky and ran into an asteroid.”

He disdains Der’s assertion that a space traveler wouldn’t be able to move or feel, see, smell or hear anything. “This is complete rubbish. According to special relativity, time is personal. We each have a clock attached to our bodies. The space travelers would live in their own time frame exactly as long as you live in your own time frame. They would not have the sensation of experiencing life any longer than you do. What would be true is that in the frame of reference in which you measure time, they would live a long time.”

As for Mills’ theory that space travel would require thousands of G’s, Zuckerman says “yet more rubbish.”

(I cannot comprehend Zuckerman’s explanation of special relativity, but I am accepting him on his credentials.)

Dennis Anthony writes, “I have rarely read anything in The Times that so reminds me of Mark Twain’s observation that what people don’t know is not nearly as vexing as what they know that isn’t so.”

David C. Johannsen, whose Ph.D. dissertation is titled “Highly Relativistic Quark-Anti-quark Bound States,” says “you have been led astray by a couple of smooth-writing correspondents with limited grasps of relativity theory.”

Johannsen explains the relativity involved in space travel, but I don’t trust myself to condense it. But he also quashes Mills’ idea that space travel would require high forces. “If you are willing to spend a year at the start of your journey accelerating, and another year at the end decelerating, you can travel at near-light speed while experiencing no more stress than you would experience sitting in your living room.”

Johannsen does not, however, support sending off interstellar travelers. “Not because it can’t be done, but because I don’t want to see humankind split up. . . . Better, I feel, that we send out unmanned probes which can spend centuries or millennia radioing back information for all of us to share as one community of people. Just think, the day may come when robot-produced travelogues of distant solar systems will replace the sex and violence movies you now watch on television.”

OK by me. I’m grounding myself.