A fellow blogger of exotic science, Jim Essig, is a thinker of great thoughts.
He is a regular commenter on Centauri Dreams and has his own blog. His thoughts he posts on his site I think might scare some people away in their complexity, but he dreams of manned interstellar travel like Paul Gilster and others do.
Maybe one of Jim’s ideas will come to fruition, he literally thinks outside of the box at times.
But when it comes to rockets, I seriously doubt humanity will ever use them for interstellar flight, because of the limits on travel times and the cost and weight of the fuel necessary to accomplish the mission.
But that doesn’t stop Jim from coming up with some pretty far-out schemes:
I had an interesting idea regarding optimized photon rockets.
The first idea involves the concept of simply an ordinary photon rocket chamber with a blackbody emitter which is anywhere from the temperature of a tungsten filament of an incandescent light bulb (about 3600 K) to that of some exotic yet to be developed black body emitter at say 100,000 K.
The idea is augmented by the concept of a nuclear fusion reactor power source that powers a turboelectric steam driven generator wherein all of the waste heat or almost all of the waste heat is captured and used to drive lower transition temperature material based steam turbines. The whole ship could be enclosed by highly conducting if not superconducting outer walls in order to keep sub millimeter IR and microwave energy from escaping into the interstellar medium.
The beautiful aspect of such a machine is that the effective Isp at least for the exhaust stream would be 30,000,000 seconds commensurate with the speed of light in a vacuum. Another idea would be to power lasers which direct their energy in a beam that is essentially unidirectional for added efficiency over a non-coherent energy emitter.
Another option would entail a matter antimatter reactor to provide turboelectric power for the blackbody emitter or laser beam generator all else being essentially the same as the previous example given above.
Still a more efficient system would carry only antimatter fuel and collect the reactive normal matter from interstellar space. Can you imagine the gamma factor possible for a photon rocket powered by such a system wherein the end cycle efficiency in terms of the latent fuel energy to final kinetic energy transfer to the ship approached 100 percent, or even only 95 percent.
Jim talks a lot about gamma factors. I think it has something to do with time dilation. I have to ask him later.
The point is, despite Jim’s esoteric rocket tech, I believe it’ll only be used for the initial, primitive excursions.
Which brings me to Paul’s post yesterday about the bet he made with Tibor Pacher and that it might have already been lost :
In the midst of all this interstellar musing, in came an e-mail from the SETI League’s Paul Shuch, opining that the bet has already been won and, moreover, that Tibor is the victor! Let me quote Paul:
I would argue that the first interstellar missions have already launched, and that (with only a little imagination) they meet the conditions of the bet. They are not spacecraft, but rather streams of photons. Think about it: interstellar microwave transmissions probe other civilizations’ interest in dialog, and pass numerous stars, thus are “flyby probes” in a sense. They are transmitted specifically for the purpose of reaching other solar systems. They have been “launched” (transmitted) several times from Earth, which is clearly within the orbit of Neptune. Some have conveyed scientific information about Earth, which satisfies the condition that they “deliver data for at least one scientific measurement.” They travel at the speed of light, so within the 2,000 year mission duration, will reach stars within 2,000 LY of our own Sun. And they are widely supported by the public, as witness the large number of humans who have submitted messages to the various projects that beam them into space. So, congratulations Tibor, you win!
Remind me not to play poker with Paul, who in the following e-mail exchange added that his argument was a bit of a Kobayashi Maru — a more or less no-win situation, for those of you not familiar with Star Trek lore. The key word here is ‘deliver,’ for now that I read through our Long Bets terms, I see that the operative sentence is ‘As a minimum requirement for the mission the spacecraft shall be capable to deliver data for at least one scientific measurement.’ Now, slapping forehead with palm, I wish Tibor had written (and I had agreed to) ‘return’ instead of ‘deliver’ data! Although I’m not conceding, I do invite Paul to join us for Champagne in 2025, and maybe Ray Villard can join us as well.
Ray Villard is the science writer who recently wrote an article about the rocket engineers who lament the impossibility of interstellar travel via rockets, though the impression I get is he thinks the concept is possible.
The common link between these two posts is the use of photons to carry out the mission, though in different ways.
After reading these ideas, my own concept would require the use of quantum entanglement of photons between here and the target being investigated in order to perform a variation of “remote viewing”. No fuss, no muss and no rockets to fuel up.
Of course it would require advanced computer tech and extreme software, the very thing Gilster admits that he didn’t take into account enough.
We are at the stage where we have our own contemporary Tsiolkovskys and Bernals putting forward advanced theories of interstellar travel and how to conduct it like they did for interplanetary rocket flight one hundred years ago.
Without the wars and genocide of course.
A Multitude of Interstellar Space Travel Concepts, PART 1: The Possibility of Highly Isp Optimized Photon Rockets, Rapidly Orbiting Extremely Electrically Charged Black-holes Regarding Electrogravatic Effects, Musings on the Indefinate Human Life Expectancy Extension Regarding Moderately Relativistic Manned Interstellar Space Travel Through Space, The Possible Use of Paralell Histories to Provide Fuel to Enhance the Yield of Thermonuclear Devices, Cold Dark Matter Analogues of Fusion Pellet Runways for Powering Manned Interstellar Space Craft, and Musings on the Distant Future Construction of Particle Accellerators of Cosmic Dimensions