Centauri Dreams
Imagining and Planning Interstellar Exploration
SETI’s Colossus
For the most part, the focus of SETI since Project Ozma has been directed at intercepting signals deliberately sent our way. It doesn’t have to be so, of course, because extraneous signals from a civilization going about its business would also be profoundly interesting, and even a civilization not much more advanced than ours might be throwing off powerful evidence of its existence through the planetary radars it uses to detect potential impactors in its own system.
Whether or not the Ohio State WOW! signal was a SETI detection remains unresolved, but I always think back to the original Cocconi and Morrison paper “Searching for Interstellar Communications,” published in Nature in 1959. Neither man could know in that year whether exoplanets even existed, but it was a reasonable supposition, and technology had advanced to the point where detecting SETI signals was consistent with all we knew. And as the duo wrote: “The probability of success is difficult to estimate, but if we never search, the chance of success is zero.”
Again I’m reminded of Freeman Dyson’s dictum ‘look for what’s detectable, not for what’s probable,’ which reminds us not to bring too many assumptions into the mix. Thus today we’re seeing the growth of interest in interstellar artifacts, perhaps in the form of gigantic engineering projects that would be observable across light years. And now we have a new proposal, one that would use a gigantic telescope housed here on Earth to look for infrared signatures around other stars. These would not be beacons but the infrared excess inevitably generated by a civilization going about its business. We needn’t, in other words, wait for them to send to us.
The Largest of All Telescopes
Four researchers have outlined the prospect in How to Find ET with Infrared Light, an article appearing in the June, 2013 issue of Astronomy. Jeff Kuhn (University of Hawaii), Svetlana V. Berdyugina (University of Freiburg), David Halliday (Dynamic Structures, Ltd., in British Columbia), and Caisey Harlingten (Searchlight Observatory Network, Norwich, England) believe that a survey out to 60 light years using their methods could make a definitive call on the existence of any civilizations there. The attempt revolves around the use of power.
Consider that Earth’s current terrestrial power production is 15 terawatts, which turns out to be 0.04 percent of the total solar power received on Earth from the Sun. The authors designate the ratio of a civilization’s power production to the amount of solar power it receives as ?. The article points out that the total power used by photosynthesis on Earth is 0.2 percent of the total light falling on the planet from the Sun — it’s interesting to see that our civilization consumes only 20 percent as much power as the biology that supports us. But let’s carry this forward:
As Earth-like civilizations evolve, they use more power. For example, in Roman times, we estimate ? was about 1/1000 what it is today. Humans’ global power consumption is growing by about 2.5 percent per year, even though the world’s population is growing at less than half this rate. In contrast, our knowledge base (the combined total of all recorded information) doubles in just two years. As cultures advance, their information content also must grow, and the power required to manipulate this knowledge eventually dominates a civilization’s total power use.
Finding a civilization through its waste heat radiation thus appears possible, given the right equipment, and what equipment it is. Right now the three largest infrared telescopes being planned are the Giant Magellan Telescope, the Thirty Meter Telescope and the European Extremely Large Telescope. But Kuhn and his colleagues need to go bigger. They’re talking about an instrument with a primary mirror of 77 meters, fittingly called Colossus.
Image: The Colossus Telescope, a high-resolution, multiple-mirror giant instrument, will have the ability to directly image the heat generated by other civilizations on planets orbiting stars near us in the Milky Way. Credit: Innovative Optics/Colossus Corporation.
A huge collecting area and an adaptive optics system to correct for the effects of Earth’s atmosphere are essential, as are techniques of ‘thin-mirror slumping’ and polishing technologies being developed by the team through their company Innovative Optics, which operates its research and development out of the University of Hawaii’s Institute for Astronomy in Maui as well as at the National University of Mexico in Ensenada. I pulled this from the Innovative Optics website in a section describing the team’s methodology:
Our proprietary processes drastically reduce the time and cost of production of precision optics. Our optics are produced by fire polishing flat glass (which avoids time-consuming abrasion techniques and leaves a smoother, optically-superior mirror surface), then “slumping” the hot glass under controlled conditions to the desired final shape; no grinding or rough polishing step is required.
The site goes on to describe what it calls ‘Live Mirror’ technologies that provide the adaptive optics needed to eliminate atmospheric distortion. Innovative Optics claims its mirrors can be very thin (2.5 cm thick for an 8-meter diameter Live Mirror) and therefore lightweight, at roughly 70 kg per square meter of surface area, a significant reduction over conventional mirrors. Colossus is envisioned as comprising approximately sixty of these 8-meter mirror segments, with a field of view that would take in only a few arcseconds of the sky at any time, allowing the designers to optimize for star-like sources even as the design holds down costs.
Using a sensitive coronagraph to remove scattered light that would obscure an exoplanet, Colossus would be able to find hundreds of Earth-sized or larger planets in the habitable zone including any civilizations on their surfaces. Innovative Optics is working with Dynamic Structures (Vancouver, BC) on design and construction issues, although issues of funding and location remain to be resolved. Backed by ‘a group of physicists, engineers, telescope builders, philanthropists, and businessmen,’ the team believes the technology exists to make Colossus a reality. “The Colossus would give us insight into whether civilization is a fragile development or if it is common,” the article concludes. “And we’d learn this without announcing ourselves.”
Oceans Under the Ice Worlds?
One of the things we’re going to be looking for at Pluto is evidence of a sub-surface ocean. About eighteen months ago I wrote about the work of Guillaume Robuchon and Francis Nimmo (University of California at Santa Cruz). With Pluto’s outer surface thought to be a thin shell of nitrogen ice covering a shell of water ice, these researchers have been asking what surface features might flag an ocean deep inside. An equatorial bulge left over from the days when Pluto was spinning more rapidly – or the lack of one – could be the evidence they’re looking for.
The thinking is this: Such a bulge could be as much as 10 kilometers high and New Horizons should be able to spot it. The presence of the bulge would indicate no ocean beneath, for the movement of liquid water would over time have reduced or eliminated the protrusion. But if New Horizons finds instead evidence of tensional stresses, indicating the outer shell was stretched because of temperature changes over time, then the possibility of an ocean is enhanced. If it’s there, Pluto’s ocean would most likely be maintained by isotopes undergoing radioactive decay. Robuchon and Nimmo think a planet-wide ocean would be about 165 kilometers deep under a crust of the same thickness. For more on their work, see The Case for Pluto’s Ocean.
Meanwhile, we’re also getting interesting news about Saturn’s moon Dione. Here we’re working with data from the Cassini orbiter, whose magnetometer has found hints of a faint particle stream coming from the moon, with evidence in other imagery of features not unlike those associated with the geyser activity on Enceladus. The findings are examined in a paper published in March in the journal Icarus that focuses on Janiculum Dorsa, an 800 kilometer long, 1-2 kilometer tall mountain under which the crust of Dione seems to be flexing.
Image: The Cassini spacecraft looks down, almost directly at the north pole of Dione. The feature just left of the terminator at bottom is Janiculum Dorsa, a long, roughly north-south trending ridge. Lit terrain seen here is on the anti-Saturn and trailing sides of Dione (1,126 kilometers, or 700 miles across).The image was taken with the Cassini spacecraft narrow-angle camera on March 22, 2008 using a spectral filter sensitive to wavelengths of ultraviolet light centered at 338 nanometers. The view was acquired at a distance of approximately 650,000 kilometers (404,000 miles) from Dione and at a Sun-Dione-spacecraft, or phase, angle of 99 degrees. Image scale is 4 kilometers (2 miles) per pixel. Credit: NASA/JPL/Space Science Institute.
Here again we’re looking for evidence of activity that may have ended long ago, just as we keep our eyes open for that bulge on Pluto. But Noah Hammond (Brown University), lead author of the paper on this work, notes that what we see on Dione is intriguing: “The bending of the crust under Janiculum Dorsa suggests the icy crust was warm, and the best way to get that heat is if Dione had a subsurface ocean when the ridge formed.”
This JPL news release goes into the possibilities in a bit more detail, noting that tidal effects from Dione’s orbit and an icy crust that can move independent from the moon’s core could create the heat we’re witnessing here. But were the tidal forces on Enceladus so much stronger that they produced the geysers still active there? Or are the Enceladus geysers actually the result of more radioactive heating from heavy elements? Whatever the case, a possible ocean under Dione reminds us that other worlds of high interest — Ceres as well as Pluto and Charon — may show evidence for liquid water, which may in fact exist inside objects deep into the Kuiper Belt.
The paper is Hammond et al., “Flexure on Dione: Investigating subsurface structure and thermal history,” Icarus Volume 223, Issue 1, (March 2013), pp. 418-422 (abstract).
The Angle on Pluto
The progress of New Horizons through the outer Solar System has me thinking back to Voyager’s great encounters. In 1986, when Voyager 2 whisked past Uranus, I was about to head off for a weekend of intensive work as a flight instructor — a client we had contracted with had a large number of pilots in need of recurrent training, and I knew I would be in the cockpit well into each night, as indeed I was.
Those long days and the memory of Voyager at Uranus are, of course, tinged with the explosion of Challenger, which took place a scant four days after Voyager’s closest approach to the planet. We were all riveted by the coverage of the event but could only catch it in between training flights, but I remember trying to keep my mind off the fallen Shuttle as we dealt with constantly challenging weather over Maryland and West Virginia. And it was only later that I was able to really sit down and go over the images from Uranus, whose system of moons had always intrigued me — it has continued to do so, especially after my first glimpse of Miranda.
Image: Launch of New Horizons atop an Atlas V rocket. Credit: NASA/KSC.
Triton had much the same effect on me later. Neptune was in the summer of 1989, twelve years after launch, and I remember taping the encounter on a couple of VCR tapes that I still have around here someplace. New Horizons, we can hope, will offer up equal wonders, for it seemed that everything that Voyager — and for that matter, Cassini — saw has re-written our knowledge and assumptions about outer system objects. We’re assuming, of course, that New Horizons can stay healthy through the encounter, which is the subject of principal investigator Alan Stern’s most recent update from the Applied Physics Laboratory at Johns Hopkins University.
Parameters of the Encounter
There are ways of maximizing science, something we definitely want to do, and ways of minimizing danger, and the New Horizons team has to balance between the two. After all, with the discovery of a fifth moon in the system in 2012, rising concern that passage through Pluto/Charon space might be hazardous was inevitable. Stern says a NASA-appointed technical review team and a separate group of senior executives at NASA headquarters has signed off on the findings of the New Horizon team. He adds:
The Pluto system appears to be far safer than early fears and initial calculations indicated when the new moons began popping up. In fact, the best current models predict a 0.3% (1-in-300) chance of a mission-ending impact near closest approach on the nominal trajectory. Much of the reason for this lowered risk assessment is that more sophisticated dust-impact models revealed a decrease (by about a factor of 100) in lethal impact probability for trajectories that fly into the region where New Horizons is aimed now – a region where the gravitational effects of Pluto’s largest moon Charon clear debris. Another important factor is that when we tested spacecraft components against high-velocity impacts using gun ranges in New Mexico and Ohio, we found the spacecraft shielding is considerably “harder”- that is, more resistant to impacts – than preflight estimates indicated.
How will New Horizons maximize its chances? For one thing, the spacecraft’s approach trajectory is steeply inclined to the plane of Pluto’s satellites and any debris that may accompany them. The highest risk would be during closest approach. And that closest approach is in the region where Charon effectively cleanses the area of debris. The encounter plan, then, seems sound despite the recent satellite discoveries. Add to that the fact that New Horizons will itself search for hazards during the final weeks of its approach in the summer of 2015.
Image: The New Horizons trajectory (red line) is steeply inclined to Pluto’s satellite plane, thereby restricting satellite debris hazards – which lie near the satellite plane – to the short time near closest approach. Credit: JHU/APL/Alan Stern.
Stern adds:
…we’ve also added “fail safe” data downlinks just two days and one day before the encounter to send home the best images and spectra stored on the spacecraft’s recorders, just in case our current estimates are wrong and we do lose New Horizons at closest approach.
Moreover, New Horizons has two alternate encounter sequences that can be uploaded to the spacecraft in the final weeks if needed. Stern’s post gives an explanation of these SHBOT’s (Safe Haven by Other Trajectory), in which the spacecraft can be repointed to protect its dish antenna, or the spacecraft itself directed toward a closer encounter with Pluto just inside 3000 kilometers from the surface (the planned encounter is at 12,500 kilometers). Going closer in allows more ‘drag clearing’ of debris particles, caused by Pluto’s tenuous upper atmosphere.
Let’s assume that prudent planning like this will give us a survivable encounter in 2015. New Horizons’ first image of Pluto/Charon is scheduled to be made this July, which happens to be the 35th anniversary of the discovery of Charon. The craft recently emerged from hibernation for summer encounter rehearsals and systems checks, and green onboard beacons continue to tell us that all is well. Ahead of us we have not just Pluto but Charon, a moon the size of Texas (Nix and Hydra are about the size of Rhode Island, according to the New Horizons team, while P4 and P5 are just the size of counties). Interestingly enough, Nix and Hydra are also about the size of the Kuiper Belt objects the team is hoping to flyby years after the Pluto/Charon encounter.
Supporting Starship Congress
Following last week’s highly successful Starship Century conference, I’m looking forward to the Starship Congress coming up in August under the auspices of Icarus Interstellar. Be aware that there is a Kickstarter campaign now in place to support the event and the organization. From the description:
Icarus Interstellar, a non-profit organization dedicated to achieving interstellar spaceflight by the end of the century, will facilitate such a forum as a means for allowing individuals to present and share knowledge and ideas among colleagues within the space exploration community. As an organization run by volunteers, Icarus Interstellar is reaching out to space enthusiasts and supporters to assist in funding this important event, which will incur significant expenses pertaining to venue rental, A/V technical requirements, live streaming of the conference, featured guest speaker travel procurement, and marketing.
I’ve just made my own contribution and hope you’ll consider doing the same. Good luck to our friends at Icarus Interstellar as they move forward with the event. I’m looking forward to seeing many Centauri Dreams readers in Dallas.
An Open Question on Priorities for Interstellar Efforts
At the 2012 100YSS Symposium, Heath Rezabek presented what he calls the ‘Vessel Archives’ proposal, a strategy for sustaining and conveying Earth’s cultural and biological heritage that was directly inspired by Gregory Benford’s Library of Life proposal (preprint available here). Heath tells me his major concern is in “improving the prospects for Earth-originating life through the longevity of our interstellar aspirations and through the application of advanced discoveries to enhance life’s prospects on Earth.” Independent of his role as Outreach and Collaborations Coordinator for Icarus Interstellar’s Starship Congress 2013, he is also an accepted presenter for that conference. Recently Heath contacted me about a research project he is conducting with implications for the interstellar community, as explained below.
In his non-interstellar work, Heath Rezabek (MLIS) is a futurist librarian, technology grants coordinator, writer, and systems designer. He lives in Austin, TX, where he serves as the Teen Services Coordinator within Youth Services at the Austin Public Library, focusing on digital literacy initiatives for at-risk youth.
by Heath Rezabek
If you’re interested in space and space exploration, or if you’re interested not only in space but in long-term efforts to achieve interstellar travel in the fullness of time, I would like to survey your thoughts and feedback for a research project. The survey data collected will be presented in an accepted session at the 2013 Starship Congress (August 15-18, Dallas TX). Results will be fully documented online and reported for the benefit of all stakeholders in the future.
Through the use of the open source surveying platform at allourideas.org, I am asking long-term space exploration advocates the following question:
What do you see as a priority for interstellar efforts over the next 10-20 years?
The survey is stocked with priorities submitted thus far, running the gamut from the very specific to the broad and general. Skeptical or constructively critical submissions are also welcomed! I am gathering as many new or additional ideas as you are willing to submit.
Because of the way a wikisurvey works, the system can handle a very large number of ideas, and individuals can vote as many times as they like. This inclusive approach yields nonchaotic results because of the way a wikisurvey strictly limits poll matchups to two randomly drawn ideas per round.
The resulting data and polling set will be designated CC0 (public domain), so that the ideas this open question yields can be of open benefit to others who may explore this same question in the future. This project is an experiment in a new series of such surveys on a wide range of challenges, called Open Questions: Questions of priority whose answers may be developed and used by all.
If you want to know more, feel free to email me at heath.rezabek@gmail.com — and if you are interested in Starship Congress, join us at —
https://plus.google.com/communities/106211644371328533812
And register at —
http://www.icarusinterstellar.org/congress-registration
Thanks for participating and passing this on.
Star Trek, Star Tech
Tau Zero’s founding architect (and the former head of NASA’s Breakthrough Propulsion Physics project) weighs in on the kind of technology we see in the new Star Trek movie and ponders what it would take to make at least some of it real.
by Marc Millis
Another Star Trek film just hit the screen – with the venerable Starship Enterprise and its iconic warp drives and in-flight gravitation. How close are we toward realizing such a fantastic “Starship Enterprise”? How do such visions compare to other starflight pursuits? And finally, what is being done about it?
STARFLIGHT CHALLENGES AND OPTIONS
To send a spacecraft to our nearest neighboring star system (Alpha Centauri is over 4 lys distant) within a human lifespan would require a speed of roughly 1,000 times faster than the Voyager spacecraft. The two Voyager spacecraft were launched by NASA about 3 decades ago, and are just now passing through the edge of our solar system, at a distance of roughly 1/500th of a light year.
To increase speed by a factor of 1,000 requires at least 1,000,000 times more energy, and then at least twice more if you want to stop at the destination. And think about the researchers left behind on Earth, the people who build the equipment and the experiments aboard the starship. Considering that a human lifespan is about 100 years (rough orders of magnitude), they’ll be able to track a mission only out 80 light years or so even if it’s moving close to lightspeed. While that might be enough to reach a habitable planet (whose closest distance estimates span roughly 25-ly – 200-ly), the provisional estimates to reach the nearest civilizations (if there are any) are between 500-ly – 6000-ly. [Click for more destination info]. To reach these more profound destinations within the lifetime of the starship builders back home requires either faster-than-light (FTL) flight, or a much longer human lifespan.
Image: Star Trek‘s Enterprise, an icon of breakthrough propulsion. Credit: The Light Works (www.thelightworks.com).
Absent FTL flight, most starflight researchers explore probe missions based on foreseeable technology. Armed with estimates of what might be ultimately feasible within existing physics, they determine what further technological advancements would be needed to enable meaningful missions. Early projections suggest that probe missions with flight times of only decades might be possible. To develop that technology and to prepare the supporting systems to collect the energy to launch such missions, however, might take several decades or centuries. Those estimates vary wildly depending on which conclusion is being advocated.
When considering human interstellar flight, the prominent concept is to build self-sustaining world ships that can support many generations of humans on their slow journey to eventually reach habitable planets to colonize, or to just coast through space as isolated pockets of humanity. Not much work has progressed toward this theme, since we still do not know the minimum number of colonists required and the minimum life support to keep them going… including what societal structure can sustain peace and satisfying lives in such isolation for so long.
And finally, for those that want to reach “new worlds, new life, and new civilizations” within short attention spans, further physics advances are required. This includes FTL flight and other breakthroughs typical of the Star Trek visions. This motivation includes the desire to usher in a whole new era of profound technological prowess – new technologies enabled by further advances – targeted advances – in physics. Some have characterized this last approach like the crazy uncle who indulges in wild dreams and playful tinkering.
At this stage it is too early to objectively determine which of these pursuits is ‘best,’ in large part because there is no definition of ‘best.’ The motivations, pros and cons are so varied, and the hard facts still so uncertain, that the choice is more based on personal preference. From those I know who work on these, they seem to pick the version that they, as individuals, can contribute the most to making them happen.
Note – the Build the Enterprise website is not about a true starship, but rather something that just looks like the Enterprise with far, far less capabilities. If you are seeking the realization of the Enterprise, keep reading.
FANTASTICAL STARFLIGHT REQUIREMENTS
Star Trek made starflight look easy and other inspiring fiction contributed to our yearnings. According to Jeff Greenwald, in his 1999 book, Future Perfect, about how Star Trek affected people around the world: “… it fulfills a deep and eternal need for something to believe in: something vast and powerful, yet rational and contemporary. Something that makes sense.”
An important element of Trek that went beyond technology is its society: creating a cooperative culture that can harness the power of starflight without killing themselves in the process. In reality, when considering the potency of the energy required for real starflight, this is critically important. This subject could be book unto itself, and why societal and human aspects are an integral part of contemplating real starflight. Personally, I am concerned that this challenge might turn out to be harder than creating new physics for warp drives and controlling gravity.
Back now to the inspiring spaceflight physics. For fun, and to appeal to a wider fan base, here is a composite of some of the biggest visual inspirations for starflight, our “2001 Millennium Enterprise, C57-D.”
Image: The “2001 Millennium Enterprise, C57-D”, a kludge of favorite fictional vehicles: two alien slabs (with FTL transport capability) from 2001, A Space Odyssey; the 1966 Star Trek Enterprise; the 1977 Millennium Falcon (Star Wars); and the 1956 saucer ship C57-D from Forbidden Planet. Graphic courtesy of Aldo Spadoni, 2013, based on a rough sketch from Millis.
Regardless of your favorite fiction, when it comes to enabling such fantastical star flight, here is what we need:
(I) Faster-than-light (FTL) engines: Compared to the distances between stars, lightspeed is actually slow. It takes years for light to travel the distance between stars. Our nearest neighboring star system (Alpha Centauri) is over 4 years away at lightspeed. The nearest habitable planet might be anywhere from 25-ly to 200-ly distant. And to consider meeting new aliens for each week’s episode, our ship would need a naive cruise speed of at least 25,000 times lightspeed. The word ‘naive’ is used here to remind us that we don’t really know what happens to time and space beyond lightspeed. For traditional slower-than-lightspeed flight, Special Relativity tells us what to expect about our perceptions of time and length changes as we get closer to the lightspeed limit.
(II) Control of gravitational and inertial forces: This is a hugely important feature that often gets neglected in shadow of FTL. It is so ubiquitous in science fiction that many people do not even realize it’s there and it has breakthrough implications – plus it does not yet have a cool-sounding name to convey its essence. Picture your favorite fictional starship – where the crew is walking around normally – as if in a studio back on Earth. This means that the ship is providing a gravitational field for the comfort and health of the crew – in the middle of deep space where such fields do not exist. This would be a profound breakthrough!
But wait, there’s more. Given this ability to create acceleration forces inside a spacecraft, it is not much of a leap of imagination to suggest that acceleration forces could be created outside the spacecraft too – thus propelling the spacecraft. This too – a non-rocket space drive – would be a profound breakthrough.
But wait, again there’s more. The physics of being able to manipulate gravitational and inertial forces also implies the ability to have “Tractor Beams” for moving distant objects, and the ability to sense properties of spacetime that we cannot yet even fathom.
(III) Unprecedented energy storage and power usage: Last on our list of top requirements is having enough energy onboard to power our magical FTL engines and space drives. On Star Trek, they use matter-antimatter to provide energy (which is existing physics), by fully converting matter into energy. Think Einstein’s E=mc2. Our fantastical spacecraft – and even some of the technological versions – will need at least that much energy.
ARE WE THERE YET?
In the book The Physics of Star Trek, physicist Lawrence Krauss compared the visions of Trek to contemporary physics. But it did not go far enough. It only compared the methods of Trek to the physics, rather than the overall requirements, and it did not suggest what we can do about it today.
Progress toward Trek-like ambitions is actually being made. Notions of controlling inertial and gravitational forces, plus FTL flight, ceased to be just science fiction decades ago. Here is that legacy of some of pertinent publications:
1963 Induced Gravitation: Forward, R. L. “Guidelines to Antigravity,” in American Journal of Physics, Vol. 31, p. 166-170.
1988 Wormholes: Morris, M. S. & Thorne, K. S. “Wormholes in spacetime and their use for interstellar travel: a tool for teaching general relativity,” American Journal of Physics Vol. 56, p. 395-412.
1994 Warp Drives: Alcubierre, M. “The warp drive: hyper-fast travel within general relativity,” Classical and Quantum Gravity 11, p. L73-L77.
1997 Space Drives: Millis, M. G. “Challenge to Create the Space Drive,” AIAA Journal of Propulsion & Power 13(5), pp. 577-582.
2004 Quantum Vacuum Propulsion: Maclay, J. & Forward, R., “A Gedanken spacecraft that operates using the quantum vacuum (adiabatic Casimir effect),” Foundations of Physics 34(3), p. 477 – 500.
2009 Compilation of Approaches: Millis, M. G. & Davis, Eric. W., Frontiers of Propulsion Science, Vol. 227 of Progress in Astronautics and Aeronautics, (AIAA).
To be clear, this does not mean that these breakthroughs are on the threshold of discovery. What is does mean is that these notions have advanced to where they are now attackable problems. In terms of the scientific method, the first step of ‘defining the problem’ has been completed, the second step of ‘collecting relevant data’ is underway, and some ideas have even matured as far as testing hypotheses.
For those who can handle a graduate-level treatise, the first scholarly book on the topic (scholarly means peer-reviewed, objective, with equations and with traceable citations) was compiled by myself and co-editor, Eric W. Davis, with the help of over a dozen contributing authors, and so many reviewers that I can’t remember. In 2009, this book, Frontiers of Propulsion Science, was published as part of the Progress in Astronautics and Aeronautics series of the American Institute for Aeronautics and Astronautics (AIAA).
For those who want just the executive level summary, here are short descriptions, along with some notes about continuing work. I’ve attempted to convey this sanely, between the extremes of sensationalist hype and pedantic disdain:
• Faster-than-Light Flight: Wormholes and Warp Drives are theoretically possible, but our theory is not yet advanced enough to guide their actual construction. These theories are based on, and consistent with, Einstein’s General Relativity. The ongoing progress (I rely on Eric W. Davis to track this for Tau Zero) mostly focuses on the energy conditions – how to lower the energy required and how to create and apply the required ‘negative energy.’ One conclusion already is that Wormholes are more energy-efficient at creating FTL than the Warp Drive. A recent account of those details is available as:
Eric W. Davis, “Faster-Than-Light Space Warps, Status and Next Steps,” paper AIAA 2012-3860, 48th AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit, Atlanta, GA, (January 9-12, 2012) (abstract).
Recent news about the work of Harold “Sonny” White at NASA’s Johnson Space Center has been a bit exaggerated, but the essence of the work is that it is an attempt to measure spacetime distortions caused by the presence of negative energy. Unfortunately, I do not have an article to cite about that hypothesis or the methods being used, since such information has not (yet?) been published. Although Eric Davis is tracking this for Tau Zero, even he does not yet know enough to render judgment. We shall have to wait and see, and hope that the information is submitted for rigorous review.
Additionally, Quantum Physics presents some tempting phenomena that might be relevant to FTL pursuits. A number of phenomena, such as ‘tunneling’ and ‘entanglement’ fall under the header of “quantum non-locality” – a term I learned from physicist John Cramer at the University of Washington, Seattle. That term encompasses the notion that quantum events or phenomena can exist over more than one place at the same time. Cramer’s attempt to test the possible time-paradox implications of such phenomena still remains incomplete. The last update I saw was this publication:
J.G. Cramer, K. Hall, B. Parris, and D.B. Pengra, “Status of nonlocal quantum communication test”, Section 7.2, Univ. Washington CENPA Annual Report 2010-2011, April 2011, pp. 94-95.
But wait, still again there’s more. The hot topics of Warp Drives, Wormholes, and ‘Retrocausal Signaling’ are not the only ways to ponder FTL, but they are the only ones in the peer-reviewed literature, so far. For the budding pioneers amidst us, here is a breakout of other ways of pondering FTL:
Image (click to enlarge): This diagram points out that there is more than one way to ponder FTL. The items in blue boxes are already in the scientific literature, while the remaining green boxes are some of the playful speculations we have heard along the way. Credit: Marc Millis, from the Tau Zero Foundation site.
• Controlling Inertial and Gravitational Forces (in-flight gravitation for crew comfort, maneuvering the ship without rockets, tractor beams, etc.): More than one way to generate acceleration fields has been published and both methods are theoretically consistent with Einstein’s general relativity [Forward’s 1963 paper cited earlier, and the Levi-Civita effect]. Both of these have daunting theoretical and implementation challenges, similar to Warp Drives and Wormholes.
Similar to the FTL work, there is more than one way to approach this challenge, as shown in this graphic:
Image (click to enlarge): There is more than one way to ponder how to create a space drive, and these have been sorted by the physics discipline in which each is based. The items in red boxes have been reliable shown to be dead-ends. Credit: Marc Millis, from the Tau Zero Foundation site.
The details behind this diagram, and the next-step research of each approach are available in:
Marc Millis, “Space Drive Physics: Introduction & Next Steps,” JBIS 65, pp. 264-277 (2012). Abstract available.
This is the area that piques my interest, more specifically the “Space Coupling Propulsion” block in that diagram above. I’ve been working on grant proposals to get that work supported – which involves going back to old works of Eddington and Mach, and scalar potentials where relativity is cast in terms of retarded potentials. For those of you who do not speak that level of geek – I’m trying a different approach to understand the coupling between spacetime (inertial frames) and electromagnetism. The work involves the design and test of new sensors, based on those older perspectives.
• Ample On-board Power: Nuclear power is a technological reality now that, if used for spaceflight, would greatly increase the extent of space activities. The power levels required for interstellar flight, even slower-than-light, are still beyond the accrued prowess of humanity, but optimistic trends suggest they might be achievable sooner than later. The power levels required for faster-than-light (FTL) were once astronomically high, but those values have dropped with continued research to where they are now just fantastically daunting.
Are there new ideas to harness vast amounts of energy? There are credible theoretical and experimental approaches to improve our understanding of “quantum vacuum energy,” but this field is still too young to have developed plausible methods of ample energy exchange. What is possible are miniscule energy conversions when dealing with small electrodes. Today, these serve as good tools to empirically explore this young topic in physics, but are not close to suggesting how to achieve the kind of energy levels needed for FTL flight — levels that might be impossible to achieve..
WHAT YOU CAN DO ABOUT IT
If you want to become a practitioner in pursuit of Star Trek-ish spaceflight, you will need a degree in physics, a vivid imagination, steady rigor to work through the details and persevere through the setbacks, and the personal savvy to navigate amidst a world more interested in short-term returns, and sometimes even back to reruns.
For those who would rather support from the sidelines, Tau Zero will gladly accept donations and is now also open for memberships. If, by some chance, you are a generous philanthropist reading this and wondering if we have what it takes to run a whole program around this theme, the answer is “Yes.” I led the NASA project toward such ambitions, including developing the process to sort through proposals to avoid the detriments of pedantic dismissals and the lunatic fringe. Those details are in the last chapter of our Frontiers of Propulsion Science book. We have a network of qualified practitioners who would gladly assist, even if only for a modest honoraria. And if you are a researcher hoping to find funds for this topic, please let us know if you find any. As yet, we do not have enough funds to invite proposals.
Lastly, I should alert you that there are scams out there on these topics. Rather than risk the legalities of explicit names, please take this advice: If they claim amazing performance – don’t believe it. If they offer no test data to back up their claims, ignore them. If the data they offer has not been independently scrutinized, then look elsewhere. Conversely, the promising signs to look for include: The service providers have a track record of confronting these edgy issues in a manner where increments of progress are published in peer-reviewed journals. Quality practitioners are as open to the possibilities that an idea may or might not work, with the emphasis on getting a reliable answer, instead of hyping the claims or being dismissive.
CONNECTING THE DOTS – ONE VISION
This topic is at such an early stage that it is difficult to project into the future to see how these small steps might lead to the desired breakthroughs. To help fill this gap, I have leaped (below) into wild speculation and conjecture – science fiction, if you will.
First: a dose of reality. Consider how nature has been throwing us curve-balls regarding our physical understanding of space and time. Rotating galaxies do not obey Newton or Einstein, but rather these galaxies hold together as if some “dark matter” is keeping their stars within the galaxies. Next, when viewing our most distant spacetime, we see redshifts that suggest that spacetime is expanding faster than theory – as if some “dark energy” or “antigravity force” were accelerating the expansion of spacetime. Quantum physics, with its incredible predictive power and practical utility, also presents us with oddities like the quantum vacuum energy and non-locality. And finally, consider the Cosmic Microwave Background Radiation, whose properties let it serve as an absolute reference frame for motion relative to the mean rest frame of our Universe. This phenomenon is at odds with assumptions that the Michelson-Morley experiment and the very successful Special Relativity seemed to dismiss the notion of an absolute electromagnetic reference frame. In short, physics is not complete. New discoveries await – discoveries that might open the way for whole new classes of technology.
Now, armed with those uncertainties, consider that other perceptions about the relations between space, time, inertia, and electromagnetism might match nature better. For example, what about the older notions of inertial frames from Mach, Eddington’s other way of describing why light bends in a gravitational field, and the retarded potential perspective of deducing magnetism as a relativistic effect of moving charges. By combining these, it might be possible to first detect, and then induce, perturbations of inertial frames. Such transducers – which convert changes in inertial frames into electromagnetic energy – could reveal new phenomena, new waveforms within inertial frames. Those observations then lead to reversing that conversion – where electromagnetic energy is used to perturb inertial frames – creating momentary gradients that move matter.
This ability would be the beginnings of tractor beams and space drives. From there, imagine when those effects get strong enough to create 0-g recreation rooms on Earth, or 1-g habitats for long-duration, deep spaceflight. Powerful enough devices, ‘space drives,’ could propel spaceships faster and faster. As higher speeds are achieved, experiments to test various FTL theories could commence. Perhaps, just one of those theories might lead to the first FTL transport. And finally, with the combination of non-rocket space drives, cabin gravitation for the crew, and light speed travel… we would have our Enterprise.
Ad astra incrementis
Help us start taking some small risks, today, that might eventually escalate to fantastic starflight – enabling humanity to survive and thrive across the galaxy.
Follow with RSS or E-Mail
