Einstein, Plus Other Theoretical Systems of Propulsion
Accepted wisdom is that the speed of light is the ultimate speed, and at the moment, we have no reasons to doubt that. But it is important not to get hung up on the speed of light, primarily because Albert Einstein’s laws of relatively suggest that time slows down relative to an object traveling close to light speed.
And as an object’s speed increases and edges closer to the speed of light, space bends or curves, and time slows even more. In other words, the savings of time become greater.
Sophisticated experimentation has suggested that Einstein’s “slow time” theory is correct. Additionally, exciting news from early 2016, the faraway collision of two black holes, seems to have confirmed Einstein’s thinking.
Interstellar travel may be possible without exceeding the speed of light. It is conceivable that other civilizations have devised technology that makes interstellar travel practicable. Here are some possibilities: Antigravity: The pull of gravity is what tethers us to Earth, and prevents our lakes and oceans from disappearing into the sky. In that, and a lot more, gravity is a desirable thing. On the other hand, if you’re five feet two and long to dunk a basketball, you’re probably out of luck. Blame it on gravity. Gravity’s pull also mandates that our aircraft carry their own power sources, to generate the thrust needed to send them aloft and achieve a useful speed. Antigravity—a force that opposes gravity—is appealing for frivolous reasons, such as the ability to hoist an engine block with the palm of your hand, and for serious ones, such as eliminating the force that wants to return aircraft to the ground.
In the early 1890s, the visionary American scientist and inventor Nikola Tesla deduced the underpinnings of what he later called a “dynamic theory of gravity.” His ideas are at odds with Einstein’s later theory of the curvature of space, and are thus considered radical: Tesla felt that the physical law of action and equivalent reaction “straightened” space, eliminating Einstein’s vision of curved space and casting doubt on our understanding of the movement of bodies there.
Tesla believed that space carries atomic and subatomic matter, and a field of “luminiferous ether,” a force that influences gravity, momentum, and inertia.
The ether, Tesla said, moves in whorl patterns at nearly the speed of light, creating ponderable matter (also referred to by Tesla as “gross matter”: matter with measurable mass). When the force subsides, “the motion ceases and matter disappears.” Tesla dreamt of harnessing the power he had deduced. He said that if that could be managed, mankind would “have powers almost unlimited and supernatural.”
People could control the size of Earth and the planet’s seasons, physically guide Earth through the universe, and “create and annihilate material substance” [emphasis added]. Mated with what Tesla learned about electrostatic emissions and conductors, his gravitational theory suggested aircraft with sharply curved leading edges (where electrostatic emissions will concentrate), and with interior chambers of vacuum, and atmospheric pressure designed to create “free” power that allows the craft to work in opposition to gravity.
In the early 1920s, an American physics student named Thomas Townsend Brown discovered a relationship between the manipulation of positive and negative electric fields, and concomitant increases and decreases in mass of an X-ray vacuum tube. This relationship, he felt, suggested a way to control gravity by creating an ascendant “G-hill” wave and a descendant “G-well” wave on an imaginary horizontal. A mobile object designed to create those waves, and maintain them, could “defy” gravity.” Brown eventually dubbed his field of study electrogravitics.
Forty years after Brown, aviation firms Northrop, Grumman (before the creation of Northrop-Grumman), and Avco experimented with high-voltage charges laid against the leading edges of experimental high-speed aircraft. Wind- tunnel tests showed that the voltage pushed the rush of air away from the planes’ bodies. Although in no way suggestive of antigravity, the tests did display relationships between flight, aircraft bodies, and electrostatics, as Tesla and Brown had suggested.
Tesla’s antigravity claims have been neither proved nor disproved. As for Brown, electrogravitics became a preoccupation of scientifically trained hobbyists, as well as of conspiracy theorists convinced that antigravity technology has been tested, proved, and then deep-sixed or otherwise concealed.
Around 1995, enthusiast claims of NASA experiments with antigravity surfaced, suggesting technology that utilized spinning, superconducting ceramic; liquid nitrogen; and solenoids that created and maintained magnetic fields, to allow levitation. Eight or ten years later, stories circulated about Boeing’s Seattle “Phantom Works,” where researchers in touch with Russia and Finland worked on Project GRASP (Gravity Research for Advanced Space Propulsion). Boeing claimed that the original Russian research was “plausible,” but the project apparently yielded no useful results.
The allure of antigravity flight is no less potent today than it was in 1956, when interviewer William Gladych met visionary aircraft designer William Lear. Mr. Lear said, All matter within the [antigravity] ship would be influenced by the ship’s gravitation only. This way, no matter how fast you accelerated or changed course, your body would not feel it any more than it now feels the tremendous speed and acceleration of the Earth.
Gladych clarified: “In other words, no more pilot blackouts or any such acceleration headaches. The G[ravity]-ship could take off like a cannon shell, come to a stop with equal abruptness and the passengers wouldn’t even need seat belts.” In just four sentences, Lear and Gladych explained the astonishing in-flight behavior of numberless UFO sightings.
Wormhole Travel: For all the eighty years of chatter about wormholes—those fabulous theoretical portals that transcend time and distance in deep space—the wormhole concept is hypothetical. A wormhole has two mouths connected by a passage called a throat. Science fiction suggests easy travel through the throat, but many factors relegate wormhole travel to theory. No wormhole has been observed, though physicists are reasonably confident wormholes exist.
But wormholes are apt to be very small, even microscopic, and thus impractical for use by space travelers. The encouraging news is that the universe is expanding, and as it does, wormholes may expand too. If wormholes exist, interstellar flights of short duration are theoretically possible. A 1935 paper by Albert Einstein and Nathan Rosen proposed that, given Einstein’s theories about gravity as having a warping effect on space and time, “bridges” (wormholes) might exist for very brief periods.
The space-time bridges collapse before even light can escape from them, but if they could be kept “open,” spaceships might pass through, overcoming the constraints of normal time to hop from one galaxy to another.
Harvard astrophysicist Rudolph “Rudy” Schild’s thoughts about a magnetic variant of black hole theory—what he calls a magnetospheric eternally collapsing object (MECO)—bring fresh dimension to wormhole theory. During close study of a brilliant quasar located nine billion light years from Earth, Schild and his colleagues found evidence of a magnetic field. The discovery flew in the face of accepted notions about quasars, which had been understood to be “powered” by black holes. But a black hole prevents the escape of light, radiation, and matter from its event horizon (a black hole’s theoretical boundary). Schild counters common belief by asserting that the magnetic properties of a MECO, in concert with quantum electrodynamics, prevent the formation of an event horizon. With the event horizon denied, a MECO’s collapse is never completed, and goes on endlessly. Instead of becoming a black hole, the eternally collapsing MECO remains a hot ball of plasma.
If black holes are removed from the theoretical picture, the universe may not be shrinking. To the contrary, it may again be expanding, creating a negative gravity (colloquially known as dark energy) that enables wormholes. And wormholes are one way extraterrestrials might manage space travel to Earth.
Schild’s theory has its supporters, particularly among UFO researchers and other enthusiasts, but has yet to be widely accepted by the scientific community.
American theoretical physicist Kip Thorne has suggested that exotic matter might prop wormholes open long enough for the passages to allow through travel. Exotic matter is repelled by gravity; until recent years, its existence was only theoretical. But quantum physics experiments since the millennium— notably the four-hundred-member Belle Collaboration and the Large Hadron beauty (LHCb) Collaboration—verify the existence of “the ghost particle”: exotic matter.
A quark is a fundamental, subatomic particle. Ordinary matter is made from tightly knit composite particles called hadrons. Hadrons exist in two classifications: baryons and mesons. Baryons are created when three quarks combine. Two familiar building blocks of matter, protons and neutrons, are baryon hadrons.
Quarks have opposite numbers, called antiquarks. Quarks and antiquarks are identical in mass, but have opposite charges. When a quark and an antiquark pair up, the result is a meson. Like baryons, mesons are hadrons. However, mesons do not obey conservation laws; because they are composed of a quark and an antiquark, they are unstable. They are exotic matter.
Because exotic matter has been theoretically verified, its theoretical role in wormholes has not been disproved. Wormholes lacking an exotic-matter bridge are unstable. Even one large enough to admit a spaceship might suddenly collapse. If travelers could introduce exotic matter to a wormhole, the stability challenge would be solved.
That’s good, but we don’t know what will happen when the ordinary matter of the spaceship meets the exotic matter. Explosion? Disintegration? Or perhaps nothing violent at all.
Extraterrestrials that have mastered wormhole travel are technologically far ahead of us—so far ahead that we may not interest them at all, except as biologic footnotes.
Suspended Animation: In the opening sequence of the 1979 science-horror thriller Alien, the crew of the interstellar cargo ship Nostromo awakens after an unspecified period in hypersleep. Crew members have slumbered in discrete pods, and are awakened automatically when needed to resume tasks and continue the ship’s commercial mission. Groggy for a few minutes, each quickly recovers. Wherever in space they are, it’s a long way from Earth. Apparently lacking access to wormholes or other cosmic shortcuts (though “hypersleep” does imply “hyperdrive”), the Nostromo’s mission is feasible because during the period of suspended animation, the crew members require little food and water, and age relative to their immediate environment, rather than to Earth.
Long familiar in science fiction, suspended animation now may have a future in medical treatment of trauma victims. Researchers at Pittsburgh’s UPMC Presbyterian Hospital began human trials in 2014, replacing portions of subjects’ blood with chilled saltwater. With the body cooled to about fifty degrees Fahrenheit in fifteen minutes, bodily functions slow dramatically and give surgeons the time needed to make repairs.
Although akin to animal hibernation, the process does not yet have long-term applications. Still, it may be a signpost toward practical suspended animation of space travelers to Mars and elsewhere. NASA now works with SpaceWorks, an Atlanta company with technology that can shoot cooling liquid up an astronaut’s nose and into the base of the brain. The process produces what NASA and SpaceWorks describe as “torpor,” a sort of hibernation that will eliminate the need for galleys, exercise rooms, and full-dimension living quarters. And smaller quarters mean weight savings, less fuel, and increased long-journey practicality.
Granted, neither hibernation nor torpor is desirable for prolonged space travel.
An induced slowdown of body systems is just that: a slowdown. Whether bear or human, the organism still ages; in other words, torpor will not prolong space travelers’ lives. So even assuming that torpor could be maintained in space, the thirty-five-year-old astronaut that left Earth is going to be eighty-five after fifty years of hibernation-like travel. Besides saving on weight and stores, all that’s been accomplished is that the astronaut didn’t become bored during her journey.
At eighty-five, even with scheduled muscle stimulation during the trip, the astronaut isn’t going to be as spry—or as useful—as she had been fifty years earlier.
Alternatively (and strictly theoretically), infant astronauts could awaken as healthy middle-aged adults . . . with the mentalities of infants. Well, that’s an obvious dead end.
Cryogenic suspended animation, by which bodies are frozen until a scheduled thaw, is unappealing because when ice crystals are thawed, migrating water can crush or dehydrate cell membranes. Cells might also be damaged by dissolved substances (solutes) that remained separate from the ice crystals.
Chemically induced hypoxia slows body functions, but may bring unavoidable brain damage. Humans and extraterrestrials may share certain basic physical commonalities.
If freezing damages human cells, the process may damage alien cells, as well.
For this reason, wormhole travel, for all of the guesswork and theory attached to it here on Earth, may be more viable an option for interstellar travel than any form of suspended animation.
Photon Power: Photon propulsion, which has been discussed in scientific circles since the 1920s, may emerge during the next twenty to fifty years. Or it may not. Monumentally expensive and complex, photon power is a theoretical technology grounded in the nature of light.
All light is characterized by two qualities: electromagnetic waves and packets of fundamental subatomic particles called photons. All light is made of photons.
Because photons—unlike those other familiar subatomic particles, electrons and quarks—have no mass, photons travel at, naturally enough, the speed of light.
The speed is constant, regardless of whether the electromagnetic waves are manifest (as determined by wavelength) as visible light, X rays, infrared rays, ultraviolet rays, radio waves, or gamma rays. Optimum speed, though, is achieved only in a vacuum.
The energy of each photon varies according to wavelength: the shorter the wave, the more energy contained by each photon. But regardless of the apparent intensity of the light source, each photon contains the same amount of energy. Intensity is simply a function of the number of photons striking a given surface area during a prescribed time.
All rockets propel themselves forward by pushing a reaction mass (matter) out of an exhaust. The so-called “rocket equation” demonstrates that forward speed is directly proportional to exhaust velocity—that is, the speed at which the reaction mass leaves the exhaust. Maximum exhaust thrust produces, in theory, maximum velocity: the speed of light.
Speculation about photon propulsion’s light or near-light speeds, which peaked in the 1970s and ’80s, is certainly attractive: a journey of fifty light years (to, say, the star Mu Arae) would require just over fifty Earth years—while to the crew, fewer than ten would have passed (as posited by Einstein’s Special Relativity).
More recently, velocity estimates have been scaled back to about 10 percent of the speed of light. Whatever the speed, how might photon propulsion be attained? In 1957, the German physicist Eugen Sänger proposed that a propulsion system bringing electrons together with positrons (antielectrons) would induce a matter-antimatter reaction as electrons and positrons annihilate each other and create gamma ray photons. According to Sänger, thrust is generated when the gamma photons are reflected rearward by a parabolic mirror.
The theory is scientifically valid. However, positrons do not lie around in convenient heaps, and would have to be generated by the photon rocket’s propellant. To generate sufficient energy is, at present, not possible, and even if it were, a photon rocket would have to be immense—perhaps two thousand miles in diameter—if it were to carry all the propellant needed to generate a matter-antimatter reaction. A ship of that size could not be easily moved at all, let alone brought up to near-light speeds. Acceleration to top speed could take years, even decades.
Further, the high heat involved in a matter-antimatter reaction is almost unimaginable, great enough so that the giant rocket’s exhaust could seriously damage planets or other bodies that got in its way. (For an eye-opening narrative of such damage in a martial context, see Larry Niven’s 1966 short story “The Warriors.”) And unless the parabolic mirror was 100 percent perfectly reflective, the rearward blast of gamma ray photons would melt the mirror and destroy the ship.
The scientific, material, and economic feasibility of photon propulsion is debated, with more physicists than not feeling that the obstacles are too great to be overcome. Nevertheless, in a paper presented to the 2012 Space Technology and Applications International Forum II, American physicist Young K. Bae declared that photon propulsion is possible with development of accepted scientific principles. Bae suggested a twenty-to fifty-year development period, contingent on what he described as “consistent long-term world-scale economic interest and investment.” In Bae’s view, interest and investment would follow from “positive financial returns from routine interstellar commutes that can transport highly valuable commodities in a profitable manner.” In other words, photon propulsion may be all about business.
If a proportion of UFOs are photon-drive extraterrestrial craft, the alien pilots may have been sent to Earth not by curious or aggressive intelligences, but by consortiums of dispassionate, off-world MBAs. Earth may be, for them, just one more potential profit center, one more bar chart in a financial portfolio or annual report.
Hyperdrive, Jump Drive, and Warp Drive: Each of these related terms is a sort of catch-all that suggests (but does not satisfactorily describe) various hypothetical faster-than-light (FTL) or “cosmic shortcut” propulsion systems. In conversation and casual, non-scientific writing, the terms are roughly equivalent, rendering them simultaneously colorful and meaningless. In more careful writing, such as studies of the employment of FTL drives by discrete television series, hyperdrive and jump drive remain roughly equivalent (and cluttered with impenetrable pseudoscience). As we’ll see below, warp drive stands apart.
A spaceship running with hyperdrive has the capacity to take advantage of simultaneous, alternate dimensions of space and, frequently, time. Some definitions suggest that hyperdrive is a prepared “slip” or a “slide” into those dimensions, during which the journey from A to B is achieved in a sideways eyeblink. (“Slipspace” is, in fact, a sometime-synonym for hyperdrive.) Jump drive (not to be confused with a synonym for a present-technology USB flash drive) is interstellar teleportation that allows instantaneous travel. The mechanics can be handled by computers or, in rare instances, by a human commander. Some sources establish that a ship must carefully coordinate itself in space-time prior to use of jump drive, an activity that requires hours or even days. Alternatively, in some instances the initial jump is made with little preparation, only to be followed by (for vague reasons) a time-consuming “after- drive” period in which the ship re-synchs itself with the universe. The science of all this is unavoidably vague; really, the word “jump” probably provides the clearest sense of what goes on.
Unlike hyperdrive and jump drive, warp drive requires a time expenditure to travel from here to there; its capabilities are not instantaneous. A special quality of warp drive is its ability to accelerate exponentially from Warp 1 (the speed of light) to Warp 10, the presumed maximum velocity. At Warp 10 (or perhaps Warp 9), the ship may bend the fabric of space, “double back” on itself, and travel into the future.
Sources suggest that any of these FTL systems may involve selective or mandatory wormhole travel. We will again stress that these drive systems are stoutly hypothetical. If humans wish to master one anytime soon, the best hope is to capture and reverse-engineer an extraterrestrial craft that runs one of them.