Saturday, December 29, 2012

Is Interstellar Travel "Preposterous"?


It occurs to me that a solid statement of the case against the feasibility of interstellar travel is not easily available, and hence is not well-known to the public. Following on my recent posting Is There a Warp Drive in your Future?, which considers the question of what technologies are or are not likely to exist in the future, let us now examine the general question of the feasibility of interstellar travel. In this inquiry, we are not concerned with technological difficulties or breakthroughs, but with fundamental laws of physics. Even if the only limits we faced were those of physics, not technology, what are the prospects of making interstellar travel a reality?

Stanton Friedman, the “Flying Saucer Physicist,” is confident that interstellar travel is not only possible, but likely. In his essay UFO Propulsion Systems, Friedman writes,
a one-way trip of thirty-seven years (the distance to Zeta 1 or 2 Reticuli) at 99.9 percent c would take only twenty months’ crew time; at 99.99 percent c it would take only six months’ crew time. Thus even a trip to a distant galaxy such as Andromeda, two million light-years away, would take under sixty years’ crew time if the intergalactic ship somehow could manage to keep accelerating at one G, using some yet unknown technique.      
various proposals for fusion-powered rockets
Ah, that pesky little “yet unknown technique.” Now this is all perfectly true, but it blithely ignores some very fundamental problems that are not related to any level of technology. A trio of “classic” papers written in the 1960s by physicists examine the fundamental physics involved in proposed interstellar travel, and explain the formidable obstacles: obstacles imposed by fundamental laws of physics, not by limits of technology. Note that nothing here rules out the possibility of travel within our solar system, even to its edges, or rules out non-relativistic interstellar travel, taking thousands of years to reach one's destination. But the notion that we will someday travel between stars the way we now sail between seaports is pure fantasy.

These articles sufficed to convince the scientific community that the concept of interstellar travel is utterly implausible, and explanations for UFO sightings must be sought elsewhere, in psychology and sociology, not in physics. However, in recent years these articles have largely been overlooked, so I think it’s very important to examine each one in some detail and explain its consequences. 

            1. Radioastronomy and Communication Through Space by Edward M. Purcell. (U.S. Atomic Energy Commission Report BNL-658, reprinted in Cameron, A.G.W. (editor), Interstellar Communication. New York: W.A. Benjamin, Inc., 1963.) Purcell (1912-1997) was in the physics department at Harvard University, and shared in the 1952 Nobel Prize for physics. He was a pioneer in radio astronomy, the first to detect the famous 21-cm radio emission line from neutral hydrogen in the galaxy. He also is credited with the discovery of Nuclear Magnetic Resonance.
Edward M. Purcell
            Most of the paper is uncontroversial and explains then-recent discoveries in radio astronomy. But in the section titled Space Travel, Purcell examines claims that someday we will travel to the stars at almost the speed of light. “The performance of a rocket depends almost entirely on the velocity with which the propellant is exhausted,” he notes. Thus, “the elementary laws of mechanics – in this case relativistic mechanics, but still the elementary laws of mechanics – inexorably impose a certain relation between the initial mass and the final mass of the rocket in the ideal case… It follows very simply from conservation of momentum and energy, the mass-energy relation, and nothing else.” (Emphasis in original.)
            “For our vehicle we shall clearly want a propellant with a very high exhaust velocity. Putting all practical questions aside, I propose, in my first design, to use the ideal nuclear fusion propellant… I am going to burn hydrogen to helium with 100 percent efficiency; by means unspecified I shall throw the helium out the back with kinetic energy, as seen from the rocket, equivalent to the entire mass change. You can’t beat that, with fusion. One can easily work out the exhaust velocity; it is about 1/8 the velocity of light. The equation of Figure 13 tells us that to attain a speed 0.99c we need an initial mass which is a little over a billion times the final mass.”
            A billion times the final mass?????!!!!!!! In fact, the exact figure is 1.6 X 10^^9. So in the ideal case, where you had somehow mastered nuclear fusion with 100% efficiency and could control and direct the energy in whatever way you choose, you still will need 1.6 billion tons of fuel for each ton of payload! Surely, such a rocket has never been built, and never will be built, in our solar system, or any other. Thus Purcell has demonstrated, beyond any possibility of doubt, that all proposals to reach near-light speed using nuclear fusion propulsion are complete absurdity.
            But supposing some other, more energetic reaction could be found? Nuclear fission produces an even lower exhaust velocity than fusion, so it’s less plausible still. Is there any reaction more energetic than nuclear fusion? “This is no place for timidity, so let us take the ultimate step and switch to the perfect matter-antimatter propellant…. The resulting energy leaves our rocket with an exhaust velocity of c or thereabouts. This makes the situation very much better. To get up to 99 percent the velocity of light only a ratio of 14 is needed between the initial mass and the final mass.” That sounds very much better. If I can “somehow” procure sufficient antimatter, “somehow” store it, and “somehow” control its reaction with matter, and “somehow” direct the resulting energy where I want it to go, I need only 7 tons of matter, and 7 tons of antimatter for each ton of payload. That sounds almost possible. But Purcell points out that all that buys you is a one-way ticket out of the galaxy: you have no way to slow down and stop when you get where you want to go. So to stop when you reach your destination requires a fuel-to-payload ratio of 196. And if you want to someday return, unless you know of a convenient matter-antimatter fueling station at your destination, you will need to square that again, for a fuel-to-mass ration of almost 40,000.
            And even if you could “somehow” construct such a vehicle, your problems are not over. “If you are moving with 99 per cent the velocity of light through our galaxy, which contains one hydrogen atom per cubic centimeter even in the ‘empty spaces,” each of these hydrogen atoms looks to you like a 6-billion-volt proton, and they are coming at you with a current which is roughly equivalent to 300 cosmotrons per square meter. So you have a minor shielding problem to get over before you start working on the shielding problem connected with the rocket engine.” Also, “In order to achieve the required acceleration our rocket, near the beginning of its journey will have to radiate about 10^^18 watts. This is a little more than the total power the earth receives from the sun. But this isn’t sunshine, it’s gamma rays. So the problem is not to shield the payload, the problem is to shield the earth.”
            “Well, this is preposterous, you are saying. That is exactly my point. It is preposterous. And remember, our conclusions are forced on us by the elementary laws of mechanics.” Nothing else needs to be written about the possibility of relativistic travel – Dr. Purcell has shown it to be completely preposterous. Purcell concludes his paper, however, by demonstrating that interstellar communication using radio waves is perfectly possible. His final words are, “All this stuff about traveling around the universe in space suits – except for local exploration, which I have not discussed – belongs back where it came from, on the cereal box.”

Sebastian von Hoerner
            2. The General Limits of Space Travel by Sebastian von Hoerner (Science 137, 18, 1962; reprinted in Cameron 1963). Immediately following Purcell’s paper in the Cameron volume is this related paper by von Hoerner (1919-2003), a German radio astronomer who was influential in early discussions and proposals for SETI. He examines the physical difficulties of propulsion for space travel, including possibilities not covered by Purcell. Von Hoerner considers ion thrust propulsion, but concludes that “nuclear reactors and all the equipment needed to give a strong ion thrust are so complicated and massive, as compared with the relatively simple combustion equipment, that there is no hope at present of reaching, with reactors, the value of P [engine power to mass ratio] already attained with combustion rockets.” He also considers proposals for a huge “scoop” or funnel for a rocket to fuel itself as it goes along, scooping up galactic hydrogen. But he notes that interstellar matter has very low density, and “in order to collect 1000 tons of matter (10 times the fuel of one Atlas rocket) on a trip to a goal 5.6 parsecs away, one would need a funnel 100 km in diameter; we will rule out this possibility.”
            After several pages of equations covering much the same ground as Purcell, Von Hoerner concludes, “there is no way of avoiding these demands [for power], and definitely no hope of fulfilling them…space travel, even in the most distant future, will be confined completely to our own planetary system, and a similar conclusion will hold for any other civilization, no matter how advanced it may be. The only means of communication between different civilizations thus seems to be electro-magnetic signals.”

William Markowitz
3. Physics and Metaphysics of Unidentified Flying Objects by William Markowitz (Science 157, 1274, 1967). Markowitz (1907-1998) was an Austrian-born astronomer who worked at the U.S. Naval Observatory, and also taught astronomy and physics at Pennsylvania State University and Marquette University. He was a pioneer in the use of atomic clocks for astronomy, and specialized in precision time measurement issues. Markowitz wrote, “Aristotle wrote on natural phenomena under the heading ‘physics’ and continued with another section called ‘metaphysics’ or ‘beyond physics.’ I use a similar approach here. First I consider the physics of UFO’s when the laws of physics are obeyed. After that I consider the case where the laws of physics are not obeyed. The specific question to be studied is whether UFO’s are under extraterrestrial control.” By the laws of physics, he is concerned with only the simplest and best-known ones, like those of motion, gravitation, conservation of energy, and the restrictions of special relativity. He points out an obvious but seldom-noted problem: “Apart from propeller and balloon action, a spacecraft can generate thrust only by expelling mass.” And something that uses propellers or balloons is an aircraft, not a spacecraft.
            UFOs are sometimes reported to land, and take off again. “If an extraterrestrial spacecraft is to land nondestructively and then lift off, it must be able to develop a thrust slightly less than its weight on landing… if nuclear energy is used to generate thrust, then searing of the ground at 85,000 deg C should result, and nuclear decay production equivalent in quantity to those produced by an atomic bomb should be detected. This has not happened. Hence, the published reports of landing and lift-offs of UFO’s are not reports of spacecraft controlled by extraterrestrial beings, if the laws of physics are valid.”
            “We can reconcile UFO reports with extraterrestrial control by assigning various magic properties to extraterrestrial beings. These include ‘teleportation’ (the instantaneous movement of material bodies between planets and stars), the creation of ‘force-fields’ to drive space ships, and propulsion without reaction. The last of these would permit a man to lift himself by his bootstraps. Anyone who wishes is free to accept such magic properties, but I cannot.”
            To those who were following the controversy at that time over the proposal championed by J. Allen Hynek and Jacques Vallee for a “scientific study of UFOs,” an ‘ulterior motive’ for the Markowitz article was immediately apparent. The previous year Hynek had a letter published in Science, arguing that UFOs were worthy of scientific study (Science 154, 329, 1966). Markowitz carefully notes several instances where Hynek and his colleagues were contradicting themselves in their statements about UFOs. For example, in his letter in Science, Hynek wrote, “Some of the very best, most coherent reports have come from scientifically trained people.” But Markowitz noted that Hynek had written quite the opposite in his article in the Encyclopedia Britannica in 1964: “It appears unreasonable that spacecraft should announce themselves to casual observers while craftily avoiding detection by trained observers.” Markowitz further noted that Vallee’s 1966 book Challenge to Science presents the “classic” 1948 sighting of pilots Chiles and Whitted, who reported a dramatic close encounter with a huge metallic object while flying a DC-3; “the book fails to mention that Hynek had identified the object as an undoubted meteor in his report of 30 April 1949 to the Air Force… This omission is curious because Hynek wrote a foreword to Challenge to Science.” These and other self-contradictions, carefully noted by Markowitz, showed that the Hynek/Vallee case for the UFO was utterly lacking in intellectual rigor. Markowitz unmasked the real Hynek: disorganized, indecisive, and confused. This revelation, published in the peer-reviewed pages of Science, was fatal to the credibility of Hynek’s proposed “scientific study of UFOs.” There were, and still are, a few scientists who took Hynek’s UFO theorizing seriously, but they have always been a tiny minority.
                                
What About “Wormholes”?

             Some theorists of interstellar travel are quite aware of the extreme difficulties involved in actually traveling to interstellar destinations, in the sense of going from Point A to Point B. So they hypothesize easier ways to reach interstellar destinations, without the pesky problem of traversing every point between them. Maybe we can warp space so that the distance between earth and the Andromeda galaxy is not two million light years, as in ordinary space travel, but far, far less? Suppose there is a wormhole with one end where we now are, and the other where we want to go?
            The “Bohemian physicist” Jack Sarfatti of San Francisco is a colorful figure. He has written papers claiming that wormholes can be used not only to travel through space, but through time as well. (He has also studied Uri Geller.) He suggests that UFOs are real, and travel through wormholes to reach us from some other place or time.

Unfortunately for Sarfatti, according to Wikipedia,
 Wormholes which could actually be crossed, known as traversable wormholes, would only be possible if exotic matter with negative energy density could be used to stabilize them. (Many physicists such as Stephen Hawking, Kip Thorne, and others believe that the Casimir effect is evidence that negative energy densities are possible in nature.) Physicists have not found any natural process which would be predicted to form a wormhole naturally in the context of general relativity, although the quantum foam hypothesis is sometimes used to suggest that tiny wormholes might appear and disappear spontaneously at the Planck scale, and stable versions of such wormholes have been suggested as dark matter candidates. It has also been proposed that if a tiny wormhole held open by a negative-mass cosmic string had appeared around the time of the Big Bang, it could have been inflated to macroscopic size by cosmic inflation.

supposed travel through a wormhole
            So yes, a wormhole is something that might theoretically exist, although their actual existence is frankly extremely dubious. There is no reason to think that they could occur naturally, and no observational evidence that they actually do exist (unlike Black Holes). Even if they do exist, they may exist only on the Planck scale (subatomic quantum size). It seems extremely dubious that traversable wormholes exist in nature, and even if they do, we still have seemingly insurmountable problems. How do we find wormholes? How do we determine whether they are stable? How do we know where their destination is? If we go into one, is it possible to return? There is also the problem of simply getting to the wormhole’s mouth. If a wormhole were near our solar system, we would already detect its disturbing effects of warped space. And if it is far from our solar system, we need to develop interstellar travel simply to travel to the wormhole’s mouth!
            Can we create a wormhole to go from where we are to where we want to be? Perhaps in theory we might, but the reality of a recipe for creating a wormhole will undoubtedly be something like this:
Take 100 solar masses. Bake at one million degrees for ten thousand years. Stir in 100 solar masses of exotic matter with negative energy density. Stretch out the mix from desired source to destination. Let cool for one million years.
             So the idea of using wormholes as a convenient transportation network to wherever in the universe we want to go is, well, fanciful and implausible in the extreme. We can’t proclaim it completely “impossible,” but the person who proclaims it as a reality had better have extraordinarily good evidence that such a thing exists.

Monday, December 17, 2012

Friedman's Frenzy

I just learned, to my great honor, that I am the main subject of a full two-page enraged diatribe by Stanton T. Friedman in the December issue of The MUFON Journal.  Throughout this piece, he refers to me as "Bobby." It's not entirely about me. Friedman, who calls himself "the Flying Saucer Physicist," directs some of his invective against Joe Nickell, with little arrows fired at Carl Sagan, Donald Menzel, and Seth Shostak. That puts me in pretty fine company, I'd say.

Stanton Friedman speaks to MUFON
Titled "Debunkers Running Out of Material?", it mainly talks about my Blog posting of October 29, The Pseudo-Science of Anti-Anti UFOlogy.  (He doesn't give the full URL). The Blog posting is a reprint of my Psychic Vibrations column of that title, published in The Skeptical Inquirer, September/October, 2009. Hence Friedman's suggestion that we "debunkers" must be running out of material. Sorry, Stan, that's not it. There's plenty of new junk to debunk. The reason I posted the 2009 column is that it describes the total invalidation of the famous Betty Hill UFO Star Map, and that information had previously not been available on-line, only in print. Friedman has made the Fish version of the supposed Star Map a major focus of his public lectures for over forty years. Now that large numbers of UFO followers have found out that Stan's precious has been mortally wounded and he is taking heat for not admitting it, he is thrashing about in a blind rage. We wants it, we needs it. Must have the precious. They stole it from us. Sneaky little debunkers. Wicked, tricksy, false! 

Must have The Precious!
Friedman begins his screed by vigorously objecting to my statement
Stanton T. Friedman, who calls himself the “Flying Saucer physicist,” because he actually did work in physics about fifty years ago (although not since).
He says, "I received my MS degree in Physics from the University of Chicago in 1956. Fifty years earlier than the 2009 date would have been 1959." He explains that he worked full-time as a physicist until 1969. OK Stan, I was wrong about that: It hadn't been 50 years since your primary career as a physicist ended, only 40 years. And you even did some physics consulting work on the side during the time you were the world's most prominent full-time UFOlogist. My apologies.

Friedman continues,
Bobby is unhappy about my criticism of Joe Nickell, noting that "he is a former magician and of course the stock in trade of magicians is intentional deception with another sterling example being The Amazing Randi."
About which statement I wrote, "So by Friedman logic anyone who has practiced prestidigitation can never be trusted in anything," to which Friedman replies, "Of course I said no such thing." True enough, Stanton, but you certainly are implying it by suggesting we should expect "intentional deception" from current or former magicians.

Friedman says, "my primary criticism of Nickell was that his three degrees were in English, so there seemed little background in science." Stanton, if that is your primary criticism of anybody, you are a fool. English majors can learn science like anyone else, and Nickell consults with specialists and experts when appropriate. Friedman continues, "Bobby likes Joe's [Roswell] explanation of a Mogul balloon train. That account (July 9) was published after Brazel had been taken into custody and given a second story to recite." Got that? Mac Brazel, who first found the Roswell debris that looked like "tinfoil and sticks," was taken into custody by the military and forced to learn and recite a false 'cover story' to cover up the truth. This was just two weeks after the first "flying saucer" sighting of Kenneth Arnold - that Saucer Coverup program must have been put together in record time! This 'taken into custody by the military' story was a late addition to the Roswell yarn, long after Brazel was dead, and is of course entirely without proof.

Stanton also proclaims "Bobby doesn't like my mentioning the Aztec case of 1948 and Frank Scully's book... obviously he would like to ignore the incredibly detailed investigation of that case as reported by Scott and Suzanne Ramsey in The Aztec Incident: Recovery at Hart Canyon." Stan doesn't explain how my 2009 article could have discussed a book not published until 2011. But don't worry, Stan: if you look in the November/December 2012 issue of The Skeptical Inquirer, you'll seen my very detailed debunking of the Ramseys' new book. In fact, I'm not alone in that. UFO proponents Kevin Randle and Jerome Clark have each written their own reviews of that book, and while the three of us might agree on little else, all three reviews agree that The Aztec Incident: Recovery at Hart Canyon is not credible or convincing. What's amazing is that there is virtually no overlap in the approaches taken in the three reviews. Three entirely separate lines of investigation lead three very different UFO theorists to the same conclusion. Practically the only  well-known UFOlogist who believes The Aztec Incident is Stanton Friedman.

Friedman also objects to my dismissal of the significance of the 1955 report Blue Book Special Report 14, which to him seems ironclad proof that "unidentified" UFO reports are different from "identified" ones. I will only repeat here the quote I used from Alan Hendry, an investigator formerly with the J. Allen Hynek Center for UFO Studies:  “If the Battelle group [Special Report 14] had had a real appreciation for how loose the data were, they never would have bothered with a statistical comparison to begin with” (UFO Handbook, Doubleday, 1979, p. 266). [For more on Blue Book Special Report 14, see my discussion of Jacques Vallee, J. Allen Hynek, and the "Pentacle Memorandum."]

The Precious!


But the real root of Friedman's rage is my explanation of how his precious Fish Map - the supposed identification of an alleged star map drawn by Betty Hill after her "abduction" on board a UFO - is now entirely invalidated by newer data. Friedman writes, "Bobby wants me to renounce all of Marjorie's work because there is better data now." No, Stan, that's a gross misrepresentation. I expect you, and anyone else who claims to be "scientific," to renounce the Fish Map because the pattern it claims to find is now known to be incorrect. 

The supposed match of the Fish pattern with Betty Hill's sketch was never very good to begin with. Compare the "Hill Map" at top right with the "computer generated map" below it. Do they look like a "match" to you?  (The "computer generated map" shows the Fish pattern plotted correctly, using the old Gliese catalog data.). As noted in 1976 by Steven Soter and Carl Sagan, the only reason that the patterns seem to match is because of the way that the lines are drawn.
The inclusion of these lines (said to represent trade or navigation routes) to establish a resemblance between the maps is what a lawyer would call "leading the witness".
Eliminate the lines, and the patterns of dots look as different as could be. And that is the Good News for Stanton Friedman. Now the situation gets even worse.
Betty Hill's "UFO Star Map" contains twenty-six stars, while the Fish "identification" of it contains only fifteen stars. What happened to the remaining eleven stars? They were insignificant 'background' stars, not connected by lines, and hence ignored. Except for three "important" background stars in a triangle. As noted in my book UFO Sightings (p. 70-73) there are several ad hoc practices used in constructing the Fish Map. And that's the Good News for Friedman. It gets worse.


Special Zeta Reticuli Incident issue of Astronomy magazine, 1976: Without the lines drawn, there is no resemblance between the two at all. (And this is using the old star data!)

Nearby stars in the volume of space represented by the Fish pattern are included, or excluded, by certain criteria. A star must be a single star, not multiple (except for Zeta1 and Zeta2 Reticuli, which are widely-separated). They must be main sequence stars similar to the Sun, and they must not be variable. "Every one of the stars on the map are the right kind of stars, and all of the right kind of stars in the neighborhood are part of the map," according to Friedman (ignoring a few ad hoc problems).

As explained in my earlier Blog posting, the newer and much more accurate astronomical data shows that at least six of the fifteen stars must now be tossed out, under the same rules that once included them. Two are close binaries, two more appear to be variable, and two more are not even in the volume of space in question, their distances having been erroneously measured in the older data. So from fifteen stars supposedly matching the twenty-six Betty drew, subtract six more. Goodbye, Zeta Reticuli. "Bobby doesn't bother to stress the fascinating results especially the identification of the base stars Zeta 1 and Zeta 2 Reticuli.... the closest to each other pair of sun-like stars in the neighborhood." Sorry Stanton, forget it - game over. The only reason to think that Betty's sketch has anything to do with the two Zetas is that dubious match, using the forty-year old astronomical data, where the patterns sort of maybe look similar if you squint and close one eye, but really don't. Now re-draw the map according to the same criteria, using the most accurate present-day star catalog data, and six of the fifteen stars disappear, leaving you with nine stars to try to match Betty's twenty-six. Goodbye, Zeta Reticuli.

But Friedman has invested so much time and effort into convincing the world that his precious Fish Map is proof of extraterrestrial visitations that he is simply incapable of admitting the obvious: that it has no validity whatsoever. There is no way he can go to MUFON or any other UFO group and say, "I'm sorry folks, I've been wrong for these past forty years. The Fish Map does not prove anything." 
               
While we are talking about Zeta Reticuli, one interesting question is: What did Betty Hill intend to represent at the bottom of her "Star Map" where we see two large globes, connected by several parallel lines? The best suggestion I have heard comes from star map researcher Charles Atterberg (more about him is in my book UFO Sightings). He suggested that the two globes represent an old planetarium projector, similar to the one you see here. It makes perfect sense. When Dr. Simon asked Betty to draw, as best she could, the "star map" she claims to have seen, her mind wandered back to a planetarium show she presumably saw years earlier. She drew the stars she saw, and also the projector below them!
An old Zeiss planetarium: Is this what Betty Hill
 drew at the bottom of  her "Star Map"?

Sunday, December 2, 2012

Is there a Warp Drive in your Future?

We regularly hear UFOlogists claiming that, while reported UFO encounters cannot be accepted as consistent with present-day science, future science will be able to accomodate them, and so therefore we should not reject the claims. As astronomer and Project Blue Book consultant Dr. J. Allen Hynek famously said to the House Committee on Science and Astronautics in 1968,
I cannot dismiss the UFO phenomenon with a shrug. The "hard data" cases contain frequent allusions to recurrent kinematic, geometric, and luminescent characteristics. I have begun to feel that there is a tendency in 20th-century science to forget that there will be a 21st-century science, and indeed, a 30th-century science, from which vantage points our knowledge of the universe may appear quite different. We suffer perhaps, from temporal provincialism, a form of arrogance that has always irritated posterity.
Dr. J. Allen Hynek makes a cameo appearance in the movie Close Encounters of the Third Kind
And echoes of this statement are commonplace among UFO proponents. The situation is further confused by Arthur C. Clarke's famous statement that "Any sufficiently advanced technology is indistinguishable from magic," which people interpret to mean "reports of something that seems to be magic must be an example of an advanced technology." (Sometime I need to write an entry about some of Clarke's really loopy predictions for future breakthroughs, like how wheels and roads will soon be obsolete because we'll all be riding in hover cars.)

A landed UFO is alleged to simply take off from the ground and zoom away, without expelling anything in the opposite direction. Momentum has been created - how? The UFO has acquired kinetic energy as it speeds away. Where did that energy come from?  Magic, perhaps? So it would appear that "future science" will no longer be limited by simplistic concepts such as conservation of energy or momentum. Even many skeptics fall into this trap. Once I was being interviewed by a well-known skeptic for a podcast, who suggested that 'before long, our technology will be able to do the things that these UFOs are reportedly doing.' And I replied that's not true, unless you are willing to cavalierly toss out fundamental physical laws.

I was very interested to read in the San Diego Union Tribune a December 2 story by science reporter Gary Robbins titled "Flying cars and teleporters aren't in your future,"  based upon an interview with UCSD physics professor Tom Murphy. Murphy relates how one day when he was talking with a group of physics students, one of them said, "If it can be imagined, it can be done." Other students nodded their heads in agreement. Said Murphy, "It took me all of two seconds to violate this dictum as I imagined myself jumping straight up to the Moon... I wondered how pervasive this attitude was among physics students and faculty. So I put together a survey. The overriding theme: experts say don't count on a Star Trek future."

Prof. Tom Murphy
Murphy designed a survey on Futuristic Physics to determine physicists' expectations of the likelihood of hypothetical future breakthroughs. The details are in his Blog Do The Math. One, "autopilot cars," already exists today: Google has built one, and it seems to work well. But the survey asks about a lot of other things: practical personal jetpacks; a flying car; teleportation; warp drive; wormhole travel; visiting a black hole; artificial gravity; time travel, etc. Estimates were solicited from physics undergrads, physics grad students, and physics professors. For each "breakthrough," survey participants were asked to choose one of six answers, from "likely within 50 years" to "<1% likely to ever happen, or impossible."

As might be expected, undergrads are the most optimistic about future "breakthroughs," grad students less so, and physics professors the most pessimistic of all. It seems that the more you know about physics, the less likely you are to accept the far-out stuff. However there was one dissenting faculty member:
Note the optimistic outlier in the faculty ranks. We saw this individual stand out on the wormhole question. Examining this person’s responses, it’s all 1, 2, and 3 responses, save one 4 for time travel. Nothing is off limits to this professor, and most things deserve a timescale. This individual is clearly out of step with the cohort, and tying the most optimistic undergrad: forever young.
Participation in the survey was anonymous for invited persons, but if I had to take a wild guess, I'd say that Prof. Michio Kaku probably participated. (He praised Leslie Kean's problem-ridden UFO book as the "gold standard" of UFO research.) Murphy notes,
The biggest differences between faculty and grad students crop up on questions pertaining to flying cars, cloaking, and studying astrophysical objects up close. The largest graduate-undergraduate discrepancy appears for the question about artificial gravity. The largest end-to-end discrepancies (faculty to undergraduate) relate to flying cars, artificial gravity, and warp drive.
The physics faculty members' expectations of the likelihood of certain developments, from most to least probable, is as follows:
Autopilot Cars likely within 50 years
Real Robots likely within 500 years
Fusion Power likely within 500 years
Lunar Colony likely within 5000 years
Cloaking Devices likely within 5000 years
200 Year Lifetime maybe within 5000 years
Martian Colony probably eventually (>5000 yr)
Terraforming        probably eventually (> 5000 yr)
Alien Dialog probably eventually (> 5000 yr)
Alien Visit                 on the fence
Jetpack         unlikely ever
Synthesized Food unlikely ever
Roving Astrophysics unlikely ever
Flying “Cars”        unlikely ever
Visit Black Hole       forget about it
Artificial Gravity       forget about it
Teleportation        forget about it
Warp Drive             forget about it
Wormhole Travel     forget about it
Time Travel forget about it
So to those who are proclaiming that UFOs are real, and that 'future physics' will explain how they operate via wormholes, warp drives, teleportation, or time travel, the message from physics professors is: forget about it.