Faster
Than Light Travel: Now There Is a Way Forward
Many
years ago, when NASA decided it should fund a blue-sky open-ended effort to
look for workable concepts for faster than light (FTL) travel, Marc Millis, who
ran the program, invited me to be the National Science Foundation partner. At
that time, it was basically too speculative for NSF, and even for me. The goal
was a worthy goal, and one might ask: “How
can we ever have any hope of finding an answer if we don’t devote at least SOME
effort to thinking about the question?” At that time, however, my response to
the question was: “We won’t ever have any real chance at this until and unless
we make a whole lot of progress in updating our very basic understanding of basic
physics. Until we do more of that, it is premature to expect any kind of
specific, concrete way forward.”
But
now – that has changed, at least for me. I have done a lot to update my
knowledge of basic physics this past year, and, as part of that – I now see a
reasonable, more concrete way forward to TRY to achieve FTL. When it comes down
to political and economic constraints – I can’t guarantee that humans will ever
learn to tie their shoelaces, but from an objective scientific viewpoint, I do
see a way forward on FTL which is far more solid and plausible than earlier
approaches (though the new approach draws heavily on previous work). Until I
get to publish all the many aspects of what I have learned this past year, is
it premature for me to say what it adds up to? Maybe, but I can’t be sure I
will live long enough to dot all the i’s and cross all the t’s as normal
practice demands.
1. Space-Bending
spacecraft in general versus other approaches *****************************
The
most mainstream approach to achieving FTL starts with the question: “Now that
Einstein has shown that space can be bent, can we bend space in a way that lets
us build FTL spacecraft?” That is the
approach I will discuss here, but probably I should briefly review more of what
this means.
There
are other folks who like to hope for “hyperspace craft,” which assume that our
cosmos has more than just the three dimensions of space and the dimension of
time, linked to each other as Einstein described (3+1-D). In fact, many very serious mainstream physicists
argue strongly for superstring theories or brane theories which assume the
existence of such additional dimensions. However, I view that as speculative
stuff, because I see no real empirical data at all yet in science to give us
any practical understanding of what those additional dimensions would really be
like, if they exist at all. Yes, that is
a valid area for research, to try to get past speculation, but for a concrete
way forward now I would only assume the 3+1-D dimensions that we now know well.
(That also applies to concepts like exploiting the “digital universe” as in the
wonderful novel Moving Mars by Greg Bear.)
To
bend space in 3+1-D, one needs a mathematical model of bending space. Einstein’s
General Relativity (GR) is the obvious model, but FTL is not so easy in GR.
Thus it makes a lot of sense to support research which really probes GR for
possible changes, possible gaps in the theory, especially the kind of gaps
which might make FTL easier. It still makes a lot of sense to intensify such
efforts ... but at present, it looks ever more speculative that gaps will be
found. A year or two ago, there seemed to be growing hope that a model like
Moffat’s model of gravity might supersede GR, even though some of the key terms
look suspiciously odd. GR requires the weird concepts of dark energy and dark
matter to explain some of the basic observations we made a few years ago, but
Moffat’s model was predicting them without dark matter or dark energy. But new
information has come in on dark matter and dark energy, and the complexities of
Moffat’s model no longer seem helpful of justified. And so, the practical way
forward now is to aim for space-bending spacecraft, bending space exactly in
accord with what GR allows.
How
mainstream can one get? In fact, the famous guys at CalTech talk both about
space-bending spacecraft and about wormholes as mainstream, GR-based approaches
to FTL. The spacecraft approach and the wormhole approach are somewhat related;
one might even view the spacecraft approach as a step towards wormhole
capabilities (just as low cost RLV may be viewed as a prerequisite to “space
elevators”, for those folks who like space elevators more than RLVs).
2. A New
Way Forward with space-bending spacecraft
****************************************
The
word “Alcubierre” is maybe the best google search term to get into the serious
literature on how to build space-bending FTL spacecraft. It all goes back to
Alcubierre himself, who found a solution to the equations of GR (i.e. a state
of the world allowed according to GR, a design) in which space is bent around a
spacecraft enough to allow it to travel faster than light. The Alcubierre
solution generated a lot of rightful excitement, but it entailed two
overwhelming obstacles, which kept it from being a practical way forward for
now, even for folks like me who usually support high-risk high-benefit
technologies: (1) it requires the use of “exotic matter,” i.e. matter or energy
whose mass/energy density is negative; and (2) it requires a huge amount of
that.
There
was great excitement a few years ago when a physicist at NASA published a
variation of the Alcubierre solution which appeared to get (2) under control.
With a new design, much less exotic matter is needed. I have not looked up the
details, but I remember an email from someone involved in that saying something
vaguely like: “Before, we needed a hunk of exotic matter as big as Jupiter. Now
we only need something as big as the Edmonton Mall, something we could actually
build.” (We could even AFFORD to build something as big as the Edmonton Mall in
space, if our politicians would allow us to build the low-cost RLV which previous
work at Boeing, at AF and at NASA has validated, using off-the shelf technology
and data!) That was nice – but at the
time I sadly grinned: “Too bad we don’t have ANY exotic matter, not even a
thimble full, let alone a Mall full.”
But
now, it looks better. Maybe even much better. There is a way forward to check
and even to do if the checks work. If I still had a government funding mandate,
and were allowed to go international and so on... but whatever.
“Where
is there ANY exotic matter?” I did give
Marc Millis a recommendation to give special priority to that question....
Folks
like Puthoff funded by Marc Millis offered a possible answer: “Why not squeeze
the vacuum?” Strictly speaking, exotic
matter/energy does not really require that energy density be zero in an
ABSOLUTE sense. It only requires that we create a zone of energy or matter
where the average energy is LESS THAN the average density of the outer space we
are traveling through. Many mainstream physicists believe that ordinary outer
space is already at a very high level of energy density, because of “zero point
fluctuations (ZPE).” For example, even Weinberg’s authoritative book the
Quantum Theory of Fields, has section
explaining and endorsing ZPE as a way to explain the Casimir effect. “Squeezing
the vacuum,” they suggest, is baiscally just a matter of excluding those vacuum
fluctuations from a region of space.
As it
happens, I don’t believe in that mainstream Feynmann ZPE theory. The logic
seems very clear to me, but, since it is heresy and since new heresy takes many
years to percolate through the ever more complex and bureaucratic systems of
our world, I simply posted a paper giving the logic at vixra.org this year. For
those capable of logic, that should be enough, but for those who must watt for endorsements
from Ginsparg or from the President of Liberty University, it is too early. The
ZPE theory implies that there is a truly immense amount of energy out there in
the vacuum of outer space, something like 10**120 somethings per cubic
centimeter of free space.
But could
there still be some vacuum energy out there in reality, at a level we could
use?
That
is what I find most exciting here. At an elite workshop at Princeton in May
2015, I was delighted to learn about the work of the group of Alfred
Leitenstorfer, which has since been published in a number of credible places
like Nature and Science and PRL. My vixra paper gives specific citations. I
disagree with their conclusion that they have measured vacuum energy as large
as what ZPE implies; if they lower the temperature of their measurement crystal
(EOX), I predict a much lower energy density, energy density more like that of
dark matter and dark energy (also discussed in the vixra paper). But that
energy density is already very large and very serious!
By combining a more general Boltzmann equation
in the space of density operators, together with any variant of electroweak theory
capable of explaining the existence of elementary particles, I predict a vacuum
density of subquantal fluctuation of the well-established B and W fields roughly
on the same order as what is needed to explain observations on dark energy.
(The vixra paper cites a recent review of that data.) That is a substantial
energy density; recall that dark matter is many times denser than ordinary
matter.
Of
course, “way forward” does not mean “yes we can.” Lots of numbers to be
checked, and not lightly. For example, consider that the energy density of
light now on its way out from the sun, not yet beyond Pluto, is a VERY tiny
fraction of the mass-energy of our solar system, but still of some use to technology
(the very basis of all earth life!). The subquantal B/W component of dark
matter may likewise be “small and big at the same time.” There is an amusing possibility that we will
find that FTL is practical in a way WITHIN spiral arms, but much more difficult
across Rifts. Leitenstorfer’s group appears sanguine about the possibility of “squeezing
the vacuum’; lots of approaches may work, but I suspect it will take a lot of
effort and reasonable creativity to find the most cost-effective way. The EOX technology is probably one part of
what it will take. But there is a way forward. (Perhaps also... or in
parallel... quantum separators and coherent baryon number changers may also
feed into strengthening such new technology, e.g. providing more energy... and
perhaps someday I will post that last work of Schwinger, which is risky but
maybe important on this path.)
Best
of luck...
No comments:
Post a Comment