The answer about how a wormhole can appear in the solar system is quite simple. It was sent here by an advanced alien civilization as part of their setting up a galaxy-spanning faster-than-light transportation network.
The concept has been proposed by the physicist John Cramer building on the ideas of others, but weaving them together in a creative manner.
However, Matt Visser has metric-engineered a different solution to
Einstein’s equations of general relativity from that to Morris,
Thorne, and Yurtsever, in which the wormhole is stabilized by another
artifact of general relativity, a negative-tension cosmic string36.
Such an object would be self contained, have no dangerous space
curvature except near the cosmic string surfaces, and could, in
principle, be very large or very small, even down to the Planck-length
scale. A Visser wormhole might also occur naturally in the aftermath
of the Big Bang, since both of its components are GR solutions. We
can also hypothesize that if there were passive stability problems
with a Visser wormhole, it might be dynamically stabilized externally
by an active negative feedback system acting directly on and through
one of the wormhole mouths.
Let us assume that we have the capability of producing such Visser
wormholes and controlling their size. If we keep a wormhole mouth
microscopic in mass and size, it behaves much like a fundamental
particle with a very large mass, perhaps somewhat in excess of the
Planck mass of 21.8 micrograms. For the purposes of calculation, let
us assume that we can produce a stabilized microscopic wormhole with a
mass of, say, ten Planck masses or 218 micrograms.
Now, we take the two wormhole mouths of this object and thread lines
of electrical force through them, until we have passed about 20
coulombs of charge through the wormhole. This can be done, in
principle, with a 20 microampere electron beam passing through the
wormhole for about 12 days. The result is that the wormhole mouth
will now have the same charge-to-mass ratio as a proton and will
behave like a proton in the electric and magnetic fields of a particle
accelerator. (We note that such an object would have to have some
minimum radius, because if the electric field at the throat was too
strong, it would pull positrons out of the vacuum and reduce the
charge by field emission.)
Now we transport what we will henceforth call the “traveling wormhole
mouth” to Meyrin, Switzerland near Geneva and put it into CERN’s new
Large Hadronic Collider (LHC) there. The other wormhole mouth remains
in our laboratory, along with various stabilizing and steering
equipment (described later). We assume that by the time that we are
able to do this, the LHC will have achieved its full design capacity
and will be able to accelerate each of its colliding proton beams to 7
TeV (7 x 1012 electron volts). We use the LHC to accelerate the
wormhole mouth to the same energy per unit rest mass as a 7 TeV
proton, extract the beam that contains it, point it at a star of
interest, and send it on its way. (Presumably, we would do this in an
operation with a number of wormhole-mouths pointed at a selection of
candidate stars that might have earth-like planets in orbit around
them.)
A proton with a total energy of 7.0 TeV will have a Lorentz gamma
factor (g = [1-(v/c)2]-½ = E/M) of 7,455. The accelerated wormhole
mouth will have the same Lorentz factor. This is the factor by which
the total mass-energy E of the proton moving at this high velocity v
exceeds its rest mass M. It is also the factor by which time dilates,
i.e., by which the clock of a hypothetical observer riding on the
proton would slow down. The wormhole is traveling at a velocity that
is only a tiny fraction less than the speed of light, so it travels a
distance of one light-year in one year. However, to an observer
riding on the wormhole mouth, because of relativistic time dilation
the distance of one light year is covered in only 1/7,455 of a year or
70.5 minutes.
Moreover, back on Earth if we peek through the wormhole mouth at rest
in our laboratory, we see the universe from the perspective of an
observer riding on the traveling wormhole mouth. In other words, in
70.5 minutes after its launch from CERN, through the wormhole we will view the universe one light year away. Later, in 11.7 hours we will
view the surroundings 10 light-years away. In 4.9 days, we will view
the surroundings 100 light years away. And so on.
This is a remarkable result. How is it possible that, if the
traveling wormhole mouth requires 100 years, as viewed from Earth, to
travel 100 light years, we can view its destination as observers
looking through the wormhole in a bit less than 5 days? It is
because, as pointed out by Morris, Thorne and Yurtserver7, the special
relativity of time dilation makes a wormhole with one high-velocity
mouth into a time machine. The wormhole mouth, which from our
perspective has taken 100 years to reach a point 100 light years away,
connects back in time to its departure point only 5 days after it
left. In effect, it has moved 100 light years at a speed of 7,455 c.
But could the traveling wormhole mouth be aimed so accurately from its
start at CERN that it might it actually pass through another star
system many light years away, to survey its planets, etc.? And could
it stop when it got there? The fortunate answer is yes.
Momentum back reaction can be used to steer the traveling wormhole
mouth. The direction of travel, as viewed through the wormhole, can
be monitored. Course corrections can be made by directing a
high-intensity light beam through the laboratory based wormhole mouth
at right angles to the direction of travel. The beam will emerge from
the traveling wormhole mouth “sideways” giving it momentum sideways
momentum in the other direction. The exit mouth will lose a bit of
mass-energy in this process, but it will also be gaining some mass
energy as interstellar gas passes through it and emerges from the
laboratory wormhole mouth. We note that, in terms of momentum change
vs. mass gain of the wormhole mouth, the use of light is preferable to
high energy particles, even though the momentum carried by light is
only its energy divided by the speed of light, because it keeps the
wormhole mass gain/loss small per unit momentum change.
Assuming precision steering can be accomplished by applying such
momentum changes, stopping is not too difficult. The exit mouth will
still have the large electric charge used for acceleration in the LHC
and consequently will lose energy rapidly by ionizing interactions as
it passes through any gas. It can be steered to make passes through
the upper atmospheres of planets or to have grazing collisions with
atmosphere of the star itself, until its great initial velocity has
been dissipated. In this process, considerable mass will pass through
the traveling mouth, and it will gain this mass-energy by back
reaction. This can be compensated by sending low-velocity mass
through in the other direction. The large charge can be reduced at
the same time by sending charged particles through.
The decelerated wormhole mouth can tour the star system, propelled by
high momentum beams sent through the stay-at-home mouth in the
laboratory. Such steering will tend to reduce the wormhole mass,
partially compensating for the mass-gain it received in decelerating
and perhaps in sampling planetary atmospheres.
Now that the wormhole mouth has arrived at the star system of
interest, a survey of the planets can begin. We assume that we have
laboratory control of the diameter of the wormhole mouth, and that it
can be enlarged to a diameter that is convenient for sampling. If a
habitable planet is found, the wormhole mouth can be brought to its
surface, and samples can be extracted through the wormhole and
analyzed, (perhaps sending compensating mass back in the other
direction to keep the wormhole mouth masses in balance).
Ultimately, when the survey is complete, the wormhole can be expanded,
permitting robot precursors, planetary explorers, colonists, and
freight to move through. Again, the mass of the wormhole mouths would
have to be managed, moving equal masses in the two directions during
wormhole transits, perhaps by sending compensating masses of water
through pipes. This scheme could allow very rapid travel to and
colonization of various star systems containing earth-like planets.
Thus, if stable wormholes are possible at all, they may represent a
path to the stars that would sweep away many of our previous concepts
and prejudices about how the stars can and should be reached.
While Cramer suggested this wormhole transportation network might be built by space-faring humans, there is no reason why advanced aliens couldn't get there first.
In summary, the wormhole arrives in the solar system because it was dispatched here to form part of a faster-than-light galactic wormhole transport network.
