Wish Upon a Little Star,
Inside Sunlight, Eternally Bright....
One of the greatest mysteries of Pellucidar is its sun. That
sun is a peculiar thing, isn't it? What the hell is it? How
is it burning? What is it burning?
It's been burning, at least, since the era of dinosaurs, so you gotta
figure minimum 200 million years, and probably lots, lots, longer.
Likely since the beginning of the formation of the hollow earth.
We know our sun is a gigantic flaming ball of gas (sort of like Dick
Cheney) many times larger than the earth (like Cheney's ego). Its reactions
are atomic fusion, powered by gravity from its immense mass.
But Pellucidar’s sun is at most, a few hundred miles across, probably
smaller. That's not enough volume or enough mass under normal circumstances,
to sustain a fusion reaction. Normal rules of stellar physics do not apply.
But, on the other hand, the physical laws of the Universe, like relativity,
have not changed. So what's going on?
Pellucidar’s sun is at the geographical centre of the Earth.
That means that it is in a relationship with the rest of the planet, a
stable relationship. Given its position at the centre, its
got to be a gravitational mass of its own, or it would simply be pulled
apart by the surrounding gravity of the hollow Earth.
Looked at from the other side, its stable position at the centre, and relationship
to the planet, suggests that its internal mass and gravity may well be
a nexus, an axis of stability for the entire planet.
But that doesn't jibe with apparent mass and volume. To
hold itself together, and to play a stabilizing role in the the system,
it needs to be far more massive than its volume suggests.
How about this: It's a black hole. Normally, black holes are believed
to be several times the mass of the sun. But science allows for microscopic
mini-black holes. So it's possible that there are intermediate
or tiny 'freak' sizes, of dubious stability. Or, if our physics
don't allow for it, then perhaps there's a tiny wrinkle in the physics
of the Burroughs universe that will produce this celestial object.
Drop a black hole into Earth, what happens.
SHLOOMPH!!!! And that's all she wrote. A pretty short story.
But that's not really the whole story. A black hole's ability
to devour matter is limited to diameter of its event horizon (the point
at which the gravity is so immense that not even light can escape, it's
the point where the black hole goes ‘black.’ After all, matter has
to crowd around it, and cross that event horizon before it can be swallowed.
Which means, it would or could take a comparatively long time to swallow
the entire earth. And what if you weren't actually on the event
horizon, but merely orbiting really fast? An orbital velocity could stabilize
the gravitational pull, leaving you circling the hole just like any other
satellite circles its sun.
there was a German physicist named Weizsäcker
(I know the name is suspect, but he was a real person, real mathematics,
real physics), who predicted that if you balanced out rates of spin, you
could wind up with toroid (donut) shaped stable cosmic bodies, like asteroids
or even planets. Burroughs' hollow world is essentially a thin
flat version of a Weizsäcker celestial toroid.
So, let's revisit our hypothetical black hole again.
It falls into primeval Earth about four billion years ago, creates a huge
splash, disrupting the planet. The shock wave and gravitational
effects act like a churn, causing the planet material to spin rapidly.
This causes as much core material to migrate outwards as is devoured by
the core, perhaps the majority of core material is distributed out.
Debris ejected out of the atmosphere eventually coalesces as the moon.
This is only a little more weird than the real theory of Earth formation
currently in vogue. In that theory, the proto-Earth is struck
by a Mars sized planet. The two planets are shattered, the
core of the Mars planet sinks into and merges with the core of Earth.
Earth reforms, but the energy of impact keeps the core hot and the planet
geologically active for billions of years longer than the other planets
of the inner solar system. Venus, Mercury and Mars are all
now geologically dead, their cores having given up their heat eons ago.
Meanwhile, the debris of that impact eventually coalesced into the Moon,
which is a baked, hot dry world without a metallic core composed of relatively
As I said, the black hole theory is only a bit weirder than the real
theory, and Burroughs' hollow world is definitely weirder than our solid
world. Still, this would seem to be a one shot fluke.
It's hard to imagine the same process happening with Barsoom and Amtor.
But then again, it's possible that these dwarf black holes are relatively
common at some stages of stellar evolution in Burroughs universe, and that
this is the standard way, over there, that small rocky inner worlds form.
They may all be protective shells around heavy little dwarf black holes.
This may seem bizarre, but then again, we're finding out that our universe,
and the planets and solar systems we're now discovering seem to be bizarre
their own ways.
Anyway, the black hole then winds up sitting there in the gravitational
centre of the destroyed proto-Earth, at the centre of the axis of rotation.
By virtue of its status as a black hole, wherever it happens to be,
becomes by definition, the centre of the axis of rotation.
Rotation stabilizes an orbital Weizsäcker shell all around it.
At this point, most of the planet's surviving mass is safely and stabley
out of its reach.
Earth, our Earth, forms as a distorted toroid or Weizsäcker shell,
in a stable relationship with the black hole at its centre.
In a weird way, the relationship is not radically different, in Einsteinian
or Newtonian terms, than any other relationship of stellar bodies, such
as that between suns and planets, planets and moons, and double star or
double planet systems.
The intrinsic gravity of the Weizsäcker shell and perhaps the additional
gravity of the black hole makes for normal gravity up top.
The intrinsic gravity of the underside, of Pellucidar, is the same as
the topside, of course. But here, on the inside, the gravity is not
bolstered by the black hole, rather, the gravity of the black hole pulls
or counteracts the intrinsic gravity. Thus, apparent the gravity
of Pellucidar may be anywhere from five to fifteen per cent less than on
the surface. No big deal for land and sea creatures, but murder
for flying animals. The ‘tidal’ effects of the black hole would
also tend to accelerate the internal plate tectonics, which is one of the
reasons why geology and geography are moving faster on the underside (but
only in geological terms, its still immensely and unnoticeably slow by
Black Holes / Bright Sun?
But here is a problem. Black holes are obviously black.
Light doesn't escape. Pellucidar’s sun is obviously letting light
escape. It provides the heat and light for the inner world.
How does that work? How can a black hole be a bright sun?
There are a couple of possibilities, neither comforting. One, is that
the 'dwarf' black hole may not be stable, and in fact, may be degenerating.
That is, its physics are no longer sufficient to keep light escaping, and
it is now leaching off its energy. Give it a billion years or so, and it
may reach a point where it goes boom. Or, for all we know, it might reach
that point next Thursday.
In Burroughs universe, the Asteroid belt may well be the remains of
a similar hollow world with a black hole at the centre that eventually
But for now, we've had hundreds of millions of years of stable
decay, providing light, warmth and sunshine to the inhabitants of Pellucidar,
and if the end is to come like this in Burroughs universe, it will, at
least, be quick.
Alternatively, if we want to be more exotic, remember what I said
about actually having to cross the event horizon? Well,
gravity is pretty immense just before the event horizon, there's a lot
of mass to get through.
So, what if, as it approaches the event horizon, matter chokes?
There is so much mass, and its packed
so thick, that literally, it can't get through. Instead
of simply devouring all, mass accretes around the black hole, just outside
the event horizon, like a thick shell.
Stray molecules and atoms are constantly falling in, the shell is permanently
But at the same time, its constantly being added to, so it appears
All right, so we've got the egg of doom. So what?
Well, here's an interesting thing about black holes.
It turns out, they do radiate. I think its called Cherenkov radiation.
What happens is, that when black holes cross the event horizon, they're
being torn apart, and release a tiny burst of energy just before they cross.
Thus, every particle that crosses over leaves a signature.
Which then sterilizes every dinosaur and corsair in Pellucidar?
Not quite. All that radiation is then trapped in the outer shell which
acts like lead shielding. The vast amount of released energy is trapped,
degrading until it finally escapes as heat and light.... Pellucidar’s
Further, matter doesn't simply fall straight in, but spirals in, in
a deteriorating orbit. The closer it gets, the faster it goes.
Just outside the event horizon, particles may be approaching light speed,
and in doing so, releasing large amounts of energy. Energy
that is trapped in the shell and escapes as heat and light.
Of course, certain kinds of energy or force will reach beyond the shell.
Gravity, of course, is one factor. Electromagnetic energy is
another, the spinning black hole in its shell generates the planetary magnetic
field. We know that Quasars release radiation or radio waves
from its polar axis, this likely occurs here between the shell and the
black hole. But because the black hole is permanently oriented
on Earth's axis, these bursts of radiation and radio simply go through
the poles, where the energy illuminates the aurora borealis.
The net result is that we've got a local cosmology almost similar to Plato's
theory of a Universe composed of shells within shells. We have the
outer world, the intervening layer, the inner world, the inner world atmosphere,
the 'shell' of the sun and the black hole at the centre.