I
remember long ago when I was a teenager hungry for knowledge about
the universe that fascinated me even then. Back in those days there
was no internet, nor were there any of the great science cable TV
shows that we now have. So to quench my thirst for knowledge about
science and the universe, I would almost always use the public
library. There were two great magazines I would read: a thin little
weekly called Science News, and a monthly called Scientific American.
Science News seems to have undergone almost no change in the past 40
years, and when I see a copy now in the library I get a kind of
time-warp sensation.
But
the Scientific American magazine seems to have changed. Perhaps the
editors have felt a need to resort to sensationalism in order to keep
up their readership. We have an example in the latest edition. The
cover is dominated by a huge headline: The Black Hole at the
Beginning of Time. When we go to a page on their online site,
the headline says: The Black Hole That Birthed the Big Bang.
Wow,
so I guess with this breathless headline, scientists must have
finally figured out that “origin of the universe” thing, right?
Wrong. The article in question is a discussion of a purely
speculative theory, a theory that is one of the wackiest and most
ornate pieces of baseless speculation since the Maori story that all
of creation stems from the six sons of a primordial couple named
Rangi and Papa.
I
would link to the Scientific American story directly, but it is
blocked by a pay wall. But the same theory advanced by the same
authors is found at this link.
Here
is how the authors describe their theory:
We
describe a braneworld description of cosmology with both 4d induced
and 5d bulk gravity (otherwise known as Dvali-Gabadadze-Porati, or
DGP model), which exhibits this feature: The universe emerges as a
spherical 3-brane out of the formation of a 5d Schwarzschild black
hole.
Here
the 4d and 5d refer to dimensions. The authors are speculating about
dimensions other than the known three dimensions of width, height,
and depth. This should immediately alert us that they are engaging in
a baroque flight of fancy, rather like someone speculating about vast
galactic empires.
What
does this phrase “braneworld description of cosmology” mean?
Braneworld cosmology might be described as an ornate speculation
built on top of a baroque speculation built on top of an intricate
speculation. Let's sort out the tower of speculations.
At
the bottom of the tower of speculations is supersymmetry, an ornate
theory for which there is no evidence (some say it is on “life
support” after Large Hadron Collider observations have failed to
back it up). Built on top of supersymmetry is string theory, an even
more ornate theory which also is not supported by observations. Then
built on top of string theory is brane cosmology. As wikipedia notes
in its article on brane cosmology, “There is no experimental
evidence for this hypothesis, nor is there any definite need for the
brane multiverse in M-theory or string theory.” Then built on top
of brane cosmology is the new theory of Afshordi, Mann and Pourhasan.
So
their theory is an ornate speculation built on top of an ornate
speculation (brane cosmology) built on top of an ornate speculation
(string theory) built on top of an ornate speculation
(supersymmetry). What is hilarious is that some people must be
seeing Afshordi, Mann and Pourhasan's theory featured on the cover
of the venerable old magazine Scientific American, and many such
people must be confusing the theory with science, which it is not.
It is actually a super-speculative theory very distantly related to
scientific observations, which is an entirely different thing.
The
following visual illustrates the point. We see a yellow circle
representing science. To its left we see a blue circle representing
speculations based on science. There is a big arrow pointing from the
blue circle to a trashcan. This is because most speculations based on
science end up being discarded. There is a much smaller arrow
pointing from the blue circle of speculation to the yellow circle of
science. This represents the small number of speculations derived
from science which end up becoming established science.
Afshordi,
Mann and Pourhasan's speculations are very much in the blue circle,
not the yellow one. Their speculations have an overwhelming
likelihood of ending up in the trashcan. Sadly, magazines such as Scientific
American cause people to confuse something in the blue circle as
something in the yellow circle.
According
to a Science Daily article, part of the inspiration for Afshordi,
Mann and Pourhasan's theory is a dissatisfaction with the standard
cosmological theory that our entire universe arose from a point of
infinite density called a singularity.
Science
Daily says, “The problem, as the authors see it, is that the big
bang hypothesis has our relatively comprehensible, uniform, and
predictable universe arising from the physics-destroying insanity of
a singularity. It seems unlikely.”
Yes,
quite a mystery; but that mystery persists.
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