Eventually
it was found out that it was not at all true that string theory
predicted a reality only like the one we have. It was found that
there could be something like 10500
possible universes in which
something like string theory could be true, each with a different set
of characteristics. Did the string theorists then give up? No, they
invented the name “the landscape” to describe this imaginary set
of possible universes. They then started speaking as if speculating
about this “landscape” is some proper business of physicists.
This
makes no sense. It is the business of science to study reality, not
imaginary possibilities. The only case in which it makes sense to
study an imaginary universe would be to throw some light upon our own
universe. For example, I might study a hypothetical universe in which
the proton charge is not the very exact opposite of the electron
charge, as it is in our universe. This might shed some light on how
fine-tuned our universe is. But except for rare cases like these, it
is a complete waste of time to speculate about imaginary hypothetical
universes.
String
theorists like Dijkgraaf use various verbal tricks to fool us into
thinking that they are doing something more scientific than Tolkien
spinning stories about the imaginary landscapes of Middle Earth. One
trick they use is to call their imaginary universes “models.”
Such a word is inappropriate when talking about any speculation about
a hypothetical universe different from the one we observe, such as a
universe with different laws or different fundamental constants. In
science a model is a simplified representation of a known physical
reality. So, for example, the Bohr solar system model of the atom is
an example of a model. But you are not creating a model when you
imagine some unobserved universe with different laws. That's just
imaginative speculation, not model building.
Another
trick used by Dijkgraaf is to try to make it sound like the weird
speculations of string theory have become accepted by most
physicists. For example, he writes the following:
With
this kind of talk you would think that string theory has taken over
physics, wouldn't you? But that didn't happen. During the late 1980's
there was talk about how string theory was going to take over
physics. But as we can see in the diagram below (from a physics
workshop), the popularity of string theory has plunged since about
1990. String theory is now like a weird little cult in the world of
theoretical physicists, not at all something which most physicists
endorse.
Another
verbal trick used by Dijkgraaf is to use metaphors that might make
us think that string theory is talking about something more
substantial than speculations about where angels fly about or how
long ghosts haunt a house. So in the quote above he compares string
theorists to geographers and geologists and gold diggers and mappers,
who are all hard-headed down-to-earth people who deal with solid
physical reality. But string theorists are not at all like such
people, since string theorists deal so much with imaginary universes for
which there is no evidence.
Dijkgraaf
also tries to insinuate that the
so-called models of string theory (a plethora of imaginary universes)
are “results of modern quantum physics.” He states the
following:
First
of all, the conclusion that many, if not all, models are part of one
huge interconnected space is among the most astonishing results of
modern quantum physics. It is a change of perspective worthy of the
term “paradigm shift.”
A
result in physics is something established by observation or
experiments. Quantum mechanics has results, but string theory has no results. It has merely ornate
speculations. You don't get a paradigm shift by speculating about
the unobserved.
What
Dijkgraaf conveniently fails to tell us is that string theory has been a
complete bust on the experimental and observational side. String
theory is based on another theory called supersymmetry. Attempts to
find the particles predicted by supersymmetry have repeatedly failed.
There is no evidence for any version of string theory.
As
for Dijkgraaf's claim that “there are no laws of physics, there's only the
landscape,” this seems to be a bad case of confusing reality and
the imaginary. The “landscape” of string theory is imaginary, but
the laws of physics are realities that our existence depends on
every minute. For example, if there were no laws of electromagnetism, none of us
would last for even 30 seconds. Claims like “there are no laws of
physics” by a string theorist suggests that string theory is just an
aberrant set of science-flavored speculations out-of-touch
with reality. You might call it runaway tribal folklore, the tribe
in question being a small subset of the physicist community. And
when a string theorist speaks about an imaginary group of possible
universes (what string theorists call the landscape), and says that
scientists are “mapping the landscape in detail and studying the
forces that have shaped it,” as if the imaginary “landscape”
was real, it again seems to be a case of confusing the real and the
imaginary. Similarly, a Skyrim player might get so lost in
the video game's fantasy that he might say, “There's no America, there's
only Tamriel.”
Given
string theorists, it's hardly a surprise that nbcnews.com has a story
entitled “Why some scientists say physics has gone off the rails.”
In that story the cosmologist Neil Turok is quoted:
"All
of the theoretical work that's been done since the 1970s has not
produced a single successful prediction," says Neil Turok,
director of the Perimeter Institute for Theoretical Physics in
Waterloo, Canada. "That's a very shocking state of affairs."
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