Sure, they already know a lot. The standard model of elementary particle physics is a great success, and they’ve made many exciting cosmological discoveries in the past few years. The discovery and analysis of the variations in the temperature of the cosmic microwave background radiation have finally settled the long-standing question of whether the universe is flat or curved—it’s flat, or nearly so, and that’s that. But that raises other questions. There’s not enough visible matter in the universe to make it flat. The visible matter only amounts to about four percent of what would be needed to make the universe flat. They’ve found lots more matter in halos around galaxies, but it’s stuff they can’t see. They can only infer its existence from the behavior of the matter they can see. What is the dark matter? No one knows. At any rate, the dark and visible matter together only amount to about 30% of the matter and energy required to make the universe flat. The remaining 70% or so must be there and must be something. What is it? No one knows. No one even has the slightest clue. They call it dark energy.
That the dark energy is really there has been confirmed by observations of distant supernovae that show that the expansion of the universe is accelerating, rather than slowing down as would be the case if the universe contained only matter. When Albert Einstein first developed the equations of General Relativity, he thought that the universe was static, which led to the obviously wrong result that the pressure of matter was negative. To fix this, he inserted an extra term into his equations. It specified a cosmological constant that generated a repulsive force to counteract the attractive force of gravity. Later, when Hubble showed that the universe isn’t static but is really expanding, Einstein is said to have labeled the cosmological constant his biggest mistake. Now the cosmological constant is being seen as the leading candidate to explain the dark energy. It doesn’t really explain it, of course, because no one knows where the cosmological constant comes from, either.
In the summer of 2004 I attended the SLAC Summer Institute
at the Stanford Linear Accelerator Center at Stanford University (now the SLAC
National Accelerator Laboratory), where science means elementary particle
physics. The theme was, “Nature’s Greatest Puzzles.” Here is their list of the
greatest puzzles:
Where and what is dark matter?
How massive are neutrinos?
What are the implications of neutrino mass?
What are the origins of mass?
Why is there a spectrum of fermion masses?
Why is gravity so weak?
Is nature supersymmetric?
Why is the universe made of matter and not antimatter?
Where do ultrahigh-energy cosmic rays come from?
Did the universe inflate at birth?
“What is dark energy?” should be there, too.
A decade later, we still don’t have answers. Two of the
speakers at the Institute, acknowledging the lack of progress towards answers,
asked the same question: “What are we missing?” Of course, they didn’t know,
but one thought it might be a basic principle, like Einstein’s constant speed
of light, that isn’t obvious but once acknowledged would open up new ways of
thinking, leading to new truths. Nowadays a lot of the energy of the
theoretical physics community is focused on the search for a theory of quantum
gravity, a unification of quantum field theory and Einstein’s general
relativity. The quest hasn’t gone very far in spite of many years of effort.
One reason why progress in physics seems so hard to come by
these days is that theoretical physicists don’t have a good model of spacetime.
The mathematics they’ve been taught treats spacetime as an amorphous background
in which physics happens. It’s true that this paradigm has led to the great
successes of the standard model of particle physics. By applying symmetry
principles, theorists concluded that the electromagnetic, weak, and strong
forces had to be transmitted by certain gauge particles, most of which were
quickly found by experimentalists. As a result, theorists are now by and large
convinced that this is the only approach that is likely to lead to further
successes. However, if spacetime is a physical thing representing a more
fundamental layer of reality, they’ll never find it because it can’t be expressed
in terms of the current mathematical toolbox.
Another reason why
progress in physics is stalled is that physicists have erected a barrier to
that progress by rejecting any involvement with metaphysics. That might not be
so bad in itself had they not drawn an arbitrary line between physics and
metaphysics—a line they now refuse to cross. By their definition, anything
physicists aren’t comfortable with is metaphysics. Yet, concepts of existence
and consciousness are inescapable elements of reality. How can you ignore them
and have any hope of understanding reality? Progress in physics has always
coincided with a pushing back of the boundaries that separate physics from
religion and philosophy. That must happen again if progress is to resume.
The ideas I’ll tell you about in this blog go beyond physics
to metaphysics and show the connection between consciousness and physical
phenomena. It turns out to be pretty easy to see existence and
consciousness—metaphysical concepts—as physical things and to deal with them
using physical concepts. The bogey-man that physicists are so afraid of doesn’t
exist. In later posts I’ll present all the metaphysics you need to know, and
I’ll show how it leads to a spacetime model that answers nature’s greatest
puzzles..