October 25, 2009 at 2:38 pm #32460
note: How timely: the physicists are butting up against the end of “materialism”. As you read these 7 issues hat trouble physicists, you can see how a “science of consciousness” could solve all of them. – Michael
SEVEN QUESTIONS THAT KEEP PHYSICISTS UP AT NIGHT
by Ivan Semeniuk
October 23, 2009
It’s not your average confession show: a panel of leading physicists
spilling the beans about what keeps them tossing and turning in the wee
That was the scene a few days ago in front of a packed auditorium at the
Perimeter Institute, in Waterloo, Canada, when a panel of physicists was
asked to respond to a single question: “What keeps you awake at night?”
The discussion was part of “Quantum to Cosmos”, a 10-day physics
extravaganza, which ends on Sunday.
While most panelists professed to sleep very soundly, here are seven key
conundrums that emerged during the session, which can be viewed here.
Why this universe?
In their pursuit of nature’s fundamental laws, physicists have essentially
been working under a long standing paradigm: demonstrating why the universe
must be as we see it. But if other laws can be thought of, why can’t the
universes they describe exist in some other place? “Maybe we’ll find there’s
no other alternative to the universe we know,” says Sean Carroll of Caltech.
“But I suspect that’s not right.” Carroll finds it easy to imagine that
nature allows for different kinds of universes with different laws. “So in
our universe, the question becomes why these laws and not some other laws?”
What is everything made of?
It’s now clear that ordinary matter — atoms, stars and galaxies — accounts
for a paltry 4 per cent of the universe’s total energy budget. It’s the
other 96 per cent that keeps University of Michigan physicist Katherine
Freese engaged. Freese is excited that one part of the problem, the nature
of dark matter, may be nearing resolution. She points to new data from
experiments like NASA’s Fermi satellite that are consistent with the notion
that dark matter particles in our own galaxy are annihilating with one
another at a measurable rate, which in turn could reveal their properties.
But the discovery of dark energy, which appears to be speeding up the
expansion of the universe, has created a vast new set of puzzles for which
there are no immediate answers in sight. This includes the nature of the
dark energy itself and the question of why it has a value that is so
extraordinarily small, allowing for the formation of galaxies, stars and the
emergence of life.
How does complexity happen?
From the unpredictable behaviour of financial markets to the rise of life
from inert matter, Leo Kadananoff, physicist and applied mathematician at
the University of Chicago, finds the most engaging questions deal with the
rise of complex systems. Kadanoff worries that particle physicists and
cosmologists are missing an important trick if they only focus on the very
small and the very large. “We still don’t know how ordinary window glass
works and keeps it shape,” says Kadanoff. “The investigation of familiar
things is just as important in the search for understanding.” Life itself,
he says, will only be truly understood by decoding how simple constituents
with simple interactions can lead to complex phenomena.
Will string theory ever be proved correct?
Cambridge physicist David Tong is passionate about the mathematical beauty
of string theory — the idea that the fundamental particles we observe are
not point-like dots, but rather tiny strings. But he admits it once brought
him to a philosophical crisis when he realised he might live his entire life
not knowing whether it actually constitutes a description of all reality.
Even experiments such as the Large Hadron Collider and the Planck satellite,
while well positioned to reveal new physics, are unlikely to say anything
definitive about strings. Tong finds solace in knowing that the methods of
string theory can be brought to bear on less fundamental problems, such as
the behaviour of quarks and exotic metals. “It is a useful theory,” he says,
“so I’m trying to concentrate on that.”
What is the singularity?
For cosmologist and Perimeter Institute director Neil Turok, the biggest
mystery is the one that started it all, the big bang. Conventional theory
points back to an infinitely hot and dense state at the beginning of the
universe, where the known laws of physics break down. “We don’t know how to
describe it,” says Turok. “How can anyone claim to have a theory of
everything without that?” Turok is hopeful that string theory and a related
development known as the “holographic principle”, which shows that a
singularity in three dimensions can be translated into a mathematically more
manageable entity in two dimensions (which may imply that the third
dimension and gravity itself are illusory). “These tools are giving us new
ways of thinking about the problem, which are deeply satisfying in a
mathematical sense,” he says.
What is reality really?
The material world may, at some level, lie beyond comprehension, but Anton
Zeilinger, professor of physics at the University of Vienna, is profoundly
hopeful that physicists have merely scratched the surface of something much
bigger. Zeilinger specialises in quantum experiments that demonstrate the
apparent influence of observers in the shaping of reality. “Maybe the real
breakthrough will come when we start to realise the connections between
reality, knowledge and our actions,” he says. The concept is mind-bending,
but it is well established in practice. Zeilinger and others have shown that
particles that are widely separated can somehow have quantum states that are
linked, so that observing one affects the outcome of the other. No one has
yet fathomed how the universe seems to know when it is being watched.
How far can physics take us?
Perhaps the biggest question of all is whether the process of inquiry that
has revealed so much about the universe since the time of Galileo and Kepler
is nearing the end of the line. “I worry whether we’ve come to the limits of
empirical science,” says Lawrence Krauss of Arizona State University.
Specifically, Krauss wonders if it will require knowledge of other
universes, such as those posed by Carroll, to understand why our universe is
the way it is. If such knowledge is impossible to access, it may spell the
end for deepening our understanding any further.
Turok says that’s exactly why the Perimeter Institute exists, to harness the
thinking of the world’s brightest young minds in an unrestrained
environment. By optimising conditions for creative thinking, it may be
possible to avoid such an impasse.
“We’re used to thinking of theoretical physics as accidental,” says Turok.
“We need to ask whether there’s a more strategic way to speed up
understanding and discovery.”
Perhaps then all those troubled physicists can finally get some rest — or
at least switch to more mundane worries.October 26, 2009 at 12:42 am #32461
>>>What is everything made of?
>>>It’s now clear that ordinary matter — atoms, stars and galaxies
>>>– accountsfor a paltry 4 per cent of the universe’s total
>>>energy budget. It’s the other 96 per cent that keeps
>>>University of Michigan physicist Katherine Freese engaged.
>>>Freese is excited that one part of the problem, the nature
>>>of dark matter, may be nearing resolution.
>>>But the discovery of dark energy, which appears to be
>>>speeding up the expansion of the universe, has created a
>>>vast new set of puzzles for which there are no immediate
>>>answers in sight. This includes the nature of the dark
>>>energy itself and the question of why it has a value that
>>>is so extraordinarily small, allowing for the formation
>>>of galaxies, stars and the emergence of life.
Understanding only 4% of the universe means they don’t
understand much. The 96% dark matter/dark energy is
the important part.
Here’s an amusing thought that just came to mind:
Just the way the paragraph was written makes me feel
as if the universe is actually a living organism, and
the 4% known items are just the “inert” parts of the
organism. Planet Earth with all its life, human
inquiry and investigation, is the “dantian” of the
organism. The organism was “born” in the “Big Bang”
and continues to “grow” to this day . . . maybe they
should view the universe as a living organism, and the
components inside are just organ systems . . . S
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