Scientific
mysteries – the next time someone tells you science has everything under
control, send him here
control, send him here
https://www.sciencenews.org/blog/context/top-10-scientific-mysteries-21st-century
Top 10
scientific mysteries for the 21st century
Solving
the toughest problems posed by nature is not just fun and games
BY
8:00AM, JANUARY 28, 2015
The
last few centuries have been pretty good for science. In the 17th century,
Isaac Newton solved the ancient controversy over the nature of forces and
motion with his three laws. In the 18th, Ben Franklin figured out a lot about
electricity. In the 19th, Darwin explained the diversity of species, Maxwell
revealed the physics of light, Mendeleyev defined the families of chemical
elements. In the 20th we had Einstein, who figured out all sorts of stuff,
including gravity. No to mention Watson and Crick, who deciphered the molecular
foundation for genetics and life. What more do you want?
Well,
there are still lots of mysteries left for the 21st century to solve, and it
has only 86 years left in which to solve them. So it’s a good idea to put them
in a list, just to avoid any danger that everybody will forget to work on them.
Actually
there are many more than 10, so this list will have to be restricted to my
favorites. To select from all the many possibilities, let’s make a game of it.
10.
How did life originate?
It
doesn’t seem like this one should be so hard, but it continues to defy
solution. There’s plenty of speculation, often related to RNA’s ability to act
both as catalyst and bio–hard drive to store information. And new findings turn
up all the time about how life’s basic building blocks could have been
generated in primordial conditions or delivered to Earth from space. I think
this question will end up having something to do with game theory, as
biomolecules interact in competitive ways that
could be described as strategies, and the math for calculating optimal
strategies is what game theory is all about.
9.
What is the identity of the dark matter?
It
has been eight decades or so since astronomers began to notice that there is
more gravity pulling stuff around out in space than there is visible matter
able to produce such effects. Attempts to detect the supposedly exotic (as in,
unknown) species of subatomic particle responsible for the extra gravity have
been frustrating. Hints seen in some experiments have been ruled out by other
experiments. I think there’s a missing piece to this puzzle, but it probably
has nothing to do with game theory.
8.
What is the nature of the dark energy that drives cosmic acceleration?
If
you think dark matter is frustrating, try explaining dark energy. Something is
driving space to expand at an ever increasing rate. Physicists think that they
know what it is — the never-changing density of energy residing throughout all
of space, referred to by Einstein as the “cosmical term” and now called the
cosmological constant. But when you calculate how strong the cosmological constant
should be, the answer is too big by dozens of orders of magnitude — much more
than the difference between the size of the entire universe compared with a
proton. So dark energy’s identity remains a mystery; if it is the cosmological
constant, something else is seriously wrong with what physicists think they
know. And so far game theory has been absolutely no help.
7.
How to measure evidence
This
one is so mysterious that many scientists don’t even know there’s a mystery.
But if they paused to think, they’d realize that the standard way of inferring
conclusions from experimental data — calculating “statistical significance” —
makes about as much sense as punting on fourth and seven when you’re down by 15
with eight minutes to go. One small example: if you do an experiment and get a
statistically significant result, and then repeat it and get a statistically
significant result again, you’d think you have better evidence than doing the
experiment only once. But if the significance level was a little less the
second time, the combined “P value” would be less impressive after the second
experiment, even though the evidence ought to be regarded as stronger. It’s a
mess. Game theory would surely be able to help somehow, possibly by virtue of
its relationship to thermodynamics.
6.
Genes, cancer and luck
You
might have read recently that
most cancer is caused by bad luck, as a study published in Sciencesupposedly
concluded. (Actually, the study concluded that the disparity in prevalence of
cancer of various types was largely due to luck.) A firestorm of protest followed,
essentially based on the belief that such a study must be wrong because it
would “send the wrong message” to the public. Proving the illogic of that
syllogism should be left as an exercise for the reader. Other responses
revealed that experts do not agree on how random mutations (bad luck) compare
with heredity (parent’s fault) plus lifestyle (your fault) and environmental
exposure to bad things (somebody else’s fault) in causing cancer. Sorting all
that out, and in the process solving cancer’s other mysteries, should be a
high-priority exercise for 21st century science. And yes, there is a
considerable amount of research relating game theory to cancer.
5.
Are there extra dimensions of space?
I
don’t know why people keep thinking this is a mystery, as I have on several
occasions pointed out that there are no extra dimensions. However many there
are, they are all absolutely necessary. Posed properly, this question should be
how many dimensions of space are there? (For that matter, you could also ask
about how many time dimensions there are, but that might overlap with No. 4.)
Many physicists believe more dimensions than the ordinary three will be needed
for physics to make sense of the universe. (Don’t even ask if they’re talking
about bosonic or fermionic dimensions.) A key to understanding this issue is
the mathematics of Calabi-Yau manifolds,
which can curl up in gazillions of different ways to prevent easy detection of
the additional dimensions’ existence. And that makes it really hard to figure
out which of the gazillion possibilities would correspond to the universe we
inhabit (unless there is some sort of fixed point theorem that would choose
one, like a Nash equilibrium in game theory). In any
event, anyone attempting to solve this riddle should first read Edwin
Abbott’s Flatland, in which the
protagonist character, A. Square, demonstrates the existence of an extra
dimension and is promptly thrown in jail.
4.
The nature of time
So
many mysteries, so little time in which to solve them, unless solving this one
would reveal some clever tricks to play with time. Many submysteries underlie
this one, corresponding to almost all of the 44 definitions of time in the
dictionary (and that’s just as a noun). What’s the nature of duration and the
flow of time — is it illusory or “real” in some elusive way? What about the
direction of time — does it always go forward? Why? Is time travel possible, or
can messages at least be sent backward in time? (Forward in time is easy — just
print this blog post out and read it a year from now.) Perhaps the biggest
mystery is whether all these issues about time are related or are completely
separate questions. Of course, it would all be simpler if somehow time could be
connected to game theory, which it might be, because game theory can be related
to cellular automata, which
in turn can be related to time.
3.
Quantum gravity
Quantum
physics and general relativity (aka Einstein’s theory of gravity) both seem to
describe the universe and its components with compelling accuracy, yet they
seem wholly incompatible with one another. Attempts to combine them into a
coherent unified theory have been as successful as brokering compromise in the
U.S. Congress. Yet there are clues. In 1930, Einstein tried to refute quantum
mechanics (specifically, the Heisenberg uncertainty principle) by suggesting a
clock attached to a box hanging on a scale could measure both the mass of a
photon and the precise time that it escaped from the box. (Heisenberg said you
couldn’t measure both at the same time). But Niels Bohr pointed out that the
time on the clock would be uncertain, because as the box moved upward in the
gravitational field, Einstein’s relativity required a change in time that would
introduce just the amount of uncertainty in the timing that Heisenberg
required. So how, you might ask, did the uncertainty principle know about this
effect of general relativity? Maybe if the experts posed the question that way
they would be able to figure out the quantum gravity mystery. The next best bet
would be to undertake the study of quantum game theory,
which hasn’t been adequately exploited yet in this regard.
2.
Does intelligent life exist elsewhere?
It’s
tempting to delete the “elsewhere,” but given what passes for intelligence on
Earth, it makes sense to wonder if anything like it could be blundering about
on some distant world. It seems likely, given how many other worlds there are
out there. But finding out for sure will probably require receiving an actual
message. Projects like SETI have been listening for some such
message, so far unsuccessfully. There are two (at least) possible explanations:
One, there have been no messages (perhaps the aliens are experts at game theory
and calculated that contacting humans would be a bad strategy). Two, the
messages are there, but nobody knows how to detect or recognize them. Perhaps
enhanced scrutiny is in order on Twitter, where numerous tweets every day seem
most plausibly to be the work of aliens.
1.
The meaning of quantum entanglement
All
sorts of quantum mysteries remain unsatisfactorily resolved, but maybe the rest
would succumb if entanglement does. Entanglement occurs in systems with widely
separated parts that share a common history; a measurement of one of the parts
reveals what you will find out when you measure its distant relative.
Entanglement is a fact of nature, well-established by experiment. It suggests
that time and space do not constrain quantum phenomena the way they do ordinary
human activity. Among the latest intriguing aspects of entanglement to be
studied involves black holes. It seems that black
holes can be entangled, which apparently is equivalent to their
being connected by a wormhole. Related work suggests that space, time
and gravity are all part of a vast quantum entanglement network. Since both the
evolution of networks and quantum entanglement fit
nicely into game theory, solving all sorts of mysteries might boil down to
viewing the world from a game-theoretical perspective. But maybe that will
still be too hard for human brains — it might take advanced artificial
intelligence, which, as this paper suggests,
might be created with the help of some version of quantum game theory.
Editor’s
Note: It might not surprise readers to find out that Tom Siegfried is the
author of a book about game theory.
But he says the book did not include the sort of wild speculation that is
suitable only in blog posts.
https://www.newscientist.com/round-up/physics-questions/
10
mysteries that physics can’t answer… yet
From why we travel forwards in
time to how bicycles travel forwards at all, we present the questions great and
small that our finest minds can't explain
Image: Carlo Giambarresi
COSMOLOGY
Has
the universe existed forever? Or was there something before it? To find out, we
need a working theory of quantum gravity and a new conception of time
CYCLING
We
thought we knew the maths behind cycling. We were wrong – and our efforts to
figure it out are leading to some weird and wonderful new bike designs
QUANTUM
SCIENCE
In
the bizarre reality of the quantum world, particles can be in two places at
once. Why can’t golf balls or milk do the same?
TIME AND
SPACE
Time
goes by, or so it seems. It could be an illusion, or we might need to rescue
the flow of time by meddling with our concept of space
MISSING
DIMENSIONS
The
universe might go awry if not for the familiar three dimensions, but theories
of everything say there should be more. What are we missing?
CASIMIR
EFFECT
The
Casimir effect suggests that the vacuum is fizzling with ephemeral particles.
Is it real? And can we harness this energy concealed in empty space?
LIQUID
CHAOS
Things
aren’t as clear as you might think. Glass is a weird kind of solid liquid – and
how it comes to be like that defies all explanation
FIELD OF
ICE
Most
think it’s down to a liquid layer, but can’t agree on how it forms. One theory
insists it’s a “supersolid skin” capable of electrostatic repulsion
PARTICLE
PHYSICS
They
are the essential heart of every atom, so it’s just as well we’ve never seen a
proton fall apart. But they can’t live forever – can they?
SOLAR
SYSTEM
The
size of the observable universe is easy enough to measure, but what lies beyond
the cosmic horizon? We have a long way to go to find out
HUMAN
BRAIN
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