[Paleopsych] New Scientist: 13 things that do not make sense
Premise Checker
checker at panix.com
Tue Apr 5 17:50:10 UTC 2005
13 things that do not make sense
http://www.newscientist.com/channel/space/mg18524911.600
5.3.19
[On the first item, there was an article in Science a few years back that
gave evidence that the placebo effect correlates with the actual medicinal
effect, while one would think the two would be random. I never found out
about any followups. And keep your eyes on the astounding homeopathy
results. Are we entering a new spiritual age, after all?]
1 The placebo effect
DON'T try this at home. Several times a day, for several days, you
induce pain in someone. You control the pain with morphine until the
final day of the experiment, when you replace the morphine with saline
solution. Guess what? The saline takes the pain away.
This is the placebo effect: somehow, sometimes, a whole lot of nothing
can be very powerful. Except it's not quite nothing. When Fabrizio
Benedetti of the University of Turin in Italy carried out the above
experiment, he added a final twist by adding naloxone, a drug that
blocks the effects of morphine, to the saline. The shocking result?
The pain-relieving power of saline solution disappeared.
So what is going on? Doctors have known about the placebo effect for
decades, and the naloxone result seems to show that the placebo effect
is somehow biochemical. But apart from that, we simply don't know.
Benedetti has since shown that a saline placebo can also reduce
tremors and muscle stiffness in people with Parkinson's disease
(Nature Neuroscience, vol 7, p 587). He and his team measured the
activity of neurons in the patients' brains as they administered the
saline. They found that individual neurons in the subthalamic nucleus
(a common target for surgical attempts to relieve Parkinson's
symptoms) began to fire less often when the saline was given, and with
fewer "bursts" of firing - another feature associated with
Parkinson's. The neuron activity decreased at the same time as the
symptoms improved: the saline was definitely doing something.
We have a lot to learn about what is happening here, Benedetti says,
but one thing is clear: the mind can affect the body's biochemistry.
"The relationship between expectation and therapeutic outcome is a
wonderful model to understand mind-body interaction," he says.
Researchers now need to identify when and where placebo works. There
may be diseases in which it has no effect. There may be a common
mechanism in different illnesses. As yet, we just don't know.
2 The horizon problem
OUR universe appears to be unfathomably uniform. Look across space
from one edge of the visible universe to the other, and you'll see
that the microwave background radiation filling the cosmos is at the
same temperature everywhere. That may not seem surprising until you
consider that the two edges are nearly 28 billion light years apart
and our universe is only 14 billion years old.
Nothing can travel faster than the speed of light, so there is no way
heat radiation could have travelled between the two horizons to even
out the hot and cold spots created in the big bang and leave the
thermal equilibrium we see now.
This "horizon problem" is a big headache for cosmologists, so big that
they have come up with some pretty wild solutions. "Inflation", for
example.
You can solve the horizon problem by having the universe expand
ultra-fast for a time, just after the big bang, blowing up by a factor
of 10^50 in 10^-33 seconds. But is that just wishful thinking?
"Inflation would be an explanation if it occurred," says University of
Cambridge astronomer Martin Rees. The trouble is that no one knows
what could have made that happen.
So, in effect, inflation solves one mystery only to invoke another. A
variation in the speed of light could also solve the horizon problem -
but this too is impotent in the face of the question "why?" In
scientific terms, the uniform temperature of the background radiation
remains an anomaly.
"A variation in the speed of light could solve the problem, but this
too is impotent in the face of the question 'why?'"
3 Ultra-energetic cosmic rays
FOR more than a decade, physicists in Japan have been seeing cosmic
rays that should not exist. Cosmic rays are particles - mostly protons
but sometimes heavy atomic nuclei - that travel through the universe
at close to the speed of light. Some cosmic rays detected on Earth are
produced in violent events such as supernovae, but we still don't know
the origins of the highest-energy particles, which are the most
energetic particles ever seen in nature. But that's not the real
mystery.
As cosmic-ray particles travel through space, they lose energy in
collisions with the low-energy photons that pervade the universe, such
as those of the cosmic microwave background radiation. Einstein's
special theory of relativity dictates that any cosmic rays reaching
Earth from a source outside our galaxy will have suffered so many
energy-shedding collisions that their maximum possible energy is 5 ×
10^19 electronvolts. This is known as the Greisen-Zatsepin-Kuzmin
limit.
Over the past decade, however, the University of Tokyo's Akeno Giant
Air Shower Array - 111 particle detectors spread out over 100 square
kilometres - has detected several cosmic rays above the GZK limit. In
theory, they can only have come from within our galaxy, avoiding an
energy-sapping journey across the cosmos. However, astronomers can
find no source for these cosmic rays in our galaxy. So what is going
on?
One possibility is that there is something wrong with the Akeno
results. Another is that Einstein was wrong. His special theory of
relativity says that space is the same in all directions, but what if
particles found it easier to move in certain directions? Then the
cosmic rays could retain more of their energy, allowing them to beat
the GZK limit.
Physicists at the Pierre Auger experiment in Mendoza, Argentina, are
now working on this problem. Using 1600 detectors spread over 3000
square kilometres, Auger should be able to determine the energies of
incoming cosmic rays and shed more light on the Akeno results.
Alan Watson, an astronomer at the University of Leeds, UK, and
spokesman for the Pierre Auger project, is already convinced there is
something worth following up here. "I have no doubts that events above
10^20 electronvolts exist. There are sufficient examples to convince
me," he says. The question now is, what are they? How many of these
particles are coming in, and what direction are they coming from?
Until we get that information, there's no telling how exotic the true
explanation could be.
"One possibility is that there is something wrong with the Akeno
results. Another is that Einstein was wrong"
4 Belfast homeopathy results
MADELEINE Ennis, a pharmacologist at Queen's University, Belfast, was
the scourge of homeopathy. She railed against its claims that a
chemical remedy could be diluted to the point where a sample was
unlikely to contain a single molecule of anything but water, and yet
still have a healing effect. Until, that is, she set out to prove once
and for all that homeopathy was bunkum.
In her most recent paper, Ennis describes how her team looked at the
effects of ultra-dilute solutions of histamine on human white blood
cells involved in inflammation. These "basophils" release histamine
when the cells are under attack. Once released, the histamine stops
them releasing any more. The study, replicated in four different labs,
found that homeopathic solutions - so dilute that they probably didn't
contain a single histamine molecule - worked just like histamine.
Ennis might not be happy with the homeopaths' claims, but she admits
that an effect cannot be ruled out.
So how could it happen? Homeopaths prepare their remedies by
dissolving things like charcoal, deadly nightshade or spider venom in
ethanol, and then diluting this "mother tincture" in water again and
again. No matter what the level of dilution, homeopaths claim, the
original remedy leaves some kind of imprint on the water molecules.
Thus, however dilute the solution becomes, it is still imbued with the
properties of the remedy.
You can understand why Ennis remains sceptical. And it remains true
that no homeopathic remedy has ever been shown to work in a large
randomised placebo-controlled clinical trial. But the Belfast study
(Inflammation Research, vol 53, p 181) suggests that something is
going on. "We are," Ennis says in her paper, "unable to explain our
findings and are reporting them to encourage others to investigate
this phenomenon." If the results turn out to be real, she says, the
implications are profound: we may have to rewrite physics and
chemistry.
5 Dark matter
TAKE our best understanding of gravity, apply it to the way galaxies
spin, and you'll quickly see the problem: the galaxies should be
falling apart. Galactic matter orbits around a central point because
its mutual gravitational attraction creates centripetal forces. But
there is not enough mass in the galaxies to produce the observed spin.
Vera Rubin, an astronomer working at the Carnegie Institution's
department of terrestrial magnetism in Washington DC, spotted this
anomaly in the late 1970s. The best response from physicists was to
suggest there is more stuff out there than we can see. The trouble
was, nobody could explain what this "dark matter" was.
And they still can't. Although researchers have made many suggestions
about what kind of particles might make up dark matter, there is no
consensus. It's an embarrassing hole in our understanding.
Astronomical observations suggest that dark matter must make up about
90 per cent of the mass in the universe, yet we are astonishingly
ignorant what that 90 per cent is.
Maybe we can't work out what dark matter is because it doesn't
actually exist. That's certainly the way Rubin would like it to turn
out. "If I could have my pick, I would like to learn that Newton's
laws must be modified in order to correctly describe gravitational
interactions at large distances," she says. "That's more appealing
than a universe filled with a new kind of sub-nuclear particle."
"If the results turn out to be real, the implications are profound. We
may have to rewrite physics and chemistry"
6 Viking's methane
JULY 20, 1976. Gilbert Levin is on the edge of his seat. Millions of
kilometres away on Mars, the Viking landers have scooped up some soil
and mixed it with carbon-14-labelled nutrients. The mission's
scientists have all agreed that if Levin's instruments on board the
landers detect emissions of carbon-14-containing methane from the
soil, then there must be life on Mars.
Viking reports a positive result. Something is ingesting the
nutrients, metabolising them, and then belching out gas laced with
carbon-14.
So why no party?
Because another instrument, designed to identify organic molecules
considered essential signs of life, found nothing. Almost all the
mission scientists erred on the side of caution and declared Viking's
discovery a false positive. But was it?
The arguments continue to rage, but results from NASA's latest rovers
show that the surface of Mars was almost certainly wet in the past and
therefore hospitable to life. And there is plenty more evidence where
that came from, Levin says. "Every mission to Mars has produced
evidence supporting my conclusion. None has contradicted it."
Levin stands by his claim, and he is no longer alone. Joe Miller, a
cell biologist at the University of Southern California in Los
Angeles, has re-analysed the data and he thinks that the emissions
show evidence of a circadian cycle. That is highly suggestive of life.
Levin is petitioning ESA and NASA to fly a modified version of his
mission to look for "chiral" molecules. These come in left or
right-handed versions: they are mirror images of each other. While
biological processes tend to produce molecules that favour one
chirality over the other, non-living processes create left and
right-handed versions in equal numbers. If a future mission to Mars
were to find that Martian "metabolism" also prefers one chiral form of
a molecule to the other, that would be the best indication yet of life
on Mars.
"Something on Mars is ingesting nutrients, metabolising them and then
belching out radioactive methane"
7 Tetraneutrons
FOUR years ago, a particle accelerator in France detected six
particles that should not exist. They are called tetraneutrons: four
neutrons that are bound together in a way that defies the laws of
physics.
Francisco Miguel Marquès and colleagues at the Ganil accelerator in
Caen are now gearing up to do it again. If they succeed, these
clusters may oblige us to rethink the forces that hold atomic nuclei
together.
The team fired beryllium nuclei at a small carbon target and analysed
the debris that shot into surrounding particle detectors. They
expected to see evidence for four separate neutrons hitting their
detectors. Instead the Ganil team found just one flash of light in one
detector. And the energy of this flash suggested that four neutrons
were arriving together at the detector. Of course, their finding could
have been an accident: four neutrons might just have arrived in the
same place at the same time by coincidence. But that's ridiculously
improbable.
Not as improbable as tetraneutrons, some might say, because in the
standard model of particle physics tetraneutrons simply can't exist.
According to the Pauli exclusion principle, not even two protons or
neutrons in the same system can have identical quantum properties. In
fact, the strong nuclear force that would hold them together is tuned
in such a way that it can't even hold two lone neutrons together, let
alone four. Marquès and his team were so bemused by their result that
they buried the data in a research paper that was ostensibly about the
possibility of finding tetraneutrons in the future (Physical Review C,
vol 65, p 44006).
And there are still more compelling reasons to doubt the existence of
tetraneutrons. If you tweak the laws of physics to allow four neutrons
to bind together, all kinds of chaos ensues (Journal of Physics G, vol
29, L9). It would mean that the mix of elements formed after the big
bang was inconsistent with what we now observe and, even worse, the
elements formed would have quickly become far too heavy for the cosmos
to cope. "Maybe the universe would have collapsed before it had any
chance to expand," says Natalia Timofeyuk, a theorist at the
University of Surrey in Guildford, UK.
There are, however, a couple of holes in this reasoning. Established
theory does allow the tetraneutron to exist - though only as a
ridiculously short-lived particle. "This could be a reason for four
neutrons hitting the Ganil detectors simultaneously," Timofeyuk says.
And there is other evidence that supports the idea of matter composed
of multiple neutrons: neutron stars. These bodies, which contain an
enormous number of bound neutrons, suggest that as yet unexplained
forces come into play when neutrons gather en masse.
8 The Pioneer anomaly
THIS is a tale of two spacecraft. Pioneer 10 was launched in 1972;
Pioneer 11 a year later. By now both craft should be drifting off into
deep space with no one watching. However, their trajectories have
proved far too fascinating to ignore.
That's because something has been pulling - or pushing - on them,
causing them to speed up. The resulting acceleration is tiny, less
than a nanometre per second per second. That's equivalent to just one
ten-billionth of the gravity at Earth's surface, but it is enough to
have shifted Pioneer 10 some 400,000 kilometres off track. NASA lost
touch with Pioneer 11 in 1995, but up to that point it was
experiencing exactly the same deviation as its sister probe. So what
is causing it?
Nobody knows. Some possible explanations have already been ruled out,
including software errors, the solar wind or a fuel leak. If the cause
is some gravitational effect, it is not one we know anything about. In
fact, physicists are so completely at a loss that some have resorted
to linking this mystery with other inexplicable phenomena.
Bruce Bassett of the University of Portsmouth, UK, has suggested that
the Pioneer conundrum might have something to do with variations in
alpha, the fine structure constant (see "Not so constant constants",
page 37). Others have talked about it as arising from dark matter -
but since we don't know what dark matter is, that doesn't help much
either. "This is all so maddeningly intriguing," says Michael Martin
Nieto of the Los Alamos National Laboratory. "We only have proposals,
none of which has been demonstrated."
Nieto has called for a new analysis of the early trajectory data from
the craft, which he says might yield fresh clues. But to get to the
bottom of the problem what scientists really need is a mission
designed specifically to test unusual gravitational effects in the
outer reaches of the solar system. Such a probe would cost between
$300 million and $500 million and could piggyback on a future mission
to the outer reaches of the solar system
([64]www.arxiv.org/gr-qc/0411077).
"An explanation will be found eventually," Nieto says. "Of course I
hope it is due to new physics - how stupendous that would be. But once
a physicist starts working on the basis of hope he is heading for a
fall." Disappointing as it may seem, Nieto thinks the explanation for
the Pioneer anomaly will eventually be found in some mundane effect,
such as an unnoticed source of heat on board the craft.
9 Dark energy
IT IS one of the most famous, and most embarrassing, problems in
physics. In 1998, astronomers discovered that the universe is
expanding at ever faster speeds. It's an effect still searching for a
cause - until then, everyone thought the universe's expansion was
slowing down after the big bang. "Theorists are still floundering
around, looking for a sensible explanation," says cosmologist
Katherine Freese of the University of Michigan, Ann Arbor. "We're all
hoping that upcoming observations of supernovae, of clusters of
galaxies and so on will give us more clues."
One suggestion is that some property of empty space is responsible -
cosmologists call it dark energy. But all attempts to pin it down have
fallen woefully short. It's also possible that Einstein's theory of
general relativity may need to be tweaked when applied to the very
largest scales of the universe. "The field is still wide open," Freese
says.
10 The Kuiper cliff
IF YOU travel out to the far edge of the solar system, into the frigid
wastes beyond Pluto, you'll see something strange. Suddenly, after
passing through the Kuiper belt, a region of space teeming with icy
rocks, there's nothing.
Astronomers call this boundary the Kuiper cliff, because the density
of space rocks drops off so steeply. What caused it? The only answer
seems to be a 10th planet. We're not talking about Quaoar or Sedna:
this is a massive object, as big as Earth or Mars, that has swept the
area clean of debris.
The evidence for the existence of "Planet X" is compelling, says Alan
Stern, an astronomer at the Southwest Research Institute in Boulder,
Colorado. But although calculations show that such a body could
account for the Kuiper cliff (Icarus, vol 160, p 32), no one has ever
seen this fabled 10th planet.
There's a good reason for that. The Kuiper belt is just too far away
for us to get a decent view. We need to get out there and have a look
before we can say anything about the region. And that won't be
possible for another decade, at least. NASA's New Horizons probe,
which will head out to Pluto and the Kuiper belt, is scheduled for
launch in January 2006. It won't reach Pluto until 2015, so if you are
looking for an explanation of the vast, empty gulf of the Kuiper
cliff, watch this space.
11 The Wow signal
IT WAS 37 seconds long and came from outer space. On 15 August 1977 it
caused astronomer Jerry Ehman, then of Ohio State University in
Columbus, to scrawl "Wow!" on the printout from Big Ear, Ohio State's
radio telescope in Delaware. And 28 years later no one knows what
created the signal. "I am still waiting for a definitive explanation
that makes sense," Ehman says.
Coming from the direction of Sagittarius, the pulse of radiation was
confined to a narrow range of radio frequencies around 1420 megahertz.
This frequency is in a part of the radio spectrum in which all
transmissions are prohibited by international agreement. Natural
sources of radiation, such as the thermal emissions from planets,
usually cover a much broader sweep of frequencies. So what caused it?
The nearest star in that direction is 220 light years away. If that is
where is came from, it would have had to be a pretty powerful
astronomical event - or an advanced alien civilisation using an
astonishingly large and powerful transmitter.
The fact that hundreds of sweeps over the same patch of sky have found
nothing like the Wow signal doesn't mean it's not aliens. When you
consider the fact that the Big Ear telescope covers only one-millionth
of the sky at any time, and an alien transmitter would also likely
beam out over the same fraction of sky, the chances of spotting the
signal again are remote, to say the least.
Others think there must be a mundane explanation. Dan Wertheimer,
chief scientist for the SETI at home project, says the Wow signal was
almost certainly pollution: radio-frequency interference from
Earth-based transmissions. "We've seen many signals like this, and
these sorts of signals have always turned out to be interference," he
says. The debate continues.
"It was either a powerful astronomical event - or an advanced alien
civilisation beaming out a signal"
12 Not-so-constant constants
IN 1997 astronomer John Webb and his team at the University of New
South Wales in Sydney analysed the light reaching Earth from distant
quasars. On its 12-billion-year journey, the light had passed through
interstellar clouds of metals such as iron, nickel and chromium, and
the researchers found these atoms had absorbed some of the photons of
quasar light - but not the ones they were expecting.
If the observations are correct, the only vaguely reasonable
explanation is that a constant of physics called the fine structure
constant, or alpha, had a different value at the time the light passed
through the clouds.
But that's heresy. Alpha is an extremely important constant that
determines how light interacts with matter - and it shouldn't be able
to change. Its value depends on, among other things, the charge on the
electron, the speed of light and Planck's constant. Could one of these
really have changed?
No one in physics wanted to believe the measurements. Webb and his
team have been trying for years to find an error in their results. But
so far they have failed.
Webb's are not the only results that suggest something is missing from
our understanding of alpha. A recent analysis of the only known
natural nuclear reactor, which was active nearly 2 billion years ago
at what is now Oklo in Gabon, also suggests something about light's
interaction with matter has changed.
The ratio of certain radioactive isotopes produced within such a
reactor depends on alpha, and so looking at the fission products left
behind in the ground at Oklo provides a way to work out the value of
the constant at the time of their formation. Using this method, Steve
Lamoreaux and his colleagues at the Los Alamos National Laboratory in
New Mexico suggest that alpha may have decreased by more than 4 per
cent since Oklo started up (Physical Review D, vol 69, p 121701).
There are gainsayers who still dispute any change in alpha. Patrick
Petitjean, an astronomer at the Institute of Astrophysics in Paris,
led a team that analysed quasar light picked up by the Very Large
Telescope (VLT) in Chile and found no evidence that alpha has changed.
But Webb, who is now looking at the VLT measurements, says that they
require a more complex analysis than Petitjean's team has carried out.
Webb's group is working on that now, and may be in a position to
declare the anomaly resolved - or not - later this year.
"It's difficult to say how long it's going to take," says team member
Michael Murphy of the University of Cambridge. "The more we look at
these new data, the more difficulties we see." But whatever the
answer, the work will still be valuable. An analysis of the way light
passes through distant molecular clouds will reveal more about how the
elements were produced early in the universe's history.
13 Cold fusion
AFTER 16 years, it's back. In fact, cold fusion never really went
away. Over a 10-year period from 1989, US navy labs ran more than 200
experiments to investigate whether nuclear reactions generating more
energy than they consume - supposedly only possible inside stars - can
occur at room temperature. Numerous researchers have since pronounced
themselves believers.
With controllable cold fusion, many of the world's energy problems
would melt away: no wonder the US Department of Energy is interested.
In December, after a lengthy review of the evidence, it said it was
open to receiving proposals for new cold fusion experiments.
That's quite a turnaround. The DoE's first report on the subject,
published 15 years ago, concluded that the original cold fusion
results, produced by Martin Fleischmann and Stanley Pons of the
University of Utah and unveiled at a press conference in 1989, were
impossible to reproduce, and thus probably false.
The basic claim of cold fusion is that dunking palladium electrodes
into heavy water - in which oxygen is combined with the hydrogen
isotope deuterium - can release a large amount of energy. Placing a
voltage across the electrodes supposedly allows deuterium nuclei to
move into palladium's molecular lattice, enabling them to overcome
their natural repulsion and fuse together, releasing a blast of
energy. The snag is that fusion at room temperature is deemed
impossible by every accepted scientific theory.
"Cold fusion would make the world's energy problems melt away. No
wonder the Department of Energy is interested"
That doesn't matter, according to David Nagel, an engineer at George
Washington University in Washington DC. Superconductors took 40 years
to explain, he points out, so there's no reason to dismiss cold
fusion. "The experimental case is bulletproof," he says. "You can't
make it go away."
References
64. http://www.arxiv.org/gr-qc/0411077
More information about the paleopsych
mailing list