[extropy-chat] AAAS conference on retrocausation

[Damien Broderick]

[I'm told that John Cramer announced that 
backward signaling of c. 50 microseconds might be feasible...]

[and yes, I'm back--hi, folks! Damien B.]

http://www.signonsandiego.com/news/science/20060622-9999-lz1c22cause.html


By Scott LaFee
UNION-TRIBUNE STAFF WRITER

June 22, 2006


Are we not drawn onward, we few, drawn onward to new era?

The answer would seem to be yes, if only because 
time always moves forward, drawing not just “we 
few” but everyone and everything “onward to new era.”

But what if time is like the palindrome above? 
What if the so-called arrow of time flies both 
ways, forward and back? What then? What now? What next?

People have debated the nature of time since, 
well, people invented it. Time is, in many ways, 
a fabrication of our minds, a superficial 
construct that helps us explain the universe, 
plot our course through existence and show up when we're supposed to.

“The only reason for time is so that everything 
doesn't happen at once,” Albert Einstein once said.

And so it goes, one thing happens, then another – 
a phenomenon called cause-and-effect. “It's a 
notion so deeply ingrained that it's hard to 
think about things any other way,” said Daniel 
Sheehan, a professor of physics at the University of San Diego.

But Sheehan does, as do other physicists who are 
meeting this week at USD to discuss and debate 
the concept of “reverse causation,” a fantastical 
notion that suggests effects can precede causes, 
and the future can influence the past, assuming 
the past and future actually “exist” in the first place.

(The symposium is part of the 87th annual meeting 
of the Pacific Division of the American 
Association for the Advancement of Science.)

“I don't think we've reached any kind of 
consensus coherent enough to be called a state of 
thinking,” said York Dobyns, a physicist at 
Princeton University who is attending the 
meeting. “There's a tremendous amount of 
disagreement about reverse causation between 
people who think the whole subject is just too 
speculative to deal with and people who have 
actually grappled with it, either theoretically or experimentally.”

This much, however, can be said: While reverse 
causation (also called backward or 
retro-causation) may sound like science fiction, 
it is firmly grounded in classical laws of 
physics. These laws say time is symmetrical, that 
it moves – or should be able to move – in all directions with equal ease.

Case in point: electromagnetism, one of the four 
fundamental forces of nature. (The others are 
gravity and strong and weak nuclear force.)

In the 19th century, Scottish mathematician and 
physicist James Clerk Maxwell developed equations 
explaining how electricity and magnetism work in 
tandem. It was Maxwell, in fact, who determined 
that electromagnetic energy, such as light and 
radio, traveled in waves through empty space at the speed of light.

But Maxwell's equations say nothing about the 
direction of time. It's irrelevant. The equations 
work equally well whether electromagnetic waves 
arrive after or before they are transmitted. In 
effect, writes Paul Davies, a physicist at the 
Australian Centre for Astrobiology and author of 
“About Time,” the waves “are indifferent to the 
distinction between past and future.”




Feeling dizzy yet?

Most physicists accept the idea of time symmetry 
(at least in the context of things like Maxwell's 
equations). The same cannot be said of reverse 
causation, which goes farther by suggesting the future can influence the past.

“The tendency is to ignore it, to say it's just a 
fact of nature that time moves one way,” said 
Michael Ibison, a physicist at the University of Texas at Austin.

If reverse causation is real, it most likely 
occurs at the largely theoretical and unseen 
level of quantum mechanics, a place where 
subatomic particles with names like mesons and 
quarks interact in ways contrary to both classical physics and common sense.

To wit: Mesons exist simultaneously as both 
particles and waves until they are observed. But 
until they are observed, they don't exist.

“Anyone who thinks they can talk about quantum 
theory without feeling dizzy hasn't yet 
understood the first word about it,” said the 
late, great Danish physicist Niels Bohr who, 
incidentally, invented much of the theory.

“People know how to calculate with quantum 
mechanics, but that's not to say they know what 
it means,” agreed Sheehan. “Quantum mechanics is 
like poetry. The poem is right there, for 
everyone to see, but it has many different interpretations.”

Sheehan offers a couple of scenarios to ponder:

First, imagine a large boulder at the top of a 
hill. The boulder begins rolling downhill. Now 
freeze the action with the boulder midway along 
its descent. Call this the boulder's present. At 
this point in time, Sheehan says the boulder is 
being influenced both by its past (when it was 
atop the hill) and by its future (when it will 
come to rest at the bottom of the hill). The 
boulder's current position midway down the hill 
cannot happen without the effect of both the past and the future.

“The present is always a negotiation between the 
past and the future,” said Sheehan.

Or think about this: You're invited to a Saturday 
wedding. On Friday, you go to the barber for a 
haircut. As you sit in the chair, the future is 
influencing the present. The wedding hasn't 
happened. It may not happen at all. And yet its 
possibility changes what will be the past. [[this is  all *incredibly* sloppy]]

The best evidence for reverse causation – perhaps 
the only evidence, said Sheehan – comes from 
parapsychology, which investigates phenomena not 
explained by the known laws of science, such as 
telepathy, clairvoyance and psychokinesis (the 
alleged ability to move matter with the mind).




Numbers in limbo

In 1992, a paranormal investigator named Helmut 
Schmidt set up a radioactive decay counter to 
generate sequences of random numbers, both 
positive and negative. The numbers were recorded, 
but not seen by any person. Several months later, 
these numbers were shown to a group of students 
who had been asked to use their “mind power” to 
skew the sequences in favor of positive numbers. 
Elaborate precautions were taken to prevent cheating.

According to fundamental physical laws, there 
should have been an equal number of positive and 
negative numbers. But Schmidt reported that the 
students saw more positive numbers; the 
probability of that happening was less than 1 in a 1,000.

Did the students actually influence the outcome 
of radioactive decay rates recorded months 
before? Henry Stapp, a theoretical physicist at UC Berkeley, thought so.

Stapp was one of the independent monitors of 
Schmidt's experiments. Two years later, he 
published a possible explanation for what had 
happened. In essence, he suggested that human 
consciousness had interacted with the numbers, 
effectively altering the past (when the numbers were recorded).

The idea, which Stapp and others have since 
expanded upon and promoted, is that human 
consciousness is an unexplained, nonlinear force 
of nature. Like subatomic particles in quantum 
mechanics, the numbers in Schmidt's experiment 
existed in a sort of limbo in which they were 
positive, negative and neither until the students 
saw them. At that point, human consciousness and 
intent (instructions to think positive) induced 
the numbers to assume a specific condition or quantum state.

The physics of consciousness is controversial, to 
say the least. And Stapp is first to say much 
more study and experimentation is necessary, 
especially by respected scientists in well-regarded scientific journals.

“You'd think people would want to either refute 
or confirm some of these reports,” said Stapp, 
“but the only people willing to test them are 
people who already tend to believe them. Most 
mainstream labs shy away for fear of sullying 
their reputations, as if they would be dirtying 
their hands by even imagining some of this is possible.”




Mind games

For Stapp, who now works at the Lawrence 
Livermore National Laboratories, it's not 
inconceivable that quantum mechanics plays some 
role in alleged paranormal phenomena like 
extrasensory perception (ESP) and remote viewing, 
which is the projection of one's consciousness to distant locations.

These abilities may be a consequence of 
nonlocality, a well-established quantum concept 
that says entities far-flung in distance or time 
are still entangled and interact via a 
faster-than-light, quantum mechanical connection.

Einstein called this phenomenon “spooky action at 
a distance.” He couldn't explain it, didn't like 
it and regarded it as quantum trickery.

In recent decades, nonlocality has been 
repeatedly observed, tested and measured in 
experiments. In one seminal experiment in 1982, 
physicist Alan Aspect at the University of Paris 
noted that by changing the polarity of one 
speeding photon (a particle of light) he could 
induce another photon from the same source 
speeding in the opposite direction to change its 
polarity. The interaction happened faster than 
light, with sufficient distance between the 
photons that they shouldn't have “known” what was 
happening to the other. And yet, inexplicably, there was some sort of link.

In contrast, paranormal phenomena like ESP and 
remote viewing are not as well-substantiated. 
Supporting evidence tends to be anecdotal. 
Purposeful deception and fraud are common.

In the 1970s, the U.S. Army and the CIA spent 
millions investigating the potential of remote 
viewing, but that effort apparently went for 
naught and funding ceased. In 1979, the Princeton 
Engineering Anomalies Research (PEAR) program 
began investigating interaction between human 
consciousness and the physical world. Over the 
years, PEAR has produced a wealth of data 
indicating human intent by itself, without any 
physical connection, can alter the behavior or 
results of unthinking machines. The PEAR 
experiments, many similar to Schmidt's 1992 
random number generator test, produced only small 
effects, but they were observable, measurable and repeatable.

PEAR's operations, however, are now in the 
process of closing down, with researchers moving on to other institutions.

Dobyns, an analytical coordinator for PEAR, said 
he still thinks “parapsychology and related areas 
are useful places to look for evidence (of reverse causation).”

But he is not optimistic that many mainstream 
physicists will ever take up the cause. “They say 
it's impossible because there's no evidence and 
there's no evidence because it's impossible.”

But physicists like Sheehan say what we do 
understand about the universe fundamentally 
depends upon the idea that time is fluid and 
dynamic. “To say that it's impossible for the 
future to influence the past is to deny half of 
the predictions of the laws of physics,” he said.

Nobody's predicting a speedy or conclusive 
resolution to the question of reverse causation. 
Sheehan says it's the journey that counts, how we 
get from Point A to B to C – or, perhaps, from C to B to A.