Uncommon Descent Contest 4: Can we save physics by dumping the Copernican principle? - Winner announced

The question is here. It looks at “Does Dark Energy Really Exist? Or does Earth occupy a very unusual place in the universe?” by physicist Timothy Clifton and astrophysicist Pedro G. Ferreira, who argue just that: If we give up the Copernican principle, we do not need dark energy to explain the composition of the universe.(Scientific American, March 23, 2009)

The winning entry is by KeithDP:

I liked it because he made a number of pertinent points that less often raised than they should be:

- "The problem with the principle is how do you define special?" The fact that Earth is the only known home of life should cause it to be classified as special, at least for now.

- "Unlike the multiverse, the theory [re the existence or necessity of dark energy] is testable and efforts are underway to confirm or dismiss it." Indeed. Consider the upcoming SNO+ experiment in Sudbury, Canada, whose awesome facilities I toured recently - which aims to trap a particle of dark matter. That would be a good beginning.

- " ... will we also discover that Earth’s place in the centre of a vast cosmic void is another necessary precondition for life?" That too would be useful, because we could revise current estimates of where to look for life. Too many estimates have been Drake equation-style "choose your own parameters." Fun, sure, but science fiction.

So KeithDP needs to provide me with a current postal address at oleary@sympatico.ca to receive his free copy of the Privileged Planet DVD.

I will shortly judge Question 5: Darwinian fairy tales: Why middle-aged men have shiny scalps: "What is the down side for serious Darwinists to just cutting the “evolutionary psychology” psychodrama loose, and focusing on what real science can say about evolution?"

Now here is KeithDP's entry:

Copernicus’ modest proposition was that the solar system is heliocentric and not geocentric. Centuries later came the Copernican principle: the idea that Earth does not occupy any special position in the universe. In the last few decades this principle has been expanded to include the idea that there is nothing special about humans or the Earth. This idea is often called the Copernican principle of mediocrity. In recent years some astronomers have taken the idea further still and have popularized the notion that there is nothing special about our universe, as it is just one among an infinite number of other universes: a multiverse. Although no evidence supports the theory, and as it is not testable no evidence is ever likely to, it is considered the natural and ultimate culmination of the Copernican principle.

The problem with the principle is how do you define special? In the Rare Earth hypothesis, scientists Ward and Brownlee identify no less than a dozen factors that make complex life possible on Earth. In their view these factors make the Earth, if not special, than certainly very rare. Astronomer Guillermo Gonzalez goes further and identifies factors that make the Earth particularly suitable for scientific discovery. In his view the Earth is more than a rare planet; it is a privileged one. Recently some astronomers have questioned the standard model of the universe that holds that at least 70% of the universe is composed of mystery material. They propose this material is unnecessary if we ignore the Copernican principle and assume instead that the Earth lies at or near the centre of a vast cosmic void with far lower density than other regions of space.

Unlike the multiverse, the theory is testable and efforts are underway to confirm or dismiss it. Considering what we have learned about what makes the Earth’s particular location in the solar system and in the galaxy especially suitable for life, will we also discover that Earth’s place in the centre of a vast cosmic void is another necessary precondition for life?

Do we have further need of the Copernican principle? Or is it instead merely a personal philosophical position about humanity’s place? Does it tell us more about the belief system of those who hold it than it does about the universe?

OFF TOPIC but maybe of interest: Swine flu: Why are nearly all deaths in the developing world?

Here is my most recent MercatorNet column:

Now that the World Health Organization has declared swine flu (virus H1N1) a pandemic, their first since 1968’s Hong Kong flu, we might consider how it emerged.

But first -- Panic Alert: [nonsense avoidance]: People who are not already frail will probably be sick for about 48 hours if they get swine flu. They will not likely die. Symptoms are typical flu symptoms. When visiting anyone in frail health, please observe all sanitary precautions that medical authorities advise, especially if the frail person is in a hospital already. Shouldn’t that tell us something?

So let’s not panic. The main message is, in a global society, we cannot have completely different health standards on the same continent. Now let’s talk about two cities -- Mexico City and Winnipeg, Canada, where the virus was first identified.

Health care differs greatly between the two. In Winnipeg, every sick person — rich or poor — just goes to “the hospital,” and is examined by a nurse practitioner and/or a physician who can order lab tests and a ward bed -- in an isolation unit, if necessary. It’s all tax-supported, so no one goes bankrupt using the system.

But it is all different in Mexico.

Yes, it is a tale of the difference between Canada and Mexico. Read more here.

Origin of life: The misnaming of the Great Oxidation Event - which maybe never happened

British physicist David Tyler writes,

The true story of oxygen in the Earth's atmosphere has yet to be told. Most researchers have been brought up to believe the Miller-Urey model of abiogenesis, which required the Earth to have a reducing atmosphere to facilitate the spontaneous generation of life. The atmosphere was then considered to be neutral for over a billion years. The evolution of organisms capable of photosynthesis was the next important step, with rises of oxygen levels triggering the flowering of eukaryotes, the rise of the Ediacaran fauna and then the Cambrian Explosion. The first significant rise is understood to be abrupt and sufficient of a milestone in Earth history to warrant a name of its own. Richard Kerr's comments below lead us to the new research by Ohmoto and colleagues: [quote]The first living things did not require oxygen to "breathe," but early life on Earth never would have gotten much beyond pond scum without free oxygen in the atmosphere. Conventional thinking has oxygen produced by photosynthesis gaining the upper hand 2.4 billion years ago, nearly halfway into Earth history. But new laboratory results reported in tomorrow's issue of Science challenge the late arrival of this "Great Oxidation Event."

Ohmoto's hypothesis is that significant quantities of free oxygen were present in Earth's atmosphere prior to the GOE. He represents a minority position, but he continues to provide leadership in this area and a regular stream of relevant papers. One of the issues concerns patterns found in sulphur isotopes. Here is Kerr again: "Then in 2000, geochemist James Farquhar of the University of Maryland, College Park, came up with a nifty technique involving sulfur isotopes. The proportion of one isotope to another of the same element can change during a chemical reaction. Normally, the change depends on the masses of the isotopes. But Farquhar found isotopic shifts among three sulfur isotopes before 2.4 billion years ago that hadn't depended on isotope mass. As far as anyone knew, such "mass-independent fractionation" (MIF) could have happened only under solar ultraviolet radiation in an oxygen-free atmosphere - and MIF sulfur disappeared 2.4 billion years ago."

The new paper, with Farquar as one of the co-authors, proposes an alternative origin for these isotopic signatures that keep the door open for discussion of an early, oxygen-rich atmosphere. "The significance of this finding is that an abnormal isotope fractionation (of sulfur) may not be linked to the atmosphere at all," says Yumiko Watanabe, research associate [and co-author], Penn State. "The strongest evidence for an oxygen poor atmosphere 2.4 billion years ago is now brought into question."

Read more here.

Time: Can time flow backwards in quantum physics?

In a Viewpoint article, "Weak measurements just got stronger", for This Week in Physics ( April 27, 2009) Sandu Popescu, Physics 2, 32 (2009) In the weird world of quantum mechanics, looking at time flowing backwards allows us to look forward to precision measurements:

In 1964 when Yakir Aharonov, Peter Bergman, and Joel Lebowitz started to think seriously about the issue of the arrow of time in quantum mechanics [1]—whether time only flows from the past to the future or also from the future to the past—none of them could have possibly imagined that their esoteric quest would one day lead to one of the most powerful amplification methods in physics. But in the weird, unpredictable, yet wonderful way in which physics works, one is a direct, logical, consequence of the other. As reported in Physical Review Letters by P. Ben Dixon, David J. Starling, Andrew N. Jordan, and John C. Howell at the University of Rochester this amplification method makes it possible to measure angles of a few hundred femtoradians and displacements of 20 femtometers, about the size of an atomic nucleus [2].

[ ... ]

Viewed from one angle, this story is all about fundamental philosophical ideas. Does the spin indeed have a value larger than 1/2 or is the result simply an error in the imprecise measuring device used? Does the spin indeed have both the x spin component and the z one well defined? And, above all, does time indeed flow in two directions in quantum mechanics? To be sure, the strange outcome of the measurement of Sπ/4 in this pre- and post-selected ensemble could indeed be obtained as an error in the measurement, an error in which the pointer of the measuring apparatus moved more than it should have. The explanation can be fully given by standard quantum mechanics, involving regular past-to-future-only flow of time. But the explanation is cumbersome and involves very intricate interference effects in the measuring device. Assuming that time flows in two directions tremendously simplifies the problem. As far as I can tell, Aharonov, Albert, and Vaidman hold the view that one should indeed accept this strange flow of time. I fully agree. Not everybody agrees though, and this is one of the most profound controversies in quantum mechanics.Viewed from one angle, this story is all about fundamental philosophical ideas. Does the spin indeed have a value larger than 1/2 or is the result simply an error in the imprecise measuring device used? Does the spin indeed have both the x spin component and the z one well defined? And, above all, does time indeed flow in two directions in quantum mechanics? To be sure, the strange outcome of the measurement of Sπ/4 in this pre- and post-selected ensemble could indeed be obtained as an error in the measurement, an error in which the pointer of the measuring apparatus moved more than it should have. The explanation can be fully given by standard quantum mechanics, involving regular past-to-future-only flow of time. But the explanation is cumbersome and involves very intricate interference effects in the measuring device. Assuming that time flows in two directions tremendously simplifies the problem. As far as I can tell, Aharonov, Albert, and Vaidman hold the view that one should indeed accept this strange flow of time. I fully agree. Not everybody agrees though, and this is one of the most profound controversies in quantum mechanics.

Hubble Space Telescope: An introduction

Here's a PowerPoint recommended to me.

Never mind the hesitant kid intro. It's pretty good stuff.

History moment: The moon landing recalled

In "The Moon and Sparrows," David Warren of the Ottawa Citizen reflects on the comments of the men who first landed on the moon, forty years ago:

To be fair, more was established by the research of Riley and Olsson, although their other results will surely be challenged. They are further convinced, by Commander Armstrong’s continuous movement and body language while speaking, that his line was not rehearsed. This would mean it wasn’t “scripted by the White House,” as two generations of the mildly paranoid have earnestly believed. It was the genuinely spontaneous poetical effusion of an engineer from Ohio, rising to a historic occasion.

My own view — not the product of forensic linguistics, but rather of mere literary criticism — was, and remains, that this line was prosaic, even corny. I do not condemn it on this account, however. It was a humble attempt at the grandiose, of just the sort one might expect from such a speaker, stepping out on the lunar surface, with a billion souls watching on TV. And it was beautiful for that reason.

There was high poetry, too, but it had been delivered less self-consciously, a little earlier, as the vehicle containing Armstrong and Buzz Aldrin touched down. Paradoxically, that line gained all its poetry from being spoken, not in poetical language, but in mission jargon. It was:

“Tranquillity Base here. The Eagle has landed.”

I wonder if, once we get around to mining the moon, we will still want to call the base Tranquillity.

Can the laws of physics evolve?

A friend writes to say that in "The unique universe" (PhysicsWorld.com, 2 June 2009), Toronto-based cosmologist Lee Smolin attempts to develop a different view of time that allows him the laws of physics tp evolve in time. My friend wonders, "Presumably this is an alternative way of addressing the design challenge of fine tuning?"

Here's the essay's At a Glance:

Against the timeless multiverse

- Many cosmologists today believe that we live in a timeless multiverse - a universe where ours is just one of an ensemble of universes, and where time does not exist

- The timeless multiverse, however, presents a lot of problems. Our laws of physics are no longer determinable from experiment and it is unclear what the connection is between fundamental and effective laws

- Furthermore, theories that do not posit time to be a fundamental property fail to reproduce the space-time that we are familiar with

- Many of these puzzles can be avoided if we adopt a different set of principles that postulates that there is only one universe and that time is a fundamental property of nature. This scenario also opens the way to the possibility that the laws of physics evolve in time.

Well, some people go to a lot of trouble to evade the implications of fine tuning of the universe (= design).

Here is what I wrote about Lee Smolin's work in By Design or by Chance?:

New Universes Sprout Only in Black Holes?

Cosmologist Lee Smolin is a bit more conservative than Tegmark. He speculates that new universes might erupt—but not just anywhere that a particle goes one way rather than the other. Perhaps only in the middles of cosmic black holes. The new universes are disconnected from our universe, because the laws of physics break down in black holes. That is why we don’t know about them.

Smolin believes that the eruption of new universes in black holes follows the principles of Darwinism (natural selection). He explains:

"It seemed to me that the only principle powerful enough to explain the high degree of organization of our universe—compared to a universe with the particles and forces chosen randomly—was natural selection itself. The question then became: Could there be any mechanism by which natural selection could work on the scale of the whole universe?"

In other words, natural selection (the outcome of law acting on chance), lurking in a black hole, organizes a complex universe, excruciatingly fine-tuned for life. Smolin does not claim that the black hole spouts millions of them. Alternatively, he is attracted to the idea that the universe organizes itself:

"I believe more in the general idea that there must be mechanisms of self-organization involved in the selection of the parameters of the laws of nature than I do in this particular mechanism, which is only the first one I was able to invent. "

All these universes popping up in the clouds in our coffee, in the torment of a black hole, in the futility of an escaped balloon—their existence guarantees that our universe is a product of chance. If only they would exist . . . if only they would exist . . . (pp. 34-35)

Here are some more fine tuning stories:

Astronomer vs. pop science TV

Materialism strikes back: We create the universe, not God

The universe has hallmarks of desgn: And what can anyone do about it?

Like clouds in our coffee, all these other universes

Major media, imagining themselves sober, think there are many universes, not just double vision

The Big Bang exploded; seriously, is there room for reasonable skepticism about the Big Bang?

Could God live in an infinite sea of universes? It depends.

Will the cosmic multiverse landscape ensure the triumph of intelligent design?

Now, remind me again why we need multiverse theory in the first place?

Multiverse theory: Replacing the big fix with the sure thing?