Anthropics and Myopics: Cosmological Constant

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In summary, a paper on the anthropic principle and the cosmological constant is discussed, along with some comments on its implications and the opinions of other scientists. The possibility of an anthropic cosmological principle is considered and its potential effects on the landscape of physics. The conversation also touches on the controversy surrounding the suppression of evidence in modern theoretical physics.
  • #1
marcus
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I wonder if this will be of any help in moving the discussion of Anthropixia and the String Landscape forward. :smile:

http://arxiv.org/abs/0709.0502
Anthropics and Myopics: Conditional Probabilities and the Cosmological Constant
Irit Maor (1), Lawrence Krauss (1,2), Glenn Starkman (1,2) ((1) CERCA, Case Western Reserve University, (2) Dept of Astronomy, CWRU)
(Submitted on 4 Sep 2007)

"The Anthropic Principle is claimed by many to provide a possible explanation for the observed smallness of the cosmological constant. However, correlations between the value of the cosmological constant and the existence of life can be demonstrated only under quite restrictive assumptions. Even allowing for a possible correlation, we demonstrate here that suggesting any such correlation is in fact causative is a much more subtle issue, and in general this latter claim will not be implied by the former."

exerpt: "We thank ... Raphael Bousso for lively discussions."
 
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  • #2
Myopia is about right...

Like I *tried* to say on Woit's blog:

From the paper:
Finally, the correlations illuminated by anthropic reasoning imply that what we ultimately learn from anthropic arguments is that the existence of us and the existence of the observed value of Lambda do not contradict each other. That is nice, but hardly surprising.

Yeah, maybe because the cc alone - an anthropic principle does not make.

It’s like dumb vs. dumber when everybody is premotivated.

~

In the mean time, Raphael Bousso, Maor, Krauss and Starkman all fail to recognize that a true anthropic cosmological principle *necessarily* defines a dynamical principle that would "make the landscape go away". So it will remain "the biggest failure of physicists in the last 20 years"... as David Gross would say, because you can't get to that answer from any of the motivated party's frames of reference.

The funniest part to all of this is this:

IF and even only IF there truly is an anthropic cosmological principle in effect, then this is defining the ToE via the reason that the parameters are constrained in the otherwise unexpected manner that is observed. Whatever we do, whatever new evidence gets discovered, and whatever we learn that supports this... let's NOT look here, at all costs.

Modern theoretical physics has become sick entertainment.
 
  • #3
I do not find it surprising that physics, as we know it, allows for our existence. I'm all in favor of using the anthropic principle as a humor check - theories that forbid our existence must be rejected - I'm nearly certain I exist and doubt you can persuade me to abandon that assumption.
 
  • #4
That's not a principle, it's a selection effect.
 
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  • #5
I'd so love to reply to this ideologically motivated hack, but Woit is still censoring me:
http://www.math.columbia.edu/~woit/wordpress/?p=594#comment-28266

Jim Clarage (astonished biophysicist) Says:
As I’ve posted here before, even most modern theologians would blush at such anthropocentric reasoning. It genuinely goes beyond anything Ptlolemy or any other pre-Copernican cosmologists might have guilty of about Man’s central place in the universe and its laws.

Only if you willfully ignore the observational evidence by wrongly assuming that it necessarily will be explained away, rather than to act like an honest scientist by at least giving the smoking gun equal time:

Does the motion of the solar system affect the microwave sky?
http://cerncourier.com/cws/article/cern/29210

LambdaCDM cosmology: how much suppression of credible evidence, and does the model really lead its competitors, using all evidence?
http://arxiv.org/abs/0705.2462

Alignment and signed-intensity anomalies in WMAP data
http://arxiv.org/abs/0704.3736

Extragalactic Radio Sources and the WMAP Cold Spot
http://arxiv.org/abs/0704.0908v2

A second paper confirms that the CBR is not symmetrical, as conventional theory predicts, but is asymmetrical on both large and small scales.

Testing Isotropy of Cosmic Microwave Background Radiation
http://arxiv.org/abs/0708.2816v1

A third paper on this subject raises doubts that the radio radiation from our own galaxy can be so accurately subtracted from the CBR observed by WMAP that the precision claimed for CBR measurements are valid.

Some doubts on the validity of the foreground Galactic contribution subtraction from microwave anisotropies
http://arxiv.org/abs/0708.4133v1

Michael J. Longo, who had previously shown that there was an alignment in the direction of spin of thousands of spiral galaxies across a huge stretch of the universe, shows the same alignment for elliptical galaxies.

The Axis of Opportunity: The Large-Scale Correlation of Elliptical Galaxies
http://arxiv.org/abs/0708.4013


But when you look at CMB map, you also see that the structure that is observed, is in fact, in a weird way, correlated with the plane of the Earth around the sun. Is this Copernicus coming back to haunt us? That's crazy. We're looking out at the whole universe. There's no way there should be a correlation of structure with our motion of the Earth around the sun — the plane of the Earth around the sun — the ecliptic. That would say we are truly the center of the universe.
-Lawrence Krauss
 
  • #6
A potent observation. It speaks volumes of assumptions.
 
  • #7
The Krauss quotation is from
http://www.edge.org/3rd_culture/krauss06/krauss06.2_index.html
right at the very end of the article, and it continues by laying out three possible conclusions which I will highlight, as follows:

"The new results are either telling us that

all of science is wrong and we're the center of the universe,

or maybe the data is imply incorrect,

or maybe it's telling us there's something weird about the microwave background results and that maybe, maybe there's something wrong with our theories on the larger scales.

And of course as a theorist I'm certainly hoping it's the latter, because I want theory to be wrong, not right, because if it's wrong there's still work left for the rest of us."

The piece in Edge is Krauss impressions after a get-together of some 20 scientists, in the Virgin Islands summer 2006, that he organized.
 
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  • #8
Topology is the long and short of it. Janna Levin has offered some interesting observations.
 

1. What is the cosmological constant and why is it important?

The cosmological constant is a mathematical term used in Einstein's theory of general relativity to represent the energy density of the vacuum of space. It is important because it has a significant impact on the expansion rate of the universe and the overall shape of the universe.

2. How does the cosmological constant relate to anthropic and myopic principles?

The anthropic principle suggests that the universe is fine-tuned for the existence of intelligent life, and the cosmological constant plays a role in this fine-tuning. The myopic principle, on the other hand, suggests that our observations of the universe are limited by our own existence. The value of the cosmological constant has implications for both principles.

3. What is the current value of the cosmological constant?

The current accepted value of the cosmological constant is approximately 10^-52 m^-2. This value is incredibly small, but it has a significant impact on the expansion rate of the universe and the overall structure of the universe.

4. How does the cosmological constant affect the fate of the universe?

The cosmological constant plays a role in determining the ultimate fate of the universe. If its value is positive, it will cause the universe to continue expanding at an accelerating rate, potentially leading to a "Big Rip" scenario where the universe is torn apart. If its value is negative, it will eventually cause the universe to collapse in a "Big Crunch" scenario.

5. What are the implications of different values of the cosmological constant?

The value of the cosmological constant has implications for the structure and fate of the universe, but it also has implications for the existence of intelligent life. A slightly different value could drastically change the conditions necessary for life to evolve. It also has implications for our understanding of the laws of physics and the fundamental nature of the universe.

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