Archive for the 'Peter Woit' Category

Mankind ‘shortening the universe’s life’ Dent Krauss Fallacy

November 23, 2007

“This is really weird, this scientist claims the more we look at the universe the faster we cause it’s destruction. It’s way over my head!” By Roger Highfield, Science Editor
Last Updated: 12:01am GMT 21/11/2007

“The damaging allegations are made by Profs Lawrence Krauss of Case Western Reserve University in Cleveland, Ohio, and James Dent of Vanderbilt University, Nashville, who suggest that by making this observation in 1998 we may have caused the cosmos to revert to an earlier state when it was more likely to end. “Incredible as it seems, our detection of the dark energy may have reduced the life-expectancy of the universe,” Prof Krauss tells New Scientist.”

The interpretation of quantum mechanics used by the authors of this article is not appropriate for this application. Quantum systems evolve without human observation. The authors claim the universe had already switched from one state to another before humans.

Now they claim because humans observe the universe for the first time this causes a change of state by that alone, not the measurement apparatus itself. Cosmic rays already produce high energy events. The electronic apparatus used to observe dark matter is all composed of molecules acting at normal energy levels.

X-ray observations can’t do what they say. “Five years ago, a team at the University of Alabama in Huntsville lead by Prof Richard Lieu reported finding large amounts of extra “soft” (relatively low-energy) x-rays coming from the vast space in the middle of galaxy clusters. Although the atoms that emitted them were thought to be spread thinly through space (less than one atom per cubit metre), they would have filled billions of billions of cubic light years.”

The observation used normal electronics to measure x-rays. We create x-rays on earth at x-ray machines. X-rays are part of atomic and molecular physics and are created and absorbed throughout the galaxy.

The particular x-rays here were created in a supernova far away. All humans did was collect the x-rays here and look at their coherence properties to understand the meaning relative to a supernova. The scientists are, in effect, claiming that this activity by humans is changing the quantum state of the universe with regard to a deep parameter.

However, the information about the super nova already exists in the coherence properties of the x-rays as they spread across the cosmos, its not created by the measurement. All the other x-rays from the event not looked at still have the same coherence properties. Thus the universe has already registered the state of the information from the supernova long before humans figure it out using normal electronic detectors operating at normal energy levels of atoms and molecules.

http://www.rawstory.com/comments/41099.html

read more | digg story

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The original paper:

http://arxiv.org/abs/0711.1821

Peter Woit implies that the Telegraph does not interpret the paper correctly.

http://www.math.columbia.edu/~woit/wordpress/?p=621

The above analysis is based on the Telegraph article, i.e. whatever Dent Krauss wrote, the Telegraph article contains a fallacy which is refuted above. Whether Dent Krauss expound that fallacy or not in their paper is a different issue.

Woit also has a column on the death of Sidney Coleman, a well-known math physics quantum field theorist at Harvard.

http://www.math.columbia.edu/~woit/wordpress/?p=620

I had heard the story that when Steven Weinberg lectured on quantum field theory at Harvard, Coleman sat in the class and asked him questions. He also was famous for smoking cigarettes. He died at age 70.

http://images.google.com/images?svnum=100&um=1&hl=en&client=firefox-a&channel=s&rls=org.mozilla%3Aen-US%3Aofficial&q=Sidney+Coleman&btnG=Search+Images

There was a cartoon of Coleman smoking a cigarette, saying “Its as easy” relative to a problem in math/physics. This doesn’t seem to be on the internet.

http://www.physics.harvard.edu/QFT/sidneyfest.htm

http://en.wikipedia.org/wiki/Sidney_Coleman

http://www.chicagotribune.com/news/local/chi-hed_coleman_20nov20,0,7943823.story

==A comment at Raw Story

http://www.rawstory.com/comments/41099.html 

November 23rd, 2007 at 17:39:54 From: TonyRage
 
Fallaci Admirer. I think you missed the anaology to Schroedinger’s Cat. The scientists are saying that by ackowleding the existing of dark matter, and the effect is has on the expansion of the universe (which can apparently expand only so far before… implosion?), we have created the possibility of increasing the speed at which the universe is heading towards it’s end. Basically, we looked in the box, and saw the dead cat. Before that, the universe existed in two states simultaneously. The good news is that the difference between time at which the two universes will end, while possibly huge, is stil irrelavant because mankind will not be along to experience it. Something will smash us from space long before that happens.

The Cat issue relates to say a measurement on say spin of an electron that can be up or down.  The photons in this case have spread out all over the universe.  The coherence properties used to make the inference are already in the x-rays at space like separations.  Thus its long past the point at which reduction has happened when the light gets here.

There are plenty of x-rays from the nova not observed by us, which have the same coherence properties.  We therefore didn’t change the state of the universe, it had already registered the needed coherence properties of the light long before the measurement was made.

The paper by Einstein Podolsky and Rosen can be referenced on this and Wiki or others should have articles on EPR.

http://en.wikipedia.org/wiki/EPR_paradox

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