Sunday, February 12, 2012

Reading: A Universe from Nothing by Lawrence Krauss

On  January 14, 2012, I attended a talk by Lawrence Krauss hosted by the National Capitol Area Skeptics.  Dr. Krauss was promoting his new book, A Universe From Nothing.

While NCAS did not record this talk for posting on their YouTube channel, various versions of it are available online.  A discussion of the book with Dr. Krauss is also available on the Point Of Inquiry Podcast.

The major point of the book is that modern physics has demonstrated that even what we think of as 'nothing', even empty space, is rippling with activity, virtual particle pairs popping in and out of existence.  We have detected the effects of this process in laboratory experiments, and it provides a mechanism whereby a universe can form 'from nothing'.

Here I'll cover a few high-points of the book which are relevant to the topics of this blog.

In chapter 1, Krauss discusses Lemaitre's original proposal of an expanding universe (1927-1930) which were solutions of Einstein's field equations of General Relativity.  He also talks about how in 1951 Pope Pius XII  tried to use Lemaitre's work as evidence that scientists had proved the biblical account of Genesis (pg 5).  Lemaitre, who had trained for the priesthood, opposed this effort by the Pope, recognizing that scientific theories are subjected to continual testing and that the expanding universe could be overturned by evidence that would come later.  It should be noted that many Electric Universe supporters use Lemaitre's religious training as evidence that the Big Bang is inherently religious - but that's like arguing that Kepler's Laws are invalid as science since Kepler (Wikipedia) was a practicing astrologer.

Krauss also provided a nice demonstration of how ANY system that expands where the distance between particles grows at a rate proportional to that distance (also called homologous expansion) will have any location appear to be the 'center' of the expansion (pg 11-14).  Various versions of this are around the web and I'll have a version for a future post, linking it to claims of the Biblical Geocentrists that galaxy surveys show that we are at the 'center' of the Universe.

The next few chapters goes into detail about the historical development of our cosmological knowledge and its connection to the sub-atomic world.  Krauss covers the discovery of gravitational lensing to antiparticles and their connection to how we now understand that even space we would consider empty is bubbling with activity - where particles and anti-particles pop in-and-out of existence over incredibly short amounts of time (Wikipedia: vacuum energy).  I have also described some of these connections in "The Cosmos In Your Pocket" and other posts in this blog.

One nice thing about a book by someone like Krauss, who is actually connected with the cosmology and particle physics community as a professional, is that it provides some insights into some of the 'professional' challenges created by the participants.  In the 1990s, cosmological problems inspired some cosmologists to re-examine Einstein's cosmological constant (one of my professors in grad school actually had this as an exercise for the cosmology class they were teaching at that time).  The cosmological constant implied that even the vacuum had energy, something which physicists understood from quantum mechanics, but cosmologists opposed on more philosophical grounds.  Krauss relates how Saul Perlmutter claimed that he would prove space doesn't have energy (pg 80).  Perlmutter's group and another group both set out to prove that Einstein's cosmological term was zero, and wound up demonstrating the exact opposite.  The groups recently won the Nobel Prize for this effort (Nobel site).

Chapter six explores one of the energy problems in cosmology, pointing out how if we compute the Newtonian energy of all the galaxies, the energy of their motion combined with the potential energy of the cosmological gravitational field, the total energy adds up to precisely zero.  This also appears to be a condition for the universe to be flat on a cosmological scale (pg 103).  Krauss implies that these two conditions may be physically equivalent, but I've had discussions with some cosmologists who have heard this equivalence expressed, but are not sure if it is mathematically rigorous.

By Chapter seven, Krauss is examining the evolution of the Universe far into the future, when galaxies will have redshifted to undetectability.  Astronomers in that time will have limited observational evidence for determining the expansion nature of the universe and might reach some incorrect conclusions about the nature of the cosmos.  Krauss points out that these incorrect conclusions, while based on the limited evidence available, are not the same as the demonstrably false picture advocated by young-earth creationists (pg 118).

In Chapter 10, Krauss talks about the problem with our definition of energy on cosmological scales (pg 166).  I've had issues with some cosmologists who word this poorly, claiming that the cosmological expansion violates conservation of energy.  These types of statements are picked up by various crank science supporters as evidence against mainstream cosmological models (and always in favor of their cosmological model).  In reality, the issue is far more subtle.  General relativity does indeed define conserved quantities, and one of them has the mathematical form of energy when we define it on small scales (such as galaxies, etc.).  However this mathematical form does not map well to cosmological scales.  I've had some discussions/arguments with cosmologists about the best analogy for this, but we've yet to find one.

Theological Implications
Throughout the book, Krauss makes the point that these physical laws eliminate the need for a God to be the creator of the universe.  In actual fact, I would say it only eliminates the need for an interventionalist God that actively intervenes in physical laws.  It does not rule out a non-intervening God, where the true spiritual test is the ability of intelligent beings to deal with the physical limitations in the real universe as a test of character (what I like to call the God of the Kobayashi Maru Scenario, wikipedia, Memory Alpha).  Some of this theology is described in Martin Gardner's “The Why's of a Philosophical Scrivener”, pp 263-264.

While written for a very general audience interested in a quick review of modern cosmology, and how we got there, I found the book an enjoyable read.

At the book signing, I asked Krauss about a possible invitation from Geocentrists for some future conference they were planning.  His response was that he didn't think he had received such an invite, but that the Geocentrists would have to make it *really* worth his while to participate in one of their conferences.


john said...

"even the vacuum had energy"

...and the vacuum came from...?

W.T."Tom" Bridgman said...

To John,

Considering the vacuum is supposed to be 'nothing', it's not clear if the question makes any sense, like "What's north of the north pole."

BenYachov said...

>In actual fact, I would say it only eliminates the need for an interventionalist God that actively intervenes in physical laws.

Actually Classic Theists laugh at it too.

W.T."Tom" Bridgman said...

To BenYachov,

I had to look up exactly what is meant by Classical Theism, and after reading your link, this looks more like playing games with what we mean by "nothing" and it's relation to reality (whatever THAT means).

But I can say that we have *experimental* evidence for the quantum vacuum.