Friday, 23 November 2012

A universe from nothing

Dark energy
In 2009 Richard Dawkins introduced a talk by Lawrence Krauss by eulogizing about his work as follows: “[T]he study of origins, origins of all kinds, right across the board from the origin of the Universe to the origin of Life, to the origin of everything that you can think of [ - w]hat an amazingly exciting initiative.” Krauss himself - whose talk is entitled “A Universe From Nothing” - then goes on to extoll the virtues of wonder by saying that “scientists love mysteries. They love not knowing. That's a key part of science. The excitement of learning about the Universe.” What a great way to start a talk: origins and wonder!

The only thing left for me to do to enjoy the rest of Krauss' lecture about cosmology is to filter out the recurring jabs at “sterile” religion, “where the excitement is apparently knowing everything although clearly knowing nothing” and many more throughout the talk. In fact, Krauss’ and Dawkins’ view of religion reminds me very much of the view that young-earth creationists have of science - both equally ignorant of the other. Leaving those aside (engaging with them would be fruitless), this is what I understood as being Krauss’ argument for the Universe having come into being from nothing:

After establishing that the universe is expanding (with reference to Edwin Hubble’s discovery of it in the 1920s, who observed that all other galaxies were moving away from us and were doing so faster, the further away they were1), Krauss presents three alternatives for how that expansion may be occurring: "[A] closed Universe would expand and stop and then recollapse in a Big Crunch, the reverse of the Big Bang. An open Universe would expand forever and a flat Universe will expand and slow down and never quite stop." The following illustration shows the open and closed cases - the flat one being similar to the open one, but having a limit (bound) to its (still infinite) expansion as opposed to being unbounded.

Big crunch open and flat universe

In the process of determining which of the three cases of expansion our Universe is undergoing, the challenge of measuring the mass of galaxies (to infer from them the curvature of their light-bending effects and therefore the curvature of the universe) and the whole universe arises and attempts to do so show that “most of the mass in [a] system of clusters of galaxies is not where the galaxies are. It's between the galaxies. It is where nothing is shining.” This in turn leads to the realization that “dark matter is a new type of elementary particle,” which further complicates the quest for measuring the mass and energy of the universe.

The consequences of the universe being flat (i.e., expanding infinitely but asymptotically towards a limit) are then spelled out:
“It turns out that in a flat Universe, the total energy of the Universe is precisely zero. Because gravity can have a negative energy. So the negative energy of gravity balances out the positive energy of matter. What's so beautiful about a Universe with total energy zero? Well, only such a Universe can begin from nothing. And that is remarkable, because the laws of physics2 allow Universes to begin from nothing! You don't need a deity.3 You have nothing. Zero total energy and quantum fluctuations can produce a Universe.”

This nothing is further illustrated by results obtained recently about the mass of protons, where:
“it turns out most of the mass of the proton comes not from the quarks within a proton, but from the empty space between the quarks. These fields popping in and out of existence produce about 90% of the mass of a proton, and since protons and neutrons are the dominant stuff in your body, the empty space is responsible for 90% of your mass. So this empty space is vital to science and these calculations are vital to understanding not just protons, but electrons and atoms and produce the best comparisons.”

In other words, the nothing from which a universe can come into being is a “boiling bubbling brew of virtual particles that are popping in and out of existence” “because of the laws of quantum mechanics and special relativity.” This nothing is an “empty space” that is empty insofar as matter and gravity cancel out each other’s energy and insofar as quantum mechanics deals in fields that may or may not yield particles.

As far as this being what I understood, I actually find it quite beautiful - and Krauss would agree by saying that “the only mathematically beautiful Universe” is a flat one, like ours. There is a symmetry between positive and negative energy, light and dark matter, there is infinite expansion that is at the same time bounded, there is a constant dynamic of being potentially versus actually and there is a tremendous amount of beautiful science that has lead to this view of the universe. We have Lemaître’s and Hubble’s insights into the universe’s expansion, we have the astonishing work on measuring the universe’s curvature by means of looking at it's background radiation, we have ways of measuring the mass of distant galaxies and their distances from us and so much more. From this point of view, I do recommend Krauss’ talk wholeheartedly.

Sadly, there is another side to it, which is its being peppered with jabs at religion and a profound ignorance of what many religious people believe. The underlying view of religious faith that informs the criticisms leveled against it here, and in many other atheist forums, seems to have people like Young-Earth creationists, Pentecostal snake-handlers and members of groups like the Westboro Baptist Church as their model. This is akin to me taking someone like Dr. Josef Mengele as the archetype of a scientist and projecting prejudices from him to all scientists. I have about as much in common with the lunacy of the above mentioned “religious” groups as with the barbarity of the above mentioned “scientist.”

Let me be a bit more specific though about why the religion-related claims of Krauss don’t stick, as it can otherwise seem like this is just a lot of hand-waving. First, let’s look at the cosmology (and cosmogeny) presented by Krauss, which postulates a coming-into-being of the universe from nothing. If anything, this scientific insight is fully consistent with the Christian account of creation, where God creates the world from nothing - hence the emblematic Latin phrase: “ex nihilo.” The Christian view of how the world came into being is not one of a God having inhabited space-time and then decided to turn parts of himself into planets, vegetation, animals, humans. Instead, the Catechism here affirms that “God gave a beginning to all that exists outside of himself” (§290), where (in some sense) there was nothing before: “All things came to be through him, and without him nothing came to be” (John 1:3). The Nicene Creed even speaks about God as the creator of “all things visible and invisible,” which can comfortably be applied to dark matter or the negative energy of gravity.

In fact, the Catechism (§296) is insistent on there having been nothing before the Universe started:
“We believe that God needs no pre-existent thing or any help in order to create, nor is creation any sort of necessary emanation from the divine substance. God creates freely “out of nothing”: “If God had drawn the world from pre-existent matter, what would be so extraordinary in that? A human artisan makes from a given material whatever he wants, while God shows his power by starting from nothing to make all he wants.” (St. Theophilus of Antioch, Ad Autolycum II)”

So, if anything, the model of a flat universe and of the nothingness that is at its origin is in perfect accord with what the Church has come to believe through revelation and the guidance of the Holy Spirit over the centuries (and as early as in the 2nd century in the writings of St. Theophilus!). There simply is no conflict here - listening to the science Krauss talks about just makes me delight in how much better we understand how it was that the universe came into being from nothing. I can therefore happily conclude, again with the Catechism (§283):
“The question about the origins of the world and of man has been the object of many scientific studies which have splendidly enriched our knowledge of the age and dimensions of the cosmos, the development of life-forms and the appearance of man. These discoveries invite us to even greater admiration for the greatness of the Creator, prompting us to give him thanks for all his works and for the understanding and wisdom he gives to scholars and researchers.”

Catholics (and adherents of many other Christian denominations and other religions) are in no way at odds with the advances of science, since - in addition to the benefits that it enables for the good of all, it sheds light on how the universe works and how it has worked since its beginning. Those who believe in God having created the universe (from nothing!), being the source of its laws and continuously sustaining its being can enjoy the advances of science as much as those who don’t hold those beliefs, and I wish that neither side would try to ridicule the other or force them to change their views!

1 Incidentally, it was Georges Lemaître - the Belgian priest and physicist, who made this realization based on Hubble’s data a couple of years before Hubble did.
2 It always baffles me how many atheists hail the latest developments of science as proofs of the non-existence of God, while quite happily relying on pre-existing “laws of physics.”
3 I. e., a “god of gaps” deity ...