Tag Archives: Quantum Gravity

Neil Shenvi: can quantum fluctuations make something appear out of nothing?

Christianity and the progress of science
Christianity and the progress of science

New article from Dr. Neil Shenvi.

Author bio:

As it says on the main page, my name is Neil Shenvi; I am currently a research scientist with Prof. Weitao Yang at Duke University in the Department of Chemistry. I was born in Santa Cruz, California, but grew up in Wilmington, Delaware. I attended Princeton University as an undergraduate where I worked on high-dimensional function approximation with Professor Herschel Rabitz. I became a Christian in Berkeley, CA where I did my PhD in Theoretical Chemistry at UC – Berkeley with Professor Birgitta Whaley. The subject of my PhD dissertation was quantum computation, including topics in quantum random walks, cavity quantum electrodynamics, spin physics, and the N-representability problem. From 2005-2010, I worked as a postdoctoral associate with Prof. John Tully at Yale where I did research into nonadiabatic dynamics, electron transfer, and surface science.

Here is the introduction to the new article:

Many modern Christian apologists such as William Lane Craig or John Lennox present the origin of the universe in the finite past as evidence that God exists. In response, many modern atheists have sought to undermine such arguments by claiming that the existence of God is not required to account for the universe’s origin, usually by appealing to various scientific models of the universe’s origin. Because my expertise is in theoretical chemistry and quantum physics rather than in cosmology, I don’t have the background to evaluate the scientific plausibility of these cosmological models as alternatives to traditional Big Bang cosmology (nor -I expect- do most atheists!) However, I am qualified to address a claim that I frequently see advanced on the internet as a purportedly knock-down response to the claims of theists: the idea that ‘quantum fluctuations’ in some vague and unspecified sense explain the universe’s origin. In this essay, I’ll briefly explain what quantum fluctuations are and why they should not be invoked to explain the origin of the material universe out of nothing.

My argument is straighforward:

  • P1. If a ‘quantum fluctuation’ occurs, then it can be described by a wavefunction
  • P2. Wavefunctions describe ‘something’, not ‘nothing’
  • C. Therefore, if a ‘quantum fluctuation’ occurs, then it is ‘something’ not ‘nothing’

If this argument is correct, then atheists should not argue that ‘quantum fluctuations’ show that ‘something’ can come from ‘nothing’ because quantum fluctuations assume the existence of ‘something’ not ‘nothing’.

Quantum mechanics is a pretty mysterious area for me, but it’s Neil’s specialty.

Here is his argument in brief:

  • P1. If a ‘quantum fluctuation’ occurs, then it can be described by a wavefunction
  • P2. Wavefunctions describe ‘something’, not ‘nothing’
  • C. Therefore, if a ‘quantum fluctuation’ occurs, then it is ‘something’ not ‘nothing’

He writes:

Regardless of how we view the ontological status of wavefunctions, there is little question that they somehow describe something that actually exists. To say it another way, it seems extremely strange to insist that this particular wavefunction describes something which does not exist! When we make use of wavefunctions in experimental physics, they never refer to ‘nothing’; they always refer to ‘something.’ Even the ‘quantum vacuum’, which people sometimes confuse with ‘nothing’, actually refers to an entity with real properties, the most obvious of which is a zero-point energy that has measurable effects on experiments. To posit a wavefunction which describes ‘nothing’ is therefore to posit a wavefunction which is unlike any wavefunction we’ve ever encountered.

So, you can’t get something from nothing by appealing to quantum mechanics after all.

Now, I’ll just add to his article based on something he mentioned – the quantum vacuum. A further requirement of cosmologies that have our universe come into being as a result of a quantum fluctuation is that there exists a quantum vacuum outside our universe that provides the environment for the quantum fluctuation that creates the universe. And of course, this quantum vacuum is not nothing. Alexander Vilenkin explains:

And of course, we have no direct evidence of that quantum vacuum that must exist outside of our universe. If it exists, then it’s outside our universe – outside of our ability to investigate it. The only argument for its existence is that naturalists need it to be there in order to undermine the cosmological argument.

Here’s William Lane Craig talking about quantum vacuum models of the universe:

William Lane Craig has an article that he published a while back which lists problems with naturalistic cosmologies.

I hope that’s enough for everyone to respond to the speculation that QM can cause a beginning of the universe out of nothing.

Previously, I’ve featured Neil’s defense of objective morality, his lecture on science and religion, his lecture on the resurrection of Jesus, and his introduction to quantum mechanics, all of which were really popular. These are easy to understand, but substantive, too.

The kalam cosmological argument defended in a peer-reviewed science journal

Here’s the peer-reviewed article. It appears in a scientific journal focused on astrophysics.

Here’s the abstract:

Both cosmology and philosophy trace their roots to the wonder felt by the ancient Greeks as they contemplated the universe. The ultimate question remains why the universe exists rather than nothing. This question led Leibniz to postulate the existence of a metaphysically necessary being, which he identified as God. Leibniz’s critics, however, disputed this identification, claiming that the space-time universe itself may be the metaphysically necessary being. The discovery during this century that the universe began to exist, however, calls into question the universe’s status as metaphysically necessary, since any necessary being must be eternal in its existence. Although various cosmogonic models claiming to avert the beginning of the universe predicted by the standard model have been and continue to be offered, no model involving an eternal universe has proved as plausible as the standard model. Unless we are to assert that the universe simply sprang into being uncaused out of nothing, we are thus led to Leibniz’s conclusion. Several objections to inferring a supernatural cause of the origin of the universe are considered and found to be unsound.

The whole text of the article is posted online here.

Here’s an excerpt in which the author, Dr. William Lane Craig, explains the Big Bang cosmology:

The monumental significance of the Friedman-Lemaitre model lay in its historization of the universe. As one commentator has remarked, up to this time the idea of the expansion of the universe “was absolutely beyond comprehension. Throughout all of human history the universe was regarded as fixed and immutable and the idea that it might actually be changing was inconceivable.”{8} But if the Friedman-Lemaitre model were correct, the universe could no longer be adequately treated as a static entity existing, in effect, timelessly. Rather the universe has a history, and time will not be matter of indifference for our investigation of the cosmos. In 1929 Edwin Hubble’s measurements of the red-shift in the optical spectra of light from distant galaxies,{9} which was taken to indicate a universal recessional motion of the light sources in the line of sight, provided a dramatic verification of the Friedman-Lemaitre model. Incredibly, what Hubble had discovered was the isotropic expansion of the universe predicted by Friedman and Lemaitre. It marked a veritable turning point in the history of science. “Of all the great predictions that science has ever made over the centuries,” exclaims John Wheeler, “was there ever one greater than this, to predict, and predict correctly, and predict against all expectation a phenomenon so fantastic as the expansion of the universe?”{10}

As a GTR-based theory, the Friedman-Lemaitre model does not describe the expansion of the material content of the universe into a pre-existing, empty, Newtonian space, but rather the expansion of space itself. This has the astonishing implication that as one reverses the expansion and extrapolates back in time, space-time curvature becomes progressively greater until one finally arrives at a singular state at which space-time curvature becomes infinite. This state therefore constitutes an edge or boundary to space-time itself. P. C. W. Davies comments,

An initial cosmological singularity . . . forms a past temporal extremity to the universe. We cannot continue physical reasoning, or even the concept of spacetime, through such an extremity. . . . On this view the big bang represents the creation event; the creation not only of all the matter and energy in the universe, but also of spacetime itself.{11}

The popular expression “Big Bang,” originally a derisive term coined by Fred Hoyle to characterize the beginning of the universe predicted by the Friedman-Lemaitre model, is thus potentially misleading, since the expansion cannot be visualized from the outside (there being no “outside,” just as there is no “before” with respect to the Big Bang).{12}

The standard Big Bang model thus describes a universe which is not eternal in the past, but which came into being a finite time ago. Moreover,–and this deserves underscoring–the origin it posits is an absolute origin ex nihilo. For not only all matter and energy, but space and time themselves come into being at the initial cosmological singularity. As Barrow and Tipler emphasize, “At this singularity, space and time came into existence; literally nothing existed before the singularity, so, if the Universe originated at such a singularity, we would truly have a creation ex nihilo.“{13}

[…]On such a model the universe originates ex nihilo in the sense that at the initial singularity it is true that There is no earlier space-time point or it is false that Something existed prior to the singularity.

Every theist should be able to understand and defend this argument. It is a scientific refutation of materialism, and it is supported by six lines of scientific evidence – all of which emerged as science has progressed.

Scientific evidence:

  1. Einstein’s theory of general relativity (GTR)
  2. the red-shifting of light from distant galaxies implies an expanding universe
  3. the cosmic background radiation (which also disproves the oscillating model of the universe)
  4. the second law of thermodynamics applied to star formation theory
  5. hydrogen-helium abundance predictions
  6. radioactive element abundance predictions

Those are the scientific discoveries that have led us to the beginning of the universe, which support’s Dr. Craig’s argument.

This is the kind of evidence I expect all Christian theists to be using when discussing the question of whether God exists. Scientific evidence. When talking to non-Christians, we first need to show that we understand science, because science is a reliable and respected way of getting knowledge about the universe. Non-Christians do not accept the Bible, but they do accept science, so we begin evangelism with science. Science (experimental, testable, repeatable science) should set limits on what anyone can believe – including non-Christians, who might otherwise not be inclined to listen to Bible verses and theology. Important: it’s not a good idea to discuss the resurrection of Jesus with a person who does not accept the scientific evidence for a Creator of the universe.

The Big Bang is not compatible with atheism

According to the Secular Humanist Manifesto, atheism is committed to an eternally existing universe, (See the first item: “Religious humanists regard the universe as self-existing and not created.”). If something non-material brought all existing matter into being, that would be a supernatural cause, and atheists deny that anything supernatural exists. The standard Big Bang theory requires that all the matter in the universe come into being out of nothing. This falsifies eternal models of the universe, which are required by the atheistic worldview.

Alexander Vilenkin: “All the evidence we have says that the universe had a beginning”

I’ve decided to explain why physicists believe that there was a creation event in this post. That is to say, I’ve decided to let famous cosmologist Alexander Vilenkin do it.

From Uncommon Descent.

Excerpt:

Did the cosmos have a beginning? The Big Bang theory seems to suggest it did, but in recent decades, cosmologists have concocted elaborate theories – for example, an eternally inflating universe or a cyclic universe – which claim to avoid the need for a beginning of the cosmos. Now it appears that the universe really had a beginning after all, even if it wasn’t necessarily the Big Bang.

At a meeting of scientists – titled “State of the Universe” – convened last week at Cambridge University to honor Stephen Hawking’s 70th birthday, cosmologist Alexander Vilenkin of Tufts University in Boston presented evidence that the universe is not eternal after all, leaving scientists at a loss to explain how the cosmos got started without a supernatural creator. The meeting was reported in New Scientist magazine (Why physicists can’t avoid a creation event, 11 January 2012).

[…]In his presentation, Professor Vilenkin discussed three theories which claim to avoid the need for a beginning of the cosmos.

The three theories are chaotic inflationary model, the oscillating model and quantum gravity model. Regular readers will know that those have all been addressed in William Lane Craig’s peer-reviewed paper that evaluates alternatives to the standard Big Bang cosmology.

But let’s see what Vilenkin said.

More:

One popular theory is eternal inflation. Most readers will be familiar with the theory of inflation, which says that the universe increased in volume by a factor of at least 10^78 in its very early stages (from 10^−36 seconds after the Big Bang to sometime between 10^−33 and 10^−32 seconds), before settling into the slower rate of expansion that we see today. The theory of eternal inflation goes further, and holds that the universe is constantly giving birth to smaller “bubble” universes within an ever-expanding multiverse. Each bubble universe undergoes its own initial period of inflation. In some versions of the theory, the bubbles go both backwards and forwards in time, allowing the possibility of an infinite past. Trouble is, the value of one particular cosmic parameter rules out that possibility:

But in 2003, a team including Vilenkin and Guth considered what eternal inflation would mean for the Hubble constant, which describes mathematically the expansion of the universe. They found that the equations didn’t work (Physical Review Letters, DOI: 10.1103/physrevlett.90.151301). “You can’t construct a space-time with this property,” says Vilenkin. It turns out that the constant has a lower limit that prevents inflation in both time directions. “It can’t possibly be eternal in the past,” says Vilenkin. “There must be some kind of boundary.”

A second option explored by Vilenkin was that of a cyclic universe, where the universe goes through an infinite series of big bangs and crunches, with no specific beginning. It was even claimed that a cyclic universe could explain the low observed value of the cosmological constant. But as Vilenkin found, there’s a problem if you look at the disorder in the universe:

Disorder increases with time. So following each cycle, the universe must get more and more disordered. But if there has already been an infinite number of cycles, the universe we inhabit now should be in a state of maximum disorder. Such a universe would be uniformly lukewarm and featureless, and definitely lacking such complicated beings as stars, planets and physicists – nothing like the one we see around us.

One way around that is to propose that the universe just gets bigger with every cycle. Then the amount of disorder per volume doesn’t increase, so needn’t reach the maximum. But Vilenkin found that this scenario falls prey to the same mathematical argument as eternal inflation: if your universe keeps getting bigger, it must have started somewhere.

However, Vilenkin’s options were not exhausted yet. There was another possibility: that the universe had sprung from an eternal cosmic egg:

Vilenkin’s final strike is an attack on a third, lesser-known proposal that the cosmos existed eternally in a static state called the cosmic egg. This finally “cracked” to create the big bang, leading to the expanding universe we see today. Late last year Vilenkin and graduate student Audrey Mithani showed that the egg could not have existed forever after all, as quantum instabilities would force it to collapse after a finite amount of time (arxiv.org/abs/1110.4096). If it cracked instead, leading to the big bang, then this must have happened before it collapsed – and therefore also after a finite amount of time.

“This is also not a good candidate for a beginningless universe,” Vilenkin concludes.

So at the end of the day, what is Vilenkin’s verdict?

“All the evidence we have says that the universe had a beginning.”

This is consistent with the Borde-Guth-Vilenkin Theorem, which I blogged about before, and which William Lane Craig leveraged to his advantage in his debate with Peter Millican.

The Borde-Guth-Vilenkin (BGV) proof shows that every universe that expands must have a space-time boundary in the past. That means that no expanding universe, no matter what the model, can be eternal into the past. No one denies the expansion of space in our universe, and so we are left with a cosmic beginning. Even speculative alternative cosmologies do not escape the need for a beginning.

Conclusion

If the universe came into being out of nothing, which seems to be the case from science, then the universe has a cause. Things do not pop into being, uncaused, out of nothing. The cause of the universe must be transcendent and supernatural. It must be uncaused, because there cannot be an infinite regress of causes. It must be eternal, because it created time. It must be non-physical, because it created space. There are only two possibilities for such a cause. It could be an abstract object or an agent. Abstract objects cannot cause effects. Therefore, the cause is an agent.

Now, let’s have a discussion about this science in our churches, and see if we can’t train Christians to engage with non-Christians about the evidence so that everyone accepts what science tells us about the origin of the universe.

William Lane Craig lectures on naturalism at the University of St. Andrews

Lets take a closer look at a puzzle
Lets take a closer look at a puzzle

Note: even if you have heard Dr. Craig’s arguments before, I recommend jumping to the 48 minutes of Q&A time, which starts 72 minutes in.

About Dr. William Lane Craig:

William Lane Craig (born August 23, 1949) is an American analytic philosopher, philosophical theologian, and Christian apologist. He is known for his work on the philosophy of time and the philosophy of religion, specifically the existence of God and the defense of Christian theism. He has authored or edited over 30 books including The Kalam Cosmological Argument (1979), Theism, Atheism and Big Bang Cosmology(co-authored with Quentin Smith, 1993), Time and Eternity: Exploring God’s Relationship to Time (2001), and Einstein, Relativity and Absolute Simultaneity (co-edited with Quentin Smith, 2007).

Craig received a Bachelor of Arts degree in communications from Wheaton College, Illinois, in 1971 and two summa cum laudemaster’s degrees from Trinity Evangelical Divinity School in Deerfield, Illinois, in 1975, in philosophy of religion and ecclesiastical history. He earned a Ph.D. in philosophy under John Hick at the University of Birmingham, England in 1977 and a Th.D. underWolfhart Pannenberg at the University of Munich, Germany in 1984.

Dr. Craig was in Scotland to lecture at a physics conference, but a local church organized this public lecture at the University of St. Andrews.

Here is the full lecture with Q&A: (2 hours)

Summary:

  • Naturalism defined: the physical world (matter, space and time) is all that exists
  • Dr. Craig will present 7 reasons why naturalism is false
  • 1) the contingency argument
  • 2) the kalam cosmological argument
  • 3) the fine-tuning of the universe for intelligent life
  • 4) the moral argument
  • 5) the ontological argument
  • 6) the resurrection of Jesus
  • 7) religious experience

Dr. Craig does mention an 8th argument early in the Q&A – the argument from the non-physicality of mental states (substance dualism), which is an argument that I find convincing, because a materialist conception of mind is not compatible with rationality, consciousness and moral agency.

Questions and Answers

He gets a couple of questions on the moral argument early on – one of them tries to put forward an evolutionary explanation for “moral” behaviors. There’s another question the definition of naturalism. There is a bonehead question about the non-existence of Jesus based on a Youtube movie he saw – which Craig responds to with agnostic historian Bart Ehrman’s book on that topic. There’s a question about God as the ground for morality – does morality come from his will or nature.

Then there is a question about the multiverse, which came up at the physics conference Dr. Craig attended the day before. There is a good question about the Big Bang theory and the initial singularity at time t=0. Another good question about transfinite arithmetic, cardinality and set theory. One questioner asks about the resurrection argument. The questioner asks if we can use the origin of the disciples belief as an argument when other religions have people who are willing to die for their claims. One of the questioners asks about whether the laws of nature break down at 10^-43 after the beginning of the universe. There is a question about the religious experience argument, and Craig has the opportunity to give his testimony.

I thought that the questions from the Scottish students and faculty were a lot more thoughtful and respectful than at American colleges and universities. Highly recommended.

Alexander Vilenkin: “All the evidence we have says that the universe had a beginning”

I’ve decided to explain why physicists believe that there was a creation event in this post. That is to say, I’ve decided to let famous cosmologist Alexander Vilenkin do it.

From Uncommon Descent.

Excerpt:

Did the cosmos have a beginning? The Big Bang theory seems to suggest it did, but in recent decades, cosmologists have concocted elaborate theories – for example, an eternally inflating universe or a cyclic universe – which claim to avoid the need for a beginning of the cosmos. Now it appears that the universe really had a beginning after all, even if it wasn’t necessarily the Big Bang.

At a meeting of scientists – titled “State of the Universe” – convened last week at Cambridge University to honor Stephen Hawking’s 70th birthday, cosmologist Alexander Vilenkin of Tufts University in Boston presented evidence that the universe is not eternal after all, leaving scientists at a loss to explain how the cosmos got started without a supernatural creator. The meeting was reported in New Scientist magazine (Why physicists can’t avoid a creation event, 11 January 2012).

[…]In his presentation, Professor Vilenkin discussed three theories which claim to avoid the need for a beginning of the cosmos.

The three theories are chaotic inflationary model, the oscillating model and quantum gravity model. Regular readers will know that those have all been addressed in William Lane Craig’s peer-reviewed paper that evaluates alternatives to the standard Big Bang cosmology.

But let’s see what Vilenkin said.

More:

One popular theory is eternal inflation. Most readers will be familiar with the theory of inflation, which says that the universe increased in volume by a factor of at least 10^78 in its very early stages (from 10^−36 seconds after the Big Bang to sometime between 10^−33 and 10^−32 seconds), before settling into the slower rate of expansion that we see today. The theory of eternal inflation goes further, and holds that the universe is constantly giving birth to smaller “bubble” universes within an ever-expanding multiverse. Each bubble universe undergoes its own initial period of inflation. In some versions of the theory, the bubbles go both backwards and forwards in time, allowing the possibility of an infinite past. Trouble is, the value of one particular cosmic parameter rules out that possibility:

But in 2003, a team including Vilenkin and Guth considered what eternal inflation would mean for the Hubble constant, which describes mathematically the expansion of the universe. They found that the equations didn’t work (Physical Review Letters, DOI: 10.1103/physrevlett.90.151301). “You can’t construct a space-time with this property,” says Vilenkin. It turns out that the constant has a lower limit that prevents inflation in both time directions. “It can’t possibly be eternal in the past,” says Vilenkin. “There must be some kind of boundary.”

A second option explored by Vilenkin was that of a cyclic universe, where the universe goes through an infinite series of big bangs and crunches, with no specific beginning. It was even claimed that a cyclic universe could explain the low observed value of the cosmological constant. But as Vilenkin found, there’s a problem if you look at the disorder in the universe:

Disorder increases with time. So following each cycle, the universe must get more and more disordered. But if there has already been an infinite number of cycles, the universe we inhabit now should be in a state of maximum disorder. Such a universe would be uniformly lukewarm and featureless, and definitely lacking such complicated beings as stars, planets and physicists – nothing like the one we see around us.

One way around that is to propose that the universe just gets bigger with every cycle. Then the amount of disorder per volume doesn’t increase, so needn’t reach the maximum. But Vilenkin found that this scenario falls prey to the same mathematical argument as eternal inflation: if your universe keeps getting bigger, it must have started somewhere.

However, Vilenkin’s options were not exhausted yet. There was another possibility: that the universe had sprung from an eternal cosmic egg:

Vilenkin’s final strike is an attack on a third, lesser-known proposal that the cosmos existed eternally in a static state called the cosmic egg. This finally “cracked” to create the big bang, leading to the expanding universe we see today. Late last year Vilenkin and graduate student Audrey Mithani showed that the egg could not have existed forever after all, as quantum instabilities would force it to collapse after a finite amount of time (arxiv.org/abs/1110.4096). If it cracked instead, leading to the big bang, then this must have happened before it collapsed – and therefore also after a finite amount of time.

“This is also not a good candidate for a beginningless universe,” Vilenkin concludes.

So at the end of the day, what is Vilenkin’s verdict?

“All the evidence we have says that the universe had a beginning.”

This is consistent with the Borde-Guth-Vilenkin Theorem, which I blogged about before, and which William Lane Craig leveraged to his advantage in his debate with Peter Millican.

The Borde-Guth-Vilenkin (BGV) proof shows that every universe that expands must have a space-time boundary in the past. That means that no expanding universe, no matter what the model, can be eternal into the past. No one denies the expansion of space in our universe, and so we are left with a cosmic beginning. Even speculative alternative cosmologies do not escape the need for a beginning.

Conclusion

If the universe came into being out of nothing, which seems to be the case from science, then the universe has a cause. Things do not pop into being, uncaused, out of nothing. The cause of the universe must be transcendent and supernatural. It must be uncaused, because there cannot be an infinite regress of causes. It must be eternal, because it created time. It must be non-physical, because it created space. There are only two possibilities for such a cause. It could be an abstract object or an agent. Abstract objects cannot cause effects. Therefore, the cause is an agent.

Now, let’s have a discussion about this science in our churches, and see if we can’t train Christians to engage with non-Christians about the evidence so that everyone accepts what science tells us about the origin of the universe.