Fire Back: Where the Readers Respond

In which we discuss inflation, the multiverse, and fine-tuning.

I had the following exchange with a reader in the comments of a previous post:

jlafan2001: What is your take on the discovery of cosmic inflation? Isn’t inflation evidence of a multiverse and doesn’t that refute the fine-tuning argument?

SS: Inflation is a compelling idea that answers some big cosmological questions, and, personally I think it’s correct. One flavor of multiverse — the bubble universe idea — is an outgrowth of the inflationary big bang model. The problem for a multiverse based on inflation is that inflation is also consistent with non-multiverse models. There is currently no way to distinguish between them based on the evidence. There is, to my knowledge, nothing that can be confidently stated about the multiverse based on evidence, therefore it would be beyond foolishness to say that the multiverse constitutes a genuine refutation of the fine-tuning argument.

jlafan2001: Thank you for your input, Dr. Salviander. Why would scientists then use the inflation model as evidence for the multiverse if it can go either way?

A not unreasonable question. The answer is, inflation is one of the very few (ambiguous) lines of evidence atheist scientists have for the multiverse, and there is considerable philosophical motivation to support the multiverse no matter how weak the evidence.

There are two main problems in physics for the atheist scientist:

  1. The big bang. A universe with a beginning logically implies a supernatural creative force for the universe.
  2. The fine-tuning of the universe, for which there are only three explanations: a) necessity; b) chance; c) design.

Contrary to what Young Earth Creationists believe, atheist scientists have never been happy with the big bang. To understand why, all you have to do is go back to February of 1961 when striking evidence in favor of the big bang was presented at a meeting of the Royal Astronomical Society in London. That evidence would later turn out to be flawed, but at the time it inspired some notable headlines in London newspapers. The Evening Standard published an article with the headline “‘How it all began’ fits in with Bible story” (Peter Fairley, 10 February 1961), and the Evening News and Star featured an article headlined, “The Bible was right” (Evening News Science Reporter, 10 February 1961).

These headlines reflected the big bang’s astounding confirmation of the first three words of the Bible. To understand the significance, consider that for millennia prior to this, the scientific consensus was that the universe was eternal. Obviously, this was a big problem for the Bible-believers, but not for atheists, who rested assured that the universe required no explanation. That all started to change in the 1920s with solutions to Einstein’s general relativity equations showing the universe could be dynamic, as well as Hubble’s evidence that the universe is expanding. Things finally changed in a big way in the 1960s with the discovery of the cosmic microwave background, which pretty much sealed the deal for the big bang.

To their credit, the vast majority of physicists accepted the big bang theory once there was sufficient evidence, even if a lot of them didn’t like it. However, there were a few notable holdouts, like renowned astrophysicist and atheist, Geoffrey Burbidge. It’s not a stretch to suggest that his steadfast support for an eternal universe in spite of the evidence was philosophically motivated, especially considering he famously accused many of his colleagues of “rushing off to join the First Church of Christ of the Big Bang.”

The evidence for the big bang is by now so overwhelming that few physicists doubt it. That leaves atheist physicists with a big problem, which is how to offer an alternative to God as the supernatural creative force behind the universe. Thus, we have the multiverse.

Now, it’s important to point out that, contra what some skeptical Christians believe, physicists did not metaphorically pull the multiverse out of a magician’s hat. There are different types of multiverse (or “levels” as physicist Max Tegmark calls them), each with a basis in physics and mathematics that makes the idea conceptually somewhat compelling. One level of multiverse is the bubble universe model. This model says that inflation — a period of extremely rapid expansion of the universe shortly after the big bang — leads to regions of localized inflation, which form like bubbles in a cosmic sea of foam. Each of these bubbles expands at such a rate that they are all causally cut off from each other, and each effectively forms its own universe. This is one type of inflationary universe; there are others that do not lead to multiverses. However, as I pointed out to jlafan2001, there is no way I’m aware of that you can observationally distinguish between an inflationary bubble universe and an inflationary non-bubble universe.

So, how does this tie into fine-tuning?

The fine-tuning argument says this: the many observable parameters of the universe that permit human life to exist are so finely-tuned as to strongly imply the universe was designed by a personal being. Physicists have ruled out necessity as an explanation for fine-tuning; this means there is nothing in any physical theory or any extension of physical theory that requires the various physical parameters describing our universe to be the way they are. That leaves chance and design. For an atheist physicist, design is obviously out, which leaves chance as the only explanation. It turns out physicists aren’t very happy about this — they would have preferred necessity as the explanation — but, they’re philosophically stuck with chance. Since there is already a theoretical basis in physics for the multiverse, and chance is built into its framework, atheist physicists latch onto it as a means to explain away the appearance of fine-tuning. It also has the virtue of addressing point #1 above by providing an alternative to God as the creative force behind the universe.

The so-far insurmountable problem with the multiverse is that there is no way to test it. One of the features of the multiverse is that each of the universes within it is causally separated from all of the other universes, which means there is no way we an observe any of them, directly or indirectly. There’s just no way we can peek outside of our universe to see if there are any others. So, we’re left with ambiguous evidence like inflation and “shadow particles” (ugh). Until physicists find a way to get around this problem, which is unlikely, the multiverse remains nothing more than a science-flavored idea.

Has physics disproved the beginning of the universe?

I’ve been asked numerous times about a scientific paper published earlier this year purporting to show the universe has always existed:

The universe may have existed forever, according to a new model that applies quantum correction terms to complement Einstein’s theory of general relativity.

Apparently, some atheists are latching onto this to show that Genesis 1:1 is wrong, and some of you are unsure how to respond to such an argument.

The first thing I would like to point out is that atheists have been trying to get around the finite age of the universe since the 1960s, when the most compelling evidence for the big bang — the cosmic microwave background — was discovered. As many atheist scientists observed at the time, big bang cosmology is uncomfortably close to Genesis 1.

If you’re a Young Earth creationist who believes the big bang theory is an atheist conspiracy, this should be a compelling reason for you to reconsider that belief. Most atheist scientists are desperate to do away with the conventional big bang theory. They were quite happy prior to the 1960s when it seemed the universe was infinitely old — an infinitely old universe requires no explanation, and therefore requires no God. But we’re stuck with a universe with a beginning, and that’s a problem for atheists. This is why we hear so much about overblown stories about the big bang not happening or all these stories about the multiverse.

Anyway, here’s what you should keep in mind about this paper.

1. It’s just a model, not evidence.

The physicists who wrote the paper are proposing an explanation for the big bang by using a mathematical model. Models that speculate about how things might work are important in science, but you should always remember that a plausible model is not evidence. Think about it this way. I could come up with some very interesting and plausible explanations for who assassinated JFK and how they did it. While these explanations would suggest possible lines of investigation, they would not constitute evidence in a court of law.

2. The study’s conclusion follows from its assumptions.

This requires a bit of background to explain. The big bang was a sudden expansion of the universe from a hot, dense state. We can see by looking at the motions of galaxies all rushing away from each other that the universe is still expanding, and it’s cooling as it does this. If you think about running the movie of the universe in reverse, all these galaxies would appear to be rushing towards each other as we go back in time. Everything would be getting more smushed, and the universe would be getting denser and hotter, until we reached some initial very dense, very hot state; possibly even infinitely dense and hot, but nobody knows for sure what that initial state was.

In Einstein’s general relativity, the shortest distance between two points in spacetime is called a geodesic. As you go further and further back in the history of the universe, as things get smushed together and hot, all geodesics eventually converge and you get a singularity. The problem is, general relativity is unreliable on extremely small — that is to say, quantum — scales. For that reason, you can’t legitimately extrapolate all the way back to a singularity using general relativity, and that’s why physicists are working on a quantum version of gravity. To get around this problem, the physicists in this study used a quantum replacement for geodesics, called Bohmian trajectories. By their very nature, these quantum trajectories cannot converge to a singularity. So, big surprise, when you assume that you can’t get a singularity in your model, you don’t get a singularity in your model. This is why the headline of the phys.org article is so annoying: “No Big Bang? Quantum equation predicts universe has no beginning.” No, it does not predict the universe has no beginning; the assumptions in the equation require it! And, it’s wrong about this “prediction” anyway (see below).

3. Do we really care about a singularity?

So, what is a singularity, anyway? If you ask a random person, he’ll probably say it’s an infinitely small point. For physicists, it’s more complicated. It can be a hypothetical infinitely small point, but it can also represent a state of infinite density, even if space isn’t infinitely small. But this is problematic, as people like to say. It’s fine to talk about infinities in terms of mathematics, but physicists don’t like infinities in reality, because they play havoc with reason. That’s why we tend to think they don’t actually exist.

Anyway, the notion that the universe might not have begun with a singularity (of whatever kind) is not new. Physicists know general relativity becomes unreliable at the very earliest moments of the universe, because it just isn’t equipped to describe what’s going on at those scales. A common way of expressing this is to say physics breaks down at the smallest scales. So, if you ever hear a physicist talking about the big bang singularity, what he really means is the place at which physics doesn’t explain what’s going on. The best we’ve been able to say for a while now is that we don’t know exactly how the universe began. This is nothing new.

4. They’re playing fast and loose with the notions of potential and beginnings.

According to the model, the universe does not start off as a singularity, but existed eternally as a quantum potential. In an article at livescience.com, one of the authors of the paper is quoted as saying this could mean the universe is infinitely old, i.e. the universe had no beginning. Popular media writers are inferring this also means there was no big bang. However, both are wrong.

Let’s get this out of the way first: the scientific paper does not claim there was no big bang. ‘No singularity’ is not the same thing as ‘no big bang.’ It just means the big bang occurred from some state other than a singularity.

As for the universe not having a beginning, let’s use an analogy to explore potentials and beginnings, and we’ll see why this is wrong. We’ll start with an obvious statement: every person begins to exist. People argue about when the beginning of human life actually occurs, but there is little doubt that the very earliest we could possibly date it is the moment when a sperm fertilizes an egg. Let’s take you, for example. You exist. We could legitimately say that you began to exist as far back as when you were conceived in your mother’s womb. We could also legitimately say that the potential for your existence predated your conception. That potential existed in your mother and father, and, before them, in their mothers and fathers, and so on, all the way back to the earliest moments of the universe. But does that mean you’ve existed for 13.8 billion years? No reasonable person would make such a claim, for the simple reason that we intuitively understand that the potential to exist is not the same thing as existing. That’s why it’s silly and misleading to claim that a hypothetical eternal quantum potential for the universe implies the universe has always existed.

Here’s what you should take away from all of this. The big bang is still the moment in cosmic history when something significant happened — space began to rapidly expand from a mysterious and extreme initial state. It doesn’t matter that we can’t exactly specify what that state was; it still marks the beginning of the universe as we know it, and Genesis 1:1 is still true.

Accolades for renegades

My department will welcome a prestigious visitor this year: a person who received the Nobel Prize in physics in 2011. I looked back at the Nobel laureates for that year, and realized something remarkable — the physical sciences appreciate renegades.

Let’s face it, we’re all resistant to having our cherished ideas upended. But that’s what makes the physical sciences so remarkable — they are dynamic and willing to go where the data lead.

It was only a decade and a half ago that physicists believed the expansion of the universe might be slowing down. They tested that idea, and when evidence was found to the contrary, the physics community went where the data led. Physicists also had enough faith in their own laws and theories to largely accept the implication — an unknown force must be driving the accelerated expansion of the universe. A decade and half after overturning what seemed to be the obvious, the discoverers — Brian Schmidt, Adam Riess, and Saul Perlmutter — received the highest accolade possible in the physical sciences.

(It was only fifty years ago that many in the physics community believed the universe was eternal. Yet a relatively short time after the discovery by Penzias and Wilson of the “echo” of the big bang, physicists largely accepted the conclusion that the universe had a beginning in time. The big bang, once derided by some of the greatest minds in science, quickly became the prevailing paradigm for all of physics.)

In the 1980s, chemist Dan Schechtman made the startling discovery that atoms in solids could arrange themselves in a peculiar way not thought possible given the known laws of nature. He was criticized, ridiculed, and shunned by his colleagues. He persevered under these conditions, and within three decades experienced a complete reversal. He was the recipient of the greatest honor there is for a scientist when he received a Nobel Prize in chemistry in 2011. His discovery of quasicrystals, once derided by some of the greatest minds in science, led the International Union of Crystallography to change the definition of a crystal to incorporate Schechtman’s discovery.

Physics and chemistry are dynamic fields, willing to adopt new paradigms. There may be some initial resistance — which is actually necessary rigor — but they eventually go where the data and logic lead them. And the renegades are rewarded. I can think of few other fields of human study that are like that.

 

The pentaquark

This has been a big week for news of all kinds, not least of which is the arrival of the New Horizons spacecraft at Pluto after its decade-long, three-billion-mile journey through the solar system. But forget all that. The really big news — what all the cool kids are talking about — is the pentaquark.

Ordinary matter, the stuff you and I, and everything else we can see and touch, is made of particles called hadrons. The two best-known examples of hadrons are the proton and the neutron. These particles are each made up of three quarks1 and thus could be called triquarks. (As far as we can tell, quarks represent the fundamental bits of matter, which means, unlike molecules, atoms, and protons, you can’t break them up into smaller bits.) Another type of hadron is the meson, which is made up of a quark and an anti-quark2 (a biquark?).

A new class of hadron was proposed by physicist Murray Gell-Mann in 1964, and, like the Higgs boson, seemed quite clever in eluding particle physicists for many years. However, that has apparently changed with what scientists at the Large Hadron Collider are pretty sure is the pentaquark. Unlike a proton or a neutron, the pentaquark, as the name suggests, is made of five quarks2. A boring old proton is made of 2 up quarks and 1 down quark1. A neutron is made of 2 down quarks and 1 up quark1. In principle, you could have a lot of different kinds of pentaquarks, all made of different combinations of quarks. The one discovered by LHC is made of 2 up quarks, 1 down quark, 1 charm quark, and 1 anti-charm quark2,3.

What’s important about this discovery is that it: a) further validates what is called the Standard Model, the prevailing theory governing particle physics; and b) raises new questions, which is music to a physicist’s ears. There is nothing better in science than a new question. One of the new questions is, what holds a pentaquark together? The quarks in a proton are bound tightly together by gluons, however it’s not clear what holds a pentaquark together. Is it tightly bound by its gluons like a proton or is it made up of a proton and a meson that are, themselves, somehow bound together? This’ll keep particle physicists busy for a while.

—–

1. Plus zillions of gluons and zillions of quark-antiquark pairs. (Yes, gluons are called gluons, because they glue quarks together.)

2. Plus, presumably, zillions of gluons and zillions of quark-antiquark pairs.

3. The six known ‘flavors’ of quark are called: up, down, top, bottom, charm, and strange. As counterintuitive as it may seem, the top quark is the strangest quark of them all.

Fire Back: Where the Readers Respond

In which we examine a curious claim about quantum mechanics and the creation of the universe.

JH writes:

[How can Christians respond to the] claim that almost every atheist is clinging to right now, namely that quantum mechanics proves something can come from nothing?

JH is referring to the common atheist tactic of explaining how the universe could be created ex nihilo without a cause (aka a Creator) by invoking a phenomenon in quantum mechanics known as virtual particle production.

Virtual particle production refers to particles suddenly popping into existence from the vacuum of space. For those of us used to the decidedly Newtonian appearance of the world, this seems very strange, but it’s a real phenomenon in the quantum mechanical world. Atheists like to invoke it when arguing about who or what caused the universe: the claim is, these particles are uncaused and come from nothing, therefore it’s possible for things like universes to pop into existence uncaused and from nothing, therefore God is superfluous. The problem with this claim is that virtual particles are neither uncaused nor do they come from nothing. Let’s examine the latter claim first.

If you were able to look at the universe at the quantum mechanical level, you’d notice it was a very jittery place, with virtual particles fluctuating into and out of existence. In order for these virtual particles to fluctuate into existence, they must “borrow” energy from the vacuum energy, which is the background energy of space. This is because, according to Einstein’s famous equation, E = mc2, matter and energy are two sides of the same coin. If you want to make matter, you use energy (the reverse is also true, which is how nuclear fusion works). Even though we’re accustomed to thinking of a vacuum as nothing, in this case it is definitely something. The vacuum energy of space is something, so right away this tells us that virtual particles don’t come from nothing.

But there’s another problem — these particles don’t exist for very long. The Heisenberg Uncertainty Principle — which tells us that we can’t simultaneously know the precise amount of energy and the precise duration of time for an event — allows virtual particles to borrow energy from the vacuum energy provided they return that energy in a very short amount of time. Here’s the key: the more energy they borrow, the more quickly they must return it.

Let’s look at a practical example using a particle called a meson with a mass about 1/10th that of a proton. (Protons reside in the nucleus of an atom, and have a mass of about 2 x10-27 kg.) For a meson to pop into existence, it could only borrow the required energy for about 10-23 second. Written out in decimal form, that’s 0.00000000000000000000001 second. Remember, the more energy a particle borrows, the more quickly it has to return it. A conservative estimate for the number of protons in the observable universe is 1080 (which I am not going to write out in decimal form), which means that for a “virtual universe” to fluctuate into existence, it would exist for an extraordinarily short amount of time — just 10-103 second, which is far shorter than the 14 billion years we’ve measured for the age of the universe.

Now let’s examine the claim that virtual particles pop into existence uncaused. That’s just false. As theoretical physicist Matt Strassler explains on his wonderful blog, virtual particles are disturbances in space caused by the presence of other particles in that space. They’re not even really particles, which is why they’re called “virtual particles.” The upshot is, if certain conditions must exist in order for something to happen, then that something is not uncaused.

Short-short version:

  • When atheists invoke quantum mechanics to try to explain how the universe could be created from nothing naturalistically, they are abusing the notion of nothing.
  • Virtual particles borrow energy from the background energy of space, therefore they do not come from nothing.
  • For something to fluctuate into existence, the more massive it is, the briefer its lifetime. According to the Heisenberg Uncertainty Principle, the observable universe could only exist for 10-103 second, far shorter than the 14 billion years we measure.
  • Virtual particles are caused by the presence of other particles, therefore they are not uncaused.
  • There is no physical evidence of anything in the universe ever coming into existence uncaused and from nothing.

Fire Back: Where the Readers Respond

In which a Twitter exchange exposes the blind faith of an anti-theist.

Here’s a person I think we can reasonably assume is an anti-theist. Last month, he pinged me on Twitter with the following:

By “FT” he means fine-tuning. What followed was an exchange that was more coherent than the one I had with “OpenMind” (see here and here), but no less demonstrative of the main problem many non-scientist anti-theists have, which is blind faith in their beliefs and unquestioned assumptions.

Before we continue, note that the reasoning I described in my testimony doesn’t really fall under what’s called the fine-tuning argument. This argument says that the improbability of our universe having precisely the right values for the many parameters and constants that permit human life to exist — the strengths of the fundamental forces, the masses of subatomic particles, the number of physical dimensions, etc. — is so high as to strongly imply the universe was designed by a personal being. However, in my testimony, I explained that I logically inferred the existence of a rational, transcendental being (God) who created the universe based on the fact that the universe is comprehensible. Not the same thing as fine-tuning. But no matter, I was game to see how exactly the fine-tuning argument for God constituted faith over reason, so I asked.

I don’t know if Joe’s World (JW) thinks the many, many atheist scientists who’ve embraced the multiverse idea on this basis are fools or what, but I suspected he didn’t understand the implications of fine tuning, so I asked him why he made his assertion.

His response surprised me a little, because it differs from the common anti-theist argument that God is merely superfluous to the workings of the universe. JW, on the other hand, believes that order arises spontaneously only in a godless universe and that a God-created universe would be nonsensical. I pointed out to him that this is the opposite of what Christians and even most atheists believe.

There are a number of problems with his assertion, the first of which is the origin of a “clockwork” universe in which complexity just arises. He’s begging the question. The problem is underscored by his metaphorical comparison of the universe to a clock — most of us are reasonably certain that precision instruments like clocks don’t just spring into being on their own, but are rather carefully designed and deliberately constructed by conscious beings.

Another problem is that he presupposes that the God of the Bible is a capricious being who would not create a rational universe with unchangeable laws. Sure, a supernatural being could in principle create anything he wants, but that’s not what’s important here. Since JW is talking to a Christian (me), that means we’re talking specifically about the God of the Bible. It doesn’t matter what anyone personally thinks about the God of the Bible, what matters is what scripture says about God and whether that’s contradicted or corroborated by reason and evidence. When we read the Bible, we see that God is not at all a capricious being, but rather a rational being. We are told throughout the Bible that God didn’t just slap together a whimsical universe, but by wisdom created a lawful universe:

By the word of the Lord the heavens were made (Psalm 33:6)

The Lord by wisdom founded the earth;
by understanding he established the heavens;
(Proverbs 3:19)

Do you know the laws of the heavens? (Job 38:33)

In the beginning was the Word, and the Word was with God, and the Word was God. (John 1:1)

Note that the Greek word translated in John 1:1 as “word” is logos, which also means logic, intellect, and wisdom. Putting all this together, Gerald Schroeder makes the argument that Genesis 1:1, properly translated, reads as follows: “With a first cause of wisdom, God created the universe.” (See Chapter Two of Schroeder’s book, God According to God.)

The heavens declare his righteousness (Psalm 50:6)

In other words, nature reveals the character of God. We see that nature operates according to knowable laws; God is not capricious.

As for corroboration, there’s a reason the Bible begins with Genesis. It first of all establishes the sovereignty of God as the creator of all things, but it also gives us a testable account of God’s creation. (See here for a discussion of Genesis 1 and modern science.)

What I found even more interesting than the backwards reasoning of JW was the tenacious way in which he clung to one particular belief in spite of the evidence, or rather the lack of it. I reminded him that there are only three options to explain why the universe is the way it is: necessity, luck, or God. I told him there’s no support for necessity, but he really, really wanted to believe it anyway.

It’s not difficult to define chance. The parameters, constants, all the things that make the universe fit for human life, can span a range of values. If there’s no physical theory requiring the universe to have three physical dimensions, the particular strengths of the various fundamental forces, the particular masses of subatomic particles, and so on, and no God to purposefully choose these values, then how did we end up with all of the “right” values? The answer is, a very, very lucky roll of the dice. In the multiverse, there is a mind-bogglingly huge number of universes, all with different parameters, and we just happen to inhabit one that hit the cosmic jackpot. (Incidentally, most physicists don’t seem to delight in this option. I get the impression most atheist physicists would prefer the necessity option, but as there’s no evidence for that, they grudgingly accept the multiverse.)

JW seemed to reject this notion, and he obviously wasn’t big on the God idea, so I challenged him, repeatedly, to show me which physical theories predict / require / necessitate the universe to be the way it is.

After a lot of back and forth, I finally got an answer out of him.

He admits he doesn’t know. The truth is, no one knows, and it’s deeply troubling to a lot of people, because it leaves as the only alternatives luck and God. Yet JW persists in his belief.

JW’s initial statement to me was that the fine-tuning argument was a triumph of faith over reason. But who’s exhibiting faith here? If you accept an explanation for why the universe is the way it is, then you must have evidence in favor of it or at least evidence ruling out the alternatives. Joe’s World has no scientific evidence, no physical theories predicting that the universe must be the way it is. Everything we know about the physical nature of the universe says that its various properties did not arise due to necessity. JW rejects God; I don’t know for certain if he rejects the multiverse, but I suspect he does. If so, then persisting in his belief in necessity is beyond faith — it’s blind faith.

Remember, having faith means holding onto a belief you once accepted through reason in spite of your transitory emotions. Blind faith means holding onto a belief without evidence or in spite of contradictory evidence. If you engage anti-theists long enough, you’ll find that a lot of them are the blind faithful. Christians, on the other hand, have good reasons to believe. If you’re a Christian, just make sure you can articulate what those reasons are.

The multiverse is not science

RTB’s Jeff Zweerink explains why we should exercise caution when considering whether the multiverse is science. While there is a legitimate place for the multiverse in scientific discussion, we must always keep in mind that at the fundamental level the multiverse is not science. Zweerink quotes eminent theoretical cosmologist, George F. R. Ellis, who reminds us that the multiverse is really just “scientifically based philosophical speculation.” In other words, it’s just a science-flavored idea.

The path to delusion

In this excellent interview, eminent physicist George F. R. Ellis discusses the ill-advised direction in which some scientists are going:

Horgan: Physicist Sean Carroll has argued that falsifiability is overrated as a criterion for judging whether theories should be taken seriously. Do you agree?

Ellis: This is a major step backwards to before the evidence-based scientific revolution initiated by Galileo and Newton. The basic idea is that our speculative theories, extrapolating into the unknown and into untestable areas from well-tested areas of physics, are so good they have to be true. History proves that is the path to delusion: just because you have a good theory does not prove it is true. The other defence is that there is no other game in town. But there may not be any such game.

Scientists should strongly resist such an attack on the very foundations of its own success. Luckily it is a very small subset of scientists who are making this proposal.

It is indeed a very small subset, but it is also a very vocal and visible subset–many of these scientists are in the popular media as representatives of science. Ellis also takes them to task for formally rejecting philosophy while unwittingly engaging in a weak form of it.

The great irony here is that many of the atheists who are self-styled champions of evidence and reason are abandoning both when they claim that the multiverse hypothesis, or any other fundamentally untestable idea put forth by scientists, is very likely true, because it’s elegant or the math is convincing or it’s beautifully consistent with what we believe, and so on. I have to check myself here, too, because I find some of these untestable ideas compelling for the same reasons. But, in terms of the irony, as Ellis points out, it was Galileo and Newton—both Christians—who revolutionized science by making it primarily an experimental, evidence-based endeavor, and now this is being dismissed by those who also ostensibly dismiss faith; they have abandoned evidence and reason in favor of what may only be a beautiful delusion.

I strongly encourage you to read the entire interview with Ellis (who is himself a Christian, incidentally) for an engaging discussion of what’s going awry on the modern scientific landscape.

Mailbag: More on Schroeder’s biblical cosmology

Physicist, Gerald Schroeder, has written four books on the relation of biblical wisdom to modern science. In his book, The Science of God, he explains his biblical cosmology in detail. I’ve created an illustrated slideshow here (see also the “Six Days” tab at the top) that covers the basics of his model. The gist is that Schroeder is able to convincingly reconcile a literal interpretation of Genesis 1 –six 24-hour days of creation –with a universe that is billions of years old by invoking the phenomenon known as time dilation. That’s the slowing down of time in one reference frame as observed from another reference frame. It’s a scientifically sound model, but it’s also a bit difficult for the average scientific layperson to understand, because it involves one of the trickiest concepts in science — the nature of time. There are also other details that can be confusing to a reader not deeply versed in science, so I’m answering questions about the model sent in by readers. 

LH sends in another question from a forum discussion on Schroeder’s biblical cosmology:

At any point in time, the CMBR is not a single frequency, but a continuous spectrum of frequencies — to choose the “average” frequency, which doesn’t correspond to any single photon, to define a clock is questionable (unlike the frequency used to define a second, which is that of an actual photon). Also, the usual way of using light of a particular frequency to act as a clock is by defining the unit of time to be a fixed number of cycles or oscillations of the light wave (this is what is done in defining the second). Since the CMBR at early times has a higher frequency (shorter wavelength), it takes less time to go through a fixed number of cycles, so the unit of time (a “Day”) defined using the CMBR in the early universe is shorter in terms of years than it would be now, i.e. the Genesis days measured in Earth time should be getting progressively longer, not shorter (7 billion years, 3.5 billion years, 1.8 billion years, …).

It’s true the CBR has a blackbody spectrum with a distribution of frequencies, but, like every blackbody, it is characterized by a peak frequency (or wavelength, as shown below) that corresponds to its temperature. Every blackbody has one, and only one, peak frequency that corresponds to its temperature. This is why astronomers refer to just one color for the surface of a star. Stars can be approximated as blackbodies, they have a distribution of frequencies in the radiation from their surfaces, but they still have just one characteristic peak frequency that corresponds to surface temperature. And, in terms of redshift, anything that happens to one of those frequencies is going to happen in the exact same way to the other frequencies. I don’t see this as a valid criticism of Schroeder’s approach.

Blackbody spectra

Blackbody spectra for various temperatures

In terms of the length of a day, this person is mistakenly assuming that the number of cycles in a Genesis day is fixed — it’s not. The problem arises from not choosing the correct reference frames for comparison. We must compare one Genesis day with another from the point of view of our position on Earth today looking backward in time. I have an example that illustrates by analogy how we should be looking at it.

Let’s take the example of the flow of time for two different reference frames where gravitational redshift is creating a time dilation effect. The duration of a second is defined as ~9.2 billion cycles based on a particular transition of the cesium atom. This is as measured from a particular reference frame — the surface of the Earth. But let’s consider another reference frame, that of an observer in a spaceship orbiting some distance from the surface of the Earth. Let’s say the spaceship guy also has a cesium atom and is measuring the same transition, and that he is also able to measure the radiation coming from the cesium transition in the lab on the surface of the Earth. Now, in the time it takes the spaceship guy to count off 9.2 billion cycles for his spaceship cesium atom, he measures fewer than 9.2 billion cycles coming from the Earth’s cesium atom. In other words, in his one second of spaceship time is “faster” than one second of Earth time. The same number of cycles are both are experienced as one second by observers within their respective reference frames, but the cycles from Earth have been stretched by some factor corresponding to the effect of Earth’s gravity as measured by the guy in his spaceship reference frame.

Now, let’s extreme-ify this example by considering a planet — Planet X — for which the gravity is so extreme that, instead of the tiny time dilation effect observed due to Earth’s gravity, time near the surface of Planet X flows at half the rate as time for a spaceship orbiting Planet X. Let’s posit hypothetical observers on the surface of Planet X and in the spaceship, respectively. The guy on Planet X has a telescope he can use to peer into the spaceship and observe everything the spaceship guy is doing. He notices that the spaceship guy is doing everything twice as fast as he is on Planet X. He notices that a day passes on Planet X while two days pass for the guy on the spaceship. Note that the same number of cycles are not taking place on Planet X and on the spaceship during this little scenario; there is no requirement that this happen.

The difference in the flow of time in the previous two examples is due to gravitational redshifting, but we can take the same principle of time getting stretched out when viewed from different reference frames and apply it the expansion of the universe. In this case, however, instead of two reference frames that differ in location, we’ll consider two reference frames that differ in time.

Let’s consider time dilation as measured from the light curves of identical supernovae. A light curve is the brightness of a supernova as a function of time (usually measured in days). Type Ia supernovae have characteristic light curves that are always the same, because they all originate from the same type of star — this is what makes them excellent standards by which we measure cosmological effects. We can observe a nearby (roughly corresponding to the present time) Type 1a supernova and see that it takes about 20 days for the supernova to fade appreciably from peak brightness. If we observe another Type 1a supernova that’s at a distance corresponding to when the universe was about half its present age, the light curve makes it appear as though it takes 40 days for its brightness to fade by the same amount — twice as long for the exact same type of supernova. This is the time dilation effect due to the expansion of the universe. The light we receive now from an event that happened billions of years ago has been stretched to half the frequency — time appears to be flowing at half the rate now that it was when the light was emitted then. Again, there is no requirement that the number of cycles be made to equal each other in this comparison.

sn_light_curves

Light curves for nearby (blue) and distant (red) supernovae.

In the last example, we are comparing the flow of time at two different times in cosmic history from the point of view of the Earth, looking backward in time. There is no requirement that the number of cycles be the same for each day. Each successive day, when compared this way, is shorter than the previous day, because the flow of time has slowed down compared with the previous day. This forms the basis of Schroeder’s biblical cosmological model.

Previous: Mailbag: Time dilation in Schroeder’s biblical cosmology

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

Traffic’s up after the announcement of the publication of our Astronomy and Astrophysics curriculum, so we’re replaying some of our more important posts from the archives for our new readers. This article was originally posted on February 21, 2012

So says Tufts University physicist, Alexander Vilenkin, who made this statement at a meeting in January in honor of Stephen Hawking’s 70th birthday. (I’m a little late getting around to this, but it’s worth commenting on.)

To fully appreciate the magnitude of this statement, consider that the prevailing view of cosmology for more than two thousand years was that of an eternal universe. This view began to change in the 1920s, when astronomer Edwin Hubble discovered that the spectra of most galaxies are redshifted, and the further away a galaxy is from the Milky Way, the more its spectrum is redshifted. What this means in plain English is that almost all of the galaxies he observed are rushing away from each other, and those that were further away are rushing away faster. Incredibly, it appeared the universe was not only changing, but expanding. If you imagine running the expansion in reverse, so that galaxies rush toward one another as you go back in time, you end up with a point at which the expansion started — a beginning in time and space.

Belgian physicist and priest, Georges Lemaître, anticipated this discovery with what he called the “hypothesis of the primeval atom,” based on his solution to the Einstein field equations. The universe’s beginning was predicted to have been very energetic and violent, and was therefore dubbed as the “big bang.” Four decades later, physicists Arno Penzias and Robert Wilson discovered the predicted afterglow of this big bang, which eventually earned them Nobel prizes. By the late 1980s, sophisticated satellites were mapping the tiny fluctuations in the intensity of the big bang afterglow, which allowed physicists to calculate an age for the universe. By the end of the 20th century, there was near-consensus that the universe had a beginning that occurred some 11-17 billion years ago. (The cosmological model-based number is ~14 billion years.)

The big bang has had its detractors. It was astrophysicist Fred Hoyle, out of deep skepticism for the idea, who sarcastically applied the term “big bang” to this cosmological model. (Let it not be said that physicists are overly sensitive — the term stuck and has been used in all seriousness ever since.) Hoyle’s collaborator, astrophysicist Geoffrey Burbidge, famously ridiculed physicists who had hopped on the big bang bandwagon as “rushing off to join the First Church of Christ of the Big Bang.” There were two reasons scientists reacted this way. First, some scientists found the idea of a universe with a beginning uncomfortably close to the Genesis account of creation. Second, from the point of view of physics, mathematics, and philosophy, a universe with a beginning is far more messy to deal with than an eternal universe, which requires no explanation. Even still, the evidence for a beginning is now so overwhelming that most physicists have come to accept it, and the big bang has become the prevailing paradigm governing all of physics.

Nevertheless, some physicists had not given up on the idea of an eternal universe, but the focus changed to devising sophisticated models for an eternal universe that fit the observed data — in other words, an eternal universe that incorporated key features of the big bang model. Some of these features are explainable by invoking what’s called inflation, which refers to an early period of exceedingly rapid expansion. This idea was proposed by Alan Guth in the 1980s, and it can also be applied to an eternally inflating universe in which regions of the universe undergo localized inflation, creating “pocket universes.” This inflation continues forever, both in the past and into the future, and so in a sense it represents an eternal universe. Another idea was the cyclical universe, which posited that the universe is eternally expanding and contracting. In this way, the big bang that occurred 14 billion years ago would be just one of an infinite number of big bangs followed by ‘big crunches.’

All of the evidence indicates ours is a universe undergoing perpetual change. To replace Aristotle’s age-old idea of an eternal, unchanging universe, physicists came up with hypothetical eternal universes that were perpetually changing. This was an ingenius approach, but as Vilenkin announced last month, they just don’t work. Guth’s idea turns out to predict eternal inflation in the future, but not in the past. The cyclical model of the universe predicts that with each big bang, the universe becomes more and more chaotic. An eternity of big bangs and big crunches would lead to a universe of maximum disorder with no galaxies, stars, or planets — clearly at odds with what we observe.

As the journal New Scientist reports, physicists can’t avoid a creation event. Vilenkin’s admission exemplifies the reason physics is the king of all the sciences — physicists are generally willing to admit when their cherished ideas don’t work, and they eventually go where the data and logic lead them. Whether this particular realization will pave the way to serious discussion of God and consistency with the Genesis account of creation remains to be seen. Physicists can be a stubborn bunch. As Nobel laureate George P. Thomson observed, “Probably every physicist would believe in a creation if the Bible had not unfortunately said something about it many years ago and made it seem old-fashioned.” Still, some physicists are open to the idea. Gerald Schroeder, who is also an applied theologian, has written profoundly on the subject. His book, The Science of God, is an illuminating discussion of how the Bible and biblical commentary relate to the creation of the universe.