The discovery of gravitational waves

I had been anticipating the biggest null result in science in the last century, perhaps ever, to be announced sometime this year, when just under ten days ago this paper came out: Observation of Gravitational Waves from a Binary Black Hole Merger. LIGO, the U.S. gravitational wave observatory, has received signals from what appears to be the merger of two black holes. What would have been the null result of the century has turned out to be the result of the century.

Aristotle’s physics

There’s a bit of a rehabilitation of Aristotle going on lately (Edward Feser is the one doing it that I’m most familiar with), and one of the things you’ll hear if you read that stuff is that we can reject Aristotle’s physics without rejecting his metaphysics. Surely we are more clever at physics than he was — right? Well, as it turns out, not exactly. Here’s a recent paper by a physicist showing that Aristotle’s physics is to Newton’s physics as Newton’s is to Einstein’s. In other words, it was (and is) perfectly rigorous in its domain of validity. The most obvious example he cites is of objects falling under the influence of gravity. In his famous experiment on the leaning tower of Pisa, Galileo showed that objects fall at the same speed, independent of their size and composition. Aristotle made the opposite claim, and what could he have been thinking? The short answer is that Aristotle’s result holds in the presence of a medium, such as air or water, and Galileo’s result holds in the absence of such a medium (or on short enough time scales that the medium doesn’t matter; if you repeat Galileo’s experiment from an airplane, you will come to Aristotle’s conclusions). There you go, the rehabilitation is complete. Aristotle wasn’t a moron.

WWED

I told you we scientists are good at predicting things. My previous post predicted that eventually we will be able to predict the origin of the universe, and, by golly, it looks as if we’ve done it. I didn’t think it would happen this quickly, but then one always tends to underestimate the power of Equations. A paper just came out today that predicts the spontaneous creation of the universe from nothing. From the abstract:

An interesting idea is that the universe could be spontaneously created from nothing, but no rigorous proof has been given. In this paper, we present such a proof based on the analytic solutions of the Wheeler-DeWitt equation (WDWE).

Aren’t Equations simply awe-inspiring? You’ll notice that rearranging the acronym in the above quote provides the inspiration for a catchy cliche for scientism: WWED (What Would Equations Do?).

 

Postmodern inflation

You may have noticed some noise in the news recently about a telescope at the South Pole finding evidence for cosmic inflation. (Inflation is something that is supposed to have happened immediately after the Big Bang, where instead of the universe expanding near the rate at which it appears to be expanding today, the universe inflated at a much faster rate over a very short time period. It’s an idea that is supposed to explain the fact that the Cosmic Microwave Background is so smooth when there is no causal connection between its various parts. None of this matters much for the purposes of this post, but that’s the background in case you’re wondering.)

I was surprised to see this news, because I had just read a paper suggesting that we may need a new cosmological paradigm since the standard picture of inflation is now disfavored by observational data (data from other telescopes, not the data that was announced recently). Two of the authors on the paper are well-respected scientists from Harvard and Princeton (Abraham Loeb and Paul Steinhardt), and their criticisms are being addressed by the originators of the inflationary picture, so this is something that people are taking seriously. (It so happens that the announcement of the new results that generated the recent excitement came three days after the paper critical of inflation appeared online. This is rather coincidental and more than a little fishy, especially considering the fact that the new results contradict some of the previous ones. You’ll also notice in the news article linked above that the results weren’t expected to be announced for another year or so. My main purpose here, however, isn’t to engage in speculation about cosmological politics, but to highlight some of the criticisms of inflation that have been pointed out recently by serious thinkers.)

As described in the critical paper linked to above, the champions of inflation regard the standard inflationary picture to be outdated, and “they describe an alternative inflationary paradigm that has been developing in recent years and revises the assumptions and goals of inflation, and, as Linde suggests, perhaps of science generally. This makes clear that a schism has erupted between classic inflation and what might appropriately be called
postmodern inflation.” The critical paper then goes on to summarize the conceptual problems that have always existed in classic inflation. The worst of these conceptual problems is that “our observable universe is exponentially unlikely by a factor exceeding 10⁻¹⁰⁵⁵ or more! Classic inflation is a catastrophic failure by this measure; numerically, it is one of the worst failures in the history of science.” They go on to say

How has a theory that fails catastrophically continued to survive in scientific discourse? For the most part, it is because… classic inflation seems to produce predictions that perfectly match observations. The point of [1] was to show that this is no longer the case.

(The paper referred to in this quote is another critical paper that came out about a year ago; the paper I’m discussing here is the response to the responses to that paper.)

Under the new paradigm, the solution to this catastrophic failure is to essentially change the way quantities are measured, and in particular to measure them in such a way that the theory matches the data, no matter what the data is, and no matter how much fine tuning the theory requires. As the authors point out, this is not really science.

In postmodern inflation, volume-weighting is abandoned in favor of selecting a measure a posteriori to fit observations. In this approach, the notion of generic predictions is sacrificed… In fact, observations cannot falsify postmodern inflation – failure to match observations leads instead to a change of measure. This places postmodern inflationary cosmology squarely outside the domain of normal science. Linde concurs [3], quoting Steven Weinberg [15], “Now we may be at a new turning point, a radical change in what we accept as a legitimate foundation for a physical theory.”

The final conclusion of the paper is this:

The scientific question we may be facing in the near future is: If classic inflation is outdated and a failure, are we willing to accept postmodern inflation, a construct that lies outside of normal science? Or is it time to seek an alternative cosmological paradigm?

Those are strong words, and it will be very interesting to see how this plays out.

One of the responses to the original criticisms highlights the fact that cosmology is not the only scientific discipline where these types of questions are relevant. One of the arguments put forth in favor of the postmodern paradigm by Guth (the originator of inflation), Kaiser and Nomura (from MIT and Berkeley, respectively), is very instructive:

We do not reject Darwinian evolution because it does not explain the actual origin of life; we do not reject big-bang nucleosynthesis because it does not explain the homogeneous thermal equilibrium initial state that it requires; and we should similarly not even consider rejecting the inflationary paradigm because it is not yet part of a complete solution to the ultimate mystery of the origin of the universe.

The primary feature of science that supposedly demands our respect is its ability to predict. We can predict the phases of the moon, which naturally implies that we can predict everything (the phases of the moon, the climate, the origin and fate of the universe, the origin of life, these are all pretty much the same kinds of things and if you’ll just give us a little more time, we’ll have the answer for you). Don’t miss the irony here: Guth et al are so confident in the power of science to provide answers that they are willing to defend a “scientific” paradigm that is not predictive.

Doesn’t matter

Defending creationists

A refreshing change of tone towards fundamentalists, the favorite whipping boy of modern writers:

In defense of creationists

Defending fundamentalism

It’s very easy to deflect any criticism of Christianity to fundamentalist crackpots. While affirmation of six-day creation may not be a test of orthodoxy, it is a good test of one’s loyalties, along with one’s willingness to invite ridicule from respectable people.

The big-bang-quicksand argument for the existence of God

Creationists are finally getting some recognition. Not only does one of us have a slot in the upcoming meeting of the American Physical Society, but it’s also featured in a session entitled “New Directions in Astrophysics” (cutting edge, in other words). Click on the title for a link to the abstract:

Creator God Rules The Universe Because Hawking Built The Big Bang On A Foundation Of Quicksand

It turns out that Hawking isn’t the originator of the Big Bang theory, but that factual error aside, I think this is likely to end up alongside the cosmological argument as one of the primary arguments for the existence of God. Did I just say recently that we creationists have a lot of work to do? I take it back.

Geocentrism

A friend recently asked for my thoughts on geocentrism, a view held by some Christians as a consistent approach to taking Biblical language at face value. Does faithfulness to the Bible necessitate a geocentrist view of the universe? Is there any scientific evidence for such a view? Despite our ready association of geocentrism with backward medievalism, these are actually not easy questions to answer. There are in fact at least three scientific questions to answer: 1) Does the universe have a center? 2) If yes, is the earth at (or near) the center? 3) Is the earth stationary? These are independent questions, although they can easily be conflated. One can imagine a stationary earth at the center of the universe (as in the medieval cosmology), a spinning off-center earth, or a stationary earth in a universe without a center. As far as I understand their views, modern geocentrists want to insist on yes to all three of these questions (they are geostationists as well as geocentrists).

To begin with, it is helpful to distinguish between two types of center: the center of mass and the center of motion. The sun is more or less at the center of mass of the solar system, simply because the sun is much more massive than the planets. Locating the center of motion is more subtle, and in fact it cannot be located by any measurement. Tycho Brahe’s model with a stationary earth at the center (of motion) of the solar system is scientifically equivalent to Copernicus’s model with the sun at the center (of motion). In both cases the sun is at the center of mass, but as there is no absolute rest frame the choice of a center of motion is in a sense arbitrary. (I say in a sense because the reference frame associated with the center of mass is a reference frame in which calculations are simpler; this is an important caveat that is easily missed in discussions of relativity.)

Since defining a center of motion is arbitrary, a yes to question #1 above would imply that the universe has a non-uniform distribution of mass on large scales (i.e., it is inhomogeneous so that one can meaningfully define a center of mass). The question of whether the universe has a center of motion is a question without a meaningful answer. The correct answer to #3, then, is that there is no scientific difference between the earth spinning within the universe and the rest of the universe rotating about the earth (whether or not we’re at the center). All motion is relative, including rotational motion. So even if we are located near the center of mass of the universe, the geocentrists are incorrect to insist that the earth is motionless in an absolute sense, just as it is incorrect to insist that the earth is spinning in an absolute sense. It is okay to say that the earth is spinning, and it is okay to say that the universe is rotating about the earth; neither reference frame is absolute. This implies that Biblical language indicating a motionless earth is neither incorrect nor scientifically inaccurate.

It is also important to distinguish between the exact center of the universe and an approximate center. The universe is so huge that the precise center could be in the next galaxy and we wouldn’t see the difference in cosmological observations. The scales are similar to placing an atom at the center of a star ten times larger than the sun; on the scale of the atom, you would have quite a bit of flexibility in defining the center.

So what is the answer to the first two questions? Does the universe have a center of mass, and are we near it? A little-known fact is that observations of galactic redshifts seem to point to the earth being near the center of the universe. Redshifts increase with distance away from us in the same manner in every direction; in other words, it looks like we’re at the center of the redshift distribution. Edwin Hubble, the discoverer of the redshifts, points this out in some of his lectures on the subject:

The true distribution must either be uniform or increase outward, leaving the observer in a unique position. But the unwelcome supposition of a favoured location must be avoided at all costs. Therefore, we accept the uniform distribution…

Thus the density of the nebular distribution increases outwards, symmetrically in all directions, leaving the observer in a unique position. Such a favoured position, of course, is intolerable; moreover, it represents a discrepancy with the theory, because the theory postulates homogeneity. Therefore, in order to restore homogeneity, and to escape the horror of a unique position, the departures from uniformity, which are introduced by the recession factors, must be compensated by the second term representing effects of spatial curvature. There seems to be no other escape…

Well, perhaps the interpretation is correct and we do inhabit a rapidly expanding universe.

Assuming that we are not near the center of the universe, then, implies that the universe is expanding. Extrapolating an expanding universe back in time is what leads to the Big Bang and an age for the universe of 13.8 billion years. Notice, however, that all of this rests on an assumption that for us to be near the center of the universe is far too improbable to have actually happened. Hubble again:

Relativity contributes the basic proposition that the geometry of space is determined by the contents of space. To this principle has been added another proposition, formulated in various ways and called by various names, but equivalent, in a sense, to the statement that all observers, regardless of their location, will see the same general picture of the universe. The second principle is a sheer assumption. It seems plausible and it appeals strongly to our sense of proportion. Nevertheless, it leads to a rather remarkable consequence, for it demands that, if we see the nebulae all receding from our position in space, then every other observer, no matter where he may be located, will see the nebulae all receding from his position. However, the assumption is adopted. There must be no favoured location in the universe, no centre, no boundary; all must see the universe alike. And, in order to ensure this situation, the cosmologist, postulates spatial isotropy and spatial homogeneity, which is his way of stating that the universe must be pretty much alike everywhere and in all directions.

In short, either we are located near the center of the universe or we inhabit an expanding universe that has no center. The observations can be interpreted either way.

In addition, there are several secular scientists who have recently suggested that the earth is near the center of an expanding universe in order to remove the need for dark energy. They are well aware of the fact that the Copernican Principle (the second principle Hubble refers to above), the idea that there is no favored location in the universe, is an untested assumption, and some have been exploring possible ways to test it. What some of us creation scientists need to do is explore models like these in a universe that’s not expanding.

As a final note (and more could be said about this), notice the strong language with which Hubble rejects geocentrism. Why does he want to “escape the horror of a unique position”? This isn’t simply the standard way of viewing the universe and our place in it; he’s actually afraid of the possibility that we could be near the center. Why? There may be several reasons, but one possibility that immediately springs to mind is this: it’s so improbable that Someone might have done it on purpose.

ICC 2013: John Baumgardner’s talk

John Baumgardner gave a talk with the imposing title:

EXPLAINING THE CONTINENTAL FOSSIL-BEARING SEDIMENT RECORD IN
TERMS OF THE GENESIS FLOOD:  INSIGHTS FROM NUMERICAL MODELING
OF EROSION, SEDIMENT TRANSPORT, AND DEPOSITION PROCESSES ON A
GLOBAL SCALE

He is basically trying to explain sediment layers in term of natural processes occurring during Noah’s flood. It takes a lot of water to move around the amount of sediment that we see in the layers today, and to get the amount of water required he invokes a moon-sized body passing near the earth that lifts huge tides in midst of the seas. As the tide waters fall back down, they churn up the ocean floor and spread a sediment layer around the earth. There are six main layers, and so the moon-sized body would have to pass near the earth six times during the flood. Now that is what is referred to in the scientific community as a tooth fairy, moon-sized bodies passing near the earth not being something that we see on a regular basis, and I think it highlights our need to think through the limitations of our scientific modeling.

Now John is a serious scientist, and has been in the creation science game since the early days. I’m sure he knows what he’s talking about and has thought through alternative scenarios. My thoughts went immediately to the fountains of the great deep referred to in Genesis – why couldn’t they have caused this massive flow of water? I talked with him about that afterwards, and apparently this is a scenario that has been proposed by one Walt Brown (a crackpot among crackpots) and rejected by the majority of creationists. According to Baumgardner, storing the volume of water required to form the sediment layers underground is a very unstable situation – if the magma squirts out on occasion, then so would the water, I believe was the way he put it.

Fair enough. But how is invoking an unrealistic astronomical event (actually six such events) supposed to be an improvement? We creation scientists should start putting ourselves in God’s shoes more. Here you are planning to cover the world with water (and sediment layers). Forget for the moment the fountains of the great deep (according to John these were jets coming up between the continental plates that didn’t contain nearly enough water to cause the sediment layers). You have all this ocean water available to you, if only you can figure out a way to get it up high and let it fall back down. And all you have to work with is Newton’s Laws, set in place at the foundation of the world for the purpose of maintaining order and giving scientists something to do. Well, here’s one option. Send a moon-sized body near the earth to lift the water up by its gravity. That oughta work.

Now at this point (and I wished I had asked about this), either John would have to invoke a miracle to get this moon-sized body to do this, or he (or some other creation scientist) would have to do an absolutely heroic astronomical calculation to explore the plausibility of such a scenario occurring naturally. I find the latter extremely implausible myself, although I am no expert in orbital mechanics and couldn’t say offhand that it’s impossible. If the former is the route John would take, how is that any different (from a scientific perspective) or any more attractive (from the perspective of common sense) than God just telling the water to rise up? A cataclysm such as the flood seems like a very likely place for miracles to occur, and I hate to say it but miracles are usually associated with – with – the breakdown of scientific laws. As I’ve argued before, however, the thing that is really breaking down is our ability to model everything God does with unchanging laws. He’s the law-giver, after all, the One giving the commands. He is not constrained by the laws of physics. I’m sure most creation scientists would agree with that, but if we are reluctant to invoke miracles because they limit science, we end up limiting God instead.

Getting back to Walt Brown’s scenario, I actually would have a problem with a scenario that was physically unstable and yet persisted over a couple thousand years. God is dependable, and the laws of physics are a glorious manifestation of that truth. But even here I wonder how hard serious creation scientists such as Baumgardner have tried to make something like that work scientifically. It doesn’t sound any harder than the problem of getting the astronomy to work out in John’s scenario. Was it quickly dismissed because Brown is an actual crackpot and we are desperate not to be regarded as crackpots ourselves? Perhaps they have considered it in depth. Another question I should have asked.

ICC 2013

I attended the 2013 International Conference on Creationism this past week. It was good to meet some fellow creation scientists, especially those with an astronomy/astrophysics background, and there were several talks that I enjoyed listening to. My father attended the conference as well, and it was good to spend some time with him. His passion for creation science is one of the primary reasons for my own interest in the subject. Here are my initial reactions to the week:

1. We creation scientists have a lot of work to do.
2. We should stop pretending like we don’t have a lot of work to do. There appears to be an increasing emphasis on building a scientific creation model and a decreasing emphasis on pointing out the flaws in evolution, and that trend needs to continue. In my mind there was still too much of the latter going on in a scientific conference dedicated to developing the creation model.
3. There were a few crackpots among the presenters, and even more in the audience, and if I had my druthers they would be filtered more than they were. From what I’ve been told, however, things on that front have been improving as well.
4. The crackpots should be filtered because they are doing bad science, not because they are crackpots. Every single creation scientist is a crackpot on some level, and I see too much concern among us about how we might come across to the secular scientific community. We should do good science because we love the Lord and are fascinated by the study of His creation, not because we want our position to be more palatable to those who hate Him.
5. We need to work through our understanding of the relationship between God’s providence and His miraculous intervention in the world. There is a strong reluctance among creation scientists to use “God did it” as an explanation, a reluctance that I find somewhat baffling. Is it because we’re more interested in science than in the truth? It may be difficult to model miraculous events using the scientific method, but if the events really happened and science doesn’t describe them well, who cares? This is particularly true of the events during the creation week; we should expect  science to be an unreliable tool for improving our understanding of miracles. Some of the reluctance in this area also appears to be due to an embarrassment about using a God-of-the-gaps type of argument. We’re just invoking God as a cop-out. The proper response to that accusation is not to fill the gaps with science instead of God but to insist that there are no gaps. “God did it” is the Biblical explanation for everything, including those things that we can model with science.

I’ve gotten the easy part over by pointing out the flaws in ICC. I really did enjoy myself, and I will try to follow this post up with a description of some of the talks and interactions I found particularly interesting.